- Email: [email protected]
Dosimetric Comparison of Four Different External Beam Partial Breast Irradiations: Proton, Tomotherapy, Intensity Modulated and 3D Conformal Radiation Therapy
Proceedings of the 49th Annual ASTRO Meeting in the brain, at 8 months and 7.5 years post-radiation. Because of bias induced by the study design, all long-term survivors (five are alive at 74–118 months) were those receiving PCI. Long-term complications have occurred in these patients, including two documented cases of neurocognitive impairment. Of these, a previously high-functioning patient required full care for leukoencephalopathy and treatment-related dementia. Conclusions: We present a small series of patients with stage IIIB-IV breast cancer treated prophylactically with whole-brain radiotherapy following an aggressive chemotherapy regimen. Our data precludes any conclusion regarding the therapeutic benefit of PCI in this context. Nevertheless, with the potential for brain metastases despite PCI, and for serious long-term neurological sequelae, any further investigation of PCI in high-risk breast cancer will need to be approached with caution. Author Disclosure: F. Huang, None; M. Al Refae, None; A. Langleben, None; D. Roberge, None.
2028
Repeat Computed Tomography Simulation to Assess Lumpectomy Cavity Volume During Whole Breast Irradiation
E. M. Nichols, T. W. Flannery, K. M. Markham, E. Zahidi, M. Mohiuddin, S. B. Cheston Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD Purpose/Objective(s): To determine if the lumpectomy cavity decreases in volume during whole breast radiation therapy (RT) and what factors may influence the decrease. Materials/Methods: Thirty-five patients from the University of Maryland School of Medicine were prospectively enrolled on this study between 1/3/06 and 3/1/07 to assess the change in volume of the lumpectomy cavity during whole breast radiation therapy. Eligible patients underwent lumpectomy for invasive breast cancer or ductal carcinoma in situ (DCIS) followed by a planning CT simulation (CT 1) within 60 days of surgery. No lumpectomy volume criteria made patients ineligible. CT 1, mammographic and radiographic data, pathological/surgical reports, and surgical clips aided in defining the lumpectomy cavity. Patients were treated to the entire breast to a dose of 45–50.4 Gy with opposed tangents and underwent a second planning CT simulation (CT 2) after 21–23 treatments. Patients were treated based on the lumpectomy cavity from CT 2. Results: The median volume of the lumpectomy cavity was 26.3 cc (range, 5.37–363.83 cc). The median times from surgery to CT 1 and surgery to the first day of RT were 32 (range, 4–56 days) and 43 days (range, 22–72 days), respectively. The median decrease in volume was 29%, and the lumpectomy cavity decreased in volume by $25% in 21/35 (60%). Patients with lumpectomy volumes .15 cc were more likely to have a volume reduction $25% versus those with #15 cc (18/24 (75%) vs. 3/11 (27%), p = 0.007). Patients with lumpectomy cavities .15 cc had a $25%, $33%, and $50% decrease in volume in 18/24 (75%), 14/24 (58%), and 8/24 (33%) patients, respectively. When stratifying patients that had CT 1 at #32 days (N = 18) versus .32 days (N = 17), the likelihood of having a decrease in volume of $25% was not statistically different (p = 0.581). Conclusions: Patients who undergo lumpectomy for breast cancer or DCIS can have a significant decrease in the size of their lumpectomy cavity during the course of their RT. In our cohort, 60% of patients experienced a decrease in their lumpectomy cavity size of $25%, while 23% of patients had a $50% decrease. A significant difference was seen in the cohort of patients with lumpectomy cavities .15 cc. Based on the results of this study, patients who have a lumpectomy cavity size .15 cc should be considered for a second planning CT simulation. Re-simulation can potentially decrease dose to normal tissues, improve delineation of the lumpectomy cavity after weeks of RT, decrease acute and late radiation-induced side effects, and improve cosmesis. Author Disclosure: E.M. Nichols, None; T.W. Flannery, None; K.M. Markham, None; E. Zahidi, None; M. Mohiuddin, None; S.B. Cheston, None.
2029
Dosimetric Comparison of Four Different External Beam Partial Breast Irradiations: Proton, Tomotherapy, Intensity Modulated and 3D Conformal Radiation Therapy
K. Shin1, S. Moon1, N. Jang2, D. Lee1, M. Yoon1, S. Park1, J. Kim1, H. Yoo3, S. Park4 1 National Cancer Center, Gyeonggi, Republic of Korea, 2Seoul National University College of Medicine, Seoul, Republic of Korea, 3Korea Cancer Center Hospital, Seoul, Republic of Korea, 4Chung-Ang University Medical Center, Seoul, Republic of Korea
Purpose/Objective(s): To compare the dosimetry of four different external beam partial breast irradiation (PBI) plans of proton, tomotherapy, intensity-modulated radiation therapy (IMRT) and 3D conformal radiation therapy (3D-CRT). Materials/Methods: Ten breast cancer patients were included and the plans were developed for each patient using each methods of PBI. The PTV was constructed as a uniform expansion of 1.5 cm margin from lumpectomy site marked with surgical clips. To facilitate dosimetric comparisons, total dose were held constant with 30 Gy. Results: Proton and tomotherapy plans provided better homogeneity indices (0.21, 0.18, respectively) compared with IMRT and 3D-CRT (0.44, 0.29, respectively). Conformity index of tomotherapy (1.14) was better than others (proton 1.31, IMRT 1.30, 3DCRT 1.26). Coverage index was acceptable in all plans of $0.95. The average percentage of the PTV receiving 95% of the prescribed dose (PD) was 100%, 99%, 100%, and 98% for proton, tomotherapy, IMRT and 3D-CRT, respectively. The total volume of ipsilateral breast receiving 75% and 50% of PD was highest in the 3D-CRT (41% and 53%, respectively) compared with others, among which proton plan was best (32% and 36%, respectively). Proton also reduced the volume of non-PTV breast tissue receiving 50% of PD significantly by an average of tomotherapy (7%), IMRT (10%) and 3D-CRT (16%). In lung and heart dosimetry, proton was best and tomotherapy was worst. The ipsilateral lung volume percentage receiving 5 and 10 Gy (V5 Gy and V10 Gy) was significantly lower in proton (1.7%, 0.9%) compared with tomotherapy (20.7%, 4.5%), IMRT (4.3%, 1.1%) and 3D-CRT (8.1%, 3.5%). The heart V5 Gy and V10 Gy of proton was negligible (0.15%, 0.04%), but tomotherapy plan showed high V5 Gy and V10 Gy of 26.3% and 7.2%, respectively.
S221
I. J. Radiation Oncology d Biology d Physics
S222
Volume 69, Number 3, Supplement, 2007
Conclusions: Though four techniques showed acceptable coverage of PTV, proton provides excellent normal tissue sparing. Tomotherapy does not seem to be suitable for PBI with unacceptably high dose exposure of heart and lung. Author Disclosure: K. Shin, None; S. Moon, None; N. Jang, None; D. Lee, None; M. Yoon, None; S. Park, None; J. Kim, None; H. Yoo, None; S. Park, None.
2030
Postmastectomy Intensity Modulated Radiation Therapy (IMRT) in Women Who Undergo Immediate Breast Reconstruction
L. Koutcher, A. Ballangrud, P. Cordeiro, B. McCormick, M. Hunt, K. Beal Memorial Sloan-Kettering Cancer Center, New York, NY Purpose/Objective(s): For women with breast cancer who undergo mastectomy, immediate reconstruction with tissue expanders (TE) is a frequently used technique at our center. Previous studies1 have questioned this approach of immediate reconstruction in women who may need post-mastectomy radiation therapy (PMRT), citing compromises in the treatment plan. We evaluated plans of patients with implant reconstruction receiving PMRT to determine if radiation could be delivered safely and effectively. Materials/Methods: This study was a retrospective review of all patients at our institution who were treated with mastectomy, immediate reconstruction with TE, and PMRT with IMRT, which was started in 2004. Forty patients were identified who had their TE placed before 9/1/06. Thirty patients had their TE exchanged with a permanent implant by the start of IMRT, and 10 were treated with their TE in place. We assessed three parameters: volume of lung irradiated, volume of heart irradiated, and adequacy of chest wall (CW) coverage. The CW superior border was defined as the base of the clavicle, the CW inferior border as 2 centimeters inferior to the contralateral inframammary fold, the CW medial border as the mid-sternum, the CW lateral inferior border as the mid-axillary line, and the CW lateral superior border as the posterior axillary line. Dose-volume histograms were constructed for the ipsilateral and contralateral lungs, as well as the heart. Results: All patients were treated with IMRT to a dose of 50 or 50.4 Gy except 1 patient, who was treated to 44 Gy. All patients were treated with 3-field technique utilizing single isocenter to match the 2 tangent fields with the anterior oblique supraclavicular field. Patients were treated with daily bolus over their chest wall. Six patients had their internal mammary nodes (IMN) treated, all with deep tangents. Adequate coverage of either 4 or 5 out of the 5 CW borders was achieved in 38/40 patients. The V20 of the combined lungs was #20% in 39/40 patients. The mean V20 of all 40 patients was 13% (range 3–23%). The Dmean to the heart was 2.77 Gy (range 0.57–9.60 Gy). In patients with left-sided lesions who did not have their IMN treated, the mean lung V20 was 13% and the heart Dmean was 3.90 Gy, and in those who did, the mean lung V20 was 18% and heart Dmean was 8.04 Gy. For right-sided lesions in which the IMN were not treated, the mean lung V20 was 12% and heart Dmean was 0.90 Gy, and in those who did, the mean lung V20 was 17%, and heart Dmean was 1.24 Gy. Conclusions: In women undergoing immediate breast reconstruction, PMRT can be delivered with adequate chest wall coverage and acceptable heart and lung doses. This can be done regardless of whether the IMN are being treated, though doses to the heart and lungs usually will be higher in this setting. 1. Schechter et al., Am J Clin Oncol 2005;28: 485–494. Author Disclosure: L. Koutcher, None; A. Ballangrud, None; P. Cordeiro, None; B. McCormick, None; M. Hunt, None; K. Beal, None.
2031
Concurrent versus Sequential Administration of CMF Chemotherapy and Radiotherapy After Breast Conserving Surgery in Early Breast Cancer: A Retrospective Comparative Study
E. Chie1, K. Kim1, W. Han2, D. Noh2, S. Im3, T. Kim3, Y. Bang3, S. W. Ha1 1 Department of Radiation Oncology, 2Department of Surgery, 3Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
Purpose/Objective(s): To compare concurrent versus sequential administration of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) chemotherapy and radiotherapy after breast conserving surgery in early breast cancer. Materials/Methods: From February 1992 to January 2002, 156 patients underwent CMF chemotherapy and radiotherapy after breast conserving surgery for stage I/II breast cancer. Of these, 88 patients received concurrent chemoradiotherapy (CCRT), 42 received chemotherapy first followed by radiotherapy, and 26 received a ‘‘sandwich’’ regimen. The latter two treatment schedules were grouped into sequential chemoradiotherapy (SCRT). As regards to prognostic factors, there was a predilection of patients with larger tumor (p = 0.0035), with nodal involvement (p = 0.0686), and of younger age (p = 0.0776) in the CCRT group. Median follow-up period was 95 months for CCRT group, and 69 months for SCRT group. Results: All patients completed the planned radiotherapy. No grade 3 or higher late radiation toxicity was observed in the CCRT group. Ninety-five percent of patients in the CCRT group and 93% of those in the SCRT group completed the planned 6 cycles of chemotherapy (p = 0.5045). Cosmetic outcome of the two groups was comparable. Despite more adverse factors of local-regional recurrence in the CCRT group, the 5-year local-regional control rate of the CCRT group was similar to that of the SCRT group (97.7% vs. 93.8%, respectively (p = 0.1688)). Moreover, in multivariate analysis taking into consideration of age, TNM stage, resection margin status, the combination of hormonal therapy, estrogen receptor status, and chemotherapy sequencing, concomitant administration of chemotherapy and radiotherapy was associated with increased local-regional control (p = 0.0463). Conclusions: Concurrent administration of CMF chemotherapy and radiotherapy is a safe and effective regimen as an adjuvant treatment after breast conserving surgery for early breast cancer, and may enhance local-regional control for patients with high risk factors of local-regional recurrence. Author Disclosure: E. Chie, None; K. Kim, None; W. Han, None; D. Noh, None; S. Im, None; T. Kim, None; Y. Bang, None; S.W. Ha, None.
2028
Repeat Computed Tomography Simulation to Assess Lumpectomy Cavity Volume During Whole Breast Irradiation
E. M. Nichols, T. W. Flannery, K. M. Markham, E. Zahidi, M. Mohiuddin, S. B. Cheston Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD Purpose/Objective(s): To determine if the lumpectomy cavity decreases in volume during whole breast radiation therapy (RT) and what factors may influence the decrease. Materials/Methods: Thirty-five patients from the University of Maryland School of Medicine were prospectively enrolled on this study between 1/3/06 and 3/1/07 to assess the change in volume of the lumpectomy cavity during whole breast radiation therapy. Eligible patients underwent lumpectomy for invasive breast cancer or ductal carcinoma in situ (DCIS) followed by a planning CT simulation (CT 1) within 60 days of surgery. No lumpectomy volume criteria made patients ineligible. CT 1, mammographic and radiographic data, pathological/surgical reports, and surgical clips aided in defining the lumpectomy cavity. Patients were treated to the entire breast to a dose of 45–50.4 Gy with opposed tangents and underwent a second planning CT simulation (CT 2) after 21–23 treatments. Patients were treated based on the lumpectomy cavity from CT 2. Results: The median volume of the lumpectomy cavity was 26.3 cc (range, 5.37–363.83 cc). The median times from surgery to CT 1 and surgery to the first day of RT were 32 (range, 4–56 days) and 43 days (range, 22–72 days), respectively. The median decrease in volume was 29%, and the lumpectomy cavity decreased in volume by $25% in 21/35 (60%). Patients with lumpectomy volumes .15 cc were more likely to have a volume reduction $25% versus those with #15 cc (18/24 (75%) vs. 3/11 (27%), p = 0.007). Patients with lumpectomy cavities .15 cc had a $25%, $33%, and $50% decrease in volume in 18/24 (75%), 14/24 (58%), and 8/24 (33%) patients, respectively. When stratifying patients that had CT 1 at #32 days (N = 18) versus .32 days (N = 17), the likelihood of having a decrease in volume of $25% was not statistically different (p = 0.581). Conclusions: Patients who undergo lumpectomy for breast cancer or DCIS can have a significant decrease in the size of their lumpectomy cavity during the course of their RT. In our cohort, 60% of patients experienced a decrease in their lumpectomy cavity size of $25%, while 23% of patients had a $50% decrease. A significant difference was seen in the cohort of patients with lumpectomy cavities .15 cc. Based on the results of this study, patients who have a lumpectomy cavity size .15 cc should be considered for a second planning CT simulation. Re-simulation can potentially decrease dose to normal tissues, improve delineation of the lumpectomy cavity after weeks of RT, decrease acute and late radiation-induced side effects, and improve cosmesis. Author Disclosure: E.M. Nichols, None; T.W. Flannery, None; K.M. Markham, None; E. Zahidi, None; M. Mohiuddin, None; S.B. Cheston, None.
2029
Dosimetric Comparison of Four Different External Beam Partial Breast Irradiations: Proton, Tomotherapy, Intensity Modulated and 3D Conformal Radiation Therapy
K. Shin1, S. Moon1, N. Jang2, D. Lee1, M. Yoon1, S. Park1, J. Kim1, H. Yoo3, S. Park4 1 National Cancer Center, Gyeonggi, Republic of Korea, 2Seoul National University College of Medicine, Seoul, Republic of Korea, 3Korea Cancer Center Hospital, Seoul, Republic of Korea, 4Chung-Ang University Medical Center, Seoul, Republic of Korea
Purpose/Objective(s): To compare the dosimetry of four different external beam partial breast irradiation (PBI) plans of proton, tomotherapy, intensity-modulated radiation therapy (IMRT) and 3D conformal radiation therapy (3D-CRT). Materials/Methods: Ten breast cancer patients were included and the plans were developed for each patient using each methods of PBI. The PTV was constructed as a uniform expansion of 1.5 cm margin from lumpectomy site marked with surgical clips. To facilitate dosimetric comparisons, total dose were held constant with 30 Gy. Results: Proton and tomotherapy plans provided better homogeneity indices (0.21, 0.18, respectively) compared with IMRT and 3D-CRT (0.44, 0.29, respectively). Conformity index of tomotherapy (1.14) was better than others (proton 1.31, IMRT 1.30, 3DCRT 1.26). Coverage index was acceptable in all plans of $0.95. The average percentage of the PTV receiving 95% of the prescribed dose (PD) was 100%, 99%, 100%, and 98% for proton, tomotherapy, IMRT and 3D-CRT, respectively. The total volume of ipsilateral breast receiving 75% and 50% of PD was highest in the 3D-CRT (41% and 53%, respectively) compared with others, among which proton plan was best (32% and 36%, respectively). Proton also reduced the volume of non-PTV breast tissue receiving 50% of PD significantly by an average of tomotherapy (7%), IMRT (10%) and 3D-CRT (16%). In lung and heart dosimetry, proton was best and tomotherapy was worst. The ipsilateral lung volume percentage receiving 5 and 10 Gy (V5 Gy and V10 Gy) was significantly lower in proton (1.7%, 0.9%) compared with tomotherapy (20.7%, 4.5%), IMRT (4.3%, 1.1%) and 3D-CRT (8.1%, 3.5%). The heart V5 Gy and V10 Gy of proton was negligible (0.15%, 0.04%), but tomotherapy plan showed high V5 Gy and V10 Gy of 26.3% and 7.2%, respectively.
S221
I. J. Radiation Oncology d Biology d Physics
S222
Volume 69, Number 3, Supplement, 2007
Conclusions: Though four techniques showed acceptable coverage of PTV, proton provides excellent normal tissue sparing. Tomotherapy does not seem to be suitable for PBI with unacceptably high dose exposure of heart and lung. Author Disclosure: K. Shin, None; S. Moon, None; N. Jang, None; D. Lee, None; M. Yoon, None; S. Park, None; J. Kim, None; H. Yoo, None; S. Park, None.
2030
Postmastectomy Intensity Modulated Radiation Therapy (IMRT) in Women Who Undergo Immediate Breast Reconstruction
L. Koutcher, A. Ballangrud, P. Cordeiro, B. McCormick, M. Hunt, K. Beal Memorial Sloan-Kettering Cancer Center, New York, NY Purpose/Objective(s): For women with breast cancer who undergo mastectomy, immediate reconstruction with tissue expanders (TE) is a frequently used technique at our center. Previous studies1 have questioned this approach of immediate reconstruction in women who may need post-mastectomy radiation therapy (PMRT), citing compromises in the treatment plan. We evaluated plans of patients with implant reconstruction receiving PMRT to determine if radiation could be delivered safely and effectively. Materials/Methods: This study was a retrospective review of all patients at our institution who were treated with mastectomy, immediate reconstruction with TE, and PMRT with IMRT, which was started in 2004. Forty patients were identified who had their TE placed before 9/1/06. Thirty patients had their TE exchanged with a permanent implant by the start of IMRT, and 10 were treated with their TE in place. We assessed three parameters: volume of lung irradiated, volume of heart irradiated, and adequacy of chest wall (CW) coverage. The CW superior border was defined as the base of the clavicle, the CW inferior border as 2 centimeters inferior to the contralateral inframammary fold, the CW medial border as the mid-sternum, the CW lateral inferior border as the mid-axillary line, and the CW lateral superior border as the posterior axillary line. Dose-volume histograms were constructed for the ipsilateral and contralateral lungs, as well as the heart. Results: All patients were treated with IMRT to a dose of 50 or 50.4 Gy except 1 patient, who was treated to 44 Gy. All patients were treated with 3-field technique utilizing single isocenter to match the 2 tangent fields with the anterior oblique supraclavicular field. Patients were treated with daily bolus over their chest wall. Six patients had their internal mammary nodes (IMN) treated, all with deep tangents. Adequate coverage of either 4 or 5 out of the 5 CW borders was achieved in 38/40 patients. The V20 of the combined lungs was #20% in 39/40 patients. The mean V20 of all 40 patients was 13% (range 3–23%). The Dmean to the heart was 2.77 Gy (range 0.57–9.60 Gy). In patients with left-sided lesions who did not have their IMN treated, the mean lung V20 was 13% and the heart Dmean was 3.90 Gy, and in those who did, the mean lung V20 was 18% and heart Dmean was 8.04 Gy. For right-sided lesions in which the IMN were not treated, the mean lung V20 was 12% and heart Dmean was 0.90 Gy, and in those who did, the mean lung V20 was 17%, and heart Dmean was 1.24 Gy. Conclusions: In women undergoing immediate breast reconstruction, PMRT can be delivered with adequate chest wall coverage and acceptable heart and lung doses. This can be done regardless of whether the IMN are being treated, though doses to the heart and lungs usually will be higher in this setting. 1. Schechter et al., Am J Clin Oncol 2005;28: 485–494. Author Disclosure: L. Koutcher, None; A. Ballangrud, None; P. Cordeiro, None; B. McCormick, None; M. Hunt, None; K. Beal, None.
2031
Concurrent versus Sequential Administration of CMF Chemotherapy and Radiotherapy After Breast Conserving Surgery in Early Breast Cancer: A Retrospective Comparative Study
E. Chie1, K. Kim1, W. Han2, D. Noh2, S. Im3, T. Kim3, Y. Bang3, S. W. Ha1 1 Department of Radiation Oncology, 2Department of Surgery, 3Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
Purpose/Objective(s): To compare concurrent versus sequential administration of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) chemotherapy and radiotherapy after breast conserving surgery in early breast cancer. Materials/Methods: From February 1992 to January 2002, 156 patients underwent CMF chemotherapy and radiotherapy after breast conserving surgery for stage I/II breast cancer. Of these, 88 patients received concurrent chemoradiotherapy (CCRT), 42 received chemotherapy first followed by radiotherapy, and 26 received a ‘‘sandwich’’ regimen. The latter two treatment schedules were grouped into sequential chemoradiotherapy (SCRT). As regards to prognostic factors, there was a predilection of patients with larger tumor (p = 0.0035), with nodal involvement (p = 0.0686), and of younger age (p = 0.0776) in the CCRT group. Median follow-up period was 95 months for CCRT group, and 69 months for SCRT group. Results: All patients completed the planned radiotherapy. No grade 3 or higher late radiation toxicity was observed in the CCRT group. Ninety-five percent of patients in the CCRT group and 93% of those in the SCRT group completed the planned 6 cycles of chemotherapy (p = 0.5045). Cosmetic outcome of the two groups was comparable. Despite more adverse factors of local-regional recurrence in the CCRT group, the 5-year local-regional control rate of the CCRT group was similar to that of the SCRT group (97.7% vs. 93.8%, respectively (p = 0.1688)). Moreover, in multivariate analysis taking into consideration of age, TNM stage, resection margin status, the combination of hormonal therapy, estrogen receptor status, and chemotherapy sequencing, concomitant administration of chemotherapy and radiotherapy was associated with increased local-regional control (p = 0.0463). Conclusions: Concurrent administration of CMF chemotherapy and radiotherapy is a safe and effective regimen as an adjuvant treatment after breast conserving surgery for early breast cancer, and may enhance local-regional control for patients with high risk factors of local-regional recurrence. Author Disclosure: E. Chie, None; K. Kim, None; W. Han, None; D. Noh, None; S. Im, None; T. Kim, None; Y. Bang, None; S.W. Ha, None.