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The role of post-mastectomy radiotherapy (PMRT) and prognostic factors of locoregional recurrence
S28
Abstracts
Results: The median age at the time of diagnosis was 82.7 (range 77 to 88). The median follow up was 42 months. Fifty five patients (65%) received partial mastectomy and 30 patients (35%) total mastectomy (MT). Fifty four patients (63%) received whole breast or chest wall irradiation, while 31 patients (37%) received locorregional irradiation. Five patients presented cutaneous toxicity grade 3. Overall survival was 70% at 5 years and breast cancer specific survival (BCSS) was 94% at 5 years. Four patients (4.2%) died of cardiovascular disease. In the univariate analysis clinical preoperative nodal stage, clinical and pathological tumour size, locorregional irradiation and pathologic tumor stage were significant variables for worst overall survival (Table 1). No other examined factor was significantly related. Conclusion: Patients older than 80 treated by Stage I−III breast cancer have long survival after treatment. OS and BCSS is high at five years. Patients with locally advanced preoperative disease, pathologic tumor size and locorregional irradiation contributed negatively to survival. No conflict of interest. 214 POSTER The role of post-mastectomy radiotherapy (PMRT) and prognostic factors of locoregional recurrence D. Delishaj1 , S. Ursino1 , V. Mazzotti1 , S. Spagnesi1 , L.R. Fatigante1 , B. Manfredi1 , A. Cristaudo1 , F. Pasqualetti1 , F. Orlandi1 , R. Morganti2 , L. Concetta1 , M. Roncella3 , M. Cantarella1 , E. Lombardo1 , A. Fontana4 , F. Matteucci1 , A. Michelotti4 , M.G. Fabrini1 , A. Falcone4 , F. Paiar1 . 1 Department of Experimental and Clinical Medicine, Division of Radiation Oncology-University of Pisa, Pisa, Italy; 2 Department of Experimental and Clinical Medicine, Section of Statistics, University of Pisa, Pisa, Italy; 3 Department of Experimental and Clinical Medicine, Breast Surgery-University of Pisa, Pisa, Italy; 4 Department of Experimental and Clinical Medicine, Division of Oncology-University of Pisa, Pisa, Italy Background: The purpose of the study was to evaluate the outcome of patients (pts) undergone to mastectomy followed or not by postmastectomy radiotherapy (PMRT) and to investigate the clinicopathological prognostic factors of locoregional recurrence (LRR). Methods and Materials: We retrospectively reviewed data of patients underwent total mastectomy and sentinel lymph node examination +/− axillary dissection. Patients were staged according to AJCCU/UICC 7º Edition. According to consensus in literature PMRT was limited to the chest wall (CW-PMRT) in stage pT3 N1 or extended to the lymphatic drainages of apex axilla and supraclavicular nodes (CWLD-PMRT) in stage pT4 N2−3. Patients underwent salvage mastectomy after a previous conservative surgery and RT or with of systemic disease at diagnosis were excluded from the study. Radiotherapy treatment was performed with linear accelerator and 3DCRT technique using X photons of 6 and/or 15 MV energy. Two tangential beam technique was used for CW-PMRT whereas an half beam technique with the addiction of 1−2 anterior-posterior (AP-PA) beam was used for CWLDPMRT. The prescribed dose was 50 Gy delivered in 25 fractions adding a boost of 20 Gy and 14−16 Gy for positive and close (<2 mm) surgical margins, respectively. Neoadjuvant chemotherapy (CT), adjuvant CT, Trastuzumab, Tamoxifen and systemic endocrine therapy were prescribed according to international guidelines. Radiotherapy was deferred after the completion of adjuvant CT. Univariate and multivariate analyses were performed using SPSS 22 (SPSS Inc., Chicago, IL, USA) technology. Results: Between January 2004 and June 2013 a total of 912 patients underwent total mastectomy; of whom 269 (29.5%) underwent PMRT and 643 (70.5%) did not. Among PMRT group 77 underwent CW and 202 CWLD irradiation. The median follow up was 40 months (range, 3– 118). No significant difference in terms of LRR was found between the noPMRT and PMRT groups (p = 0.175; HR = 1.613; 95% CI = 0.808−3.219). The uni- and multivariate analysis of LRR for patients not undergone to PMRT showed a significant correlation with the presence of ECE (p = 0.049), Mib-1 >30% (p = 0.048) and triple negative status (p = 0.001). On the contrary, the triple negative status resulted as the only variable significantly correlated to LRR (p < 0.0001) in the PMRT group whereas ECE and Mib-1 >30% lost the significance. Finally, no significant difference was shown between CWLD and CW-PMRT (p = 0.078; HR = 0.375; 95% CI = 0.126−1.116). Conclusions: Based on our data, we strongly confirm the positive impact of PMRT in local advance disease and recommend to carefully consider it in presence of ECE and Mib-1 >30% regardless T and N stage. CW irradiation might be a valid option in selected intermediate disease (i.e. less than 3 positive lymph nodes). Future “well designed” prospective studies are needed to properly validate our results. No conflict of interest.
Poster Session, Saturday 28 January 2017 214A POSTER Breast irradiation using personalised thermoplastic mask for immobilisation: Pros and cons A. Dinu1 , T. Flonta1 , V. Virag1 , L. Marcu2 . 1 Gavril Curteanu Municipal Hospital, Radiotherapy department, Oradea, Romania; 2 University of Oradea, Faculty of Science, Oradea, Romania Background: The goal of radiotherapy is to achieve a high therapeutic ratio by increasing tumour control via adequate CTV dosimetry and decreasing normal tissue toxicity through better protection of the organs at risk. To attain this goal, solutions are often required for treatment optimisation, such as the use of immobilising devices for setup error reduction. There is a scarcity of literature data regarding thermoplastic masks for breast immobilisation when no prone breast board is available. Thus, the aim of the current study was to assess the advantages and drawbacks of thermoplastic masks used for patients with large breasts undergoing radiotherapy. Materials and Methods: Patients with large breasts presenting with invasive left-sided breast carcinomas were treated post-segmentectomy in our radiotherapy department. Personalised thermoplastic masks were prepared to assist with immobilisation during fractionated radiotherapy. In order to evaluate the pros and cons of thermoplastic mask for breast immobilisation, 7 patients have been irradiated with the mask while other 7 were used as control. Dose prescriptions were identical for the two patient groups: 50 Gy in 25 fractions to the whole breast CTV and boost dose to the tumour bed of 60 Gy in 25 fractions. The two main aspects assessed in the study were: (1) the reduction of setup errors with the immobilising mask; (2) the acute effects with/without the mask. Results: For an accurate determination of the setup errors, EPID images were fused with the DRR images for each patient. Weekly positioning errors were determined for the two patient groups along the X and Y axes. The results indicated a clear advantage of the thermoplastic mask, which has reduced the errors to one third of the no-mask scenario. Furthermore, while the setup errors over the first two treatment weeks in both groups ranged between 1 and 2 mm, after the third week of treatment the errors in the no-mask group started to increase up to 4 mm. The immobilised group presented no changes. These errors could pose long-term risks to the heart. A shortcoming of the thermoplastic mask is the increase in the skin dose which resulted in grade 3 radiodermatitis, which however, resolved in 3 months post-irradiation. Conclusions: The use of breast masks considerably increases the reproducibility of patient positioning and limits the setup errors. This is an important outcome, since positioning errors are often a challenge when treating large-breasted patients, given the fact that after 15−20 dose fractions the inflammatory processes can change the shape and the volume of the breast. The error reductions allowed an accurate D95% dose delivery, while the heart was adequately protected. A drawback of this irradiation technique is the increase in the skin dose, a consequence that can be managed with suitable medical care. No conflict of interest. 215 POSTER Hypofractionated radiotherapy after conservative surgery in breast cancer patients: a phase I-II trial (MARA-1) M. Pieri1 , R. Frakulli1 , G. Macchia2 , A. Farioli3 , S. Cilla4 , F. Deodato2 , I. Ammendolia1 , G. Tolento1 , S. Cammelli1 , L. Di Lullo5 , M. Taffurelli3 , C. Zamagni6 , D. Smaniotto7 , F. Marazzi7 , V. Valentini7 , G. Ferrandina8 , A.G. Morganti1 . 1 S. Orsola-Malpighi Hospital-University of Bologna, Radiation Oncology Center- Department of Experimental- Diagnostic and Specialty Medicine- DIMES, Bologna, Italy; 2 Fondazione Giovanni Paolo II, Radiation Oncology Unit, Campobasso, Italy; 3 S. Orsola-Malpighi Hospital-University of Bologna, Department of Medical and Surgical Sciences DIMEC, Bologna, Italy; 4 Fondazione Giovanni Paolo II, Medical Physic Unit, Campobasso, Italy; 5 General Hospital, Department of Oncology, Isernia, Italy; 6 S. Orsola-Malpighi Hospital-University of Bologna, Medical Oncology Unit, Bologna, Italy; 7 Catholic University of the Sacred Heart, Radiation Oncology Department, Rome, Italy; 8 Catholic University of the Sacred Heart, Gynecologic Oncology Unit, Rome, Italy Background: The aim of this study is to evaluate late toxicity after hypofractionated radiotherapy (MARA-1 protocol) in early stage breast carcinoma as compared to a control group (CG) treated with standard fractionation. Material and Methods: MARA-1 is a prospective phase I-II study on accelerated IMRT. In the CG the whole breast received 50.4 Gy in 28 fractions (fx) with a sequential boost on the tumour bed of 10 Gy in 4 fx with 3D technique. In MARA-1 an IMRT technique was used and prescribed dose to the breast was 40 Gy in 16 fx with a concomitant boost of 4 Gy.
Abstracts
Results: The median age at the time of diagnosis was 82.7 (range 77 to 88). The median follow up was 42 months. Fifty five patients (65%) received partial mastectomy and 30 patients (35%) total mastectomy (MT). Fifty four patients (63%) received whole breast or chest wall irradiation, while 31 patients (37%) received locorregional irradiation. Five patients presented cutaneous toxicity grade 3. Overall survival was 70% at 5 years and breast cancer specific survival (BCSS) was 94% at 5 years. Four patients (4.2%) died of cardiovascular disease. In the univariate analysis clinical preoperative nodal stage, clinical and pathological tumour size, locorregional irradiation and pathologic tumor stage were significant variables for worst overall survival (Table 1). No other examined factor was significantly related. Conclusion: Patients older than 80 treated by Stage I−III breast cancer have long survival after treatment. OS and BCSS is high at five years. Patients with locally advanced preoperative disease, pathologic tumor size and locorregional irradiation contributed negatively to survival. No conflict of interest. 214 POSTER The role of post-mastectomy radiotherapy (PMRT) and prognostic factors of locoregional recurrence D. Delishaj1 , S. Ursino1 , V. Mazzotti1 , S. Spagnesi1 , L.R. Fatigante1 , B. Manfredi1 , A. Cristaudo1 , F. Pasqualetti1 , F. Orlandi1 , R. Morganti2 , L. Concetta1 , M. Roncella3 , M. Cantarella1 , E. Lombardo1 , A. Fontana4 , F. Matteucci1 , A. Michelotti4 , M.G. Fabrini1 , A. Falcone4 , F. Paiar1 . 1 Department of Experimental and Clinical Medicine, Division of Radiation Oncology-University of Pisa, Pisa, Italy; 2 Department of Experimental and Clinical Medicine, Section of Statistics, University of Pisa, Pisa, Italy; 3 Department of Experimental and Clinical Medicine, Breast Surgery-University of Pisa, Pisa, Italy; 4 Department of Experimental and Clinical Medicine, Division of Oncology-University of Pisa, Pisa, Italy Background: The purpose of the study was to evaluate the outcome of patients (pts) undergone to mastectomy followed or not by postmastectomy radiotherapy (PMRT) and to investigate the clinicopathological prognostic factors of locoregional recurrence (LRR). Methods and Materials: We retrospectively reviewed data of patients underwent total mastectomy and sentinel lymph node examination +/− axillary dissection. Patients were staged according to AJCCU/UICC 7º Edition. According to consensus in literature PMRT was limited to the chest wall (CW-PMRT) in stage pT3 N1 or extended to the lymphatic drainages of apex axilla and supraclavicular nodes (CWLD-PMRT) in stage pT4 N2−3. Patients underwent salvage mastectomy after a previous conservative surgery and RT or with of systemic disease at diagnosis were excluded from the study. Radiotherapy treatment was performed with linear accelerator and 3DCRT technique using X photons of 6 and/or 15 MV energy. Two tangential beam technique was used for CW-PMRT whereas an half beam technique with the addiction of 1−2 anterior-posterior (AP-PA) beam was used for CWLDPMRT. The prescribed dose was 50 Gy delivered in 25 fractions adding a boost of 20 Gy and 14−16 Gy for positive and close (<2 mm) surgical margins, respectively. Neoadjuvant chemotherapy (CT), adjuvant CT, Trastuzumab, Tamoxifen and systemic endocrine therapy were prescribed according to international guidelines. Radiotherapy was deferred after the completion of adjuvant CT. Univariate and multivariate analyses were performed using SPSS 22 (SPSS Inc., Chicago, IL, USA) technology. Results: Between January 2004 and June 2013 a total of 912 patients underwent total mastectomy; of whom 269 (29.5%) underwent PMRT and 643 (70.5%) did not. Among PMRT group 77 underwent CW and 202 CWLD irradiation. The median follow up was 40 months (range, 3– 118). No significant difference in terms of LRR was found between the noPMRT and PMRT groups (p = 0.175; HR = 1.613; 95% CI = 0.808−3.219). The uni- and multivariate analysis of LRR for patients not undergone to PMRT showed a significant correlation with the presence of ECE (p = 0.049), Mib-1 >30% (p = 0.048) and triple negative status (p = 0.001). On the contrary, the triple negative status resulted as the only variable significantly correlated to LRR (p < 0.0001) in the PMRT group whereas ECE and Mib-1 >30% lost the significance. Finally, no significant difference was shown between CWLD and CW-PMRT (p = 0.078; HR = 0.375; 95% CI = 0.126−1.116). Conclusions: Based on our data, we strongly confirm the positive impact of PMRT in local advance disease and recommend to carefully consider it in presence of ECE and Mib-1 >30% regardless T and N stage. CW irradiation might be a valid option in selected intermediate disease (i.e. less than 3 positive lymph nodes). Future “well designed” prospective studies are needed to properly validate our results. No conflict of interest.
Poster Session, Saturday 28 January 2017 214A POSTER Breast irradiation using personalised thermoplastic mask for immobilisation: Pros and cons A. Dinu1 , T. Flonta1 , V. Virag1 , L. Marcu2 . 1 Gavril Curteanu Municipal Hospital, Radiotherapy department, Oradea, Romania; 2 University of Oradea, Faculty of Science, Oradea, Romania Background: The goal of radiotherapy is to achieve a high therapeutic ratio by increasing tumour control via adequate CTV dosimetry and decreasing normal tissue toxicity through better protection of the organs at risk. To attain this goal, solutions are often required for treatment optimisation, such as the use of immobilising devices for setup error reduction. There is a scarcity of literature data regarding thermoplastic masks for breast immobilisation when no prone breast board is available. Thus, the aim of the current study was to assess the advantages and drawbacks of thermoplastic masks used for patients with large breasts undergoing radiotherapy. Materials and Methods: Patients with large breasts presenting with invasive left-sided breast carcinomas were treated post-segmentectomy in our radiotherapy department. Personalised thermoplastic masks were prepared to assist with immobilisation during fractionated radiotherapy. In order to evaluate the pros and cons of thermoplastic mask for breast immobilisation, 7 patients have been irradiated with the mask while other 7 were used as control. Dose prescriptions were identical for the two patient groups: 50 Gy in 25 fractions to the whole breast CTV and boost dose to the tumour bed of 60 Gy in 25 fractions. The two main aspects assessed in the study were: (1) the reduction of setup errors with the immobilising mask; (2) the acute effects with/without the mask. Results: For an accurate determination of the setup errors, EPID images were fused with the DRR images for each patient. Weekly positioning errors were determined for the two patient groups along the X and Y axes. The results indicated a clear advantage of the thermoplastic mask, which has reduced the errors to one third of the no-mask scenario. Furthermore, while the setup errors over the first two treatment weeks in both groups ranged between 1 and 2 mm, after the third week of treatment the errors in the no-mask group started to increase up to 4 mm. The immobilised group presented no changes. These errors could pose long-term risks to the heart. A shortcoming of the thermoplastic mask is the increase in the skin dose which resulted in grade 3 radiodermatitis, which however, resolved in 3 months post-irradiation. Conclusions: The use of breast masks considerably increases the reproducibility of patient positioning and limits the setup errors. This is an important outcome, since positioning errors are often a challenge when treating large-breasted patients, given the fact that after 15−20 dose fractions the inflammatory processes can change the shape and the volume of the breast. The error reductions allowed an accurate D95% dose delivery, while the heart was adequately protected. A drawback of this irradiation technique is the increase in the skin dose, a consequence that can be managed with suitable medical care. No conflict of interest. 215 POSTER Hypofractionated radiotherapy after conservative surgery in breast cancer patients: a phase I-II trial (MARA-1) M. Pieri1 , R. Frakulli1 , G. Macchia2 , A. Farioli3 , S. Cilla4 , F. Deodato2 , I. Ammendolia1 , G. Tolento1 , S. Cammelli1 , L. Di Lullo5 , M. Taffurelli3 , C. Zamagni6 , D. Smaniotto7 , F. Marazzi7 , V. Valentini7 , G. Ferrandina8 , A.G. Morganti1 . 1 S. Orsola-Malpighi Hospital-University of Bologna, Radiation Oncology Center- Department of Experimental- Diagnostic and Specialty Medicine- DIMES, Bologna, Italy; 2 Fondazione Giovanni Paolo II, Radiation Oncology Unit, Campobasso, Italy; 3 S. Orsola-Malpighi Hospital-University of Bologna, Department of Medical and Surgical Sciences DIMEC, Bologna, Italy; 4 Fondazione Giovanni Paolo II, Medical Physic Unit, Campobasso, Italy; 5 General Hospital, Department of Oncology, Isernia, Italy; 6 S. Orsola-Malpighi Hospital-University of Bologna, Medical Oncology Unit, Bologna, Italy; 7 Catholic University of the Sacred Heart, Radiation Oncology Department, Rome, Italy; 8 Catholic University of the Sacred Heart, Gynecologic Oncology Unit, Rome, Italy Background: The aim of this study is to evaluate late toxicity after hypofractionated radiotherapy (MARA-1 protocol) in early stage breast carcinoma as compared to a control group (CG) treated with standard fractionation. Material and Methods: MARA-1 is a prospective phase I-II study on accelerated IMRT. In the CG the whole breast received 50.4 Gy in 28 fractions (fx) with a sequential boost on the tumour bed of 10 Gy in 4 fx with 3D technique. In MARA-1 an IMRT technique was used and prescribed dose to the breast was 40 Gy in 16 fx with a concomitant boost of 4 Gy.