Would you consider once weekly radiation with a simultaneous integrated boost for a patient with node negative breast cancer with a positive margin for whom reexcision is not an option?  

Due to multiple complicating factors including travel distance of ~1 hour each way, this patient (mid-60s) refuses to come any more often than 2 days a week. The radiation facility in her town is closed until September for installing a new linear accelerator and we're the next closest center. She had neoadjuvant Arimidex to improve resectability and final pathology after lumpectomy and sentinel node biopsy revealed a node-negative 3.4 cm ER/PR positive grade 2 IDC with lobular features. The tumor invaded the pectoral muscle and possibly the ribs and cartilage and the deep margin was positive. The surgeon feels they won't be able to achieve a negative margin if they re-excise. 

Her Oncotype score was 24 and chemotherapy was not recommended, but my other option would be for her to start endocrine therapy until the local center reopens in September (4-5 months after her surgery).

This study by Bonzano et al., PMID 31662528, examined once weekly whole breast radiation with SIB in elderly patients with reasonable toxicity and efficacy - but have seen no other publications of weekly treatment with a boost.