De Silva K, Brown A, Edwards C. Impact of transperineal ultrasound on perineal skin dose in prostate radiation therapy.
Tech Innov Patient Support Radiat Oncol 2022;
23:27-32. [PMID:
36090010 PMCID:
PMC9460562 DOI:
10.1016/j.tipsro.2022.08.003]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/09/2022] [Accepted: 08/15/2022] [Indexed: 12/03/2022] Open
Abstract
Introduction
This study investigated the relationship between anatomical compression introduced via ultrasound probe pressure and maximum perineum dose in prostate radiotherapy patients using the Clarity transperineal ultrasound (TPUS) system.
Methods
115 patient ultrasound and computed tomography scans were retrospectively analysed. The probe to prostate apex distance (PPA), probe to inferior corpus spongiosum distance (PICS) and maximum perineum dose were calculated. Compression was represented by the PICS and the calculated corpus to prostate ratio (CPR). Demographics included treatment technique, image quality, body mass index (BMI) and age. Multiple linear regression analysis assessed the relationship between compression measures and perineum dose.
Results
The maximum dose to perineum ranged from 1.81 to 45.56 Gy, with a median of 5.87 Gy (Interquartile range (IQR) 3.17). The PICS distance and CPR recorded was 1.67 cm (IQR 0.63) and 0.51 (range 0.29-0.85) respectively. Regression analysis demonstrated both PICS and CPR were significant predictors of maximum dose to the perineum (p < 0.001). Patient-specific factors, including age, BMI, treatment technique and ultrasound image quality, were not factors that significantly impacted the maximum perineum dose.
Conclusion
There was a statistically significant association between increased anatomical compression and perineal dose measurements. A PICS of 1.2 cm or greater is recommended, with compression reduced as much as possible without losing anatomical US definition. Future investigations would be beneficial to evaluate the optimal balance between ultrasound image quality and transducer compression considering the perineum dose.
Collapse