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Purpose: To systematically review scientific literature on the use of intensity-modulated brachytherapy (IMBT), including static and dynamic shielding approaches, to enhance therapeutic ratio. Studies were evaluated for technique, disease site, dosimetry, applicators, dosimetric calculations, and planning algorithms. Comparisons with standard-of-care brachytherapy techniques, alternative IMBT methods, or both were performed for dose-to-target volumes, organs at risk (OARs), and treatment planning or delivery times., Methods and Materials: Inclusion criteria were any peer-reviewed journal articles on IMBT published from January 1, 1980, to January 1, 2019, on PubMed, Google Scholar, Cochrane Library, and EBSCO databases. Two independent investigators reviewed each article for inclusion and exclusion criteria and scope. Data collected on each study included technique, source or shield material, disease site, n of study (n = number of simulated plans/treated patients), dose-to-target/OARs, and planning or delivery times. This review adhered to the Preferred Reporting Items for Systemic reviews and Meta Analyses (PRISMA)., Results: Database queries yielded 1734 results, which were reduced to 436 after exclusion criteria and 78 peer-reviewed journal articles after evaluation of scope. Studies per disease site were 31 for cervical; 16 for rectal; 10 for oculocutaneous; 7 for breast; 6 for prostate; and 8 for other, multiple, or no specific disease site. Eighteen studies demonstrated a significant decrease in dose to OARs (5.1%-68.2%), 11 improved treatment planning or delivery times (7.6%-99.7%), and 6 increased target coverage (18.6%-71.6%) relative to standard-of-care or alternative IMBT technique. IMBT consistently decreased dose to OAR compared with the standard of care at the cost of increased planning or delivery times. Innovations in dose calculation or planning algorithms and applicators were capable of ameliorating prolonged treatment intervals., Conclusions: IMBT techniques improved the therapeutic ratio by reducing OAR doses, facilitating dose escalation, or both. Static-shielding techniques are clinically available as a result of the advent of commercially available heterogeneity-corrected dose-calculation algorithms, whereas dynamic-shielding techniques are still preclinical., (Published by Elsevier Inc.)

Purpose: The purpose of this study was to determine the relationship between patient, disease, and treatment variables and biochemical failure-free survival (bFFS) following low-dose-rate prostate brachytherapy (LDR-BT)., Methods and Materials: Data from 624 consecutive patients who received LDR-BT for localized prostate cancer between 2002 and 2012 at a single institution were collected for various patient, disease, and treatment characteristics including a 4-8 week postimplant PSA (4-8wkPSA). Subgroup analysis was stratified by risk category and treatment regimen. Analysis was performed using Kaplan-Meier survival curves, Cox proportional hazard ratios (HRs), and receiver-operator characteristic curves., Results: A total of 624 consecutive patients were included with followup time of 4.0 ± 3.1 years. Predictors of bFFS included PSA nadir and 4-8wkPSA (HR = 2.48, p = 0.000 and HR = 1.24, p = 0.000, respectively) for total population. Diabetes mellitus (p = 0.026), chronic obstructive pulmonary disease (p = 0.000), alcohol use (p = 0.024), and age (p = 0.002) were predictors for specific subgroups. Receiver-operator characteristic curves 4-8wkPSA were found to be significant (p = 0.036)., Conclusion: 4-8wkPSA is a novel predictor of bFFS for patients receiving LDR-BT across several risk categories and treatment regimens with potential clinical utility as a prognostic indicator. Certain comorbidities and exposure histories also demonstrated significant relationships with bFFS including chronic obstructive pulmonary disease, diabetes mellitus, age, alcohol history, proton pump inhibitor use, PSA nadir, and PSA density., (Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)