PV QA 1 - Poster Viewing Q&A 1
Purpose/Objective(s): Hypofractionated radiotherapy (RT) is routinely used in the palliation of patients with muscle invasive bladder cancer (MIBC), who are not fit for radical treatment. We sought to evaluate the efficacy and toxicity of hypofractionated RT in patients treated in our institution, especially in elderly group of patients (>70yrs).
Materials/Methods: Data of patients who had palliative RT for MIBC between Jan 2011 – Jul 2017 were retrospectively analysed. The schedules of radiotherapy included 36Gy/6#/once wkly (Group 1), 21Gy/3#/alt days (Group 2) and 30Gy/10#/2wk, 20Gy/5#/1wk, 8-10Gy/single # (Group 3). All patients in Grp 1 were treated with 3Dconformal CT planning and those in Grp 2 & 3, with conventional parallel opposed fields. Improvement of symptoms with radiotherapy were assessed and the toxicity was assessed using RTOG criteria. In order to explore the relationship between bowel volume at various dose levels and bowel toxicity, individual bowel loops were retrospectively outlined up to 2cm above the planned target volume. The survival was analysed by Kaplan-Meier estimates and log-rank test.
Results: One hundred and thirty (Grp1- 52, Grp2-, 35, Grp3- 43) patients received palliative RT. The median age was 82 (range: 53-99), with 86.2% being elderly. Two-thirds of the patients had a performance score (PS)≥2, 72% had localised disease, 90% had transitional cell carcinoma. Eighty six percent of patients with haematuria have been palliated, compared to only 53.5% of those with dysuria or frequency. The median overall survival (OS) was significantly higher in Grp1 compared to Grp2 &3 (15.3, 7.3, 4.2 months, respectively; p<0.0001). This was independent of patient age and PS. Fifteen percent (8/52) of patients in Grp1 did not complete the prescribed treatment (6- due to deterioration in PS, 2-due to Gr3 cystitis). Of the 119 patients who had their toxicity graded, the acute Gr2 urinary (GU) and bowel (GI) toxicity were GU: 10%, 3%, 2% and GI: 2%, 2%, 6% in Grp1,2 & 3, respectively. Gr3 GU toxicity was seen in 5% of patients (3% in Grp1 and 2% in Grp 2), but none had Gr 3 GI toxicity. The mean bowel volume was lower at higher dose levels and lower in patients with Gr 1, compared to Gr2 GI toxicity.
Conclusion: 36Gy/6#/once wkly regimen is efficacious with longer median OS when compared to 21Gy/3#/alt days, and has a favourable toxicity profile. This regimen should be considered for elderly patients with localised MIBC unfit for radical treatment. Further work is being done to establish relationship between the probability of late bowel toxicity and absolute bowel volumes.
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