In this study, authors complete a local multi-institutional retrospective assessment of their RTB biopsy diagnostic accuracy, correlated to when the biopsy is done relative to tumor ablation. They only looked at patients with cT1 tumor who went on to receive cryotherapy, radiofrequency ablation, or microwave ablation between 2007 and 2017. All biopsies were performed under CT, MRI or US guidance.
An important limitation is that they only looked at patients who underwent tumor ablation – so patients who had a pre-procedure biopsy, but didn’t end up getting ablation were not included (either due to more radical therapy or no therapy).
They identified a total of 641 patients with a median tumor size of 2.9 cm. The majority (69%) had RTB performed at the time of ablation, and 10% of patients had no ablation at all.
When looking at the pathologic outcomes of the biopsy, they limited it to patients who only had a pre-op or peri-op biopsy (excluding patients with no biopsy or biopsy at both settings).
Peri-op biopsies captured significantly more benign masses and less malignancy. However, the sample size is quite small, so differences may not be captured well. Grossly, peri-op biopsy results in high detection of benign pathology and non-diagnostic biopsy – likely due to the limitation previously discussed.
Based on these results, the authors suggest that peri-op biopsy may lead to overtreatment of benign masses, and as a result, the authors suggest that pre-op biopsy should be favored – in order to make a decision regarding need to treat.
Presented by: C.V. Widdershoven, Antoni van Leeuwenhoek, Department of Urology, Amsterdam, The Netherlands
Written by: Thenappan Chandrasekar, MD (Clinical Instructor, Thomas Jefferson University) (twitter: @tchandra_uromd, @TjuUrology) at the 34th European Association of Urology (EAU 2019) #EAU19 conference in Barcelona, Spain, March 15-19, 2019.