ESTRO 2025 - Abstract Book

S229

Brachytherapy - Gynaecology

ESTRO 2025

1573

Digital Poster Single-dose intrathecal morphine in peri-procedural analgesia improves patient experience in MRI-guided adaptive brachytherapy for cervical cancer Elki SN Cheung 1 , Ming Chi Chu 2 , Mandy HM Chu 2 , Vivian YT Cheung 2 , Janice CY Liu 2 , Inda S Soong 1 , Ken KS Wong 1 , Philip Y Wu 1 1 Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China. 2 Department of Anaesthesia, Pamela Youde Nethersole Eastern Hospital, Hong Kong, China Purpose/Objective: Pain is a significant but often underreported symptom during brachytherapy for locally advanced cervical cancer (LACC), which may impact on quality of life and treatment compliance. In the modern era of image-guided adaptive brachytherapy (IGABT), where combined intracavitary and interstitial (IC/IS) technique is increasingly utilized to improve treatment outcomes, attention to patient experience is paramount. Institutional data suggests high incidence of moderate to severe pain in patients receiving IGABT. Currently, there is no consensus on the optimal peri-procedural analgesia strategy. To improve patient experience, a multimodal analgesic protocol incorporating single-dose intrathecal (IT) morphine during spinal anesthesia (SA) was developed by the multidisciplinary team. This study reports on patient experience before and after the introduction of IT morphine. Material/Methods: Consecutive patients with LACC who received MRI-guided adaptive brachytherapy with applicator implantations under SA at our institute from July 2020 to September 2024 were included. Brachytherapy consisted of two implantations to deliver four fractions over two weeks. The multimodal analgesic protocol was introduced in August 2022, and consisted of IT morphine 0.1mg, oral celecoxib, pregabalin, dihydrocodeine, and additional subcutaneous morphine for incidental pain as required. Pain assessments were performed routinely at four time points after applicator implantation, and at occurrence of incidental pain. Pain outcomes including pain intensity on numeric rating scale, pain patterns, and requirement for additional opioid were evaluated, and compared in patient groups before and after introduction of IT morphine using Mann-Whitney U tests or Fisher’s exact tests. Side effects relating to analgesic use were evaluated. Results: Sixty-six patients receiving 115 brachytherapy applicator implantations were identified, comprising of 49 sessions before and 66 sessions after the introduction of IT morphine. Patient and treatment characteristics were comparable between groups, with slightly higher number of interstitial needles use in the patient group after IT morphine introduction. Utilization of IC/IS technique was 100% in both groups. Following the introduction of IT morphine, significant reduction in maximal pain intensity on Day 1 post-simulation and Day 1 post-treatment delivery were observed across both applicator implantations. The requirement for additional parenteral opioid for incidental pain decreased significantly from 37% to 14% (p=0.007), while requirement for additional continuous intravenous morphine infusion decreased from 47% to 8% (p<0.001). No increase in side effects related to IT morphine was observed.