Critical Organ Preservation in Reirradiation Brachytherapy by Injectable Spacer

Journal Article · Thu Oct 01 04:00:00 EDT 2009 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.03.072· OSTI ID:21282065

Kishi, Kazushi ^[1]; Sonomura, Tetsuo; Shirai, Shintaro; Sato, Morio; Tanaka, Kayo ^[1]

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1. Department of Radiology, Wakayama Medical University, Wakayama City, 641-8510 (Japan)

Purpose: This case series study evaluated the feasibility and effectiveness of an interstitial high-dose rate brachytherapy (HDR-BT) procedure combined with an at-risk organ-sparing procedure. Methods and Materials: Thirty patients who were scheduled for reirradiation treatment for recurrent cancer after receiving a median dose of 60 Gy (range, 44-70 Gy) in 2-Gy fractions of previous external beam treatment were enrolled. Thirteen patients had lesions in the head and neck, and other lesions were located in the axilla, skeleton, breast, pelvis, and abdominal wall. Chief complaints included local masses (for 25) and refractory pain (for 21). After high-dose rate brachytherapy applicator needle implantation, an optimal CT-based three-dimensional brachytherapy plan was created with a virtual at-risk organ shift from the target. According to the plan, hyaluronic acid gel was injected to maintain the shift during irradiation. The prescribed dose was the result of an individualized tradeoff between target dose and at-risk organ dose, to avoid serious complications. A single-fraction dose of 18.0 Gy (median, equivalent to 75.6 Gy at an {alpha}/{beta} value of 3; range, 16-20 Gy) was applied to the tumor. Results: The at-risk organ dose decreased from 9.1 {+-} 0.9 Gy to 4.4 {+-} 0.4 Gy (mean {+-} standard deviation, p < 0.01), and the normal tissue complication probability decreased from 60.8% {+-} 12.6% to 16.1% {+-} 19.8% (p < 0.01). The shift effect lasted at least 4 hours and disappeared gradually. Distinct tumor shrinkage in 20 of 21 eligible patients, including tumor disappearance in 6 patients, pain reduction in 18 of 21 eligible patients, and no unexpected late toxicity greater than grade 2 were observed during the 19.5-month observation period. Conclusions: This at-risk organ-sparing preservation procedure may provide a safe and efficient reirradiation treatment.

• OSTI ID: 21282065
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 75; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BRACHYTHERAPY
DOSE RATES
GELS
HAZARDS
HEAD
HYALURONIC ACID
IRRADIATION
MAMMARY GLANDS
NECK
NEOPLASMS
PAIN
PATIENTS
PELVIS
PRESERVATION
RADIATION DOSES
SKELETON
TOXICITY