Accelerated partial breast irradiation with 3-dimensional conformal and image-guided intensity-modulated radiotherapy following breast conserving surgery - 7-Year results of a phase II trial

Norbert Mészáros; Tibor Major; Gábor Stelczer; Levente Jánváry; Zoltán Zaka; Dávid Pukancsik; Zoltán Takácsi-Nagy; János Fodor Md; Csaba Polgár

doi:10.1016/j.breast.2020.10.010

Accelerated partial breast irradiation with 3-dimensional conformal and image-guided intensity-modulated radiotherapy following breast conserving surgery - 7-Year results of a phase II trial

Breast. 2020 Dec:54:222-228. doi: 10.1016/j.breast.2020.10.010. Epub 2020 Oct 30.

Authors

Norbert Mészáros¹, Tibor Major², Gábor Stelczer³, Levente Jánváry⁴, Zoltán Zaka⁴, Dávid Pukancsik⁵, Zoltán Takácsi-Nagy², János Fodor Md⁴, Csaba Polgár²

Affiliations

¹ Center of Radiotherapy, National Institute of Oncology, Budapest, Hungary; Department of Oncology, Semmelweis University, Faculty of Medicine, Budapest, Hungary. Electronic address: [email protected].
² Center of Radiotherapy, National Institute of Oncology, Budapest, Hungary; Department of Oncology, Semmelweis University, Faculty of Medicine, Budapest, Hungary.
³ Center of Radiotherapy, National Institute of Oncology, Budapest, Hungary. Electronic address: [email protected].
⁴ Center of Radiotherapy, National Institute of Oncology, Budapest, Hungary.
⁵ Department of Breast and Sarcoma Surgery, National Institute of Oncology, Budapest, Hungary.

Abstract

Purpose: To present the 7-year results of accelerated partial breast irradiation (APBI) using three-dimensional conformal (3D-CRT) and image-guided intensity-modulated radiotherapy (IG-IMRT) following breast-conserving surgery (BCS).

Patients and methods: Between 2006 and 2014, 104 patients were treated with APBI given by means of 3D-CRT using 3-5 non-coplanar, isocentric wedged fields, or IG-IMRT using kV-CBCT. The total dose of APBI was 36.9 Gy (9 × 4.1 Gy) using twice-a-day fractionation. Survival results, side effects and cosmetic results were assessed.

Results: At a median follow-up of 90 months three (2.9%) local recurrences, one (0.9%) regional recurrence and two (1.9%) distant metastases were observed. The 7-year local (LRFS), recurrence free survival was 98.9%. The 7-year disease-free (DFS), metastases free (MFS) and overall survival (OS) was 94.8%, 97.9% and 94.8%, respectively. Late side effects included G1 skin toxicity in 15 (14.4%), G1, G2, and G3 fibrosis in 26 (25%), 3 (2.9%) and 1 (0.9%) patients respectively. Asymptomatic (G1) fat necrosis occurred in 10 (9.6%) patients. No ≥ G2 or higher late side effects occurred with IMRT. The rate of excellent/good and fair/poor cosmetic results was 93.2% and 6.8%, respectively.

Conclusion: 7-year results of APBI with 3D-CRT and IG-IMRT are encouraging. Toxicity profile and local tumor control are comparable to other series using multicatheter interstitial brachytherapy. Therefore, these external beam APBI techniques are valid alternatives to whole breast irradiation and brachytherapy based APBI.

Keywords: 3-Dimensional conformal radiotherapy; Breast cancer; Image-guided intensity-modulated radiotherapy; Partial breast irradiation; Phase II trial.

Publication types

Clinical Trial, Phase II
Randomized Controlled Trial

MeSH terms

Adult
Aged
Breast Neoplasms / mortality
Breast Neoplasms / therapy*
Dose Fractionation, Radiation
Feasibility Studies
Female
Follow-Up Studies
Humans
Mastectomy, Segmental*
Middle Aged
Neoplasm Recurrence, Local / epidemiology
Postoperative Period
Radiation Injuries / etiology
Radiation Injuries / mortality
Radiotherapy Planning, Computer-Assisted / methods
Radiotherapy Planning, Computer-Assisted / mortality
Radiotherapy, Conformal / methods*
Radiotherapy, Conformal / mortality
Radiotherapy, Intensity-Modulated / methods*
Radiotherapy, Intensity-Modulated / mortality
Survival Rate
Treatment Outcome