Acute toxicity of hypo- and conventionally-fractionated radiosensitised bladder radiotherapy
Huddart, R. Hafeez, S. Omar, A. Choudhury, Ananya Birtle, A. Syndikus, I. Hindson, B. Varughese, M. Henry, A. McLaren, D.
Huddart, R.
Hafeez, S.
Omar, A.
Choudhury, Ananya
Birtle, A.
Syndikus, I.
Hindson, B.
Varughese, M.
Henry, A.
McLaren, D.
Citations
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Abstract
Purpose or Objective
Adding concurrent (chemo-)therapy to radiotherapy improves outcomes for muscle invasive bladder cancer
patients. Recent meta-analysis demonstrates superior invasive locoregional disease control for a
hypofractionated 55 gray (Gy) in 20 fractions (f) schedule compared to 64Gy in 32f. In the RAIDER clinical
trial, patients undergoing 20f or 32f radical radiotherapy were randomised (1:1:2) to standard radiotherapy or
to standard-dose or escalated-dose adaptive radiotherapy. Neoadjuvant chemotherapy and concomitant
therapy were permitted in line with standard practice at each participant’s centre. We report acute toxicity
by concomitant therapy-fractionation schedule combination.
Materials and Methods
Trial participants had unifocal bladder TCC staged T2-T4a N0 M0. Acute toxicity was assessed (CTCAE) weekly
during radiotherapy and at 10 weeks after start of treatment. Within each fractionation cohort, a non-randomised comparison of the proportion of patients reporting grade 2 or worse (G2+) genitourinary (GU),
gastrointestinal (GI) or other adverse events at any point in the acute period was performed using Fisher’s
exact tests.
Results
Between October 2015 and April 2020, 345 (163 20f; 182 32f) patients were recruited from 46 centres. Median
age was 73 years; 49% received neoadjuvant chemotherapy. 332 patients received study treatment of whom
244 (73%) received concomitant therapy (table 1).
In those having concomitant therapy, acute G2+ toxicity was reported by 88/114 (77%) in 20f cohort and
102/130 (78%) in 32f cohort and is reported for the 3 most common regimens in table 2. The proportion of
patients with G2+ GI toxicity differed by regimen (20f p=0.01; 32f p=0.005). The most common GI toxicities
were diarrhoea (20f: 15.9%, 45.0%. 11.1%; 32f: 10.6%, 22.7%, 27.2% for the MMC/5FU, gemcitabine (G) and
carbogen/nicotinamide (BCON) groups respectively) and anorexia (20f: 11.4%, 12.5%, 18.5%; 32f: 6.4%, 18.2%, 18.2% for MC/5FU, G, BCON respectively). G2+ acute adverse events are common with overall rates similar across concomitant therapy-fractionation
schedules. The toxicity profile varied by type of concurrent treatment; for both fractionation schedules, GI
toxicity rate appear higher in patients receiving gemcitabine.
Authors
Description
Date
2021
Publisher
Collections
Keywords
Type
Meetings and Proceedings
Citation
Huddart R, Hafeez S, Omar A, Choudhury A, Birtle A, Syndikus I, et al. Acute toxicity of hypo- and conventionally-fractionated radiosensitised bladder radiotherapy. Radiotherapy and Oncology. 2021;161:S396-S8.