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Maximum Skin Dose is Associated with Outcome after Breast Brachytherapy
Proceedings of the 51st Annual ASTRO Meeting
2040
Simultaneous Radiation Therapy and Hyperthermia in the Elective Treatment of Subclinical Disease in High Risk Breast Carcinoma: A Phase III Comparison of Post Treatment Normal Tissue Effects in Heated and Unheated Portions of the Chest Wall
R. J. Myerson1, M. Taylor1, I. Zoberi1, E. Moros2, W. Straube1 1
Washington University Medical Center, St. Louis, MO, 2University of Arkansas Medical Sciences, Little Rock, AR
Purpose/Objective(s): The management of subclinical disease is an indication for radiotherapy (RT) in many cancers. To determine if there is therapeutic gain from adding hyperthermia (HT) to RT in this setting, it is important to evaluate late normal tissue effects. This study reports the results of a prospective clinical trial comparing late effects in heated vs. unheated portions of the chest wall, in which each patient functions as her own control. Materials/Methods: Fifty nine patients with high-risk breast carcinoma (9 recurrent cancers, 50 T3,4 and/or N2,3) have been treated. All patients were treated electively: none had visible disease at the initiation of thermo radiotherapy, since macroscopic disease was eliminated by pre-treatment chemotherapy and/or surgery. No patient had prior RT. Ultrasound HT using the Sonotherm 1000 array system was given simultaneously with four of the chest wall RT treatments for the first 46 cases. After sufficient follow up to establish late tolerance to four fractions of HT, the last 13 cases received eight HT treatments. The 12x12 cm ultrasound field covered the primary tumor site plus an elective region, which was randomized to lie either medial or lateral to the primary tumor site. An average of 14.5 locations were monitored for temperature, with the per session average minimum monitored time at or above 41oC = 35 minutes. The strip of chest wall on the opposite side of the primary tumor bed was the unheated control region and received the same dose of RT. RT to the chest wall and regional lymphatics was 50-60 Gy in 1.8-2 Gy fractions. Heated and control sectors received the same RT dose. Results: With a mean follow up of 42 months, there have been 3 locoregional failures: one in the regional lymph nodes (radiated but not heated) and two diffusely in the chest wall (equal involvement of both heated and control sectors). A total of 31 patients had grade $ 2 chest wall morbidity (usually asymptomatic pigment changes). In 9 cases one sector was noted to have more grade $ 2 morbidity than the other (all but one was grade 2): in six cases this was the heated sector and in three it was the control sector. Tissue contracture was objectively measured by the fractional change of the product of orthogonal tattoos, the average contracture was 0.82+/-0.15 for heated sectors and 0.91 +/- 0.14 for control sectors (p = NS). Conclusions: The post treatment sequelae of 4-8 elective HT treatments appear to be clinically acceptable, with no significant morbidity difference between heated and control sectors. Locoregional control is promising. Author Disclosure: R.J. Myerson, None; M. Taylor, None; I. Zoberi, None; E. Moros, None; W. Straube, None.
2041
Maximum Skin Dose is Associated with Outcome after Breast Brachytherapy
L. W. Cuttino, J. Heffernan, R. Vera, M. Rosu, D. W. Arthur Virginia Commonwealth University, Richmond, VA Purpose/Objective(s): Multiple series have shown that a skin distance less than 6mm is associated with late toxicity after MammoSite (MS) brachytherapy. Skin distance has routinely been used as a surrogate for dose in publications describing the use of MS. However, this only approximates the skin dose as with a single lumen device, the dose will depend not only on skin thickness but also on balloon diameter and dwell position location/weighting. No publications have as yet described the relationship between actual maximum skin dose and outcome with either interstitial or MS brachytherapy. This report is a detailed analysis of the maximum skin dose delivered with breast brachytherapy and late toxicity in a large cohort of patients with prolonged follow-up. Materials/Methods: 96 patients treated with breast brachytherapy from 2000-2007 for which complete planning and follow-up data were available were included in this analysis. Median follow-up was 41 months (range 15-100 months). 40 patients were treated with multi-catheter interstitial brachytherapy, and 56 were treated with MS. The maximum doses delivered to the skin and chest wall were obtained from the 3D treatment planning system. Outcome measures including overall cosmesis, hyperpigmentation, edema, telangiectasia, pain, and fibrosis were recorded. A multivariate statistical analysis was performed to determine the relationship between the maximum doses delivered to the skin and chest wall and the outcome variables. Results: Treatment was well tolerated, with 98% of patients experiencing good to excellent cosmesis. Chronic edema or significant pain occurred in only 1% and 4.2% of patients, respectively. Moderate to severe hyperpigmentation occurred in 12.5%. Moderate to severe fibrosis occurred in 12.5%. Any degree of telangiectasia was observed in 3.3%. The maximum dose delivered to the chest wall was not associated with any outcome measures. The maximum dose delivered to the skin was significantly associated with the incidence of telangiectasia (p = 0.0018) and with the incidence of moderate to severe fibrosis (p = 0.0216). The incidence of fibrosis was significantly increased when the dose to the skin exceeded 4.07 Gy (120%). Conclusions: The present dosimetric guidelines used for planning breast brachytherapy are not based on actual patient outcome data. This investigation demonstrates that the maximum skin dose delivered is associated with telangiectasia and fibrosis. The development of fibrosis in patients with higher skin doses may result from the associated dose to the subcutaneous tissue. These results suggest that patients may benefit if more rigorous constraints are applied and if the skin dose is reduced as low is as achievable. The newer multi-lumen intra-cavitary devices may allow the control of skin dose while preserving target coverage. Author Disclosure: L.W. Cuttino, None; J. Heffernan, None; R. Vera, None; M. Rosu, None; D.W. Arthur, SenoRx, F. Consultant/ Advisory Board; Advanced Radiation Therapy, F. Consultant/Advisory Board.
2042
Racial Disparities in the Use of Radiation Therapy in Women with Early-stage Breast Cancer after Lumpectomy
E. Jung1, M. Eisner2, S. R. Martinez1, S. L. Chen1, L. V. Do1, A. M. Chen1 1
UC Davis, Sacramento, CA, 2National Institutes of Health, Bethesda, MD
Purpose/Objective(s): Breast conservation surgery (BCS) with radiation therapy is considered standard of care for patients with earlystage breast cancer. The purpose of this study is to assess racial disparities in women who do not receive radiation therapy after BCS.
S199
2040
Simultaneous Radiation Therapy and Hyperthermia in the Elective Treatment of Subclinical Disease in High Risk Breast Carcinoma: A Phase III Comparison of Post Treatment Normal Tissue Effects in Heated and Unheated Portions of the Chest Wall
R. J. Myerson1, M. Taylor1, I. Zoberi1, E. Moros2, W. Straube1 1
Washington University Medical Center, St. Louis, MO, 2University of Arkansas Medical Sciences, Little Rock, AR
Purpose/Objective(s): The management of subclinical disease is an indication for radiotherapy (RT) in many cancers. To determine if there is therapeutic gain from adding hyperthermia (HT) to RT in this setting, it is important to evaluate late normal tissue effects. This study reports the results of a prospective clinical trial comparing late effects in heated vs. unheated portions of the chest wall, in which each patient functions as her own control. Materials/Methods: Fifty nine patients with high-risk breast carcinoma (9 recurrent cancers, 50 T3,4 and/or N2,3) have been treated. All patients were treated electively: none had visible disease at the initiation of thermo radiotherapy, since macroscopic disease was eliminated by pre-treatment chemotherapy and/or surgery. No patient had prior RT. Ultrasound HT using the Sonotherm 1000 array system was given simultaneously with four of the chest wall RT treatments for the first 46 cases. After sufficient follow up to establish late tolerance to four fractions of HT, the last 13 cases received eight HT treatments. The 12x12 cm ultrasound field covered the primary tumor site plus an elective region, which was randomized to lie either medial or lateral to the primary tumor site. An average of 14.5 locations were monitored for temperature, with the per session average minimum monitored time at or above 41oC = 35 minutes. The strip of chest wall on the opposite side of the primary tumor bed was the unheated control region and received the same dose of RT. RT to the chest wall and regional lymphatics was 50-60 Gy in 1.8-2 Gy fractions. Heated and control sectors received the same RT dose. Results: With a mean follow up of 42 months, there have been 3 locoregional failures: one in the regional lymph nodes (radiated but not heated) and two diffusely in the chest wall (equal involvement of both heated and control sectors). A total of 31 patients had grade $ 2 chest wall morbidity (usually asymptomatic pigment changes). In 9 cases one sector was noted to have more grade $ 2 morbidity than the other (all but one was grade 2): in six cases this was the heated sector and in three it was the control sector. Tissue contracture was objectively measured by the fractional change of the product of orthogonal tattoos, the average contracture was 0.82+/-0.15 for heated sectors and 0.91 +/- 0.14 for control sectors (p = NS). Conclusions: The post treatment sequelae of 4-8 elective HT treatments appear to be clinically acceptable, with no significant morbidity difference between heated and control sectors. Locoregional control is promising. Author Disclosure: R.J. Myerson, None; M. Taylor, None; I. Zoberi, None; E. Moros, None; W. Straube, None.
2041
Maximum Skin Dose is Associated with Outcome after Breast Brachytherapy
L. W. Cuttino, J. Heffernan, R. Vera, M. Rosu, D. W. Arthur Virginia Commonwealth University, Richmond, VA Purpose/Objective(s): Multiple series have shown that a skin distance less than 6mm is associated with late toxicity after MammoSite (MS) brachytherapy. Skin distance has routinely been used as a surrogate for dose in publications describing the use of MS. However, this only approximates the skin dose as with a single lumen device, the dose will depend not only on skin thickness but also on balloon diameter and dwell position location/weighting. No publications have as yet described the relationship between actual maximum skin dose and outcome with either interstitial or MS brachytherapy. This report is a detailed analysis of the maximum skin dose delivered with breast brachytherapy and late toxicity in a large cohort of patients with prolonged follow-up. Materials/Methods: 96 patients treated with breast brachytherapy from 2000-2007 for which complete planning and follow-up data were available were included in this analysis. Median follow-up was 41 months (range 15-100 months). 40 patients were treated with multi-catheter interstitial brachytherapy, and 56 were treated with MS. The maximum doses delivered to the skin and chest wall were obtained from the 3D treatment planning system. Outcome measures including overall cosmesis, hyperpigmentation, edema, telangiectasia, pain, and fibrosis were recorded. A multivariate statistical analysis was performed to determine the relationship between the maximum doses delivered to the skin and chest wall and the outcome variables. Results: Treatment was well tolerated, with 98% of patients experiencing good to excellent cosmesis. Chronic edema or significant pain occurred in only 1% and 4.2% of patients, respectively. Moderate to severe hyperpigmentation occurred in 12.5%. Moderate to severe fibrosis occurred in 12.5%. Any degree of telangiectasia was observed in 3.3%. The maximum dose delivered to the chest wall was not associated with any outcome measures. The maximum dose delivered to the skin was significantly associated with the incidence of telangiectasia (p = 0.0018) and with the incidence of moderate to severe fibrosis (p = 0.0216). The incidence of fibrosis was significantly increased when the dose to the skin exceeded 4.07 Gy (120%). Conclusions: The present dosimetric guidelines used for planning breast brachytherapy are not based on actual patient outcome data. This investigation demonstrates that the maximum skin dose delivered is associated with telangiectasia and fibrosis. The development of fibrosis in patients with higher skin doses may result from the associated dose to the subcutaneous tissue. These results suggest that patients may benefit if more rigorous constraints are applied and if the skin dose is reduced as low is as achievable. The newer multi-lumen intra-cavitary devices may allow the control of skin dose while preserving target coverage. Author Disclosure: L.W. Cuttino, None; J. Heffernan, None; R. Vera, None; M. Rosu, None; D.W. Arthur, SenoRx, F. Consultant/ Advisory Board; Advanced Radiation Therapy, F. Consultant/Advisory Board.
2042
Racial Disparities in the Use of Radiation Therapy in Women with Early-stage Breast Cancer after Lumpectomy
E. Jung1, M. Eisner2, S. R. Martinez1, S. L. Chen1, L. V. Do1, A. M. Chen1 1
UC Davis, Sacramento, CA, 2National Institutes of Health, Bethesda, MD
Purpose/Objective(s): Breast conservation surgery (BCS) with radiation therapy is considered standard of care for patients with earlystage breast cancer. The purpose of this study is to assess racial disparities in women who do not receive radiation therapy after BCS.
S199