Fat necrosis after partial-breast irradiation with brachytherapy or electron irradiation versus standard whole-breast radiotherapy--4-year results of a randomized trial.

Abstract

PURPOSE:

To examine the incidence and clinical relevance of fat necrosis after accelerated partial-breast irradiation (PBI) using interstitial high-dose-rate brachytherapy (HDR-BT) in comparison with partial-breast electron irradiation (ELE) and whole-breast irradiation (WBI).

METHODS AND MATERIALS:

Between 1998 and 2004, 258 early-stage breast cancer patients were randomized to receive 50 Gy WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 x 5.2 Gy HDR-BT (n = 88) or 50 Gy ELE (n = 40). The incidence of fat necrosis, its impact on cosmetic outcome, accompanying radiologic features, and clinical symptoms were evaluated.

RESULTS:

The 4-year actuarial rate of fat necrosis was 31.1% for all patients, and 31.9%, 36.5%, and 17.7% after WBI, HDR-BT and ELE, respectively (p(WBI/HDR-BT) = 0.26; p(WBI/ELE) = 0.11; p(ELE/HDR-BT) = 0.025). The respective rate of asymptomatic fat necrosis was 20.2%, 25.3%, and 10% of patients. The incidence of symptomatic fat necrosis was not significantly different after WBI (8.5%), HDR-BT (11.4%), and ELE (7.5%). Symptomatic fat necrosis was significantly associated with a worse cosmetic outcome, whereas asymptomatic fat necrosis was not. Fat necrosis was detectable with mammography and/or ultrasound in each case. Additional imaging examinations were required in 21% of cases and aspiration cytology in 42%.

CONCLUSIONS:

Asymptomatic fat necrosis is a common adverse event of breast-conserving therapy, having no significant clinical relevance in the majority of the cases. The incidence of both symptomatic and asymptomatic fat necrosis is similar after conventional WBI and accelerated partial-breast HDR-BT.

• Authors: Katalin Lövey, János Fodor, Tibor Major, Eva Szabó, Zsolt Orosz, Zoltán Sulyok, Levente Jánváry, Georgina Fröhlich, Miklós Kásler, Csaba Polgár
• Journal: International journal of radiation oncology, biology, physics (Int J Radiat Oncol Biol Phys) Vol. 69 Issue 3 Pg. 724-31 (Nov 01 2007) ISSN: 0360-3016 [Print] United States
• PMID: 17524571 (Publication Type: Journal Article, Randomized Controlled Trial)

Topics

• Adult
• Aged
• Aged, 80 and over
• Brachytherapy (adverse effects, methods)
• Breast (pathology, radiation effects)
• Breast Neoplasms (radiotherapy)
• Electrons (adverse effects, therapeutic use)
• Fat Necrosis (diagnostic imaging, epidemiology, etiology)
• Female
• Follow-Up Studies
• Humans
• Incidence
• Middle Aged
• Radiography
• Radiotherapy Dosage