Histopathology-validated lesion detection rates of clinically significant prostate cancer with mpMRI, [ 68 Ga]PSMA-11-PET and [ 11 C]Acetate-PET.

OBJECTIVE: PET/CT and multiparametric MRI (mpMRI) are important diagnostic tools in clinically significant prostate cancer (csPC). The aim of this study was to compare csPC detection rates with [ 68 Ga]PSMA-11-PET (PSMA)-PET, [ 11 C]Acetate (ACE)-PET, and mpMRI with histopathology as reference, to identify the most suitable imaging modalities for subsequent hybrid imaging. An additional aim was to compare inter-reader variability to assess reproducibility. METHODS: During 2016-2019, all study participants were examined with PSMA-PET/mpMRI and ACE-PET/CT prior to radical prostatectomy. PSMA-PET, ACE-PET and mpMRI were evaluated separately by two observers, and were compared with histopathology-defined csPC. Statistical analyses included two-sided McNemar test and index of specific agreement. RESULTS: Fifty-five study participants were included, with 130 histopathological intraprostatic lesions >0.05 cc. Of these, 32% (42/130) were classified as csPC with ISUP grade ≥2 and volume >0.5 cc. PSMA-PET and mpMRI showed no difference in performance ( P  = 0.48), with mean csPC detection rate of 70% (29.5/42) and 74% (31/42), respectively, while with ACE-PET the mean csPC detection rate was 37% (15.5/42). Interobserver agreement was higher with PSMA-PET compared to mpMRI [79% (26/33) vs 67% (24/38)]. Including all detected lesions from each pair of observers, the detection rate increased to 90% (38/42) with mpMRI, and 79% (33/42) with PSMA-PET. CONCLUSION: PSMA-PET and mpMRI showed high csPC detection rates and superior performance compared to ACE-PET. The interobserver agreement indicates higher reproducibility with PSMA-PET. The combined result of all observers in both PSMA-PET and mpMRI showed the highest detection rate, suggesting an added value of a hybrid imaging approach.

Registration of histopathology to magnetic resonance imaging of prostate cancer.

BACKGROUND AND PURPOSE: The diagnostic accuracy of new imaging techniques requires validation, preferably by histopathological verification. The aim of this study was to develop and present a registration procedure between histopathology and in-vivo magnetic resonance imaging (MRI) of the prostate, to estimate its uncertainty and to evaluate the benefit of adding a contour-correcting registration. MATERIALS AND METHODS: For twenty-five prostate cancer patients, planned for radical prostatectomy, a 3D-printed prostate mold based on in-vivo MRI was created and an ex-vivo MRI of the specimen, placed inside the mold, was performed. Each histopathology slice was registered to its corresponding ex-vivo MRI slice using a 2D-affine registration. The ex-vivo MRI was rigidly registered to the in-vivo MRI and the resulting transform was applied to the histopathology stack. A 2D deformable registration was used to correct for specimen distortion concerning the specimen's fit inside the mold. We estimated the spatial uncertainty by comparing positions of landmarks in the in-vivo MRI and the corresponding registered histopathology stack. RESULTS: Eighty-four landmarks were identified, located in the urethra (62%), prostatic cysts (33%), and the ejaculatory ducts (5%). The median number of landmarks was 3 per patient. We showed a median in-plane error of 1.8 mm before and 1.7 mm after the contour-correcting deformable registration. In patients with extraprostatic margins, the median in-plane error improved from 2.1 mm to 1.8 mm after the contour-correcting deformable registration. CONCLUSIONS: Our registration procedure accurately registers histopathology to in-vivo MRI, with low uncertainty. The contour-correcting registration was beneficial in patients with extraprostatic surgical margins.

Swedish National Penile Cancer Register: incidence, tumour characteristics, management and survival.

OBJECTIVES: To assess penile cancer incidence, stage distribution, adherence to guidelines and prognostic factors in a population-based setting. PATIENTS AND METHODS: The population-based Swedish National Penile Cancer Register (NPECR) contains detailed information on tumour characteristics and management patterns. A total of 1 678 men with primary squamous cell carcinoma of the penis identified in the NPECR between 2000 and 2012 were included in the study. RESULTS: The mean age-adjusted incidence of penile cancer was 2.1/100 000 men, remaining virtually unchanged during the study period. At diagnosis, 14 and 2% of the men had clinical N+ and M+ disease, respectively. Most men were staged pTis (34%), pT2 (19%), or pT1 (18%), while stage information was unavailable for 18% of the men. Organ-preserving treatment was used in 71% of Tis-T1 tumours. Of men with cN0 and ≥pT1G2 disease, 50% underwent lymph node staging, while 74% of men with cN1-3 disease underwent lymph node dissection. The overall 5-year relative survival rate was 82%. Men aged ≥40 years and those with pT2-3, G2-3 and N+ tumours had worse outcomes. CONCLUSIONS: The incidence of penile cancer in Sweden is stable. Most men presented with localized disease, and the proportion of non-invasive tumours was high. During the period under study, adherence to guidelines was suboptimum. The overall 5-year relative survival rate was 82%. Older age, increasing tumour stage and grade, and increasing lymph node stage were associated with poorer survival.

Transurethral resection of non-muscle-invasive bladder transitional cell cancers with or without 5-aminolevulinic Acid under visible and fluorescent light: results of a prospective, randomised, multicentre study.

BACKGROUND: Fluorescent light (FL)-guided cystoscopy induced by 5-aminolevulinic acid (5-ALA) has been reported to detect more tumours compared with standard white-light (WL) cystoscopy. Most reports are from single centres with relatively few patients. OBJECTIVE: To evaluate whether 5-ALA-induced FL and WL cystoscopy at transurethral resection (TUR) is superior compared with standard procedures under WL only with respect to tumour recurrence and progression in patients with non-muscle-invasive bladder cancer. DESIGN, SETTING, AND PARTICIPANTS: This randomised, multicentre, observer- and pathologist-blinded, prospective phase 3 clinical trial enrolled 300 patients, and of those patients, 153 were randomised to FL cystoscopy and 147 were randomised to standard WL cystoscopy. INTERVENTION: All patients were first inspected under WL and all lesions were recorded. Patients randomised to FL underwent a second inspection. TUR was carried out in both groups. MEASUREMENTS: Control cystoscopy under WL was performed in all patients every 3 mo during the first year after randomisation and biannually thereafter. RESULTS AND LIMITATIONS: At the first TUR, the mean number of resection specimens per patient was 2.5 (FL: 2.5; WL: 2.4; p=0.37) and the resulting mean number of resected tumours was 1.7 with FL and 1.8 with WL (p=0.85). More patients were diagnosed with carcinoma in situ (CIS) in the WL group (13%) than in the FL group (4.2%). Within-patient comparison of FL patients only showed that FL detected more lesions than WL. Tumour lesions solely detected by FL cystoscopy that would not otherwise be detected by WL cystoscopy included 52% dysplasia, 33% CIS, 18% papillary neoplasms, 13% pT1, and 7% pTa. Outcome at 12 mo did not show any difference between groups with regard to recurrence-free and progression-free survival rates. CONCLUSIONS: In this prospective, randomised, multi-institutional study, we found no clinical advantage of FL cystoscopy compared with WL cystoscopy and TUR.