Hyperfractionated-Accelerated Reirradiation with Proton Therapy for Radiation-Associated Breast Angiosarcoma

Radiation-Associated Angiosarcoma of the Breast: The State of the Art of a Rare and Aggressive Disease

INTRODUCTION

Considering the increasing number of conservative surgeries (quadrantectomies) for primary breast carcinoma, especially in the early stages, often followed by adjuvant radiotherapy, the incidence of radiation-associated angiosarcoma (RAS) is expected to rise in the coming decades, and it will represent a clinical and therapeutic challenge, as limited data are available due to the rarity and heterogeneity of the disease. Though the prognosis of these patients is poor, a number of clinical and pathological factors can be evaluated to better understand the course of RAS. The aim of this systematic review is to explore the available clinical-pathological, therapeutic, and prognostic data regarding RAS to evaluate its occurrence, diagnosis, treatment, and outcomes.

METHOD

RAS clinical data were identified by a systematic review conducted in five different databases (Medline, Web of Knowledge, Google Scholar, Scopus, and Cochrane). Only RAS works published in English, with access to the full manuscript text, and with clear results, were considered as eligible.

RESULTS

We considered 52 papers comprising 319 RAS cases. The patient age at diagnosis ranged from 37 to 93 years, with most cases occurring from 5 to 10 years after breast irradiation. The most common clinical presentation was an aggressive development of macules, papules, or erythematous-violaceous skin discoloration at the site of previous radiation treatment for primary breast carcinoma. Complete surgical excision appeared to be the first-line treatment of the disease, in some cases followed by adjuvant local and/or systemic therapies. Despite different treatments, local recurrence rates ranged from 40% to 90%, leading to negative outcomes and poor prognosis for patients.

CONCLUSION

Although the literature is limited and the data are heterogeneous and contentious, our review aims to highlight the importance of early diagnosis, multimodal treatment, and long-term follow-up of RAS in order to limit and prevent the aggressiveness of this neoplasm.

Neoadjuvant Reirradiation for Radiation Therapy-Associated Angiosarcoma of the Breast

PURPOSE

Radiation-associated angiosarcoma of the breast (RAASB) is a rare side effect after breast radiation and has been associated with poor outcomes. At this time, there is no consensus regarding management of RAASB, and the role of reirradiation remains controversial. We present our modern institutional outcomes in managing RAASB with incorporation of neoadjuvant hyperfractionated reirradiation.

METHODS AND MATERIALS

Patients identified were treated between 2016 and 2020 with inclusion of any histologically proven RAASB without metastatic disease at diagnosis, while excluding those with a history of radiation therapy outside of the breast/chest wall or other sarcoma histologies. Major wound complications were defined as requiring wound care and/or wound vacuum or return to the operating room for wound repair at any time after surgery.

RESULTS

Eight patients were identified, and the median follow-up was 34 months. Median time to RAASB development was 8 years from initial radiation therapy. With respect to RAASB management, all underwent surgery and neoadjuvant reirradiation therapy, and all but 1 patient received taxol-based chemotherapy. At last follow-up, 7 patients remained free of disease, and 1 patient died with distant disease. With respect to acute toxicity after reirradiation, all patients developed at least acute grade 2 toxicities. Five of the 8 patients developed a major wound complication.

CONCLUSIONS

Our institutional analysis suggests excellent local control and survival outcomes for RAASB treated with neoadjuvant hyperfractionated reirradiation, surgery, and taxol-based chemotherapy. However, major wound complications represent a major challenge with this approach. Future studies should consider how best to improve the therapeutic ratio while maintaining high rates of local control and survival.

Comparative Evaluation of Proton Therapy and Volumetric Modulated Arc Therapy for Brachial Plexus Sparing in the Comprehensive Reirradiation of High-Risk Recurrent Breast Cancer

Purpose

Recurrent or new primary breast cancer requiring comprehensive regional nodal irradiation after prior radiation therapy (RT) to the supraclavicular area and upper axilla is challenging due to cumulative brachial plexus (BP) dose tolerance. We assessed BP dose sparing achieved with pencil beam scanning proton therapy (PBS-PT) and photon volumetric modulated arc therapy (VMAT).

Methods and Materials

In an institutional review board-approved planning study, all patients with ipsilateral recurrent breast cancer treated with PBS-PT re-RT (PBT1) with at least partial BP overlap from prior photon RT were identified. Comparative VMAT plans (XRT1) using matched BP dose constraints were developed. A second pair of proton (PBT2) and VMAT (XRT2) plans using standardized target volumes were created, applying uniform prescription dose of 50.4 per 1.8 Gy and a maximum BP constraint <25 Gy. Incidence of brachial plexopathy was also assessed.

Results

Ten consecutive patients were identified. Median time between RT courses was 48 months (15-276). Median first, second, and cumulative RT doses were 50.4 Gy (range, 42.6-60.0), 50.4 Gy relative biologic effectiveness (RBE) (45.0-64.4), and 102.4 Gy (RBE) (95.0-120.0), respectively. Median follow-up was 15 months (5-33) and 18 months for living patients (11-33) Mean BP max was 37.5 Gy (RBE) for PBT1 and 36.9 Gy for XRT1. Target volume coverage of V85% (volume receiving 85% of prescription dose), V90%, and V95% were numerically lower for XRT1 versus PBT1. Similarly, axilla I-III and supraclavicular area coverage were significantly higher for PBT2 than XRT2 at dose levels of V55%, V65%, V75%, V85%, and V95%. Only axilla I V55% did not reach significance (P = .06) favoring PBS-PT. Two patients with high cumulative BPmax (95.2 Gy [RBE], 101.6 Gy [RBE]) developed brachial plexopathy symptoms with ulnar nerve distribution neuropathy without pain or weakness (1 of 2 had symptom resolution after 6 months without intervention).

Conclusions

PBS-PT improved BP sparing and target volume coverage versus VMAT. For patients requiring comprehensive re-RT for high-risk, nonmetastatic breast cancer recurrence with BP overlap and reasonable expectation for prolonged life expectancy, PBT may be the preferred treatment modality.