Postoperative cosmetic outcome of intraoperative radiotherapy in comparison to whole breast radiotherapy in early stage breast cancer; a retrospective cohort study

Abstract

Background In this study, we aim to evaluate the cosmetic outcome differences between Intraoperative electron beam radiation therapy (IOERT) and whole breast radiotherapy (WBR) with further investigation of boosted IOERT. Methods This retrospective cohort study was conducted in two referral centers in Tehran, Iran. 116 women aged 30 to 79 with early-stage breast cancer (T0-2N0-1M0) eligible for breast conservation were divided into two groups of 58 based on the intervention they received, and further subgroups were defined based on receiving boosted IOERT. Patients in both groups underwent breast conservation surgery and those in the IOERT group received either a 21 Gy radical dose (radical IOERT) or 12 Gy boosted electron beam radiotherapy and a routine fractionated dose of 50 Gy in 25 sessions of WBR (boosted IOERT). Those in the WBR group were administered 50Gy in 32 sessions. Physician-assessed cosmetic outcome was defined as the primary result and incidence of fat necrosis and fibrosis and post-operative chronic pain were secondary outcomes. Results Post-operative cosmetic outcome scores and chronic pain, showed no significant difference between the two groups. The median cosmetic score in both groups was 9. Fat necrosis and fibrosis had significantly higher rates in the IOERT group (P. Value: 0.001). However, the majority (21/34 or 61.8%) of this complication was observed in the boosted IOERT subgroup and no statistical significance was recorded between the radical IOERT subgroup and the WBR group. Conclusions In early-stage breast cancer treatment, radical IOERT has noninferiority compared to WBR in terms of cosmesis. Regarding fat necrosis and fibrosis, boosted IOERT was associated with higher rates in comparison to other groups. Therefore, radical IOERT seems to be a better treatment option for selected patients.

A systematic review and meta-analysis of intraoperative electron radiation therapy delivered with a dedicated mobile linac for partial breast irradiation in early breast cancer

“…After eliminating duplicates, 1659 articles remained but 1575 did not meet the selection criteria; 66/84 remaining papers were excluded for not meeting clinical and outcome criteria. Consequently, only 18 articles that were published in the period 2010–2023 were suitable for inclusion in this meta-analysis and systematic review [ [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] ]. Fig.…”

“…Table 1 reports the quality of the 18 studies. Three studies [ 10 , 23 , 28 ] with a GRADE score of 2 or less, indicating poor quality, were excluded from the meta-analysis. They were used for the systematic review.…”

“…One study [ 6 ] started from 16 Gy and reached 19 Gy; another 2 [ 20 , 27 ] started from 19 Gy and reached 21 Gy. Fourteen studies [ [6] , [7] , [8] , [9] , [12] , [13] , [14] , [20] , [21] , [22] , [23] , 25 , 27 , 28 ] reported the reference isodose. In 7 [ 6 , 7 , 12 , 13 , 20 , 25 , 27 ], the dose was prescribed at 90 % isodose, in 2 [ 21 , 23 ] at 100 % isodose, in 1 [ 9 ] at 80 % isodose and in 3 [ 8 , 14 , 28 ] at varying isodoses, ranging from 90 % to 100 %.…”

“…Overall, 981 acute events such as hematoma, liponecrosis, breast pain, oedema, wound infection were reported in 10 studies [ 6 , 9 , 13 , 20 , 21 , [23] , [24] , [25] , [26] , [27] ]. A total of 87 late side effects such as fluid collection, atrophy, fat necrosis, oversensitivity were described in 5 studies [ 13 , 20 , 23 , 27 , 28 ]. Table 3 , Table 4 list type and grade of acute and late side effects, respectively.…”

Full-Dose Intraoperative Electron Radiotherapy for Early Breast Cancer: Evidence from a Single Center’s Experience

“…Moreover, the possibility of combination of different IORT treatment modalities as the use of ultrahigh dose rates in a dedicated in-room imaging system can direct to a better optimization of the treatment and consequently to achieve better clinical outcomes [ 18 ]. More recently, full-dose IOERT was shown to have non-inferiority compared with whole-breast (WB)RT in terms of cosmesis [ 19 ], and excellent LC was reported in an Italian multicenter analysis for anticipated IOERT boost for early-stage BC [ 20 ].…”