Defining the need for prostate cancer radiotherapy in the general population: a criterion-based benchmarking approach

Determining the appropriate rate of radiotherapy is important for ensuring optimal radiotherapy utilisation and accessibility. A criterion-based benchmark (CBB) approach was developed as an alternative to evidence-based methods of determining the need for radiotherapy in prostate cancer. Our primary objective was to determine the initial/lifetime CBB radiotherapy rates in prostate cancer and to compare results with evidence-based estimates. Secondary objectives were to compare observed radiotherapy rates in Ontario, Canada and the USA with the estimated rates.

Benchmarks were defined in Ontario as communities in proximity to cancer centres and without long waiting lists. Surgical and radiotherapy data, encompassing both external beam radiation and brachytherapy, for 1997-2001 were collected for Ontario cancer patients. The Surveillance, Epidemiology and End Results (SEER) public use file described treatment in the USA.

In total, 35 379 cases of prostate cancer were diagnosed in Ontario and 93 275 in SEER. CBB estimates of the initial/lifetime need for radiotherapy were 37.2% (95% confidence interval: 35.8-38.7) and 59.1% (54.3-63.9). Our group's evidence-based estimate (Ebest) rates were 32.3% (28.5-36.1) and 61.2% (55.6-66.8). Observed initial radiotherapy rates were 28.0% (27.5-28.4) in Ontario and 37.0% (36.7-37.3) in SEER. In Ontario, the estimated lifetime rate was 42.6% (41.2-44.0).

CBB provides a reasonable estimate of the need for radiotherapy in prostate cancer. Observed initial radiotherapy rates in the USA were concordant with the CBB estimate. The CBB suggests a shortfall in radiotherapy utilisation for prostate cancer in Ontario.