Radiation-associated angiosarcoma of the breast: analysis of diagnostic tools in a registry-based population.

Background: Radiation-associated angiosarcoma of the breast (RAASB) is a serious late consequence caused by breast cancer treatment. Initial symptoms are often inconspicuous, thus contributing to diagnostic delay. Most previous studies of the diagnostic aspects of RAASB are case reports.
Purpose: To perform a complete review of the imaging findings and biopsy methods in a nationwide RAASB cohort.
Material and Methods: RAASB patients were identified from a national cancer registry and additional patients were included from our hospital. All available information from imaging (mammogram [MGR], ultrasound [US], magnetic resonance imaging [MRI], and computed tomography [CT]) and biopsies was reviewed. The sensitivity of imaging and biopsy methods for detection of RAASB was calculated.
Results: Fifty-eight patients with RAASB were found. Fourteen MGR, 30 US, 24 MRI, and 25 CT studies were available for evaluation. The sensitivity of MGR, US, MRI, and CT for detection of RAASB was 43%, 50%, 92%, and 84%, respectively. Superior sensitivity was demonstrated for punch biopsy (84%) and incisional biopsy (93%) compared to fine-needle aspiration cytology (0%) and core needle biopsy (18%).
Conclusion: MRI and CT have comparable sensitivity for detection of RAASB, while MGR and US are unreliable. However, negative findings in MRI or CT must be interpreted with caution. Punch biopsy and incisional biopsy are the preferred biopsy methods.