Prostate Brachytherapy Research Articles

Saturday, July 13, 202410:30 AM - 11:30 AMPPP01 Presentation Time: 10:30 AM: A First-in-Man Randomized Clinical Trial of GPU Based Multi-Criteria Optimization (gMCO) versus IPSA in HDR Prostate Brachytherapy

Saturday, July 13, 202410:30 AM - 11:30 AMPPP01 Presentation Time: 10:30 AM: A First-in-Man Randomized Clinical Trial of GPU Based Multi-Criteria Optimization (gMCO) versus IPSA in HDR Prostate Brachytherapy

PO0110: Treatment Planning with Clinically Feasible Curved Catheter Trajectory Prediction for HDR Prostate Brachytherapy

PO0110: Treatment Planning with Clinically Feasible Curved Catheter Trajectory Prediction for HDR Prostate Brachytherapy

PSOR03 Presentation Time: 11:40 AM: Reinforcement Learning Algorithm for Catheter Optimization in HDR Prostate Brachytherapy

PSOR03 Presentation Time: 11:40 AM: Reinforcement Learning Algorithm for Catheter Optimization in HDR Prostate Brachytherapy

Saturday, July 13, 20249:00 AM - 10:00 AMPHSOR01 Presentation Time: 9:00 AM: Dosimetric Comparison of Saline-Filled Biodegradable Balloon and Hydrogel Spacer for High-Dose-Rate CT/MR-Based Prostate Brachytherapy: The Bigger the Better?

Saturday, July 13, 20249:00 AM - 10:00 AMPHSOR01 Presentation Time: 9:00 AM: Dosimetric Comparison of Saline-Filled Biodegradable Balloon and Hydrogel Spacer for High-Dose-Rate CT/MR-Based Prostate Brachytherapy: The Bigger the Better?

PO0419: Feasibility of Utilizing Markers for MRI-Based High Dose Rate Prostate Brachytherapy: Treatment Planning and Dosimetry

PO0419: Feasibility of Utilizing Markers for MRI-Based High Dose Rate Prostate Brachytherapy: Treatment Planning and Dosimetry

PO0422: Outcomes of Prostate Brachytherapy Boost in the Contemporary PET Imaging Era

PO0422: Outcomes of Prostate Brachytherapy Boost in the Contemporary PET Imaging Era

PSOR08 Presentation Time: 12:05 PM: Prospective Study of Local Relapse Patterns after MR-Assisted Salvage HDR Prostate Brachytherapy

PSOR08 Presentation Time: 12:05 PM: Prospective Study of Local Relapse Patterns after MR-Assisted Salvage HDR Prostate Brachytherapy

PO0428: Development of an MRI-Guided Needle Placement System for Prostate Brachytherapy: Proof of Principle

PO0428: Development of an MRI-Guided Needle Placement System for Prostate Brachytherapy: Proof of Principle

PPP04 Presentation Time: 10:57 AM: Long-Term Sexual Health Related Quality of Life after Whole Gland MRI-Guided High Dose-Rate Prostate Brachytherapy Boost: Impact of the Dose to the Neurovascular Bundles

PPP04 Presentation Time: 10:57 AM: Long-Term Sexual Health Related Quality of Life after Whole Gland MRI-Guided High Dose-Rate Prostate Brachytherapy Boost: Impact of the Dose to the Neurovascular Bundles

PO0412: Registration Chaining: Lesion Localization Utilizing Preoperative Magnetic Resonance Imaging Contours in Prostate Brachytherapy Planning without Needing Post-Implant Imaging

PO0412: Registration Chaining: Lesion Localization Utilizing Preoperative Magnetic Resonance Imaging Contours in Prostate Brachytherapy Planning without Needing Post-Implant Imaging

PPP06 Presentation Time: 11:15 AM: Long Term Outcomes with the Use of Blood Patch as a Spacer in High-Dose Rate Prostate Brachytherapy Another Way to Improve Outcomes in Developing Countries

PPP06 Presentation Time: 11:15 AM: Long Term Outcomes with the Use of Blood Patch as a Spacer in High-Dose Rate Prostate Brachytherapy Another Way to Improve Outcomes in Developing Countries

PO0430: Design and Implementation of an Ultrasound-Based High Dose Rate Prostate Brachytherapy (HDR-PB) Program in a Large Academic Center

PO0430: Design and Implementation of an Ultrasound-Based High Dose Rate Prostate Brachytherapy (HDR-PB) Program in a Large Academic Center

Saturday, July 13, 202411:30 AM - 12:30 PMPSOR01 Presentation Time: 11:30 AM: Dosimetric Comparison of Standard Low-Dose-Rate Prostate Brachytherapy versus Focal Sparing to One of the Prostatic Neurovascular Bundles: An Early Analysis from the PRIAPUS Trial

Saturday, July 13, 202411:30 AM - 12:30 PMPSOR01 Presentation Time: 11:30 AM: Dosimetric Comparison of Standard Low-Dose-Rate Prostate Brachytherapy versus Focal Sparing to One of the Prostatic Neurovascular Bundles: An Early Analysis from the PRIAPUS Trial

Iodine-125 low-dose rate prostate brachytherapy.

Robotic-assisted laparoscopic radical prostatectomy and intensity-modulated radiation therapy are the most common radical treatments for localized prostate cancer, and brachytherapy (BT) also plays a role in this field. Iodine-125 (I-125) low-dose rate (LDR) prostate BT is an established treatment. However, it remains controversial. Specifically, there are a variety of issues, such as indications for combined treatment with external beam radiotherapy and androgen deprivation therapy, prostate-specific antigen follow-up, the significance of postimplant biopsy, the usefulness of salvage BT and focal therapy, reduction of toxicities, and bladder cancer after BT. In this review, we summarize the recent developments in I-125 LDR BT.

Comparing the efficacy of tadalafil and tamsulosin for managing erectile dysfunction and lower urinary tract symptoms in prostate brachytherapy patients: a prospective study

IntroductionAdverse events, such as erectile dysfunction (ED) and lower urinary tract symptoms (LUTS), are significant concerns in prostate cancer (PCa) patients treated with Iodine 125 (I-125) low-dose rate (LDR) prostate brachytherapy (PB). Alpha antagonists and phosphodiesterase-5 inhibitors are used to manage these events. The present study compared the efficacy of low-dose tadalafil with that of tamsulosin for concomitant ED and LUTS in PCa patients treated with I-125 LDR PB. Materials and methodsOne hundred and seventeen patients who received PB for low- or intermediate-risk localized PCa were analyzed. They were randomized into two groups, one receiving tamsulosin (N = 58) and the other receiving low-dose tadalafil (N = 59) immediately after PB. Sexual and urinary functions were assessed at various time points post-PB using questionnaires and objective measurements. The primary endpoint was sexual function measured by the International Index of Erectile Function-15 (IIEF-15) EF domain scores 6 months after PB. Secondary endpoints were sexual function measured by total IIEF-15 scores and Erection Hardness Scores 6 months after PB. The exploratory endpoint was the LUTS status 6 months after PB. ResultsNo significant differences were observed in baseline characteristics between the two groups. Tadalafil exerted stronger effects on sexual function, particularly erection hardness, than tamsulosin. No significant differences were observed in the management of LUTS between both treatments. ConclusionLow-dose tadalafil and tamsulosin may manage LUTS equally after PB. Low-dose tadalafil may contribute to the maintenance of erectile function, particularly erection hardness, after PB; therefore, it is a viable option for patients with baseline erectile function.

Prospective evaluation of supplemental external beam radiotherapy with palladium-103 prostate brachytherapy: Long-term results of the 44/20/0 trials

PurposeThe 44/20 and 20/0 randomized trials evaluated whether different external beam radiation therapy (EBRT) dosing regimens prior to brachytherapy impacted biochemical failure (BF). We report long-term outcomes of both trials, and evaluate whether biological equivalent dose (BED) was associated with reduced BF in the combined trial cohort. Materials/methodsBoth trials enrolled patients with clinical T1c-T2b, Gleason score 7-9 and/or a pre-treatment prostate-specific antigen (PSA) 10-20 ng/ml disease. The 44/20 trial randomized patients to 44Gy EBRT with 90Gy palladium (Pd)-103 versus 20Gy EBRT with 115Gy Pd-103. The subsequent 20/0 trial randomized patients to the 20Gy arm versus monotherapeutic 125Gy Pd-103. For each trial, univariate Fine-Gray analysis evaluated whether treatment arm was associated with BF for the entire cohort and the unfavorable intermediate risk (UIR) subgroup. For the combined trial cohort, multivariate Fine-Gray analysis evaluated whether BED was associated with BF, while adjusting for clinical factors. ResultsThere were 247 analyzable patients in the 44/20 trial. At a median follow-up of 13.7 years, there were no differences in BF for the entire cohort (sub-distribution hazard ratio (sHR) 0.99; 95% CI: 0.43, 2.276; p = 0.97) or the UIR subgroup (sHR 0.72; 95% CI: 0.25, 2.08; p = 0.55). There were 383 analyzable patients in the 20/0 trial. At a median follow-up of 10.4 years, there were no differences in BF for the entire cohort (sHR 0.42; 95% CI: 0.13-1.80; p = 0.15) or the UIR subgroup (sHR 0.81; 95% CI: 0.16-4.03; p = 0.80). For the combined cohort (630 patients), BED was not associated with BF (1.00; 95% CI: 0.98-1.02; p = 0.88) on multivariate analyses, while adjusting for androgen deprivation therapy utilization, 4-tiered National Comprehensive Cancer Network category, and year of treatment. ConclusionsBrachytherapy monotherapy should be a standard-of-care treatment for clinically localized, intermediate risk prostate cancer, including UIR disease.

Overview of treatment plan quality in a high dose rate prostate brachytherapy workflow

PurposeHigh dose rate brachytherapy (HDR-BT) has been shown to be an effective treatment for prostate cancer, with treatment plan quality dependent on a number of factors. In this work, we report on the overall performance of our Ultrasound (US)-based workflow and the impact of several treatment-specific variables. Methods and MaterialsPatients who underwent HDR-BT (boost, monotherapy, and retreatment) using Varian Bravos/US from 2021-2023 were sampled for this study. Treatment plan quality was analyzed and plans were categorized with regard to a number of metrics, including: prostate volume, treating physician, planning physicist, number of needles included, estimated planning time, rectum-prostate separation, and bladder-prostate separation. The performance of this program was compared to the performance of our program using previously used modality combinations: Varian Varisource/US, Elekta microSelectron/CT. ResultsPlan quality for our Bravos/US workflow was shown to be consistently above acceptability criteria for all personnel involved; on average: prostate V100%: 98.9±0.1%, rectum V75%: 0.04±0.01cc, bladder V75%: 0.06±0.01cc, urethra V125%: 0.00±0.00cc. Prostate coverage was statistically improved with this workflow compared to that using our previous modalities. There was a statistical correlation between organ-at-risk (OAR) sparing/prostate coverage ratio and prostate volume, number of needles/prostate volume, bladder-prostate separation, and rectum-prostate separation. There was no correlation between plan quality and planning time. ConclusionsOur US-based HDR-BT program led to target coverage and OAR sparing that exceeded department thresholds. Results were acceptable regardless of the personnel involved and improved plan quality was obtained using more needles/prostate volume and increased spacing between the prostate and the rectum and bladder.

Androgen Deprivation Benefits in Low-Dose-Rate Brachytherapy With Hydrogel Spacer.

We aim to investigate the impact of rectal dose reduction of both androgen deprivation therapy (ADT) and concurrent hydrogel spacer placement (HSP) in patients treated with low-dose-rate (LDR) brachytherapy for prostate cancerand to determine whether there are variations in the degree of efficacy of dose reduction across different segments of the rectum. This study involved 130 consecutive patients treated with I-125 LDR brachytherapy, with (ADT: n = 66) or without (nADT: n = 64) prior ADT, from June 2017 to April 2021. Among these, 13 ADT and 17 nADT patients underwent HSP following induction in May 2020, whereas the remaining patients (nHSP) included 53 ADT and 47 nADT individuals. In the post plan, a rectal dose assessment was made using the rectal volume (RV), divided by horizontal sections into three equal-length subparts (sRVs), such as high-, mid-, and low-RV. The mean sRV100 values were compared between the nADT and ADT patient groups, both with and without HSP. Similarly, mean sRV100 was compared between the nHSP and HSP patient groups, both with and without ADT. In nADT patients, HSP significantly reduced the mean RV100 of the high-RV (0.002 cc versus 0.086 cc, p < 0.05) and mid-RV (0.127 cc versus 0.377 cc, p < 0.05), but not of the low-RV (0.060 cc versus 0.150 cc, p = 0.06). In contrast, in ADT patients, HSP significantly reduced the RV100 at all three sites (0.002 cc versus 0.031 cc, p < 0.05; 0.034 cc versus 0.269 cc, p < 0.05; and 0.015 cc versus 0.151 cc, p < 0.05, respectively). No significant difference was observed when comparing mean sRV100 with or without ADT in both HSP and nHSP patients. The combination of ADT and HSP for LDR prostate brachytherapy showed the potential to significantly reduce RV100, especially in the lower rectum.

Closed-loop control of a tendon-driven active needle for tip tracking at desired bending angle for high-dose-rate prostate brachytherapy

Abstract Prostate cancer is the second most common malignancy in American men. High-dose-rate brachytherapy is a popular treatment technique in which a large, localized radiation dose is used to kill cancer. Utilization of curvilinear catheter implantation inside the prostate gland to provide access channels to host the radiation source has shown superiority in terms of improved dosimetric constraints compared to straight needles. To this aim, we have introduced an active needle to curve inside the prostate conformal to the patient’s specific anatomical relationship for improved dose distribution to the prostate and reduced toxicity to the organs at risk. This work presents closed-loop control of our tendon-driven active needle in water medium and air using the position feedback of the tip obtained in real time from an ultrasound (US) or an electromagnetic (EM) tracking sensor, respectively. The active needle consists of a compliant flexure section to realize bending in two directions via actuation of two internal tendons. Tracking errors using US and EM trackers are estimated and compared. Results show that the bending angle of the active needle could be controlled using position feedback of the US or the EM tracking system with a bending angle error of less than 1.00 degree when delay is disregarded. It is concluded that the actuation system and controller, presented in this work, are able to realize a desired bending angle at the active needle tip with reasonable accuracy paving the path for tip tracking and manipulation control evaluations in a prostate brachytherapy.

Robotic MR-guided high dose rate brachytherapy needle implantation in the prostate (ROBiNSon)—a proof-of-concept study

Objective. A robotic needle implant device for MR-guided high-dose-rate (HDR) prostate brachytherapy was developed. This study aimed to assess the feasibility and spatial accuracy of HDR brachytherapy using the robotic device, for a single intraprostatic target point. Approach. Five patients were treated from November 2019–June 2022 with the robot. The robot fits a 1.5 T MR scanner and the needle can be shifted and angulated. An intraprocedural MR scan was fused with the diagnostic MR and one preplanned needle position was selected for robotic insertion. The needle entry point and angles were set for a needle tip target point within the intraprostatic target volume. The needle was tapped stepwise towards the target point pneumatically. Final needle position was verified with MR, followed by plan optimization and dose delivery. Any remaining planned needles were inserted manually. Needle tip to geometrical target error (NTG-error) was defined as the deviation of the actual tip position relative to the predefined geometric target point, using MR-coordinates. Needle tip to treatment target error (NTT-error) was defined as the deviation of the actual tip position relative to the treatment target point, using fused MR-images pre- and post-needle implantation taking into account prostate deformation. Difference between NTT-error and NTG-error and fiducial marker shifts indicated prostate movement. For determining prostate deformation, the Jaccard index and prostate volumes were assessed. Main results. The robotic device was able to tap the needle to the planned depth for all patients. Mean robotic procedure duration was 142 min. NTG-error was 3.2 (range 1.1–6.7) mm and NTT-error 4.5 (range 2.6–9.6) mm. Marker displacements were smaller than 3 mm. No treatment-related acute toxicity was reported. Feasibility of needle placement within the prostate was considered adequate. Significance. MR-guided robotic needle insertion is feasible with a mean geometric accuracy of 3.2 mm and <3 mm prostate movement.