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Purpose To examine dosimetric and clinical outcomes for Cs-131 radioactive seed implant compared to Pd-103 and I-125. Background/Significance Cs-131 is a novel isotope with relatively short half-life (9.7 days) that may have clinical advantages in seed implant treatments of prostate cancers. There may be a shorter duration of symptoms and increased PSA control rates. Methods We performed a retrospective study in which clinical and dosimetric outcomes were compared for 186 prostate implants performed over a ten-year time period at three different Ascension hospitals. Isotopes that were used included Cs-131 (n=66; half-life 9.7 days), I-125 (n=60; half-life 60 days), and Pd-103 (n=60; half-life 17 days) Results The implants used standard radiation dosages. These were 145 Gy for I-125 alone or 109 Gy when combined with external beam radiation. In the case of Cs-131 used alone, the dose was 115 Gy or 85 Gy when combined with an external beam. For Pd-103, 125 Gy was used for monotherapy and 90 Gy when combined with an external beam. The Cs-131 dosimetry was found to be similar to I-125 and Pd-103 on a quantitative basis. However, there was better homogeneity, and the delivered activity per seed and the number of seeds employed were greater compared to other isotopes. We compared the corrected total source strengths (i.e. normalized to sample mean values) and were able to demonstrate similar distributions for the three isotopes. Dosimetric analysis also suggested there was superior homogeneity with Cs-131. The median PSA value at 60 months was 0.11 ng/ml. There were only a few PSA failures in the three groups of cases, nonetheless, the Cs-131 had the fewest. Conclusions One attractive option for men with early-stage prostate cancer is interstitial brachytherapy. The use of the shorter-acting Cs-131 isotope may be expected to have dose-related side effects that resolve more rapidly. This series suggests a trend for improved PSA control outcomes for Cs-131 patients compared with I-125 and Pd-103.
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Objective To survey Urologists and Radiation Oncologists in Metropolitan Detroit regarding practice patterns in managing non-metastatic prostate cancer during the pandemic. Methods An online survey was created to capture the perspective of the impact the COVID-19 restrictions have on the management of prostate cancer by Urologists and Radiation Oncologists in the Detroit Metropolitan area. Results While most physicians felt that their facilities had adequate quantities of personal protective equipment (PPE), one in four offices reported that they did not have sufficient access to PPE. Urologists surveyed indicated that most of the low risk prostate cancer surgeries were cancelled and 56.2% had half or more of intermediate and high risk disease prostatectomies cancelled as well. Treatment options were then shifted towards either temporary surveillance or hormone therapy. Radiation Oncologists indicated that prostate cancer patients ready to start treatment were mostly delayed with temporary surveillance or hormone therapy depending on risk category (60% indicated they delayed low risk and favorable intermediate risk cases, 56% unfavorable intermediate risk cases, and 44% high risk cases). More than 80% of patients already undergoing treatment continued radiation. Conclusion In the setting of this pandemic, the management of prostate cancer has shifted to a much more conservative approach. While the response to the crisis has not been uniform, the majority of the practitioners followed newly established guidelines. The long-term outcomes of delays and deviations from standard treatment approaches will remain to be seen.
