Open AccessThe actual benefit of intraoperative radiation therapy using 50 kV x‐rays in early breast cancer: A retrospective study of 676 patients
Author(s) -
Tallet Agnès,
Racadot Séverine,
Boher JeanMarie,
Cohen Monique,
Barrou Julien,
Houvenaeghel Gilles,
Gutowski Marian,
Delmond Laure,
Lemanski Claire
Publication year - 2020
Publication title -
the breast journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.533
H-Index - 72
eISSN - 1524-4741
pISSN - 1075-122X
DOI - 10.1111/tbj.13827
Subject(s) - medicine , breast cancer , intraoperative radiation therapy , radiation therapy , retrospective cohort study , breast conserving surgery , population , surgery , cancer , radiology , mastectomy , environmental health
This French study reports the 5‐year results of partial‐breast irradiation using intraoperative radiation therapy (IORT) with 50 kV x‐rays, in select early breast cancer patients. We report a retrospective analysis of 676 consecutive early breast cancer patients treated between November 2011 and December 2015 by partial‐breast irradiation using the INTRABEAM ® system. Patients were highly selected based on the ASTRO and GEC‐ESTRO criteria and underwent breast‐conservative surgery and IORT, completed with additional whole‐breast irradiation (WBI) when unexpected unfavorable prognostic factors were found at the final pathology report. Patients' outcomes relative to local and distant control, overall and breast cancer‐specific survival, and toxicity are presented, as well as rates of additional WBI. Additional WBI was mandatory in one third of patients (31%), mainly due to lymph node involvement and extensive intraductal component. With a median follow‐up time of 54 months, the 5‐year local recurrence rate was 1.7% [95%CI: 0.9‐3.3]; the median time to local recurrence was 23 months; ipsilateral breast recurrences mainly occurred in the same quadrant (7/11); in the restricted population, meeting all predefined criteria and treated with IORT alone (406 patients), the local recurrence rate was 1.5% [95%CI: 0.6‐3.6]. Five‐year distant tumor control was 98.6% [95%CI: 97.2‐99.3], and the median time to distant recurrence was 22 months. Five‐year overall survival was 96.5% [95%CI: 94.2‐97.8], and 5‐year breast cancer‐specific survival was 98.9% [95%CI: 97.6‐99.7]. In patients treated with IORT alone, there was no grade 3 toxicity, only four grade 3 (mainly fibrosis) affected patients treated with IORT and WBI. Grade 1‐2 toxicity rates were 14% and 34.4% in patients treated with IORT alone and IORT plus WBI, respectively. Partial‐breast irradiation using IORT by a 50 kV photon device is safe and well‐tolerated in select patients with early breast cancer and is a valuable option in patients reluctant for adjuvant WBI.