V1266: Multi-parametric MRI - ultrasound fusion targeted biopsies using Varian brachytherapy software: Prec

V1266: Multi-parametric MRI - ultrasound fusion targeted biopsies using Varian brachytherapy software: Precision prostate cancer diagnostics


Introduction and Objectives
Multi-parametric MRI (mpMRI) and ultrasound fusion targeted biopsies (M-UFTB) of “suspicious lesions” is a developing area in prostate cancer diagnostics. Commercial transrectal and transperineal M-UFTB are available, but are costly. This video demonstrates our technique for M-UFTB using standard brachytherapy software (Variseed 8.0.2, Varian Medical Systems), with the additional “image – fusion” license option, purchasable from Varian Medical Systems.

MRI lesions identified on axial T2 and/or diffusion weighted images are marked by uro-radiologists as a Region of Interest (ROI). The MRI images are imported into the Variseed software and the identified lesion within the ROI and peripheral zone sectors are contoured separately. Live US images of the prostate are acquired and fused with the contoured MRI images. After fusion the MRI contours are transferred onto the live ultrasound images and fine adjustments completed manually prior to the biopsy.

The ROI is biopsied first, then targeted peripheral zone sector biopsies are carried out using a localisation protocol. Each biopsy path is recorded within the software to create a final biopsy study, which is archived. The primary pathological outcome measure was detection rate of clinically significant prostate cancer defined as a maximum cancer core length (MCCL) ≥4mm and/or Gleason Grade (GG) ≥3+4.

37 patients, mean age 64 years (49-67), mean PSA 6.7 µg/L (1.2 - 22) and a mean prostate volume 50mls (20-120) underwent M-UFTB of an identified lesion. 21 patients were on active surveillance (AS) or had previous negative biopsies, of which 5 had biopsies of the lesion alone, 16 were primary diagnostic.

Cancer was found in 70% of cases (26/37); 62% (16/26) of these had clinically significant disease.

49% (18/37) patients had cancer detected outside the ROI; of these 89% (16/18) were clinically significant.

M-UFTB can be carried out with existing Varian brachytherapy software; when combined with transperineal sector biopsies > 70% are positive, but clinically significant disease may exist within normal appearing peripheral zones. Carefully targeted biopsies of the peripheral zone may be as important as targeting the ROI.

Funding: none