Diagnostic magnetic resonance imaging strategies for the diagnosis of prostate cancer should be considered prior to biopsy of suspicious lesions, according to a recent study.
Diagnostic magnetic resonance imaging (MRI) strategies for the diagnosis of prostate cancer should be considered prior to biopsy of suspicious lesions, according to the results of a study published online in Radiology (2017 May 17:162181).
Compared with transrectal ultrasound-guided biopsies, MRI diagnostic exams followed by MRI-guided biopsies yielded net health benefits well within the commonly accepted threshold for cost-benefit ratios.
“We believe that the adoption of these strategies could be very beneficial to the patient and the health care system,” Vikas Gulani, MD, PhD, of University Hospitals Case Medical Center, Cleveland, told Urology Times on behalf of him and his partner Lee E. Ponsky, MD. “The patient benefits with fewer biopsy-related complications and more accurate diagnosis and triaging of disease. We hope this study will provide sufficient evidence that will allow MRI prior to biopsy to be incorporated into management algorithms.”
According to Dr. Gulani, prostate cancer diagnosis and treatment is quite primitive compared to other cancers. In 2017, clinicians still biopsy patients without a predetermined imaged based focus to target.
“This is not true anywhere else in the body. We all operate from the assumption that the only real way we presently have of ‘seeing’ the cancer non-invasively-MRI-is not cost-effective for all comers,” Dr. Gulani said.
Dr. Gulani and colleagues designed this study to test this assumption, and expected to find that obtaining an MRI before biopsy was not cost-effective.
They developed a decision analysis model for biopsy-naive men recommended for a prostate biopsy based on abnormal digital rectal examination or elevated PSA levels. They evaluated three strategies: standard transrectal ultrasound guided biopsy, diagnostic MRI followed by MRI-targeted biopsy with no biopsy performed if MRI was negative, and diagnostic MRI followed by MRI-targeted biopsy with a standard biopsy performed when MRI was negative.
“Ultrasound allows visualization of the prostate, but not direct visualization of a potential cancer. Transrectal ultrasound-guided biopsies involve the operator visualizing the prostate via a transrectal approach, and then obtaining a number of biopsies from the prostate by systematically sampling parts of the gland over multiple locations,” Dr. Gulani said.
In contrast, MRI-guided approaches use MRI to identify a focus of suspicion, and then obtain targeted biopsies from these suspicious foci. In the study, the authors evaluated three MRI-guided biopsy strategies: cognitive guidance, MRI-ultrasound fusion, or in-gantry MRI biopsy. These three strategies are of increasing complexity and cost, and also increasing accuracy.
The authors obtained ratios of net health benefits added by the technology (quality adjusted life years [QALYs]) and associated costs. They then applied commonly accepted criteria for cost for each QALY; methods meeting these criteria are considered cost-effective.
They found that non-contrast MRI followed by cognitively-guided MR biopsy was the most cost-effective approach, yielding an additional net health benefit of 0.198 QALYs compared with standard biopsy. Non-contrast MRI followed by in-gantry MR biopsy led to the highest net health benefit of 0.251 additional QALYs compared with standard biopsy.
“Both results were surprising. This will strengthen the collaboration between radiologists and urologists. The radiology community contributes to a more effective way of managing patients. The urology community can better counsel patients regarding appropriate treatment options for aggressive disease, while placing indolent cancers in active surveillance protocols,” Dr. Gulani said.
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