- Design
- Deep-learning development and validation study
- Population
- 3,000 fusion-biopsy patients for development; 110 prostatectomy patients for validation
- Primary outcome
- Sensitivity, specificity and lesion Dice score for significant cancer
- Effect
- Sensitivity 0.80 vs 0.73 (MRI-only); specificity 0.88 vs 0.78 for radiologists
In MRI-ultrasound fusion biopsy, misregistration between the two images can make the needle miss a significant cancer. A BJU International study trained a deep-learning model that takes both MRI and transrectal ultrasound as input to outline significant cancer directly on the ultrasound image, using fusion-biopsy cohorts of 3,000 men, with 1,700 held-out cases and an independent prostatectomy cohort of 110.
Across test cohorts, the combined model reached sensitivity 0.80 against 0.73 for an MRI-only model and 0.49 for ultrasound-only, with better lesion overlap. In the prostatectomy cohort it matched radiologists' sensitivity (0.79) and had higher specificity (0.88 against 0.78).
The comparison with radiologists rests on 110 men. It is a development study, but it addresses a real weakness of fusion biopsy and is worth watching as these tools move towards the biopsy suite.
- A combined MRI-ultrasound AI model detected significant cancer more sensitively than MRI-only or ultrasound-only models.
- Against radiologists, it had higher specificity with similar sensitivity on prostatectomy validation.
- The tool is investigational and not available for clinical biopsy targeting.
- Continue to sample around MRI targets to allow for registration error during fusion biopsy.
Why it matters
Registration error between MRI and ultrasound is a hidden source of missed cancers that AI may reduce.
Don't overread it
The radiologist comparison involved 110 men and has not been tested prospectively in live biopsies.
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