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Point A or Point H in Prescribing High-Dose-Rate (HDR) Intracavitary Brachytherapy for Cervical Carcinoma?
I. J. Radiation Oncology d Biology d Physics
S396
Volume 69, Number 3, Supplement, 2007
Table 1 Hematological toxicity
Grade 0
Grade 1
Grade 2
Grade 3
Grade 4
Leucopenia Neutropenia Anemia Thrombocytopenia
2 (83%) 7 (29%) 6 (25%) 16 (66%)
3 (13%) 4 (17%) 10 (42%) 6 (25%)
8 (33.3%) 7 (30%) 8 (33.3%) 1 (4%)
11 (46%) 5 (21%) 0 1 (4%)
0 0 0 0
Table 2 Blood parameter
Median nadir (S.D)
Hemoglobin (Hgb, g/dL) Leucocyte (WBC, 1000/mL) Neutrophill (ANC, 1000/mL) Platelets (platelets, 1000/mL)
10 (1.27) 2.2 (.86) 1.24 (.71) 124 (47)
Table 3 Site
V10
V20
V30
V45
BM-L BM-I BM-LP BM-S BM
100 (0) 99.9 (.3) 92.2 (8.3) 100 (0) 97 (3.3)
100 (0) 97.2 (2.8) 80.7 (12.5) 100 (0) 91.5 (5.5)
100 (0) 91.6 (7.2) 73.4 (13.3) 100 (.2) 86.8 (6.9)
100 (0) 66.6 (14) 55.5 (13.2) 99.2 (2.2) 71.7 (9)
Author Disclosure: G.N. Gan, None; S. Beriwal, None; D.E. Heron, None; H. Kim, None; R. Lalonde, None.
2345
Intensity-Modulated Radiation Therapy (IMRT) in the Treatment of Carcinoma of the Vagina
R. Vera, P. J. Eifel, A. Jhingran, M. Salehpour MD Anderson Cancer Center, Houston, TX Purpose/Objective(s): To discuss clinical treatment guidelines and evaluate the outcome of patients treated with IMRT for locally-advanced, squamous cell carcinoma of the vagina. Materials/Methods: Hospital records were searched for all patients treated with radiation therapy for squamous cell carcinomas of the vagina at The University of Texas M.D. Anderson Cancer Center between 2000 and 2005. Of the 50 patients identified, 13 had a portion of their primary treatment delivered with IMRT. The medical records of patients who received IMRT were reviewed to obtain information about patient, tumor and treatment characteristics as well as outcome. Rates of survival were calculated using the Kaplan-Meier method, with differences assessed using log-rank comparisons. Results: The median age of the patients studied was 64 years (range, 31–80). Patients who were selected for IMRT had either very advanced cancers or extensive recto-vaginal septal involvement that precluded brachytherapy. Of the 13 patients treated with IMRT, 2 (15%) had stage II, 5 (38%) had stage III, 5 (38%) had stage IVA, and 1 patient had a second vaginal cancer adjacent to and 10 years after radiation therapy for her initial primary. Most patients had large tumors with 8 (62%) more than 4 cm in diameter. IMRT was used either as a boost after conventional external beam irradiation (5 patients) or for the entire course of radiation therapy (8 patients) and was usually planned using 7 beams of 6 MV photons. The dose to the GTV with 5–7 mm margin ranged between 60 and 68 Gy; higher doses were sometimes delivered concomitantly to the GTV with minimal margin and 5 patients were replanned during treatment to adjust for tumor regression. Tissues at risk for microscopic disease received 45–54 Gy. 8 patients (62%) received concurrent cisplatin-based chemotherapy during radiation therapy. With a median follow up of 18 months (range, 6–60 months), there have been no pelvic recurrences. Four patients have developed distant metastases, to lung, brain, or liver. At 3 years, the projected overall survival rate is 75%. Two patients had major complications; both developed fistulas at 3 and 5 months after treatment. Conclusions: IMRT can be used to achieve high rates of pelvic disease control with an acceptable complication rate in patients who have advanced vaginal cancers that are not amenable to brachytherapy. Treatment must be carefully individualized with an understanding of the complex regional drainage of vaginal cancer and considering the effects of internal organ motion and tumor regression. Author Disclosure: R. Vera, None; P.J. Eifel, None; A. Jhingran, None; M. Salehpour, None.
2346
Point A or Point H in Prescribing High-Dose-Rate (HDR) Intracavitary Brachytherapy for Cervical Carcinoma?
T. Y. Eng1, S. Cummins2, D. Baake2 1
UTHSC/Cancer Therapy & Research Ctr., San Antonio, TX, 2Cancer Therapy & Research Ctr., San Antonio, TX
Introduction: The Manchester system is the most common system used in intracavitary brachytherapy for cervical carcinoma. Although some variations exist, it defines typically point A dose as the dose at 2 cm above the external cervical os (flange) and 2 cm lateral to midline (tandem) along the plane of the tandem. Because point A occurs in a high-gradient region of the isodose
Proceedings of the 49th Annual ASTRO Meeting
S397
distribution, minor differences in application may lead to major differences in dose received. Therefore, the American Brachytherapy Society (ABS) recommends prescribing the dose to a new point H such that it falls sufficiently superior to the ovoids where the isodose distribution runs parallel to the tandem (1). Purpose/Objective(s): The purpose of this study was to analyze the dosimetric differences between prescribing to point A and point H in HDR intracavitary brachytherapy for cervical carcinoma. Materials/Methods: Seventeen intracavitary brachytherapy treatment plans as representative samples from 9 consecutive patients treated for stage I, II and III cervical carcinoma were randomly selected and used for dosimetric analysis. These patients were treated with the HDR remote afterloading microSelectronTM intracavitary brachytherapy system (Nucletron Corp, Veenendaal, Netherlands) typically in 5 to 6 fractions, 500 to 600 cGy per fraction, twice a week after 4500 cGy external beam therapy to whole pelvis. Standard tandem and ovoids were used. The brachytherapy dose was prescribed to point A in all cases and were re-prescribed to Point H retrospectively. The ICRU rectal and bladder reference points and additional point-doses along the rectum and bladder closest to the tendem and ovoids (T&O) apparatus were identified and re-calculated. Nucletron Plato treatment planning software (v14.3.2) was utilized. The differences in radiation dose to corresponding point A, point B, bladder and rectum were tabulated and analyzed. Results: Significant dose variations in point A, point B, bladder and rectum were observed when point H was utilized. For example, point A dose differences ranged from 17.61% to 6.67% with a mean of 0.03% and a standard deviation of 3.76% (Table 1). Conclusions: The actual doses delivered to point A, B, bladder and rectum vary significantly when point H was used. The potential clinical impact in tumor control and survival is unknown because point H has not been used as long as point A has. Further clinical studies are needed. References: 1. Nag S, Erickson B, Thomadsen B, et al. The American Brachytherapy Society recommendations for high-dose-rate brachytherapy for carcinoma of the cervix. IJROBP 48(1):201–11, 2000. Table 1: Percent dose differences between prescribing to point A and point H Data Average Min Max Median Std Dev
Point A
Point B
0.03 17.61 6.67 0.8 3.76
0.35 17.61 6.67 2.27 6.03
Bladder 0.17 6.49 2.21 0.62 2.0
Rectum 0.02 8.08 5.17 1.29 3.31
Author Disclosure: T.Y. Eng, None; S. Cummins, None; D. Baake, None.
2347
Endometrial Carcinoma in Elderly Women: Disease Outcome and Treatment Morbidity
M. A. Al refae, D. Roberge, L. Portelance, M. Duclos, L. Gilbert, L. Souhami McGill University, Montreal, PQ, Canada Purpose/Objective(s): Total abdominal hysterectomy and bilateral salpingoophorectomy (TAHBSO) followed by adjuvant pelvic radiotherapy (RT) is the standard treatment for patients with intermediate and high risk endometrial cancer. Because of concerns regarding the potential for increased toxicity, RT may not be offered to elderly women despite the often worse prognosis in these patients. The aim of this study is to review our experience in endometrial cancer patients 75 years or older with a focus on the tolerance and efficacy of radiotherapy. Materials/Methods: All charts of women older than 75 years underwent TAHBSO for endometrial carcinoma of the uterus between 1995 and 2005 at McGill University Health Center were retrospectively reviewed. The primary endpoints assessed were loco-regional control, overall survival and treatment related toxicity. Results: A total of 85 cases were identified: 27 patients (median age 80) underwent only TAHBSO, 51 patients (median age 78) received adjuvant radiation therapy. Radiotherapy consisted of external beam radiotherapy (EBRT) alone in 7 patients (14%), EBRT and intravaginal high dose rate brachytherapy (HDRB) in 39 patients (76%) and HDRBT alone in the remaining 5 patients (10%). The EBRT was typically 45 Gy in 25 fractions delivered using a 4-field technique. When combined with EBRT, HDRB was typically delivered in a single fraction of 6 Gy. When used alone, HDRB doses ranged from 6 Gy in 1 fraction to 24 Gy in 4 fractions. Tumor characteristics are presented in the Table. After a median follow up of 40 months, the actuarial 5 year loco-regional recurrence rates were 61% with TAHBSO alone versus 14% with adjuvant radiotherapy (p = 0.003). 5 year cause specific and overall survival rate were the same on both groups, 85% (cause-specific) and 66–67% (overall). Grade I/II acute radiation toxicity was seen in 17 pts (33%) and mostly related to the gastrointestinal tract. One patient (2%) developed grade III abdominal cramps and her treatment was interrupted. A total of 9 patients (18%) developed grade I/II late toxicity and all of them had been treated with a component of EBRT. No grade III or higher late toxicity of the adjuvant radiotherapy was seen. One patient treated with salvage radiotherapy suffered an acetabular fracture. Conclusions: In our experience, the use of adjuvant RT in patients 75 years or older was well tolerated and effective. Older patients with intermediate or high risk endometrial cancer have a high rate of pelvic recurrence and our data suggest that they should be considered for adjuvant RT although increased loco-regional control does not appear to translate to improved overall survival.
S396
Volume 69, Number 3, Supplement, 2007
Table 1 Hematological toxicity
Grade 0
Grade 1
Grade 2
Grade 3
Grade 4
Leucopenia Neutropenia Anemia Thrombocytopenia
2 (83%) 7 (29%) 6 (25%) 16 (66%)
3 (13%) 4 (17%) 10 (42%) 6 (25%)
8 (33.3%) 7 (30%) 8 (33.3%) 1 (4%)
11 (46%) 5 (21%) 0 1 (4%)
0 0 0 0
Table 2 Blood parameter
Median nadir (S.D)
Hemoglobin (Hgb, g/dL) Leucocyte (WBC, 1000/mL) Neutrophill (ANC, 1000/mL) Platelets (platelets, 1000/mL)
10 (1.27) 2.2 (.86) 1.24 (.71) 124 (47)
Table 3 Site
V10
V20
V30
V45
BM-L BM-I BM-LP BM-S BM
100 (0) 99.9 (.3) 92.2 (8.3) 100 (0) 97 (3.3)
100 (0) 97.2 (2.8) 80.7 (12.5) 100 (0) 91.5 (5.5)
100 (0) 91.6 (7.2) 73.4 (13.3) 100 (.2) 86.8 (6.9)
100 (0) 66.6 (14) 55.5 (13.2) 99.2 (2.2) 71.7 (9)
Author Disclosure: G.N. Gan, None; S. Beriwal, None; D.E. Heron, None; H. Kim, None; R. Lalonde, None.
2345
Intensity-Modulated Radiation Therapy (IMRT) in the Treatment of Carcinoma of the Vagina
R. Vera, P. J. Eifel, A. Jhingran, M. Salehpour MD Anderson Cancer Center, Houston, TX Purpose/Objective(s): To discuss clinical treatment guidelines and evaluate the outcome of patients treated with IMRT for locally-advanced, squamous cell carcinoma of the vagina. Materials/Methods: Hospital records were searched for all patients treated with radiation therapy for squamous cell carcinomas of the vagina at The University of Texas M.D. Anderson Cancer Center between 2000 and 2005. Of the 50 patients identified, 13 had a portion of their primary treatment delivered with IMRT. The medical records of patients who received IMRT were reviewed to obtain information about patient, tumor and treatment characteristics as well as outcome. Rates of survival were calculated using the Kaplan-Meier method, with differences assessed using log-rank comparisons. Results: The median age of the patients studied was 64 years (range, 31–80). Patients who were selected for IMRT had either very advanced cancers or extensive recto-vaginal septal involvement that precluded brachytherapy. Of the 13 patients treated with IMRT, 2 (15%) had stage II, 5 (38%) had stage III, 5 (38%) had stage IVA, and 1 patient had a second vaginal cancer adjacent to and 10 years after radiation therapy for her initial primary. Most patients had large tumors with 8 (62%) more than 4 cm in diameter. IMRT was used either as a boost after conventional external beam irradiation (5 patients) or for the entire course of radiation therapy (8 patients) and was usually planned using 7 beams of 6 MV photons. The dose to the GTV with 5–7 mm margin ranged between 60 and 68 Gy; higher doses were sometimes delivered concomitantly to the GTV with minimal margin and 5 patients were replanned during treatment to adjust for tumor regression. Tissues at risk for microscopic disease received 45–54 Gy. 8 patients (62%) received concurrent cisplatin-based chemotherapy during radiation therapy. With a median follow up of 18 months (range, 6–60 months), there have been no pelvic recurrences. Four patients have developed distant metastases, to lung, brain, or liver. At 3 years, the projected overall survival rate is 75%. Two patients had major complications; both developed fistulas at 3 and 5 months after treatment. Conclusions: IMRT can be used to achieve high rates of pelvic disease control with an acceptable complication rate in patients who have advanced vaginal cancers that are not amenable to brachytherapy. Treatment must be carefully individualized with an understanding of the complex regional drainage of vaginal cancer and considering the effects of internal organ motion and tumor regression. Author Disclosure: R. Vera, None; P.J. Eifel, None; A. Jhingran, None; M. Salehpour, None.
2346
Point A or Point H in Prescribing High-Dose-Rate (HDR) Intracavitary Brachytherapy for Cervical Carcinoma?
T. Y. Eng1, S. Cummins2, D. Baake2 1
UTHSC/Cancer Therapy & Research Ctr., San Antonio, TX, 2Cancer Therapy & Research Ctr., San Antonio, TX
Introduction: The Manchester system is the most common system used in intracavitary brachytherapy for cervical carcinoma. Although some variations exist, it defines typically point A dose as the dose at 2 cm above the external cervical os (flange) and 2 cm lateral to midline (tandem) along the plane of the tandem. Because point A occurs in a high-gradient region of the isodose
Proceedings of the 49th Annual ASTRO Meeting
S397
distribution, minor differences in application may lead to major differences in dose received. Therefore, the American Brachytherapy Society (ABS) recommends prescribing the dose to a new point H such that it falls sufficiently superior to the ovoids where the isodose distribution runs parallel to the tandem (1). Purpose/Objective(s): The purpose of this study was to analyze the dosimetric differences between prescribing to point A and point H in HDR intracavitary brachytherapy for cervical carcinoma. Materials/Methods: Seventeen intracavitary brachytherapy treatment plans as representative samples from 9 consecutive patients treated for stage I, II and III cervical carcinoma were randomly selected and used for dosimetric analysis. These patients were treated with the HDR remote afterloading microSelectronTM intracavitary brachytherapy system (Nucletron Corp, Veenendaal, Netherlands) typically in 5 to 6 fractions, 500 to 600 cGy per fraction, twice a week after 4500 cGy external beam therapy to whole pelvis. Standard tandem and ovoids were used. The brachytherapy dose was prescribed to point A in all cases and were re-prescribed to Point H retrospectively. The ICRU rectal and bladder reference points and additional point-doses along the rectum and bladder closest to the tendem and ovoids (T&O) apparatus were identified and re-calculated. Nucletron Plato treatment planning software (v14.3.2) was utilized. The differences in radiation dose to corresponding point A, point B, bladder and rectum were tabulated and analyzed. Results: Significant dose variations in point A, point B, bladder and rectum were observed when point H was utilized. For example, point A dose differences ranged from 17.61% to 6.67% with a mean of 0.03% and a standard deviation of 3.76% (Table 1). Conclusions: The actual doses delivered to point A, B, bladder and rectum vary significantly when point H was used. The potential clinical impact in tumor control and survival is unknown because point H has not been used as long as point A has. Further clinical studies are needed. References: 1. Nag S, Erickson B, Thomadsen B, et al. The American Brachytherapy Society recommendations for high-dose-rate brachytherapy for carcinoma of the cervix. IJROBP 48(1):201–11, 2000. Table 1: Percent dose differences between prescribing to point A and point H Data Average Min Max Median Std Dev
Point A
Point B
0.03 17.61 6.67 0.8 3.76
0.35 17.61 6.67 2.27 6.03
Bladder 0.17 6.49 2.21 0.62 2.0
Rectum 0.02 8.08 5.17 1.29 3.31
Author Disclosure: T.Y. Eng, None; S. Cummins, None; D. Baake, None.
2347
Endometrial Carcinoma in Elderly Women: Disease Outcome and Treatment Morbidity
M. A. Al refae, D. Roberge, L. Portelance, M. Duclos, L. Gilbert, L. Souhami McGill University, Montreal, PQ, Canada Purpose/Objective(s): Total abdominal hysterectomy and bilateral salpingoophorectomy (TAHBSO) followed by adjuvant pelvic radiotherapy (RT) is the standard treatment for patients with intermediate and high risk endometrial cancer. Because of concerns regarding the potential for increased toxicity, RT may not be offered to elderly women despite the often worse prognosis in these patients. The aim of this study is to review our experience in endometrial cancer patients 75 years or older with a focus on the tolerance and efficacy of radiotherapy. Materials/Methods: All charts of women older than 75 years underwent TAHBSO for endometrial carcinoma of the uterus between 1995 and 2005 at McGill University Health Center were retrospectively reviewed. The primary endpoints assessed were loco-regional control, overall survival and treatment related toxicity. Results: A total of 85 cases were identified: 27 patients (median age 80) underwent only TAHBSO, 51 patients (median age 78) received adjuvant radiation therapy. Radiotherapy consisted of external beam radiotherapy (EBRT) alone in 7 patients (14%), EBRT and intravaginal high dose rate brachytherapy (HDRB) in 39 patients (76%) and HDRBT alone in the remaining 5 patients (10%). The EBRT was typically 45 Gy in 25 fractions delivered using a 4-field technique. When combined with EBRT, HDRB was typically delivered in a single fraction of 6 Gy. When used alone, HDRB doses ranged from 6 Gy in 1 fraction to 24 Gy in 4 fractions. Tumor characteristics are presented in the Table. After a median follow up of 40 months, the actuarial 5 year loco-regional recurrence rates were 61% with TAHBSO alone versus 14% with adjuvant radiotherapy (p = 0.003). 5 year cause specific and overall survival rate were the same on both groups, 85% (cause-specific) and 66–67% (overall). Grade I/II acute radiation toxicity was seen in 17 pts (33%) and mostly related to the gastrointestinal tract. One patient (2%) developed grade III abdominal cramps and her treatment was interrupted. A total of 9 patients (18%) developed grade I/II late toxicity and all of them had been treated with a component of EBRT. No grade III or higher late toxicity of the adjuvant radiotherapy was seen. One patient treated with salvage radiotherapy suffered an acetabular fracture. Conclusions: In our experience, the use of adjuvant RT in patients 75 years or older was well tolerated and effective. Older patients with intermediate or high risk endometrial cancer have a high rate of pelvic recurrence and our data suggest that they should be considered for adjuvant RT although increased loco-regional control does not appear to translate to improved overall survival.