ParticipantsGuilherme C. Mariotti, MD, Jundiai, Brazil (Presenter) Nothing to Disclose
Paulo Kayano, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
Priscila M. Falsarella, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
Oliver R. Claros, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
Marcelo L. Cunha, MD, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
Gustavo C. Lemos, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
Marcos R. Queiroz, MD, Barueri, Brazil (Abstract Co-Author) Nothing to Disclose
Rodrigo G. Garcia, MD, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
Ronaldo H. Baroni, MD, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
Arie Carneiro, Sao Paulo, Brazil (Abstract Co-Author) Nothing to Disclose
guilherme.mariotti@einstein.br
PURPOSETo identify candidates to High-intensity focused ultrasound (HIFU) focal therapy (FT) for localized prostate cancers (pCa), the following inclusion criteria are commonly used: serum PSA (<15 ng/ml), Gleason score (ISUP 1-3), multiparametric magnetic resonance imaging (mpMRI) with no extracapsular extension, no seminal vesicle invasion or pelvic lymph node disease and negative bone scintigraphy; however, to the best of our knowledge, no prior study has used 68Ga-PSMA PET/MR as the main feature to indicate and guide HIFU procedures.
METHOD AND MATERIALSA single-center prospective analysis of initial 14 patients, candidates for FT (hemi-gland or super-focal ablation) as the primary treatment option, from August 2018 to March 2019. All patients were re-evaluated by mpMRI and transrectal US/MR fusion prostate biopsy and follow-up 68Ga-PSMA PET/MR to better understand the indication of HIFU before the procedure.
RESULTSMean prostatic volume, age, PSA and region of interest volumes were: 47.9 cc, 68 years, 4.56 ng/dl and 1.1 cm; respectively. Pre-procedure mpMRI showed 7.1% of PIRADS 2, 21.4% of PIRADS 3, 57.3% of PIRADS 4 and 14.2% of PIRADS 5. US-guided fusion + systematic biopsy showed 3 patients with unilateral ISUP 1, 8 patients wth unilateral ISUP 2 and 3 patients with ISUP 3. Ten patients (71.4%) had concordant findings between pre-procedure mpMRI, 68Ga-PSMA PET/MR and biopsy. Four patients (28.5%) had discordant findings, altering the treatment planning or contraindicating the procedure, for the following reasons: 2 patients had larger unilateral multifocal disease on 68Ga-PSMA PET/MR than on MRI or US-MR fusion biopsy, with need to extend the treatment area; One patient presented a smaller extent of disease in 68Ga-PSMA PET/MR than in MRI, allowing a reduction of the expected area of treatment; One patient had extensive bilateral disease in 68Ga-PSMA PET/MR that was not suspected in MRI, confirmed by biopsy, contraindicating the procedure.
CONCLUSIONIn conclusion, 68Ga-PSMA PET/MR may play a fundamental role in the indication and planning of focal ablative prostatic therapy and might be introduced in the inclusion criteria for cases indicated for HIFU.
CLINICAL RELEVANCE/APPLICATIONHigh-intensity focused ultrasound is a promising novel technique but new diagnostic procedures, such as 68Ga-PSMA PET/MR for selection of patients and correct planning of the procedure may alter the oncological outcome and mortality.