Hypofractionated Postmastectomy Radiation Therapy

Complication Rates After Mastectomy and Reconstruction in Breast Cancer Patients Treated with Hypofractionated Radiation Therapy Compared to Conventional Fractionation: A Single Institutional Analysis

INTRODUCTION

Radiation therapy plays an important role in the treatment of localized breast cancer. Hypofractionated (HF) radiation therapy has emerged as a promising alternative to conventional fractionation (CF) schedules, offering comparable efficacy with reduced treatment duration and costs. However, concerns remain regarding its safety and rate of toxicity, particularly in patients undergoing mastectomy with breast reconstruction. This study aimed to assess the implant-related complications in breast cancer patients receiving HF post-mastectomy radiation therapy (PMRT) and reconstruction compared to CF PMRT.

METHODS

A retrospective study was conducted on 59 breast cancer patients who underwent mastectomy and breast reconstruction between 2013 and 2021 and received adjuvant PMRT. Patient demographics, treatment characteristics, and implant-related complications were analyzed. Statistical tests including chi-square, Fischer's exact test, and multivariable Cox regression were employed for analysis.

RESULTS

Of the 59 patients, 29 received HF PMRT and 30 received CF PMRT. At a median follow-up of 23.4 months, there was no significant difference in major implant-related complications between the two groups (24.1% in HF vs. 33.3% in CF, p = 0.436). Most complications in the HF group occurred within the first two years post-radiation. Age over 40 was identified as a significant predictor for higher implant-related complications (p = 0.029).

CONCLUSIONS

Our findings indicate that HF PMRT and reconstruction does not increase the risk of major implant-related complications compared to CF PMRT. These results align with the existing literature, supporting the safety of HF radiation in breast cancer patients who underwent mastectomy with reconstruction.

New Approaches in Breast Cancer Radiotherapy

Breast cancer stands as the most prevalent malignancy, necessitating a well-established approach to its management due to its sustained prevalence over decades. The implementation of intensive treatments, combining various modalities, has yielded excellent survival outcomes. Consequently, the optimization of quality of life and the mitigation of long-term side effects emerge as critical considerations for clinicians. As a result, discussions regarding treatment de-intensification strategies have been initiated for all treatment modalities, including surgery, radiotherapy (RT), and chemotherapy. RT plays a crucial role in adjuvant therapy. The efficacy of RT in disease control and overall survival across all stages of breast cancer has been demonstrated in numerous clinical trials and meta-analyses utilizing extensive datasets. However, advancements in genetic tumor profiling and improved identification of disease subgroups have prompted a reevaluation of RT omission in low-risk groups as a strategy for treatment de-intensification. Conversely, technological improvements and shortened total treatment times with hypofractionation make RT a secure and feasible option for enhancing local control and survival with minimal impact on the quality of life.

Increasing use of post-mastectomy hypofractionated radiation therapy for breast cancer in Victoria

INTRODUCTION

The aim of this study was to evaluate the use of post-mastectomy hypofractionationed radiation therapy (HFRT) for breast cancer in Victoria, Australia.

METHODS

This is a population-based cohort of women with breast cancer who received post-mastectomy RT to the chest wall with or without nodal irradiation between 2012 and 2017. HFRT was defined as <25 fractions of RT. Data were captured in the Victorian Radiotherapy Minimum Dataset (VRMDS). The changing pattern of HFRT use was evaluated using the Cochran-Armitage test. Patient-, treatment- and institutional-related factors associated with HFRT use were evaluated using multivariable logistic regression.

RESULTS

Two thousand and twenty-one women were included in this study, of which 238 (12%) received HFRT. This increased from 8% in 2012 to 18% in 2017 (P-trend < 0.001). Older women were more likely to have HFRT (26% in women above 70 years vs 6% in women under 50 years; P < 0.001). Women who did not have nodal irradiation were more likely to have HFRT than those who did (18% vs 9% respectively; P < 0.001). In multivariate analyses, the progressive increase in HFRT use over time remained statistically significant - women treated in 2017 were four times more likely to receive HFRT than those treated in 2012 (95% CI = 2.1-7.7; P < 0.001). Other factors independently associated with increased likelihood of HFRT use included increasing age at RT, and lack of nodal irradiation.

CONCLUSION

In this first Australian study evaluating the use of post-mastectomy HFRT, we observed increasing HFRT use in Victoria over time. We anticipate this rising trend will continue in the coming years.

Comparing TomoHelical and TomoDirect in postmastectomy hypofractionated radiotherapy after immediate breast reconstruction

BACKGROUND

Postmastectomy radiotherapy (PMRT) with TomoHelical™ (TH) or TomoDirect™ (TD) allows a uniform target coverage. In this study, we compare treatment plans using TD and TH in the setting of hypofractionated PMRT and immediate breast reconstruction.

MATERIAL AND METHODS

The TD-treatment plans of breast cancer patients treated between May 2016 and August 2019 were retrospectively selected. All the TD plans were re-planned on TH with the same prescription dose (40.05 Gy/15 fractions) and according to our dose/volume constraints. Data about the 2 treatment plans were compared with a focus on PTV coverage and all the organs at risk (OARs) constraints.

RESULTS

Fifty patients for a total number of 100 treatment plans (50 with TD and 50 re-planned with TH) were analyzed. All the median value in the TD PTV CHEST WALL plans fulfilled the predefined planning objectives, even though TH emerged as best for target coverage with statistically significant difference for V90%. TD provided the lowest V95% for the PTV SVC, but the median value was near to the recommended value of 90% (89.8 % vs 98.6% for TD and TH, respectively). Overall, TD reached the best OARs sparing. The main statistically significant differences with TH were for contralateral breast, ipsilateral and contralateral lung. All the other dose values for TH were higher than TD, but they fulfilled the recommended/acceptable predefined planning objectives.

CONCLUSIONS

In the setting of PMRT, TD compared to TH reached an acceptable target volume coverage, with an optimal sparing of OARs.