Prostatic Neoplasms: Rivard MJ

Bice WS, Prestidge BR, Kurtzman SM, Beriwal S, Moran BJ, Patel RR, Rivard MJ, Anonymous00014. · Foundation for Medical Physics Research, San Antonio, TX 78216, USA. · Brachytherapy. · Pubmed #18782682 No free full text.

Abstract: PURPOSE: Published clinical information on the safety and efficacy of (131)Cs implants is limited. We provide consensus recommendations for (131)Cs prostate brachytherapy based on experience to date. METHODS AND MATERIALS: The Cesium Advisory Group (CAG) consists of experienced (131)Cs users. Recommendations are based on three clinical trials, one of which has completed accrual and has been published in the peer reviewed literature, and combined CAG experience of more than 1200 (131)Cs implants. RESULTS: We recommend using 1.059cGyh(-1)U(-1) as the dose rate constant for the IsoRay source. The prescription for monotherapy implants is 115Gy and when combined with 45-50Gy external beam it is 85Gy. Suggested individual source strength ranges from 1.6 to 2.2U. The release criterion for (131)Cs implants is 6mRh(-1) at 1m. (131)Cs brachytherapy should be performed differently from (125)I and (103)Pd brachytherapy: source placement is further from the urethra and rectum; the prostate V(150) should be < or =45%; sufficient margins may be obtained while limiting source placement to the capsule or close to the capsule. The increased dose rate may cause degradation of postimplant quantifiers due to edema. However, large variability in the magnitude and rate of resolution of edema make determination of the most representative postoperative imaging time impossible. The CAG recommends postimplant imaging on the day of the implant. Recommended postimplant evaluation goals include prostate D(90) greater than the prescription dose; maintaining D(u)(,30)<140% of the prescription dose and keeping V(r)(,100)<0.5cm(3). CONCLUSION: It was the consensus of the CAG that optimal (131)Cs implants should be performed differently from those performed with (125)I or (103)Pd. Guidelines have been established to allow for safe and effective delivery of (131)Cs prostate brachytherapy.

Rivard MJ, Butler WM, Devlin PM, Hayes JK, Hearn RA, Lief EP, Meigooni AS, Merrick GS, Williamson JF. · Departments of Radiation Oncology and Medical Physics, Tufts-New England Medical Center, Boston, MA 02111, USA. · Brachytherapy. · Pubmed #17284383 No free full text.

Abstract: PURPOSE: In 2004, the American Association of Physicists in Medicine (AAPM) issued a report outlining recommended 125I and 103Pd datasets for consistency in calculating brachytherapy dose distributions. In 2005, to aid evaluating the clinical impact of implementing these datasets, the AAPM assessed the historical dependence of how prescribed doses differed from administered doses for 125I and 103Pd for permanent implantation of the prostate. Consequently, the American Brachytherapy Society (ABS) considered the nature of these changes towards issuing recommended dose prescriptions for 125I and 103Pd interstitial brachytherapy implants for monotherapy and standard boosts. METHODS AND MATERIALS: An investigation was performed of the 2005 AAPM analysis to determine changes in administered dose while affixing prescribed dose using 2004 AAPM 125I and 103Pd brachytherapy dosimetry datasets for prostate implants. For 125I and 103Pd, administered dose would change by +1.4% and +4.2%, respectively. The biological and societal impact of changing prescribed dose was considered. RESULTS: Based on the need for clinical constancy and in recognition of overall uncertainties, the ABS recommends immediate implementation of the 2004 AAPM consensus brachytherapy dosimetry datasets and no changes to 125I and 103Pd dose prescriptions at this time. CONCLUSIONS: Radiation oncologists should continue to prescribe monotherapy doses of 145 Gy and 125 Gy for 125I and 103Pd, respectively, and standard boost doses of 100-110 Gy and 90-100 Gy for 125I and 103Pd, respectively.