Sjoerd Jenniskens MD, Presenter: Nothing to Disclose

Christiaan Gerardus Overduin MSc, Abstract Co-Author: Nothing to Disclose

Joyce Gerda Riek Bomers MSc, Abstract Co-Author: Nothing to Disclose

Jurgen J. Futterer MD, PhD, Abstract Co-Author: Nothing to Disclose

To compare image quality and procedure time of MR-guided focal cryoablation of prostate cancer (PCa) recurrence at 1.5T and 3T field strength.

39 consecutive patients with locally recurrent PCa after radiotherapy underwent transperineal MR-guided focal cryoablation at either a 1.5T (n=16) or 3T (n=23) MR system. In these patients, quality of imaging during the procedure was retrospectively assessed. Anonymized axial T2-weighted turbo spin echo and T1-weighted gradient echo MR images were randomly read by 3 experienced prostate interventional radiologists, who were blinded for field strength and imaging parameters. Image quality was assessed using a 5 points scale (1= excellent quality – 5= non-diagnostic) for three procedure steps: tumor localization, needle targeting and treatment monitoring. Additionally, total procedure time and procedure time adjusted for the number of needles placed between field strengths were compared. For statistical analysis, the student t-test was used.

Mean total procedure times observed at 1.5T and 3T were 121 minutes (46,2 minutes per needle) and 125 minutes (40,6 minutes per needle) respectively. Procedure time per needle was 12% faster at 3T (p-value 0,10). In addition, 3T MR showed significantly higher overall image quality compared to 1.5T in tumor localization (2.0±0.6 vs. 2.8±0,5; p<0.01) and treatment monitoring (1.5±0.4 vs. 2.9±0.3; p< 0.01). In treatment monitoring, this allowed a significantly better assessment of the boundary of the ablation zone (1.3±0.4 vs. 2.3±0.5; p<0.01), as well as its location with respect to the target area (1.4±0.3 vs. 2.4±0.4; p<0.01) and critical surrounding structures (1.5±0.3 vs. 2.8±0.3; p<0.01).  

Initial comparison of image quality and procedure time shows a trend towards faster needle placement at 3T. Moreover, capability to monitor the cryoablation treatment was significantly better at 3T field strength.

3T MR imaging-guided focal cryoablation in patients with locally recurrent prostate cancer offers faster needle placement and higher image quality, improving treatment monitoring, over 1.5T.

Jenniskens, S, Overduin, C, Bomers, J, Futterer, J, MR-guided Focal Cryoablation of Locally Recurrent Prostate Cancer at 1.5 and 3T: An Initial Comparison of Image Quality and Procedure Time.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13023770.html