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Temporal Trends of Resident Experience in External Beam Radiation Therapy Cases: Analysis of ACGME Case Logs from 2007 to 2018
International Journal of
Radiation Oncology biology
physics
www.redjournal.org
Clinical Investigation
Temporal Trends of Resident Experience in External Beam Radiation Therapy Cases: Analysis of ACGME Case Logs from 2007 to 2018 Richard Li, MD,* Ashwin Shinde, MD,* Jennifer Novak, MD,* Neha Vapiwala, MD,y Sushil Beriwal, MD,z Arya Amini, MD,* Yi-Jen Chen, MD, PhD,* and Scott Glaser, MD* *Department of Radiation Oncology, City of Hope Medical Center, Duarte, California; yDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvia; and zDepartment of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania Received Apr 29, 2019. Accepted for publication Jun 11, 2019.
Summary We analyzed case volume for graduating radiation oncology residents from 2007 to 2018 and reported on temporal trends. We found overall decrease in mean number of external beam radiation therapy cases per resident, with a decrease in the ratio of non-metastatic to metastatic case volume. Stereotactic radiosurgery and stereotactic body radiation therapy volume increased over the study period. There was significant variation by disease site.
Purpose: We sought to characterize temporal trends of radiation oncology resident ereported external beam radiation therapy (EBRT) case experience with respect to various disease sites, including trends in stereotactic radiosurgery and stereotactic body radiation therapy cases. Methods and Materials: Summarized, deidentified case logs for graduating radiation oncology residents between 2007 and 2018 were obtained from the Accreditation Council for Graduate Medical Education national summary data report. Mean number of cumulative cases and standard deviations per graduating resident by year were evaluated. Cases were subdivided into 12 disease-site categories using the Accreditation Council for Graduate Medical Education classification. Analysis of variance was used to determine significant differences, and strength of association was evaluated using Pearson correlation. Results: The number of graduating residents per year increased by 66% from 114 in 2007 to 189 in 2018 (P < .001, r Z 0.88). The overall mean number of EBRT cases per graduating resident decreased by 13.2% from 521.9 in 2007 to 478.5 in 2018, with a decrease in the ratio of nonmetastatic to metastatic cases per graduating resident. There was significant variation among the disease categories analyzed; however, the largest proportionate decreases were seen in hematologic, lung, and genitourinary malignancies. Stereotactic radiosurgery volume per graduating resident increased from an average of 27.9 cases in 2007 to 50.3 in 2018 (P < .001, r Z 0.96). Stereotactic body radiation therapy volume per graduating resident increased as well, from a mean of 6 cases in 2007 to 55.6 cases in 2018 (P < .001, r Z 0.99).
Corresponding author: Scott Glaser, MD; E-mail: [email protected] Disclosures: none. Int J Radiation Oncol Biol Phys, Vol. -, No. -, pp. 1e6, 2019 0360-3016/$ - see front matter Ó 2019 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.ijrobp.2019.06.2466
Supplementary material for this article can be found at https://doi.org/ 10.1016/j.ijrobp.2019.06.2466.
2
International Journal of Radiation Oncology Biology Physics
Li et al.
Conclusions: We report a longitudinal summary of resident-reported experience in EBRT cases. These findings have implications for future efforts to optimize residency training programs and requirements. Ó 2019 Elsevier Inc. All rights reserved.
Introduction Current radiation oncology residency minimum case requirements, established by the Accreditation Council for Graduate Medical Education (ACGME), specify that graduating radiation oncology residents must treat at least 450 patients with external beam radiation therapy (EBRT) during the course of their residency.1 This includes at least 12 pediatric patients with a minimum of 9 pediatric solid tumor cases, as well as 20 stereotactic radiosurgery (SRS) and 10 stereotactic body radiation therapy (SBRT) cases. Additionally, the program requirements state that residents “must have experience with lymphomas and leukemias, breast, central nervous system, gastrointestinal, genitourinary, gynecologic, head and neck, lung, pediatric, skin, and soft tissue and bone tumors,” but they do not specify a minimum case requirement per disease site. The field of radiation oncology has undergone significant shifts in the past 15 years, driven by technological advances and evolving indications for radiation therapy.2 For example, the use of SBRT in stage I non-small cell lung cancer has increased rapidly.3,4 Additionally, with continual expansion of residency programs, there has been a substantial increase in the number of radiation oncology residentsdfrom 117 in 2006 to 189 in 2018. However, there are no published studies analyzing longitudinal trends in resident case experience during this period. Therefore, we conducted an analysis of resident case experience in EBRT and SRS/SBRT cases from 2007 to 2018. We sought to characterize temporal trends of resident EBRT experience with respect to various disease sites and with respect to SRS/SBRT experience.
Methods and Materials Analysis of ACGME case logs Summarized, deidentified case logs for all graduating residents between the academic years of 2007 and 2018 were obtained from ACGME. All data were obtained from the annual National Data Report prepared by the Department of Applications and Data Analysis at ACGME. Each report summarizes case log numbers per graduating resident, aggregated in a cumulative fashion over the total duration of their residency training. Values are reported as mean and standard deviations. All reports are deidentified and aggregated, meaning that no individual resident or training
program can be identified. The present analysis specifically focuses on EBRT, SRS, and SBRT cases. The EBRT case logs are further broken down by disease sites, which are prespecified by the ACGME and incorporated into their case log reporting system. The following 12 disease sites were analyzed according to the ACGME classification: pediatric, soft tissue sarcoma and bone, breast, central nervous system, head and neck, gastrointestinal, genitourinary, gynecologic, hematologic, benign, lung/mediastinum, and skin. SRS and SBRT cases are separately classified within the case log reports. SRS refers to intracranial cases. Starting in 2015, the SBRT classification is further broken down into lung, liver, spine, and other extracranial; before this, all extracranial stereotactic cases were grouped together. We therefore report on this breakdown only for 2018 because this is the first year in which graduating residents would have reported all 4 years of training with the new classification system.
Statistical analysis Our primary analysis was the mean number of cases per graduating resident by academic year, grouped by disease site and treatment modality. Analysis of variance was used to determine statistical significance, and strength of association was evaluated using Pearson correlation coefficient. Additional supplementary analyses were performed analyzing the 10th, 30th, 70th, and 90th percentile of case numbers among graduating residents. The purpose of these analyses was to further characterize potential deficits in case experience among radiation oncology residents. Similar to the aforementioned analyses, analysis of variance was used to determine statistical significance. All statistical analyses were performed using SPSS statistical software (version 23.0; IBM Corporation, Armonk, NY). A threshold of P .004 was used to determine statistical significance, chosen based on applying Bonferroni correction for multiple comparisons to a base threshold of 0.05.
Results Overall trends in radiation oncology case experience The number of graduating residents per year increased by 66% from 114 in 2007 to 189 in 2018 (P < .001; r Z 0.88; Fig. E1, available online at https://doi.org/10.1016/j.ijrobp. 2019.06.2466). The overall mean of EBRT cases per
Volume - Number - 2019
3
EBRT case log trends
600
Mean cases per resident
500 400 300 200 100 0 2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Graduating academic year EBRT non-metastatic (r = -0.93, P < .001)
EBRT metastatic (r = 0.87, P = .001)
EBRT total (r = -0.83, P < .001)
Fig. 1. Longitudinal trends in external beam radiation therapy cases per graduating resident over time, stratified by metastatic versus nonmetastatic cases. graduating resident decreased by 13.2% from 521.9 in 2007 to 478.5 in 2018. The mean number of metastatic EBRT cases per graduating resident increased by 8.1%, from 120.2 in 2007 to 129.9 in 2018 (P Z .001; r Z 0.96), whereas the mean number of nonmetastatic cases decreased
Table 1
by 13.2% from 401.7 to 348.6 (P < .001; r Z 0.93). The ratio of metastatic to nonmetastatic cases per graduating resident increased from 0.30 in 2007 to 0.37 in 2018. These mean case numbers do not include SBRT or SRS cases. These trends are summarized in Figure 1.
Mean number of cases per graduating resident by year, stratified by disease-site category
Mean cases by year Benign STS/bone Breast CNS Head and neck GI GU Gynecologic Hematologic Lung Skin Pediatric (total) Pediatric (nonliquid) EBRT (nonmetastatic) EBRT (metastatic) EBRT (total) SRS SBRT
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
r
P value
13.8 11.0 77.0 25.0 55.5 46.5 59.7 23.4 34.7 43.1 9.5 23.9
11.8 9.5 72.1 25.8 56 46.1 58.9 23.7 33.1 40.2 10.4 22.2
12.9 10.4 73.6 27.8 55.1 42.7 60.2 23.2 32.9 40.2 10.2 22.9
12.9 9.6 76.3 26.6 52.4 42.2 57.8 23.2 33.1 39.7 10.0 24.5
12 10.3 75.2 28.2 57.5 42.8 56.5 21.9 32.2 40.8 10.0 23.3
11.9 10.4 77.1 28.8 56.5 45.7 56.7 22.7 30.2 39.6 11.4 22.9
10.7 9.5 73.5 29.6 56.5 44.8 53.9 22.3 29.6 41.1 10.8 21.7
10 10.0 74.7 29.2 53.7 42.9 50.7 19.7 29.5 39.1 10.3 21.4
10.5 10.0 75.8 27.3 57.8 41.6 47.7 20.2 26 39 11.4 21.6
9.2 10.7 77.6 28.8 60.2 41.8 46 20.9 27.5 34.1 12 22
8.4 9.7 74.2 28.2 56.4 40.9 43.2 21.6 25.3 33 11.9 20.7
7.8 9.7 75.4 28.5 54.6 39 45.2 19.9 24 31.9 11.7 19.4
e0.95 e0.26 0.16 0.67 0.28 e0.77 e0.96 e0.84 e0.97 e0.85 0.86 e0.81
<.001 .414 .610 .017 .378 .003 <.001 .001 <.001 <.001 <.001 .001
17.3
16.2
17.1
17.7
17.9
17.1
16.5
16.1
16.2
17.1
16.6
16.1
e0.60
.038
368.4 369.8 353.4 348.6
e0.93
<.001
120.2 120.6 124.6 123.9 125.4 131.5 127.2 132.6 128.4 132.3 134.6 129.9
0.96
<.001
478.5
e0.83
.001
50.6 55.6
0.96 0.99
<.001 <.001
401.7 389.8 390.9 385.4 389.2 392.8 383.8 371
521.9 510.4 515.5 509.3 514.6 524.3 511 27.9 6.0
24.3 8.6
29.1 12.9
30.1 16.8
28.5 18.4
34.9 25.9
34.1 30.6
503.6 496.8 502.1 488 37 32.6
40.4 38.2
45.1 44.8
44.3 50.8
Abbreviations: CNS Z central nervous system; EBRT Z external beam radiation therapy; GI Z gastrointestinal; GU Z genitourinary; SBRT Z stereotactic body radiation therapy; SRS Z stereotactic radiosurgery; STS Z soft tissue sarcoma.
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International Journal of Radiation Oncology Biology Physics
Li et al. 90 80 70
Mean cases per resident
Benign (r = -0.95, P < 0.001) 60
STS/Bone (r = -0.26, P = 0.414) Breast (r = 0.16, P = 0.610)
50
CNS (r = 0.67, P = 0.017) H&N (r = 0.28, P = 0.378)
40
GI (r = -0.77, P = 0.003) GU (r = -0.96, P < 0.001)
30
Gynecologic (r = -0.84, P = 0.001) Hematologic (r = -0.97, P < 0.001)
20
Lung (r = -0.85, P < 0.001) Skin (r = 0.86, P < 0.001)
10
18
17
20
20
16
15
20
20
14
13
20
12
20
11
20
10
20
09
20
08
20
20
20
07
0
Graduating Academic Year
Fig. 2. Mean number of cases per graduating resident by year, stratified by disease category. Abbreviations: CNS Z central nervous system; EBRT Z external beam radiation therapy; GI Z gastrointestinal; GU Z genitourinary; STS Z soft tissue sarcoma.
Temporal trends by disease site Temporal trends in mean case numbers by disease site and treatment modality are summarized in Table 1 and Figure 2. Pediatric cases experienced a 19% decline, from a mean of 23.9 cases in 2007 to 19.4 cases in 2018 (r Z e0.81; P < .001). However, there was no statistically significant change for mean nonliquid pediatric cases (r Z e0.46; P Z .15).
Among the remaining 11 disease categories analyzed, the largest proportionate decreases were seen in hematology, lung, and genitourinary. From 2007 to 2018, mean cases in hematologic malignancies decreased from 34.7 to 24.0 (31% decrease; r Z e0.97, P < .001), mean cases in lung malignancies decreased from 43.1 to 31.9 (26% decrease; r Z e0.85, P < .001), and mean cases in genitourinary malignancies decreased from 46.5 to 39.0 (24% decrease; r Z e0.96, P < .001).
Table 2 Mean number of cases per graduating resident by year within the hematologic, genitourinary, and lung-disease categories, stratified by specific disease type Mean cases by year Hematologic Lymphoma Leukemia/myeloma Other hematologic Lung Small cell lung cancer Non-small cell lung cancer Other lung/mediastinum GU Prostate Bladder Testes Other GU
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
r
P value
22.2 11.3 1.2
20.7 11.3 1.1
20 11.7 1.2
19.8 11.9 1.4
19.2 11.7 1.3
18.8 10 1.4
17.4 10.9 1.3
18.2 10.1 1.2
15.4 9.2 1.4
17 9.3 1.3
15.8 7.8 1.6
14.5 7.9 1.5
e0.96 e0.90 0.72
<.001 <.001 .009
6 34.8 2.3
5.7 32.3 2.1
5.9 31.9 2.4
5.9 30.9 2.9
6 32.3 2.6
5.5 31.5 2.6
6.2 32.6 2.3
5.3 31.3 2.5
5.7 30.8 2.5
5 26.6 2.5
4.9 25.6 2.5
5.1 24.8 2
e0.75 e0.86 e0.08
.005 <.001 .794
54 2.6 2.1 1
53.5 2.7 1.8 0.9
55 2.8 1.5 0.8
52.3 3 1.6 1
51 3.2 1.3 1.1
51.1 3.1 1.3 1.2
49.3 3 0.7 0.9
45.7 3 0.9 1.1
43 3.1 0.7 0.9
41.4 3.1 0.5 1
38.5 3.2 0.4 1.1
40.5 3.3 0.4 1
e0.96 0.84 e0.97 0.27
<.001 .001 <.001 .399
Abbreviation: GU Z genitourinary.
Volume - Number - 2019
EBRT case log trends
5
Mean cases per graduating resident
60
50
40
30
20
10
0 2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Graduating academic year SRS (r = 0.96, P < .001)
Fig. 3.
SBRT (r = 0.99, P < .001)
Longitudinal trends in stereotactic radiosurgery and stereotactic body radiation therapy cases over time.
To better characterize the declines in these 3 disease sites, we performed further analysis by disease type within each of these sites (Table 2). The decrease in hematologic malignancies appeared to be driven by a 35% decline in lymphoma cases, from 22.2 cases in 2007 to 14.5 cases in 2018 (r Z e0.96; P < .001) and a decrease in mean leukemia/myeloma cases, from 11.3 cases in 2007 to 7.9 cases in 2018 (r Z e0.90; P < .001). The decrease in genitourinary malignancies appeared to be attributable to a decline in mean prostate cases from 54.0 in 2007 to 40.5 in 2018 (r Z e0.96; P < .001). Finally, the decrease in lung cases was primarily in non-small cell lung cancer, which decreased from 34.8 in 2007 to 24.8 in 2018 (r Z e0.86; P < .001).
Temporal trends in SRS and SBRT cases Regarding SRS and SBRT cases, there was a 298% increase in the total number of SRS cases performed in which residents participated, from 3181 cases in 2007 to 9511 in 2018 (P < .001; r Z 0.95). There was an increase in SRS exposure per graduating resident, from an average of 27.9 cases in 2007 to 50.3 in 2018 (P < .001; r Z 0.96). For SBRT, there was a 1536% increase in the total number of cases performed with resident participation, from 684 cases in 2007 to 10,508 cases in 2018 (P < .001; r Z 0.98). Subsequently, there was an increase in SBRT volume per graduating resident, from an average of 6 cases in 2007 to 55.6 cases in 2018 (P < .001; r Z 0.99). These trends are depicted in Figure 3. We additionally report on the breakdown of SBRT cases in 2018. Of all SBRT cases, 77.9% were classified as lung or other extracranial. The median number of liver SBRT
cases per graduating resident was 3, with a 10th percentile of 0 cases and a 30th percentile of 1 case. The median number of spine cases per graduating resident was 2, with a 10th percentile of 1 case and a 30th percentile of 2 cases.
Discussion To our knowledge, this is the first published report analyzing longitudinal trends in resident-reported case experience in radiation oncology. We found that there has been a decrease in the mean number of EBRT cases per graduating resident; however, the number and proportion of metastatic disease cases per resident has increased. There has been a sharp increase in SRS and SBRT case volume, and overall significant variation between disease sites was observed. We observed declining overall graduating resident case experience, with pronounced decreases in hematologic malignancies, lung malignancies, and genitourinary malignancies. The factors underlying these declines are likely multifactorial. However, the rapid expansion of residency training positions may be a contributing factor to the decline in case numbers per resident. Additionally, we hypothesize that the decline in hematologic malignancies is likely attributable to advances in systemic therapy and mirrors a nationwide decrease in use of RT for lymphoma and myeloma.5,6 Similarly, the decline in genitourinary experience likely reflects a nationwide shift toward more active surveillance and increased use of prostatectomy.7,8 The decline in lymphoma experience is particularly notable because it reinforces a previous survey of chief residents that found up to 30% reported inadequate experience in lymphoma malignancies with the percentage increasing over time.9,10
6
Li et al.
Regarding pediatric cases, we found that the 10th percentile of cases per graduating resident was 12, which meets the case minimum of 12. The overall case volume of pediatric cases has been decreasing over the study period, from 23.9 per graduating resident in 2007 to 19.4 per graduating resident in 2018. However, the volume of nonliquid pediatric malignancy cases has been more stable, with a mean of 17.3 cases per graduating resident in 2007 and 16.1 cases per graduating resident in 2018 (P Z .038). We found overall robust case volume for SBRT and SRS, with the most recent graduating resident averaging 50.3 SRS cases and 55.6 SBRT casesdwell above the current minimum of 20 SRS and 10 SBRT cases. However, further analysis of the 2018 class of graduating residents did reveal relatively lower numbers of liver and spine SBRT cases. The 30th percentile of graduating residents reported just 1 liver SBRT case and 2 spine SBRT cases. This raises questions regarding preparation for independent practice given expanding indications for SBRT in the treatment of oligometastatic disease.11,12 Future revisions of the ACGME case requirements may consider shifting utilization patterns of stereotactic therapies to optimize resident preparation for independent practice. Our study has several limitations. All cases are selfreported by residents and are subject to some degree of reporting bias. After meeting the minimum requirements, there is diminished incentive for residents to continue logging cases. Additionally, the maximum number of cases per year is set at 250, and this may discourage residents from logging cases beyond this quantity. However, prior studies of surgical resident case logs have shown 75% to 80% agreement with survey audit or billing data.13,14 We observed some year-to-year variation in case reporting numbers, meaning that conclusions regarding temporal trends should be regarded with caution. Finally, these statistics reflect only resident case experience and do not contain any information about trainee competency or quality of learning experience. Despite these limitations, we believe this study offers considerable value in characterizing previously unreported trends in resident case experience.
Conclusions We report a summary of resident-reported experience in EBRT cases. We found an overall decrease in mean number of EBRT cases per resident, though SRS and SBRT case volume is increasing. Our findings may help identify areas of focus for potential improvement in nationwide residency
International Journal of Radiation Oncology Biology Physics
training experience and inform future efforts to optimize residency training requirements.
References 1. Accreditation Council for Graduate Medical Education. ACGME program requirements for graduate medical education in radiation oncology. Available at: https://www.acgme.org/Portals/0/ PFAssets/ProgramRequirements/430_radiation_oncology_2017-07-01. pdf. Accessed April 3, 2019. 2. Citrin DE. Recent developments in radiotherapy. N Engl J Med 2017; 377:1065-1075. 3. Stahl JM, Corso CD, Verma V, et al. Trends in stereotactic body radiation therapy for stage I small cell lung cancer. Lung Cancer 2017; 103:11-16. 4. Chang JY, Senan S, Paul MA, et al. Stereotactic ablative radiotherapy versus lobectomy for operable stage I non-small-cell lung cancer: A pooled analysis of two randomised trials. Lancet Oncol 2015;16: 630-637. 5. Ailawadhi S, Frank RD, Meghji Z, et al. Utilization of radiation therapy in multiple myeloma: Trends and changes in practice. Blood 2017;130. 6. Vargo JA, Gill BS, Balasubramani GK, Beriwal S. Treatment selection and survival outcomes in early-stage diffuse large B-cell lymphoma: Do we still need consolidative radiotherapy? J Clin Oncol 2015;33: 3710-3717. 7. Malouff T, Mathy NW, Marsh S, Walters RW, Silberstein PT. Trends in the use of radiation therapy for stage IIA prostate cancer from 2004 to 2013: A retrospective analysis using the National Cancer Database. Prostate Cancer Prostatic Dis 2017;20:334-338. 8. Jani AB, Johnstone PAS, Liauw SL, Master VA, Rossi PJ. Prostate cancer modality time trend analyses from 1973 to 2004. Am J Clin Oncol 2009;33:1. 9. Nabavizadeh N, Burt LM, Mancini BR, et al. Results of the 2013-2015 Association of Residents in Radiation Oncology Survey of chief residents in the United States. Int J Radiat Oncol Biol Phys 2016;94: 228-234. 10. Gondi V, Bernard JR, Jabbari S, et al. Results of the 2005-2008 Association of Residents in Radiation Oncology Survey of chief residents in the United States: Clinical training and resident working conditions. Int J Radiat Oncol Biol Phys 2011;81:11201127. 11. Gomez DR, Blumenschein GR, Lee JJ, et al. Local consolidative therapy versus maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer without progression after first-line systemic therapy: A multicentre, randomised, controlled, phase 2 study. Lancet Oncol 2016;17:1672-1682. 12. Palma DA, Olson RA, Harrow S, et al. Stereotactic ablative radiation therapy for the comprehensive treatment of oligometastatic tumors (SABR-COMET): Results of a randomized trial. Int J Radiat Oncol Biol Phys 2018;102:S3-S4. 13. McPheeters MJ, Talcott RD, Hubbard ME, Haines SJ, Hunt MA. Assessing the accuracy of neurological surgery resident case logs at a single institution. Surg Neurol Int 2017;8:206. 14. Nygaard RM, Daly SR, Van Camp JM. General surgery resident case logs: Do they accurately reflect resident experience? J Surg Educ 2015;72:e178-e183.
Radiation Oncology biology
physics
www.redjournal.org
Clinical Investigation
Temporal Trends of Resident Experience in External Beam Radiation Therapy Cases: Analysis of ACGME Case Logs from 2007 to 2018 Richard Li, MD,* Ashwin Shinde, MD,* Jennifer Novak, MD,* Neha Vapiwala, MD,y Sushil Beriwal, MD,z Arya Amini, MD,* Yi-Jen Chen, MD, PhD,* and Scott Glaser, MD* *Department of Radiation Oncology, City of Hope Medical Center, Duarte, California; yDepartment of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvia; and zDepartment of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania Received Apr 29, 2019. Accepted for publication Jun 11, 2019.
Summary We analyzed case volume for graduating radiation oncology residents from 2007 to 2018 and reported on temporal trends. We found overall decrease in mean number of external beam radiation therapy cases per resident, with a decrease in the ratio of non-metastatic to metastatic case volume. Stereotactic radiosurgery and stereotactic body radiation therapy volume increased over the study period. There was significant variation by disease site.
Purpose: We sought to characterize temporal trends of radiation oncology resident ereported external beam radiation therapy (EBRT) case experience with respect to various disease sites, including trends in stereotactic radiosurgery and stereotactic body radiation therapy cases. Methods and Materials: Summarized, deidentified case logs for graduating radiation oncology residents between 2007 and 2018 were obtained from the Accreditation Council for Graduate Medical Education national summary data report. Mean number of cumulative cases and standard deviations per graduating resident by year were evaluated. Cases were subdivided into 12 disease-site categories using the Accreditation Council for Graduate Medical Education classification. Analysis of variance was used to determine significant differences, and strength of association was evaluated using Pearson correlation. Results: The number of graduating residents per year increased by 66% from 114 in 2007 to 189 in 2018 (P < .001, r Z 0.88). The overall mean number of EBRT cases per graduating resident decreased by 13.2% from 521.9 in 2007 to 478.5 in 2018, with a decrease in the ratio of nonmetastatic to metastatic cases per graduating resident. There was significant variation among the disease categories analyzed; however, the largest proportionate decreases were seen in hematologic, lung, and genitourinary malignancies. Stereotactic radiosurgery volume per graduating resident increased from an average of 27.9 cases in 2007 to 50.3 in 2018 (P < .001, r Z 0.96). Stereotactic body radiation therapy volume per graduating resident increased as well, from a mean of 6 cases in 2007 to 55.6 cases in 2018 (P < .001, r Z 0.99).
Corresponding author: Scott Glaser, MD; E-mail: [email protected] Disclosures: none. Int J Radiation Oncol Biol Phys, Vol. -, No. -, pp. 1e6, 2019 0360-3016/$ - see front matter Ó 2019 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.ijrobp.2019.06.2466
Supplementary material for this article can be found at https://doi.org/ 10.1016/j.ijrobp.2019.06.2466.
2
International Journal of Radiation Oncology Biology Physics
Li et al.
Conclusions: We report a longitudinal summary of resident-reported experience in EBRT cases. These findings have implications for future efforts to optimize residency training programs and requirements. Ó 2019 Elsevier Inc. All rights reserved.
Introduction Current radiation oncology residency minimum case requirements, established by the Accreditation Council for Graduate Medical Education (ACGME), specify that graduating radiation oncology residents must treat at least 450 patients with external beam radiation therapy (EBRT) during the course of their residency.1 This includes at least 12 pediatric patients with a minimum of 9 pediatric solid tumor cases, as well as 20 stereotactic radiosurgery (SRS) and 10 stereotactic body radiation therapy (SBRT) cases. Additionally, the program requirements state that residents “must have experience with lymphomas and leukemias, breast, central nervous system, gastrointestinal, genitourinary, gynecologic, head and neck, lung, pediatric, skin, and soft tissue and bone tumors,” but they do not specify a minimum case requirement per disease site. The field of radiation oncology has undergone significant shifts in the past 15 years, driven by technological advances and evolving indications for radiation therapy.2 For example, the use of SBRT in stage I non-small cell lung cancer has increased rapidly.3,4 Additionally, with continual expansion of residency programs, there has been a substantial increase in the number of radiation oncology residentsdfrom 117 in 2006 to 189 in 2018. However, there are no published studies analyzing longitudinal trends in resident case experience during this period. Therefore, we conducted an analysis of resident case experience in EBRT and SRS/SBRT cases from 2007 to 2018. We sought to characterize temporal trends of resident EBRT experience with respect to various disease sites and with respect to SRS/SBRT experience.
Methods and Materials Analysis of ACGME case logs Summarized, deidentified case logs for all graduating residents between the academic years of 2007 and 2018 were obtained from ACGME. All data were obtained from the annual National Data Report prepared by the Department of Applications and Data Analysis at ACGME. Each report summarizes case log numbers per graduating resident, aggregated in a cumulative fashion over the total duration of their residency training. Values are reported as mean and standard deviations. All reports are deidentified and aggregated, meaning that no individual resident or training
program can be identified. The present analysis specifically focuses on EBRT, SRS, and SBRT cases. The EBRT case logs are further broken down by disease sites, which are prespecified by the ACGME and incorporated into their case log reporting system. The following 12 disease sites were analyzed according to the ACGME classification: pediatric, soft tissue sarcoma and bone, breast, central nervous system, head and neck, gastrointestinal, genitourinary, gynecologic, hematologic, benign, lung/mediastinum, and skin. SRS and SBRT cases are separately classified within the case log reports. SRS refers to intracranial cases. Starting in 2015, the SBRT classification is further broken down into lung, liver, spine, and other extracranial; before this, all extracranial stereotactic cases were grouped together. We therefore report on this breakdown only for 2018 because this is the first year in which graduating residents would have reported all 4 years of training with the new classification system.
Statistical analysis Our primary analysis was the mean number of cases per graduating resident by academic year, grouped by disease site and treatment modality. Analysis of variance was used to determine statistical significance, and strength of association was evaluated using Pearson correlation coefficient. Additional supplementary analyses were performed analyzing the 10th, 30th, 70th, and 90th percentile of case numbers among graduating residents. The purpose of these analyses was to further characterize potential deficits in case experience among radiation oncology residents. Similar to the aforementioned analyses, analysis of variance was used to determine statistical significance. All statistical analyses were performed using SPSS statistical software (version 23.0; IBM Corporation, Armonk, NY). A threshold of P .004 was used to determine statistical significance, chosen based on applying Bonferroni correction for multiple comparisons to a base threshold of 0.05.
Results Overall trends in radiation oncology case experience The number of graduating residents per year increased by 66% from 114 in 2007 to 189 in 2018 (P < .001; r Z 0.88; Fig. E1, available online at https://doi.org/10.1016/j.ijrobp. 2019.06.2466). The overall mean of EBRT cases per
Volume - Number - 2019
3
EBRT case log trends
600
Mean cases per resident
500 400 300 200 100 0 2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Graduating academic year EBRT non-metastatic (r = -0.93, P < .001)
EBRT metastatic (r = 0.87, P = .001)
EBRT total (r = -0.83, P < .001)
Fig. 1. Longitudinal trends in external beam radiation therapy cases per graduating resident over time, stratified by metastatic versus nonmetastatic cases. graduating resident decreased by 13.2% from 521.9 in 2007 to 478.5 in 2018. The mean number of metastatic EBRT cases per graduating resident increased by 8.1%, from 120.2 in 2007 to 129.9 in 2018 (P Z .001; r Z 0.96), whereas the mean number of nonmetastatic cases decreased
Table 1
by 13.2% from 401.7 to 348.6 (P < .001; r Z 0.93). The ratio of metastatic to nonmetastatic cases per graduating resident increased from 0.30 in 2007 to 0.37 in 2018. These mean case numbers do not include SBRT or SRS cases. These trends are summarized in Figure 1.
Mean number of cases per graduating resident by year, stratified by disease-site category
Mean cases by year Benign STS/bone Breast CNS Head and neck GI GU Gynecologic Hematologic Lung Skin Pediatric (total) Pediatric (nonliquid) EBRT (nonmetastatic) EBRT (metastatic) EBRT (total) SRS SBRT
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
r
P value
13.8 11.0 77.0 25.0 55.5 46.5 59.7 23.4 34.7 43.1 9.5 23.9
11.8 9.5 72.1 25.8 56 46.1 58.9 23.7 33.1 40.2 10.4 22.2
12.9 10.4 73.6 27.8 55.1 42.7 60.2 23.2 32.9 40.2 10.2 22.9
12.9 9.6 76.3 26.6 52.4 42.2 57.8 23.2 33.1 39.7 10.0 24.5
12 10.3 75.2 28.2 57.5 42.8 56.5 21.9 32.2 40.8 10.0 23.3
11.9 10.4 77.1 28.8 56.5 45.7 56.7 22.7 30.2 39.6 11.4 22.9
10.7 9.5 73.5 29.6 56.5 44.8 53.9 22.3 29.6 41.1 10.8 21.7
10 10.0 74.7 29.2 53.7 42.9 50.7 19.7 29.5 39.1 10.3 21.4
10.5 10.0 75.8 27.3 57.8 41.6 47.7 20.2 26 39 11.4 21.6
9.2 10.7 77.6 28.8 60.2 41.8 46 20.9 27.5 34.1 12 22
8.4 9.7 74.2 28.2 56.4 40.9 43.2 21.6 25.3 33 11.9 20.7
7.8 9.7 75.4 28.5 54.6 39 45.2 19.9 24 31.9 11.7 19.4
e0.95 e0.26 0.16 0.67 0.28 e0.77 e0.96 e0.84 e0.97 e0.85 0.86 e0.81
<.001 .414 .610 .017 .378 .003 <.001 .001 <.001 <.001 <.001 .001
17.3
16.2
17.1
17.7
17.9
17.1
16.5
16.1
16.2
17.1
16.6
16.1
e0.60
.038
368.4 369.8 353.4 348.6
e0.93
<.001
120.2 120.6 124.6 123.9 125.4 131.5 127.2 132.6 128.4 132.3 134.6 129.9
0.96
<.001
478.5
e0.83
.001
50.6 55.6
0.96 0.99
<.001 <.001
401.7 389.8 390.9 385.4 389.2 392.8 383.8 371
521.9 510.4 515.5 509.3 514.6 524.3 511 27.9 6.0
24.3 8.6
29.1 12.9
30.1 16.8
28.5 18.4
34.9 25.9
34.1 30.6
503.6 496.8 502.1 488 37 32.6
40.4 38.2
45.1 44.8
44.3 50.8
Abbreviations: CNS Z central nervous system; EBRT Z external beam radiation therapy; GI Z gastrointestinal; GU Z genitourinary; SBRT Z stereotactic body radiation therapy; SRS Z stereotactic radiosurgery; STS Z soft tissue sarcoma.
4
International Journal of Radiation Oncology Biology Physics
Li et al. 90 80 70
Mean cases per resident
Benign (r = -0.95, P < 0.001) 60
STS/Bone (r = -0.26, P = 0.414) Breast (r = 0.16, P = 0.610)
50
CNS (r = 0.67, P = 0.017) H&N (r = 0.28, P = 0.378)
40
GI (r = -0.77, P = 0.003) GU (r = -0.96, P < 0.001)
30
Gynecologic (r = -0.84, P = 0.001) Hematologic (r = -0.97, P < 0.001)
20
Lung (r = -0.85, P < 0.001) Skin (r = 0.86, P < 0.001)
10
18
17
20
20
16
15
20
20
14
13
20
12
20
11
20
10
20
09
20
08
20
20
20
07
0
Graduating Academic Year
Fig. 2. Mean number of cases per graduating resident by year, stratified by disease category. Abbreviations: CNS Z central nervous system; EBRT Z external beam radiation therapy; GI Z gastrointestinal; GU Z genitourinary; STS Z soft tissue sarcoma.
Temporal trends by disease site Temporal trends in mean case numbers by disease site and treatment modality are summarized in Table 1 and Figure 2. Pediatric cases experienced a 19% decline, from a mean of 23.9 cases in 2007 to 19.4 cases in 2018 (r Z e0.81; P < .001). However, there was no statistically significant change for mean nonliquid pediatric cases (r Z e0.46; P Z .15).
Among the remaining 11 disease categories analyzed, the largest proportionate decreases were seen in hematology, lung, and genitourinary. From 2007 to 2018, mean cases in hematologic malignancies decreased from 34.7 to 24.0 (31% decrease; r Z e0.97, P < .001), mean cases in lung malignancies decreased from 43.1 to 31.9 (26% decrease; r Z e0.85, P < .001), and mean cases in genitourinary malignancies decreased from 46.5 to 39.0 (24% decrease; r Z e0.96, P < .001).
Table 2 Mean number of cases per graduating resident by year within the hematologic, genitourinary, and lung-disease categories, stratified by specific disease type Mean cases by year Hematologic Lymphoma Leukemia/myeloma Other hematologic Lung Small cell lung cancer Non-small cell lung cancer Other lung/mediastinum GU Prostate Bladder Testes Other GU
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
r
P value
22.2 11.3 1.2
20.7 11.3 1.1
20 11.7 1.2
19.8 11.9 1.4
19.2 11.7 1.3
18.8 10 1.4
17.4 10.9 1.3
18.2 10.1 1.2
15.4 9.2 1.4
17 9.3 1.3
15.8 7.8 1.6
14.5 7.9 1.5
e0.96 e0.90 0.72
<.001 <.001 .009
6 34.8 2.3
5.7 32.3 2.1
5.9 31.9 2.4
5.9 30.9 2.9
6 32.3 2.6
5.5 31.5 2.6
6.2 32.6 2.3
5.3 31.3 2.5
5.7 30.8 2.5
5 26.6 2.5
4.9 25.6 2.5
5.1 24.8 2
e0.75 e0.86 e0.08
.005 <.001 .794
54 2.6 2.1 1
53.5 2.7 1.8 0.9
55 2.8 1.5 0.8
52.3 3 1.6 1
51 3.2 1.3 1.1
51.1 3.1 1.3 1.2
49.3 3 0.7 0.9
45.7 3 0.9 1.1
43 3.1 0.7 0.9
41.4 3.1 0.5 1
38.5 3.2 0.4 1.1
40.5 3.3 0.4 1
e0.96 0.84 e0.97 0.27
<.001 .001 <.001 .399
Abbreviation: GU Z genitourinary.
Volume - Number - 2019
EBRT case log trends
5
Mean cases per graduating resident
60
50
40
30
20
10
0 2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Graduating academic year SRS (r = 0.96, P < .001)
Fig. 3.
SBRT (r = 0.99, P < .001)
Longitudinal trends in stereotactic radiosurgery and stereotactic body radiation therapy cases over time.
To better characterize the declines in these 3 disease sites, we performed further analysis by disease type within each of these sites (Table 2). The decrease in hematologic malignancies appeared to be driven by a 35% decline in lymphoma cases, from 22.2 cases in 2007 to 14.5 cases in 2018 (r Z e0.96; P < .001) and a decrease in mean leukemia/myeloma cases, from 11.3 cases in 2007 to 7.9 cases in 2018 (r Z e0.90; P < .001). The decrease in genitourinary malignancies appeared to be attributable to a decline in mean prostate cases from 54.0 in 2007 to 40.5 in 2018 (r Z e0.96; P < .001). Finally, the decrease in lung cases was primarily in non-small cell lung cancer, which decreased from 34.8 in 2007 to 24.8 in 2018 (r Z e0.86; P < .001).
Temporal trends in SRS and SBRT cases Regarding SRS and SBRT cases, there was a 298% increase in the total number of SRS cases performed in which residents participated, from 3181 cases in 2007 to 9511 in 2018 (P < .001; r Z 0.95). There was an increase in SRS exposure per graduating resident, from an average of 27.9 cases in 2007 to 50.3 in 2018 (P < .001; r Z 0.96). For SBRT, there was a 1536% increase in the total number of cases performed with resident participation, from 684 cases in 2007 to 10,508 cases in 2018 (P < .001; r Z 0.98). Subsequently, there was an increase in SBRT volume per graduating resident, from an average of 6 cases in 2007 to 55.6 cases in 2018 (P < .001; r Z 0.99). These trends are depicted in Figure 3. We additionally report on the breakdown of SBRT cases in 2018. Of all SBRT cases, 77.9% were classified as lung or other extracranial. The median number of liver SBRT
cases per graduating resident was 3, with a 10th percentile of 0 cases and a 30th percentile of 1 case. The median number of spine cases per graduating resident was 2, with a 10th percentile of 1 case and a 30th percentile of 2 cases.
Discussion To our knowledge, this is the first published report analyzing longitudinal trends in resident-reported case experience in radiation oncology. We found that there has been a decrease in the mean number of EBRT cases per graduating resident; however, the number and proportion of metastatic disease cases per resident has increased. There has been a sharp increase in SRS and SBRT case volume, and overall significant variation between disease sites was observed. We observed declining overall graduating resident case experience, with pronounced decreases in hematologic malignancies, lung malignancies, and genitourinary malignancies. The factors underlying these declines are likely multifactorial. However, the rapid expansion of residency training positions may be a contributing factor to the decline in case numbers per resident. Additionally, we hypothesize that the decline in hematologic malignancies is likely attributable to advances in systemic therapy and mirrors a nationwide decrease in use of RT for lymphoma and myeloma.5,6 Similarly, the decline in genitourinary experience likely reflects a nationwide shift toward more active surveillance and increased use of prostatectomy.7,8 The decline in lymphoma experience is particularly notable because it reinforces a previous survey of chief residents that found up to 30% reported inadequate experience in lymphoma malignancies with the percentage increasing over time.9,10
6
Li et al.
Regarding pediatric cases, we found that the 10th percentile of cases per graduating resident was 12, which meets the case minimum of 12. The overall case volume of pediatric cases has been decreasing over the study period, from 23.9 per graduating resident in 2007 to 19.4 per graduating resident in 2018. However, the volume of nonliquid pediatric malignancy cases has been more stable, with a mean of 17.3 cases per graduating resident in 2007 and 16.1 cases per graduating resident in 2018 (P Z .038). We found overall robust case volume for SBRT and SRS, with the most recent graduating resident averaging 50.3 SRS cases and 55.6 SBRT casesdwell above the current minimum of 20 SRS and 10 SBRT cases. However, further analysis of the 2018 class of graduating residents did reveal relatively lower numbers of liver and spine SBRT cases. The 30th percentile of graduating residents reported just 1 liver SBRT case and 2 spine SBRT cases. This raises questions regarding preparation for independent practice given expanding indications for SBRT in the treatment of oligometastatic disease.11,12 Future revisions of the ACGME case requirements may consider shifting utilization patterns of stereotactic therapies to optimize resident preparation for independent practice. Our study has several limitations. All cases are selfreported by residents and are subject to some degree of reporting bias. After meeting the minimum requirements, there is diminished incentive for residents to continue logging cases. Additionally, the maximum number of cases per year is set at 250, and this may discourage residents from logging cases beyond this quantity. However, prior studies of surgical resident case logs have shown 75% to 80% agreement with survey audit or billing data.13,14 We observed some year-to-year variation in case reporting numbers, meaning that conclusions regarding temporal trends should be regarded with caution. Finally, these statistics reflect only resident case experience and do not contain any information about trainee competency or quality of learning experience. Despite these limitations, we believe this study offers considerable value in characterizing previously unreported trends in resident case experience.
Conclusions We report a summary of resident-reported experience in EBRT cases. We found an overall decrease in mean number of EBRT cases per resident, though SRS and SBRT case volume is increasing. Our findings may help identify areas of focus for potential improvement in nationwide residency
International Journal of Radiation Oncology Biology Physics
training experience and inform future efforts to optimize residency training requirements.
References 1. Accreditation Council for Graduate Medical Education. ACGME program requirements for graduate medical education in radiation oncology. Available at: https://www.acgme.org/Portals/0/ PFAssets/ProgramRequirements/430_radiation_oncology_2017-07-01. pdf. Accessed April 3, 2019. 2. Citrin DE. Recent developments in radiotherapy. N Engl J Med 2017; 377:1065-1075. 3. Stahl JM, Corso CD, Verma V, et al. Trends in stereotactic body radiation therapy for stage I small cell lung cancer. Lung Cancer 2017; 103:11-16. 4. Chang JY, Senan S, Paul MA, et al. Stereotactic ablative radiotherapy versus lobectomy for operable stage I non-small-cell lung cancer: A pooled analysis of two randomised trials. Lancet Oncol 2015;16: 630-637. 5. Ailawadhi S, Frank RD, Meghji Z, et al. Utilization of radiation therapy in multiple myeloma: Trends and changes in practice. Blood 2017;130. 6. Vargo JA, Gill BS, Balasubramani GK, Beriwal S. Treatment selection and survival outcomes in early-stage diffuse large B-cell lymphoma: Do we still need consolidative radiotherapy? J Clin Oncol 2015;33: 3710-3717. 7. Malouff T, Mathy NW, Marsh S, Walters RW, Silberstein PT. Trends in the use of radiation therapy for stage IIA prostate cancer from 2004 to 2013: A retrospective analysis using the National Cancer Database. Prostate Cancer Prostatic Dis 2017;20:334-338. 8. Jani AB, Johnstone PAS, Liauw SL, Master VA, Rossi PJ. Prostate cancer modality time trend analyses from 1973 to 2004. Am J Clin Oncol 2009;33:1. 9. Nabavizadeh N, Burt LM, Mancini BR, et al. Results of the 2013-2015 Association of Residents in Radiation Oncology Survey of chief residents in the United States. Int J Radiat Oncol Biol Phys 2016;94: 228-234. 10. Gondi V, Bernard JR, Jabbari S, et al. Results of the 2005-2008 Association of Residents in Radiation Oncology Survey of chief residents in the United States: Clinical training and resident working conditions. Int J Radiat Oncol Biol Phys 2011;81:11201127. 11. Gomez DR, Blumenschein GR, Lee JJ, et al. Local consolidative therapy versus maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer without progression after first-line systemic therapy: A multicentre, randomised, controlled, phase 2 study. Lancet Oncol 2016;17:1672-1682. 12. Palma DA, Olson RA, Harrow S, et al. Stereotactic ablative radiation therapy for the comprehensive treatment of oligometastatic tumors (SABR-COMET): Results of a randomized trial. Int J Radiat Oncol Biol Phys 2018;102:S3-S4. 13. McPheeters MJ, Talcott RD, Hubbard ME, Haines SJ, Hunt MA. Assessing the accuracy of neurological surgery resident case logs at a single institution. Surg Neurol Int 2017;8:206. 14. Nygaard RM, Daly SR, Van Camp JM. General surgery resident case logs: Do they accurately reflect resident experience? J Surg Educ 2015;72:e178-e183.