Identifying Patients Who Are Unsuitable for Accelerated Partial Breast Irradiation Using Three-dimensional External Beam Conformal Techniques

Journal Article · Sun Jul 01 04:00:00 EDT 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2011.12.091· OSTI ID:22058886

Shikama, Naoto ^[1]; Nakamura, Naoki; Kunishima, Naoaki; Hatanaka, Shogo; Sekiguchi, Kenji ^[2]

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1. Department of Radiation Oncology, Saitama Medical University International Medical Center, Saitama (Japan)
2. Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan)

Purpose: Several recent studies reported that severe late toxicities including soft-tissue fibrosis and fat necrosis are present in patients treated with accelerated partial breast irradiation (APBI) and that these toxicities are associated with the large volume of tissue targeted by high-dose irradiation. The present study was performed to clarify which patients are unsuitable for APBI to avoid late severe toxicities. Methods and Materials: Study subjects comprised 50 consecutive patients with Stage 0-II unilateral breast cancer who underwent breast-conserving surgery, and in whom five or six surgical clips were placed during surgery. All patients were subsequently replanned using three-dimensional conformal radiotherapy (3D-CRT) APBI techniques according to the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39 and Radiation Therapy Oncology Group (RTOG) 0413 protocol. The beam arrangements included mainly noncoplanar four- or five-field beams using 6-MV photons alone. Results: Dose-volume histogram (DVH) constraints for normal tissues according to the NSABP/RTOG protocol were satisfied in 39 patients (78%). Multivariate analysis revealed that only long craniocaudal clip distance (CCD) was correlated with nonoptimal DVH constraints (p = 0.02), but that pathological T stage, anteroposterior clip distance (APD), site of ipsilateral breast (IB) (right/left), location of the tumor (medial/lateral), and IB reference volume were not. DVH constraints were satisfied in 20% of patients with a long CCD ({>=}5.5 cm) and 92% of those with a short CCD (p < 0.0001). Median IB reference volume receiving {>=}50% of the prescribed dose (IB-V{sub 50}) of all patients was 49.0% (range, 31.4-68.6). Multivariate analysis revealed that only a long CCD was correlated with large IB-V{sub 50} (p < 0.0001), but other factors were not. Conclusion: Patients with long CCDs ({>=}5.5 cm) might be unsuitable for 3D-CRT APBI because of nonoptimal DVH constraints and large IB-V{sub 50}.

• OSTI ID: 22058886
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 3 Vol. 83; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CHARGE-COUPLED DEVICES
FATS
FIBROSIS
IRRADIATION
MAMMARY GLANDS
MULTIVARIATE ANALYSIS
NECROSIS
NEOPLASMS
PATIENTS
RADIATION DOSES
RADIOTHERAPY
SURGERY
TOXICITY