Feasibility of intraoperative radiation therapy for early breast cancer in Japan: a single-center pilot study and literature review.

Abstract

BACKGROUND:

Intraoperative radiation therapy (IORT) is under evaluation in breast-conserving surgery because the feasibility of the IORT procedure including transportation of the patient under general anesthesia is not well established. Thus, this prospective single-center study aimed to test the feasibility of IORT at a single dose of 21 Gy in Japanese breast cancer patients.

METHODS:

The primary endpoint was early toxicity; the secondary endpoint was late toxicity. Patients with histologically or cytologically proven primary early breast cancer were eligible. Inclusion criteria were as follows: (1) T < 2.5 cm; (2) desire for breast-conserving surgery; (3) age >50 years; (4) surgical margin >1 cm; (5) intraoperative pathologically free margins; and (6) sentinel node negative. Exclusion criteria were (1) contraindications to radiation therapy; (2) past radiation therapy for the same breast or chest; (3) extensive intraductal component; and (4) a tumor located in the axillary tail of the breast. All patients gave written informed consent. Partial resection was performed with at least a margin of 1 cm around the tumor. The patient was transported from the surgical suite to the radiation room. Radiation (Clinac(®) 21EX, Varian Medical Systems, Inc.) at 21 Gy was delivered directly to the mammary gland. Toxicity was evaluated with the Common Terminology Criteria for Adverse Events V4.0.

RESULTS:

Five patients were enrolled in this pilot study and received 21 Gy. Follow-up ranged from 7.8 to 11.0 months (median 10.2). Intraoperative transportation to the radiation room during the surgical procedure under general anesthesia was performed safely in all patients. Treatment-related toxicities within 3 months were deep connective tissue fibrosis (grade 1, n = 3) and pain (grade 1, n = 3). There was no case of wound infection, wound dehiscence, or soft tissue necrosis. Overall, there was no severe adverse event.

CONCLUSIONS:

The procedure was tolerated very well in this first group of Japanese female patients treated with IORT, as was the case with European women. A longer follow-up is needed for the evaluation of any potential late side effects or recurrences. A phase II study is now being conducted for the next group of patients (UMIN000003578).

• Authors: Masataka Sawaki, Naoto Kondo, Akiyo Horio, Aya Ushio, Naomi Gondo, Eri Adachi, Masaya Hattori, Takashi Fujita, Hiroyuki Tachibana, Takeshi Kodaira, Hiroji Iwata
• Journal: Breast cancer (Tokyo, Japan) (Breast Cancer) Vol. 21 Issue 4 Pg. 415-22 (Jul 2014) ISSN: 1880-4233 [Electronic] Japan
• PMID: 23007312 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)

Topics

• Aged
• Breast Neoplasms (pathology, radiotherapy)
• Combined Modality Therapy
• Feasibility Studies
• Female
• Follow-Up Studies
• Humans
• Intraoperative Care
• Mastectomy, Segmental
• Middle Aged
• Neoplasm Grading
• Pilot Projects
• Postoperative Complications
• Prognosis
• Prospective Studies
• Radiation Injuries
• Radiotherapy Dosage
• Radiotherapy, Adjuvant