Sunday, June 19, 2022 10:30 AM - 11:30 AMPP07 Presentation Time: 10:30 AM: Trend of LDR and HDR Brachytherapy Utilization for Prostate Cancer Treatment: Analysis of a Large Hospital Based Registry

Abstract

<h3>Purpose</h3> Although brachytherapy (BT) is one of the most effective modalities in radiotherapy for the treatment of prostate cancer (PCa), popularity of BT is perceived as on the decline. In this study we have investigated the trend of utilization of low-dose-rate (LDR) and high-dose-rate (HDR) BT over the past 15 years (2004-2018), as well as the application of BT as boost versus BT as monotherapy using a large hospital-based database. <h3>Materials and Methods</h3> We analyzed an extensive data set using National Cancer Database (NCDB) of N0, M0, non-surgical PCa patients diagnosed between 2004 and 2018. Of 247,426 patients who met the criteria, 78,868 had BT monotherapy and 23,453 has BT boost following the external beam radiotherapy (EBRT). Patients were stratified according to the National Comprehensive Cancer Network (NCCN) guidelines: low-risk (clinical stage T1-T2a, Gleason Score (GS) ≤ 6, Prostate-Specific Antigen (PSA) < 10), intermediate-risk (clinical stage T2b or T2c, GS of 7, PSA of 10-20), and high-risk (clinical stage T3-T4, GS of 8-10, PSA > 20). Patients were grouped into two categories based on BT monotherapy modality (LDR, n=52,293 and HDR, n=26,575) for evaluating the utilization as well as assessing the overall survival (OS) probability that was determined using a Kaplan-Meier estimator. Propensity-score matched analysis was performed for each risk group for the two treatments (LDR, and HDR). IBM SPSS software (version 26.0) was used for statistical analysis; p-value <0.05 was considered statistically significant. <h3>Results</h3> During this time span (2004-2018), 70.3% BT was utilized as monotherapy compared to 29.7% as boost with EBRT. LDR monotherapy increased by about 8.8% while HDR increased by 24.7% between 2004 and 2007. However, after 2007 until 2014, BT was decreased by 54.7% and 65.7%, for LDR and HDR, respectively. Since 2014, BT utilization did not change over the years. Maximum decreased utilization was observed in low-risk group, whereas a slight increase in high-risk group was observed since 2013. Median OS was higher in low-risk and intermediate-risk patients treated with HDR (83.7/72.1 months), compared to treated with LDR (77.7/65.7 months). However, for high-risk PCa both the LDR and HDR performed equally well (median OS 69.2 vs. 69.6 months). PSM analysis using the matched dataset for both the risk groups confirmed the results obtained. All figures were found as statistically significant (p<0.001). <h3>Conclusions</h3> This study revealed that despite initial increase (during 2004-2006), there was a steady decline in BT utilization between 2007 and 2014. However, it remained almost unchanged after 2014. Reduction in BT application for low-risk PCa was most prominent, whereas, there was an increased trend of utilization both the LDR and HDR in high-risk group since 2013.