Brachytherapy in pelvic malignancies: a review for radiologists.

Brachytherapy, also known as sealed source or internal radiation therapy, involves placement of a radioactive source immediately adjacent to or within tumor, thus enabling delivery of a localized high dose of radiation. Compared with external beam radiation which must first pass through non-target tissues, brachytherapy results in less radiation dose to normal tissues. In the past decade, brachytherapy use has markedly increased, thus radiologists are encountering brachytherapy devices and their associated post-treatment changes to increasing degree. This review will present a variety of brachytherapy devices that radiologists may encounter during diagnostic pelvic imaging with a focus on prostate and gynecologic malignancies. The reader will become familiar with the function, correct position, and potential complications of brachytherapy devices in an effort to improve diagnostic reporting and communication with clinicians.

Late toxicity after intensity modulated and image guided radiation therapy for localized prostate cancer and post-prostatectomy patients.

PURPOSE: To examine late gastrointestinal (GI) and genitourinary (GU) toxicity profiles of patients treated for prostate cancer either definitively or post-prostatectomy with both intensity modulated radiation therapy (IMRT) and image guided radiation therapy (IGRT). METHODS AND MATERIALS: A total of 333 patients treated definitively and 104 patients treated postoperatively with IMRT and varying IGRT techniques were retrospectively examined to evaluate GI and GU toxicity profiles >1 year from treatment. Available dosimetric data were used for correlative analysis. RESULTS: The median follow-up time for the definitive patients was 41 months and the median follow-up time for the post-prostatectomy patients was 33 months. No late grade 4 or 5 GI or GU toxicities were observed. For definitive patients, the rates of grade ≥2 GI and GU toxicity at 3 years were 4.9% and 4.5%, respectively. In the postoperative cohort the rate of grade >2 GU toxicity was 11.6%, with no grade ≥2 GI toxicity. In the definitive cohort's Cox proportional hazards regression univariate analysis, use of anticoagulation was significantly associated with GI toxicity and age, bladder V50 and IGRT modality were associated with GU toxicity, and only age remained significant in the multivariate model. In univariate analysis for the postoperative cohort, no dosimetric value correlated with GU toxicity, nor did age or time from radical prostatectomy to radiation. CONCLUSIONS: IMRT with IGRT achieved low rates of GI and GU toxicity in the definitive and postoperative setting.

The efficacy of external beam radiotherapy and stereotactic body radiotherapy for painful spinal metastases from renal cell carcinoma.

PURPOSE: Palliative radiotherapy is routinely used to treat painful spinal metastases from renal cell carcinoma (RCC). Conventionally planned external beam radiotherapy (CRT) has been standard, with high-dose stereotactic body radiotherapy (SBRT) becoming increasingly common given the radioresistant nature of RCC. We compared the efficacy and durability of pain relief produced by these 2 modalities. METHODS AND MATERIALS: Patients with painful spinal metastases from RCC treated from 2002-2010 were included. Response was defined similar to the Radiation Therapy Oncology Group 0631 protocol: complete response (CR) being resolution of pain without increased narcotics; partial response (PR) included patients with an incomplete reduction in pain without increased narcotics. Patients who experienced a CR or PR were coded as having pain relief, while those with persistent pain or additional narcotics requirements were coded as failures. Achievement of pain relief was analyzed using competing risk analysis with death as the competing event. Time to pain relief was plotted using cumulative incidence analysis. RESULTS: A total of 110 patients (34 CRT; 76 SBRT) were included. Median follow-up was 4.3 months (range, 0.2-38). Median Karnofsky performance score was higher for patients treated with SBRT compared with CRT (80 vs 70; P = .0004). Overall pain response rates were 68% for CRT and 62% for SBRT, with respective CR and PR rates of 12% and 56% for CRT, and 33% and 29% for SBRT (P = .01). Median time to pain relief was 0.6 weeks for CRT versus 1.2 weeks for SBRT (P = .29). For patients who achieved pain relief (n = 79), median duration was 1.7 months for CRT versus 4.8 months for SBRT (P = .095). On univariate analysis no factors were significantly related to pain relief. CONCLUSIONS: CRT was not statistically different than SBRT for pain relief in symptomatic spine metastases from RCC and should be used as first line treatment. The appropriate use of SBRT in this population merits prospective study.

Use of radiation therapy for patients with soft-tissue and bone sarcomas.

Radiation therapy is recommended as an adjuvant to resection for intermediate- and high-grade soft-tissue sarcomas; its role in bone sarcomas is largely limited to select patients with Ewing sarcoma. Despite the integral role of radiation therapy in soft-tissue sarcoma management, its optimal timing--preoperative versus postoperative--is uncertain, with each timing scenario having advantages and disadvantages. Preparation for radiation therapy involves a detailed planning session to optimize and standardize patient positioning and determine the target volume. Side effects of radiation therapy may include skin changes, delayed wound healing and other wound complications, fatigue, reduced range of motion of the affected limb, pain, and bone fractures.