How many fractions are necessary for an accurate accumulation of bladder wall dose?

Purpose/Objective: To determine the optimal number and combinationof imaged fractions necessary for accurate accumulation of bladder walldose to uncover associations with urinary toxicity.Results: All study procedures were completed as planned, yielding 1070accumulated bladder wall DVH for analysis. The magnitude of perpatientdifferences between DA using 100% of fractions and the variousexperimental combinations varied markedly within the cohort (Table 1). Conclusions: Accumulating dose to the bladder wall using images fromonly 33% of the treatment course resulted in DVH volume discrepanciesof less the 1.5cm3 for 75% of patients, when those images weredistributed evenly throughout the treatment course.