How Do the ASTRO Consensus Statement Guidelines for the Application of Accelerated Partial Breast Irradiation Fit Intraoperative Radiotherapy? A Retrospective Analysis of Patients Treated at the European Institute of Oncology

Intraoperative Electron Radiotherapy (IOERT) in the Treatment of Primary Breast Cancer

“…Therefore, and in accordance with recent international guidelines, full-dose PBI seems to be a good treatment option for properly selected low-risk breast cancer patients classified as ‘suitable' or ‘good' candidates according to the ESTRO/ASTRO guidelines, with reported 5-year recurrence risks below 2% [21,22,25]. …”

Accelerated Partial Breast Irradiation: Executive summary for the update of an ASTRO Evidence-Based Consensus Statement

“…However, ELIOT patients with invasive cancer fitting the "suitability" criteria had a very low rate of IBTR. 23 Among these patients, the 5-year occurrence of IBTR was approximately 1.5%, pointing out the importance of patient selection. 23 In TARGIT, the 5-year IBTR risk was 3.3% (23/3375) in the low-energy x-ray IORT arm compared to 1.3% (11/3375), (P = .042) in the WBI arm.…”

“…23 Among these patients, the 5-year occurrence of IBTR was approximately 1.5%, pointing out the importance of patient selection. 23 In TARGIT, the 5-year IBTR risk was 3.3% (23/3375) in the low-energy x-ray IORT arm compared to 1.3% (11/3375), (P = .042) in the WBI arm. 22 The overall median follow up for TARGIT is 2.4 years (n = 3451).…”

Challenges in Radiotherapy

“…In our own institution, intraoperative RT with electrons has had a long tradition administered as anticipated tumor bed boost since 1998. However, according to international guidelines and recommendations [43, 44], intraoperative RT with electrons as single-shot full-dose treatment (21 Gy at the 90% reference isodose, 23.4 Gy Dmax) is offered exclusively to patients who are classified as “suitable” with unicentric(-focal) Luminal A tumors of sizes <2 cm, negative lymph nodes (cN0 and negative intraoperative frozen section histology for sentinel nodes), ≥50 years of age, clear resection margins, tumor grading G1/2 without neoadjuvant systemic treatment, respectively. Moreover, with lobular histology, preoperative breast MRT is mandatory [45].…”