Abstract
PO70: Combining External Beam Radiation, Brachytherapy, and Rectal Hydrogel Spacer for Prostate Cancer: A Study of Gastrointestinal Toxicity and Implant Quality
Brachytherapy, v 22(5), pp S103-S103
Sep 2023
Abstract
The purpose of this study was to evaluate the gastrointestinal toxicity profile of a combined modality treatment for prostate cancer, consisting of external beam radiation (EBRT) and brachytherapy with rectal spacer hydrogel. The study aimed to assess the quality of prostate brachytherapy implants with spacer hydrogel in place and assess gastrointestinal complications in a real-world dataset.
This study was a retrospective analysis of patients diagnosed with localized prostate cancer treated with combination EBRT and permanent prostate seed brachytherapy implant (PSI) after rectal hydrogel spacer placement from 2020 to 2022. Toxicity was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, and the incidence of rectal toxicity was recorded. The study also evaluated rectal wall infiltration (RWI) using a scoring method (0-3) based on CT scans after hydrogel placement, where 0 indicates no RWI, 1 represents minimal RWI, 2 represents moderate RWI, and 3 represents significant RWI. Dosimetric impact of hydrogel on the prostate and surrounding organs was assessed through ultrasound during the intra-operative seed implant procedure and post-operative CT scan by measuring Rectum D1cc, Rectum D2cc, Rectum D30%, PTV V100%, PTV D98% and PTV D90% as percentages of the prescription dose as both I-125 and Pd-103 are used in our institution.
We identified 128 men who had hydrogel spacer placed followed by EBRT and PSI. The average age was 70.28yr (53-86yr), with most being white (87.5%) and having an average PSA level of 10.7 (1.4-65.7). The vast majority of patients (91%) had unfavorable intermediate and higher stage prostate cancer. 8.06% of patients had Grade 1 or 2 rectal toxicity, with 91.94% having no bowel symptoms. There was no correlation between the incidence of Grade 1 or higher rectal toxicity and RWI by hydrogel. Dosimetric variables showed significant differences when comparing ultrasound during the intra-operative seed implant procedure with post-operative CT scans. The results of paired t-tests indicated significant differences between all paired dosimetry variables (p<.0001 for Rectum D1cc, D2cc, D30%, PTV D98%, and p=0.0006 for PTV D90%, p=0.0002 for PTV V100%). The mean, median, and IQR values for dosimetric constraints are reported in table 1.
The results of this study indicate that the majority of patients had no bowel symptoms and a low incidence of rectal toxicity when EBRT and PSI is delivered after rectal hydrogel spacer placement. Dosimetric analysis revealed significant differences between ultrasound during the intra-operative seed implant procedure and post-operative CT scans, suggesting the potential impact of hydrogel on intraoperative seed placement.
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Details
- Title
- PO70: Combining External Beam Radiation, Brachytherapy, and Rectal Hydrogel Spacer for Prostate Cancer: A Study of Gastrointestinal Toxicity and Implant Quality
- Creators
- Parisa Shamsesfandabadi - Allegheny Health NetworkHirsch Matani - Allegheny Health NetworkJohn Berzanske - Allegheny Health NetworkKyung Lim Yun - Allegheny Health NetworkMichelle Shupe - Allegheny Health NetworkLauren Hindman - Allegheny Health NetworkYue Yin - Allegheny Health NetworkAbigail Dare - Allegheny Health NetworkDaniel Pavord - Allegheny Health NetworkSushil Beriwal - Allegheny Health NetworkRodney E. Wegner - Allegheny Health NetworkZachary D. Horne - Allegheny Health Network
- Publication Details
- Brachytherapy, v 22(5), pp S103-S103
- Publisher
- Elsevier
- Resource Type
- Abstract
- Language
- English
- Academic Unit
- Radiation Oncology (and Nuclear Medicine)
- Other Identifier
- 991021897263204721