Background: In the large breast tumors or locally-advanced breast cancers, breast conserving surgery (BCS) after neoadjuvant chemotherapy (NACT) had an acceptable local control, but greater risk of recurrence. Adding boost dose radiation to whole breast radiotherapy is involved with a reduced risk of recurrence. Boost radiotherapy can be delivered in 3 methods, including (1) external beam radiotherapy (EBRT), (2) intraoperative radiotherapy with electron (IOERT), and (3) intraoperative radiotherapy with low-kV X-ray (IOXRT). Objectives: This study compared the outcomes of these 3 methods with each other. Methods: Within 60 months, 217 unselected breast cancer patients in Cancer Research Center of Shahid Beheshti were under treatment with BCS after NACT. They received boost dose radiation in 3 groups; 115 patients in the EBRT group, 39 patients IOXRT group, and 63 patients in the IOERT group. All of them received WBRT after surgery. Results: The patients had large tumors or stage 3 breast cancer. Local recurrences were 1 (2. 5%) in IOXRT, 2 (3. 2%) in IOERT, and 1 (0. 9%) in EBRT groups. Systemic recurrences were 4 (10. 3%) in IOXRT, 10 (15. 9%) in IOERT, and 16 (13. 9%) in EBRT groups. Deaths were 3 (7. 7%) in IOXRT, 2 (3. 2%) in IOERT, and 10 (6. 9%) in EBRT groups. Patients with any events were 4 (10. 3%) in IOXRT, 11 (17. 5%) in IOERT, and 33 (15. 2%) in the EBRT group. Death due to distant metastases was lower in IOERT group, but it was not significant. No significant difference was observed in disease-free survival (DFS) among 3 groups. IOXRT group had non-significant, lower events, and better DFS. Especially, in non-PCR (non-pathologic complete response) patients, multivariate COX analysis showed better outcome (DFS) in IOXRT group (HR = 0. 50), although it was not significant (P = 0. 53). Conclusions: Intraoperative radiotherapy (IORT or IOXRT) as tumor bed boost during BCS after NACT had at least non-inferiority compared with EBRT. In non-PCR patient, IOXRT group had non-significant better outcomes (DFS).

Background: Intraoperative radiation therapy (IORT) is a novel approach to breast cancer (BC) treatment. Objectives: In this study, we compared the cellular and molecular effects of IORT-treated post-lumpectomy wound fluid (seroma) at the point of IOeRT versus IOxRT on the BC cell line. Methods: Immortalized human BC cell lines: MCF-7, MDA-MB-231, and MCF10 were incubated with seroma from 3 groups of patients (as a pilot study). The first group received Intraoperative electron radiation therapy (IOeRT, Boost dose=12Gy), the second one received IOeRT (Radical dose=21Gy), and the third group was prescribed Intraoperative x-ray radiation therapy (IOxRT, X-ray=20Gy). Cellular and molecular tests were used to investigate how cells are influenced by the IORT-treated seroma. Results: We evaluated the effects of dose-time and source-dependent IORT-treated seroma on BC cell lines. In this study, weobserved that IOxRT-treated seroma has the most significant effects on the reduction of proliferation, induced cell cycle arrest, and apoptosis. Furthermore, inhibited migration and invasion of BC cell lines were compared to IOeRT-treated seroma. Conclusions: Although this is a pilot study, we suggest that at 24 h, the IORT (specifically IOxRT)-treated seroma may play an important protective role in the breast tumor bed, which is followed by local recurrence decreases.

Background:Radiotherapy plays an essential role in breast cancer treatment following breast conserving surgery even in goodrisk patients with ductal carcinoma in situ (DCIS) histology,It can be delivered by many techniques,among which is intraoperative radiotherapy (IORT),In recent years,intraoperative radiation therapy has had the same outcome compared with EBRT,Objectives:We studied whether whole breast radiotherapy (WBRT) could safely be replaced by IORT and its ability to control local recurrence like EBRT in pure DCIS,Methods:We assigned 138 patients into the external beam radiotherapy (EBRT),radical,and boost groups,The patients were treated during the last 6 years in the Cancer Research Center of Shahid Beheshti University of Medical Sciences,A total of 57 patients received EBRT,45 patients received the radical dose of radiotherapy by IORT (36 patients received intraoperative electron radiotherapy [IOeRT] and 9 patients received intraoperative X-ray radiotherapy [IOxRT]) according to the IRIORT consensus protocol,and 36 patients received the boost dose of radiotherapy by IORT (15 patients received IOeRTand21 patients received IOxRT),The IORTandEBRTgroups were compared,The primary endpoint was local recurrence and death and the secondary endpoint was the role of variables in local recurrence,Results:With the mean follow-up of 37 months for the IORT group and 40,1 months for the EBRT group,local recurrence occurred in 8,8% (5 patients),13,9% (5 patients),and 2,2% (1 patient) of the patients in the EBRT,boost,and radical groups,respectively,Concerning the local recurrence,no significant difference was observed between the radical and EBRT groups (P = 0,058) and between the boost and EBRT groups (P = 0,12),Hazard ratios (HRs) of grade,hormone receptor (HR),tumor size,and age in disease-free survival were evaluated and none of these variables had a significant role in local recurrence,Conclusions:IORT is a good alternative for WBRT in DCIS patients because of its non-inferiority results in comparison with EBRT,Being careful about age,tumor size,biological markers,and margin status is of high importance when using IORT for DCIS,