Abstracts Archive
UK & Ireland Prostate Brachytherapy Conference 2019
Abstract number 7
Acute urinary toxicity following HDR brachytherapy for prostate cancer: comparing outcomes with CT only treatment planning versus CT and MRI
Farrow E*, Simpson E**, Davies T†, Woolcot T†, Robinson AJ†, Nikapota A†
* Brighton and Sussex Medical School, United Kingdom
** Brighton and Sussex University Hospitals NHS Trust, United Kingdom
† Sussex Cancer Centre, Royal Sussex County Hospital, United Kingdom
Introduction: HDR brachytherapy treatment planning can be real-time using USS or CT/MRI based. With CT only, planning limitations include overestimation of the prostate and difficulty identifying the bladder neck/trigone1,2. This can lead to excess dosage to normal tissues, causing adverse effects, such as acute urinary toxicity (AUT)3. MRI is better at visualising soft tissue structures, due to this, incorporation of MRI into prostate brachytherapy may improve dose distribution, thus reducing likelihood of AUT4. This study will compare AUT of patients undergoing high dose (HDR) brachytherapy using CT only for contouring and those planned using CT with MRI image fusion.
Methods: Retrospective study of patients treated with HDR brachytherapy at Royal Sussex County Hospital. On a 2-patient brachytherapy list there was capacity to do MRI on 1 patient. International Prostate Symptom Score (IPSS) data was recorded at baseline (pre-treatment) and 3 months post-treatment. AUT was defined as an increase of 10 points in IPSS score at 3 months. Urinary symptom resolution was defined as an IPSS score within 5 points of baseline at 3 months.
Results: 103 patients (median age 70 ± 22) were recruited. AUT occurred in 14 of 78 (17.95%) undergoing CT and 2 of 25 (8%) undergoing CT and MRI (p=0.232). Urinary symptoms resolution occurred in 13 of 78 patients (16.66%) undergoing CT and 6 of 25 (24%) undergoing CT and MRI (p=0.411).
Conclusion: This study suggests patients planned with both MRI and CT for prostate brachytherapy had reduced acute urinary toxicity. This is probably due to improved target volume definition enabled with MRI fusion, leading to reduced dose to bladder neck/trigone. Further data is needed to validate these findings.
References
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4. Tanderup et al. Semin Radiat Oncol 2014; 24:312-9