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Purpose: Previous external beam radiation therapy (EBRT) is theoretically contraindicated for yttrium-90 ((90)Y) radioembolization (RE) because the liver has a lifetime tolerance to radiation before becoming vulnerable to radiation-induced liver disease. We analyzed the safety of RE as salvage treatment in patients who had previously undergone EBRT., Methods and Materials: Between June 2004 and December 2010, a total of 31 patients who had previously undergone EBRT were treated with RE. Three-dimensional treatment planning with dose-volume histogram (DVH) analysis of the liver was used to calculate the EBRT liver dose. Liver-related toxicities including RE-induced liver disease (REILD) were reviewed and classified according to Common Terminology Criteria for Adverse Events version 4.02., Results: The mean EBRT and RE liver doses were 4.40 Gy (range, 0-23.13 Gy) and 57.9 Gy (range, 27.0-125.9 Gy), respectively. Patients who experienced hepatotoxicity (≥grade2; n=12) had higher EBRT mean liver doses (7.96 ± 8.55 Gy vs 1.62 ± 3.39 Gy; P=.037), the only independent predictor in multivariate analysis. DVH analysis showed that the fraction of liver exposed to ≥30 Gy (V30) was the strongest predictor of hepatotoxicity (10.14% ± 12.75% vs 0.84% ± 3.24%; P=.006). All patients with V30 >13% experienced hepatotoxicity. Fatal REILD (n=2) occurred at the 2 highest EBRT mean liver doses (20.9 Gy and 23.1 Gy) but also at the highest cumulative liver doses (91.8 Gy and 149 Gy)., Conclusions: Prior exposure of the liver to EBRT may lead to increased liver toxicity after RE treatment, depending on fractional liver exposure and dose level. The V30 was the strongest predictor of toxicity. RE appears to be safe for the treatment of hepatic malignancies only in patients who have had limited hepatic exposure to prior EBRT., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: To determine the utility of focal high-dose-rate brachytherapy for localized prostate cancer, we investigated the impact on target coverage and dose to organs at risk (OARs) with hemigland (HG) compared with whole-gland (WG) treatment., Methods and Materials: A total of 10 WG implants were used to generate 10 WG and 20 HG (left and right) treatment plans optimized with the inverse planning simulation annealing algorithm using Oncentra MasterPlan (Nucletron B.V., Veenendaal, The Netherlands). The standard distribution of 17-18 catheters designed for WG was used to generate HG plans. The same OARs namely bladder, rectum, and urethra contours and dose constraints were applied for HG and WG plans. The HG contour was a modification of the WG contour whereby the urethra divided the prostate into HGs. The prescription dose was 7.25 Gy×6. Evaluated dose parameters were target dose D90, V100, and V150 and D0.1 cc, D1 cc, and D2 cc to OARs., Results: The HG plans had a D90, V100, and V150 to the HG target of 112%, 97.6%, and 33.8%, respectively. The WG plans had a D90, V100, and V150 to the WG target of 108%, 98.8%, and 26.5%, respectively. The OAR D2 cc doses were significantly lower in HG vs. WG plans: rectum (53.1% vs. 64.1%, p<0.0001), bladder (55.9% vs. 67.5%, p<0.0001), and urethra (69.3% vs. 95.2%, p<0.0001)., Conclusions: In the present model, HG plans yielded a statistically significant decreased radiation dose to OARs and provided complete target coverage with a catheter array designed for WG coverage. The good dosimetry results obtained in this study support the feasibility of HG brachytherapy by using a subset of the WG catheter array. Catheter distribution and dosimetry refinements tailored to subtotal prostate brachytherapy should be explored to see if further improvements in dosimetry can be achieved., (Copyright © 2013 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)

Purpose: A new platform for brachytherapy called electronic brachytherapy (EBT) has been developed, which uses a miniature X-ray source to generate low-energy radiation. A retrospective study of adverse events and clinical outcomes in patients treated with EBT to the vaginal cuff, either as monotherapy or in combination with external beam radiation therapy (EBRT), was conducted., Methods and Materials: Medical records were reviewed from 16 patients treated with postoperative EBT for endometrial (n=13) or cervical cancer (n=3) between February 2009 and November 2010. Patients received either intracavitary vaginal EBT alone or EBT in combination with EBRT. The radiobiologic effectiveness of EBT was assumed to be one., Results: Median follow-up was 20.5 months (range, 7-36 months). When EBT was used alone (n=5), the median dose per fraction, number of fractions, and total dose delivered were: 6Gy (range, 5.5-6.2Gy), 5 fractions (range, 5-6), and 30Gy (range, 30-34Gy), respectively. When EBT was combined with EBRT, the EBT component median dose per fraction, number of fractions, and total dose delivered were: 5Gy (range, 4.5-7Gy), 2 fractions (range, 2-4), and 14Gy (range, 9-20Gy), respectively. The median EBRT dose was 45Gy (range, 45-49.2Gy). Our local control rate, locoregional (pelvic) control rate, and overall survival rate were 94%, 94%, and 88%, respectively. Of the 16 patients, 4 patients reported Grade 2 or greater toxicity (25%); however, there were no Grade 4-5 adverse events. Gynecologic, genitourinary, and gastrointestinal adverse events accounted for 57% (n=4), 43% (n=3), and 0% (n=0) of all Grade 2 or greater side effects. No Grade 2 or higher toxicities were noted in patients treated with EBT alone., Conclusion: EBT is an acceptable means of delivering postoperative vaginal brachytherapy and appears comparable with other methods; as the sole method of treatment, the toxicity rates of EBT are low., (Copyright © 2013 American Brachytherapy Society. All rights reserved.)

PurposeTo study the dosimetric differences of various channel combinations of the Capri vaginal applicator.Methods and materialsThe Capri consists of a single central channel (R1), an inner array of 6 channels (R2), and an outer array of 6 channels (R3). Three-dimensional plans were simulated for 6 channel arrangements (R1, R2, R12, R13, R23, and R123). Treatment plans were optimized to the applicator surface or 5-mm depth while minimizing dose to organs at risk (OARs: bladder, rectum, sigmoid, and urethra). The clinical target volume (CTV) was defined as a 5-mm circumferential shell extending 4 cm in length around the applicator. Clinical target volume coverage (Dmean, D90, V100, and V150) and OAR doses (D0.1 cm3, D1 cm3, D2 cm3, and Dmean) were compared. A comparison between the Capri (R123) and a conventional single-channel applicator was also done. Statistical significance (P value

PurposeTo determine predictors of distant metastases (DM) in prostate cancer patients treated with high dose rate brachytherapy boost (HDR-B) and external beam radiation therapy (EBRT).Material and methodsFrom 1991 to 2002, 768 men with localized prostate cancer were treated with HDR-B and EBRT. The mean EBRT dose was 37.5 Gy (range: 30.6-45 Gy), and the HDR-B was 22 or 24 Gy delivered in 4 fractions. Univariate and multivariate analyses using a Cox proportional hazards model including age at diagnosis, T stage, Gleason score (GS), pretreatment PSA, biologically equivalent dose (BED), and use of androgen deprivation therapy (ADT) was used to determine predictors of developing distant metastases.ResultsThe median follow-up time for the entire patient population was 4.2 years (range: 1-11.2 years). Distant metastases were identified in 22/768 (3%) of patients at a median of 4.1 years. PSA failure according to the Phoenix definition developed in 3%, 5%, and 14% of men with low, intermediate, and high risk disease with a median time to failure of 3.8 years. Prostate cancer specific mortality was observed in 2% of cases. T stage, GS, and use of ADT were significantly associated with developing DM on univariate analysis. GS, and use of ADT were the only factors significantly associated with developing DM on multivariate analysis (p < 0.01). Patients who received ADT had significantly higher risk features suggesting patient selection bias for higher DM in this group of patients rather than a negative interaction between HDR-B and EBRT.ConclusionsIn men treated with HDR-B and EBRT, GS is a significant factor on multivariate analysis for developing distant metastasis.