Clinical utility and cost modelling of the phi test to triage referrals into image-based diagnostic services for suspected prostate cancer: the PRIM (Phi to RefIne Mri) study.

BACKGROUND: The clinical pathway to detect and diagnose prostate cancer has been revolutionised by the use of multiparametric MRI (mpMRI pre-biopsy). mpMRI however remains a resource-intensive test and is highly operator dependent with variable effectiveness with regard to its negative predictive value. Here we tested the use of the phi assay in standard clinical practice to pre-select men at the highest risk of harbouring significant cancer and hence refine the use of mpMRI and biopsies. METHODS: A prospective five-centre study recruited men being investigated through an mpMRI-based prostate cancer diagnostic pathway. Test statistics for PSA, PSA density (PSAd) and phi were assessed for detecting significant cancers using 2 definitions: ≥ Grade Group (GG2) and ≥ Cambridge Prognostic Groups (CPG) 3. Cost modelling and decision curve analysis (DCA) was simultaneously performed. RESULTS: A total of 545 men were recruited and studied with a median age, PSA and phi of 66 years, 8.0 ng/ml and 44 respectively. Overall, ≥ GG2 and ≥ CPG3 cancer detection rates were 64% (349/545), 47% (256/545) and 32% (174/545) respectively. There was no difference across centres for patient demographics or cancer detection rates. The overall area under the curve (AUC) for predicting ≥ GG2 cancers was 0.70 for PSA and 0.82 for phi. AUCs for ≥ CPG3 cancers were 0.81 and 0.87 for PSA and phi respectively. AUC values for phi did not differ between centres suggesting reliability of the test in different diagnostic settings. Pre-referral phi cut-offs between 20 and 30 had NPVs of 0.85-0.90 for ≥ GG2 cancers and 0.94-1.0 for ≥ CPG3 cancers. A strategy of mpMRI in all and biopsy only positive lesions reduced unnecessary biopsies by 35% but missed 9% of ≥ GG2 and 5% of ≥ CPG3 cancers. Using PH ≥ 30 to rule out referrals missed 8% and 5% of ≥ GG2 and ≥ CPG3 cancers (and reduced unnecessary biopsies by 40%). This was achieved however with 25% fewer mpMRI. Pathways incorporating PSAd missed fewer cancers but necessitated more unnecessary biopsies. The phi strategy had the lowest mean costs with DCA demonstrating net clinical benefit over a range of thresholds. CONCLUSION: phi as a triaging test may be an effective way to reduce mpMRI and biopsies without compromising detection of significant prostate cancers.

Transperineal prostate biopsies for diagnosis of prostate cancer are well tolerated: a prospective study using patient-reported outcome measures.

We aimed to determine short-term patient-reported outcomes in men having general anesthetic transperineal (TP) prostate biopsies. A prospective cohort study was performed in men having a diagnostic TP biopsy. This was done using a validated and adapted questionnaire immediately post-biopsy and at follow-up of between 7 and 14 days across three tertiary referral hospitals with a response rate of 51.6%. Immediately after biopsy 43/201 (21.4%) of men felt light-headed, syncopal, or suffered syncope. Fifty-three percent of men felt discomfort after biopsy (with 95% scoring <5 in a 0-10 scale). Twelve out of 196 men (6.1%) felt pain immediately after the procedure. Despite a high incidence of symptoms (e.g., up to 75% had some hematuria, 47% suffered some pain), it was not a moderate or serious problem for most, apart from hemoejaculate which 31 men suffered. Eleven men needed catheterization (5.5%). There were no inpatient admissions due to complications (hematuria, sepsis). On repeat questioning at a later time point, only 25/199 (12.6%) of men said repeat biopsy would be a significant problem despite a significant and marked reduction in erectile function after the procedure. From this study, we conclude that TP biopsy is well tolerated with similar side effect profiles and attitudes of men to repeat biopsy to men having TRUS biopsies. These data allow informed counseling of men prior to TP biopsy and a benchmark for tolerability with local anesthetic TP biopsies being developed for clinical use.

Vesico-acetabular cutaneous fistula: a delayed complication of hip surgery.

Vesico-acetabular cutaneous fistula is an uncommon but important postoperative complication of prosthetic hip surgery. We present a case and images involving a 70-year-old woman who presented with a chronically discharging gluteal wound, 5 years after a complex composite hip replacement.