Intraoperative Radiation Therapy: A Large Integrated Health Care System's Approach and Outcomes.

Introduction Intraoperative radiation therapy (IORT) may not be as effective in the community compared with clinical trials. Methods The authors reviewed data from the electronic health records of patients who received IORT between February 2014 and February 2020 at a single center within a large integrated health care system. The primary outcome was ipsilateral breast tumor recurrence. Results Of 5731 potentially eligible patients, 245 (4.3%) underwent IORT (mean age: 65.4 ± 0.4 years; median follow-up time: 3.5 years ± 2.2 months). According to the American Society for Radiation Oncology's accelerated partial breast irradiation guidelines based on final pathology, 51% of patients were suitable candidates for IORT, 38.4% were cautionary, and 10.6% were unsuitable. For adjuvant therapy, 6.5% had consolidative whole breast irradiation, and 66.4% received endocrine treatment. At the median follow-up time of 3.5 years, overall ipsilateral breast tumor recurrence was 3.7%. Recurrences tended to be more frequent in patients who refused or did not complete endocrine treatment than in those who received it (7.4% vs 1.9%, p = 0.07). The complication rate was 14.7%, with seroma being the most common (8.2%). Discussion The IORT ipsilateral breast tumor recurrence rate of 3.7% confirms a higher-than-expected rate compared to randomized clinical trials, possibly due to less compliance with endocrine therapy. Conclusion The authors subsequently revised their IORT protocol to require endocrine treatment as a part of the IORT treatment plan and to strongly recommend adjuvant whole breast irradiation for all patients deemed cautionary or unsuitable for IORT according to the American Society for Radiation Oncology's accelerated partial breast irradiation guidelines.

Patients Older 65 Years With Early Breast Cancer Prefer Intraoperative Radiation as a Locoregional Treatment Choice.

BACKGROUND: Patients 65 years old or older with early endocrine-responsive breast cancer have many treatment options, including no radiation. This study aimed to evaluate treatment preference when intraoperative radiation therapy (IORT) is offered in this population. METHODS: The study reviewed patients 65 years old or older with a diagnosis of early-stage endocrine-responsive breast cancer in 2016-2019 at a single hospital in a large integrated health care system. Electronic medical records of multidisciplinary breast tumor board discussion, treatment options documented by the treatment team, and final treatment offered were reviewed. Variables including age at biopsy, language, endocrine treatment, and comorbidities were collected. Regression analysis was used to evaluate for variables associated with patients' choice regarding radiation treatment. RESULTS: The institutional IORT guidelines were met by 63 patients in the described age group who had a documented offer of all radiation treatment options. The median age of the patients was 70 years (interquartile range 63-77 years). Overall, 74.6% of the patients chose IORT, and 14.3% opted for whole-breast irradiation. Only 4.8% chose to omit radiation after breast-conserving surgery, and 6.3% chose mastectomy. The patients who chose IORT were more likely to receive endocrine treatment (odds ratio 3.70; p = 0.03). Age, race, language, and comorbidities were not associated with preference for IORT (p < 0.05). CONCLUSIONS: Patients 65 years old or older with early-stage endocrine-responsive breast cancer preferred to have IORT despite counsel about the lack of survival benefit. This study suggests that local cancer control with the convenient radiation delivery method is important to the described patient population.