Abstract PS14-24: Multi-center trial in the treatment of ductal carcinoma in situ of breast using intra-operative electronic brachytherapy technique, results

Abstract

Abstract Purpose: To report on the technique of intra-operative electronic brachytherapy, local control, side effects and complications after a single fraction of 2000 cGy at the time of partial mastectomy. Material & Methods: 1200 patients with early stage invasive ductal carcinoma and carcinoma in situ were enrolled in the Multi-Center Trial. 246 (20.5%) patients among these 1200 patients had carcinoma in situ and were treated by a single fraction of 2000 cGy dose by intra-operative irradiation to the lumpectomy cavity using Xoft system of electronic brachytherapy at the time of partial mastectomy. 80% of the patients were Caucasian, 7% African American, 7% Hispanic and 6% others. Estrogen receptor was positive in 211 patients, negative in 28 patients and unknown/not assessed in 7 patients. Progesterone receptor was positive in 190 patients, negative in 45 patients and unknown/not assessed in 11 patients. All patients were BRCA negative. 34 (14%) patients had low grade tumors, 109 (44%) intermediate grade tumors, and 103 (42%) high grade tumors. Seroma occurred in 9.8%, induration in 7.6%, and significant fibrosis in 3.5% of the patients. 2/246 (1%) developed ipsilateral recurrence and one patient developed a gastrointestinal cancer. 118 (48%) patients had characteristics of ASTRO criteria being suitable, 108 (44%) cautionary and 20 (8%) unsuitable. Conclusion: The relatively early 2.3 year results of a single fraction of 2000 cGy by IORT to the lumpectomy cavity at the time of partial mastectomy using Xoft Axxent electronic brachytherapy in the treatment of carcinoma in situ of the breast is safe and associated with low morbidity and local recurrence with good to excellent cosmesis in 80% of the patients. Citation Format: Alam M.Nisar Syed. Multi-center trial in the treatment of ductal carcinoma in situ of breast using intra-operative electronic brachytherapy technique, results [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-24.