Low-risk prostate cancer patients undergo unnecessary imaging
MedWire News: Many urologists continue to refer low-risk prostate cancer patients for imaging to stage their disease before treatment, against the advice of international guidelines, show the results of a US study.
Almost half of the study participants underwent one form of imaging before receiving definitive therapy (robotic-assisted radical prostatectomy [RALP]), despite bodies including the American Urological Association and the European Association of Urology advising that imaging is not recommended in low PSA, low Gleason score patients.
"Not only do these examinations subject the patient to increased financial and time burdens, but the exposure to excess radiation and contrast agents is not without its own inherent risks," say David Samadi and colleagues from the Mount Sinai Medical Center in New York.
Among 677 RALP patients with a prostate-specific antigen level of 10 ng/ml or below and a biopsy Gleason score of 6 or less (the most inclusive of the definitions for low-risk disease from the international guidelines), 48% of patients underwent computed tomography (CT), bone scans, and/or endorectal-coil magnetic resonance imaging before surgery.
A total of 202 patients underwent two of the three imaging modalities, with most (56%) of these patients undergoing CT and bone scan. Eighteen patients underwent all three imaging examinations, report Samadi et al in the journal Urology.
Among the total 264 CT examinations ordered, 96% were read as negative, as were 91% of bone scans. At final pathology, 94% of patients had organ-confined disease and did not require intervention.
Imaging revealed low rates of extraprostatic extension of disease and seminal vesicle invasion in the cohort, at 6.0% and 0.4%, respectively, and there were no significant differences in the rates of positive surgical margins or biochemical recurrence between patients who underwent imaging and those who did not.
"The goal of imaging prostate cancer patients preoperatively is to detect occult locoregionally advanced or distant metastatic disease that would alter the primary treatment plan," explain Samadi and co-workers.
They conclude that in this low-risk cohort, none of the imaging examinations demonstrated metastases or intervention-changing diagnoses, and incurred an overall excess cost of US$ 644,392 (€ 461,411).
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By Sarah Guy