Inter-Rater Variability of Prostate Lesion Segmentation on Multiparametric Prostate MRI.

INTRODUCTION: External radiotherapy is a major treatment for localized prostate cancer (PCa). Dose escalation to the whole prostate gland increases biochemical relapse-free survival but also acute and late toxicities. Dose escalation to the dominant index lesion (DIL) only is of growing interest. It requires a robust delineation of the DIL. In this context, we aimed to evaluate the inter-observer variability of DIL delineation. MATERIAL AND METHODS: Two junior radiologists and a senior radiation oncologist delineated DILs on 64 mpMRIs of patients with histologically confirmed PCa. For each mpMRI and each reader, eight individual DIL segmentations were delineated. These delineations were blindly performed from one another and resulted from the individual analysis of the T2, apparent diffusion coefficient (ADC), b2000, and dynamic contrast enhanced (DCE) sequences, as well as the analysis of combined sequences (T2ADC, T2ADCb2000, T2ADCDCE, and T2ADCb2000DCE). Delineation variability was assessed using the DICE coefficient, Jaccard index, Hausdorff distance measure, and mean distance to agreement. RESULTS: T2, ADC, T2ADC, b2000, T2 + ADC + b2000, T2 + ADC + DCE, and T2 + ADC + b2000 + DCE sequences obtained DICE coefficients of 0.51, 0.50, 0.54, 0.52, 0.54, 0.55, 0.53, respectively, which are significantly higher than the perfusion sequence alone (0.35, p < 0.001). The analysis of other similarity metrics lead to similar results. The tumor volume and PI-RADS classification were positively correlated with the DICE scores. CONCLUSION: Our study showed that the contours of prostatic lesions were more reproducible on certain sequences but confirmed the great variability of prostatic contours with a maximum DICE coefficient calculated at 0.55 (joint analysis of T2, ADC, and perfusion sequences).

Research on texture images and radiomics in urology: a review of urological MR imaging applications.

PURPOSE OF REVIEW: Tumor volume and heterogenicity are associated with diagnosis and prognosis of urological cancers, and assessed by conventional imaging. Quantitative imaging, Radiomics, using advanced mathematical analysis may contain information imperceptible to the human eye, and may identify imaging-based biomarkers, a new field of research for individualized medicine. This review summarizes the recent literature on radiomics in kidney and prostate cancers and the future perspectives. RECENT FINDINGS: Radiomics studies have been developed and showed promising results in diagnosis, in characterization, prognosis, treatment planning and recurrence prediction in kidney tumors and prostate cancer, but its use in guiding clinical decision-making remains limited at present due to several limitations including lack of external validations in most studies, lack of prospective studies and technical standardization. SUMMARY: Future challenges, besides developing prospective and validated studies, include automated segmentation using artificial intelligence deep learning networks and hybrid radiomics integrating clinical data, combining imaging modalities and genomic features. It is anticipated that these improvements may allow identify these noninvasive, imaging-based biomarkers, to enhance precise diagnosis, improve decision-making and guide tailored treatment.

Optimal PSA density threshold and predictive factors for the detection of clinically significant prostate cancer in patient with a PI-RADS 3 lesion on MRI.

INTRODUCTION: While Prostate Imaging Reporting and Data System (PI-RADS) 4 and 5 lesions usually justify prostate biopsy (PBx), the management of a PI-RADS 3 lesion can be discussed. The aim of our study was to determine the optimal prostate-specific antigen density (PSAD) threshold and predictive factors of clinically significant prostate cancer (csPCa) in patients with a PI-RADS 3 lesion on MRI. PATIENTS AND METHODS: Using our prospectively maintained database, we conducted a monocentric retrospective study, including all patients with a clinical suspicious of prostate cancer (PCa), all of them had a PI-RADS 3 lesion on the mpMRI prior to PBx. Patients under active surveillance or displaying suspicious digital rectal examination were excluded. Clinically significant (csPCa) was defined as PCa with any ISUP grade group ≥ 2 (Gleason ≥ 3 + 4). RESULTS: We included 158 patients. The detection rate of csPCa was 22.2%. In case of PSAD ≤ 0.15 ng/ml/cm3, PBx would be omitted in 71.5% (113/158) of men at the cost of missing 15.0% (17/113) of csPCa. With a threshold of 0.15 ng/ml/cm3, the sensitivity and the specificity were 0.51 and 0.78 respectively. The positive predictive value was 0.40 and the negative predictive value was 0.85. According to multivariate analysis, age (OR = 1.10, CI95% 1.03-1.19, P = 0.007), and PSAD ≥ 0.15 ng/ml/cm3 (OR = 3.59, CI95% 1.41-9.47, P = 0.008) were independent predictive factors of csPCa. Previous negative PBx was negatively associated with csPCa (OR = 0.24, CI 95% 0.07-0.66, P = 0.01). CONCLUSION: Our result suggests that the optimal PSAD threshold was 0.15 ng/ml/cm3. However, in this case omitting PBx in 71.5% of cases would be at the cost of missing 15.0% of csPCa. PSAD should not be used alone, other predictive factors as age and PBx history should also be considered in the discussion with the patient, to avoid PBx while missing few csPCa.

Eliciting men's preferences for decision-making relative to treatments of localized prostate cancer with a good or moderate prognosis.

PURPOSE: In diseases where there is no real consensus regarding treatment modalities, promoting shared decision-making can contribute to improving safety and quality of care. This is the case in low- or intermediate-risk localized prostate cancer (PC) treatment. The aim of this study was to investigate the preferences guiding men's decisions regarding the characteristics of the treatment strategies for PC to help physicians adopt a more patient-centered approach. METHODS: This prospective multicenter study used a discrete choice experiment (DCE). The attributes and the modalities were identified from a qualitative study and a literature review. Relative preferences were estimated using a logistic regression model. Interaction terms (demographic, clinical and socio-economic characteristics) were added to the model to assess heterogeneity in preferences. RESULTS: 652 men were enrolled in the study and completed a questionnaire with 12 pairs of hypothetical therapeutic alternatives between which they had to choose. Men's choices were significantly negatively influenced by the risk of impotence and urinary incontinence, death, and the length and frequency of care. They preferred treatments with a rescue possibility in case of deterioration or recurrence and the use of innovative technology. Surprisingly, the possibility of undergoing prostate ablation negatively influenced their choice. The results also highlighted differences in trade-offs according to socio-economic level. CONCLUSION: This study confirmed the importance of considering patients' preferences in the decision-making process. It appears essential to better understand these preferences to allow physicians to improve communication and promote case-by-case decision-making.

Impact of age on the Quadrella index assessing oncological and functional results after prostate brachytherapy: A 6-year analysis.

Purpose: As the oncological results of prostate brachytherapy (BT) are excellent for low-risk (LR) or favorable intermediate-risk (FIR) prostate cancer (PCa), evaluating the side effects has become a major issue, especially for young men. The objective of the study was to compare the oncologic and functional results of BT using Quadrella index for patients aged 60 or less compared with older patients. Material and methods: From June, 2007 to June, 2017, 222 patients, including 70 ≤ 60 years old and 152 > 60 years old, underwent BT for LR-FIR PCa, with good erectile function at baseline according to International Index of Erectile Function-5 (IIEF-5) > 16. Quadrella index was achieved under the following circumstances: 1) Absence of biological recurrence (Phoenix criteria); 2) Absence of erectile dysfunction (ED) (IIEF-5 > 16); 3) No urinary toxicity (international prostate score symptom) IPSS < 15 or IPSS > 15, and ΔIPSS < 5; 4) No rectal toxicity (RT) (Radiation Therapy Oncology Group, RTOG = 0). Patients were treated on demand with phosphodiesterase inhibitors (PDE5i) post-operatively. Results: The Quadrella index was satisfied for about 40-80% of patients ≤ 60 years vs. 33-46% for older patients during 6-year follow-up (significant difference from the second year). At year 5, 100% of evaluable patients aged ≤ 60 and 91.8% > 60 (p = 0.29) reached Phoenix criteria. The criterion of ED (IIEF-5 < 16) largely explained the validity rate of Quadrella alone. There was no ED for 67.2-81.4% of patients ≤ 60 years compared with 40.0-56.1% for patients > 60 (significant difference since year 4 in favor of young men). After two years of follow-up, more than 90% of patients in both the groups showed neither urinary nor rectal toxicities. Conclusions: For young men displaying LR-FIR PCa, BT appears to be a first-class therapeutic option, as the oncological results were at least equivalent to those of older patients with good long-term tolerance.

PSMA-11 PET/CT for Detection of Recurrent Prostate Cancer in Patients With Negative Choline PET/CT.

INTRODUCTION: Prostate adenocarcinoma (CaP) is the leading cancer in men. After curative treatment, from 27% to 53% of patients will experience biochemical recurrence (BR). With the development of focal therapies, precise early identification of recurrence's sites is of utmost importance in order to deliver individualized treatment on positive lesions. The aim of this study was to assess the detection rate (DR) of 68Ga-PSMA-11 positron emission tomography/computed tomography (PET/CT) in selected patients with prostate cancer BR and recent negative 18F-choline PET/CT. PATIENTS AND METHODS: We performed a retrospective analysis including all patients with CaP referred for BR with a negative 18F-choline PET/CT, and who underwent 68Ga-PSMA-11 PET/CT between October, 2018 and December, 2019. The overall DR of 68Ga-PSMA-11 PET/CT was calculated, and described according to BR characteristics especially PSA levels and velocity. Patients were followed up for at least 1 year. Patient management following 68Ga-PSMA-11 PET/CT and PSA levels evolution after treatment were also recorded. RESULTS: One hundred fifty-nine patients comprising 164 examinations were analyzed. The overall DR of 68Ga-PSMA-11 PET/CT for BR was 65.9% (95CI, 58.6-73.1). The DR was 52.5% (95CI, 39.9-65.0), 70.6% (95CI, 55.3-85.9), 70.4% (95CI, 53.1-87.6), and 78.6% (95CI, 66.2-91.0) for PSA levels between 0.2 and 0.49 ng/mL, 0.5 to 0.99 ng/mL, 1 to 1.99 ng/mL and PSA ≥ 2 ng/mL, respectively. The DR was 70.7% (95CI, 59.0-82.4) with a PSA doubling time (PSA-DT) ≤6 months and 65.2% (95CI, 55.5-74.9) with a PSA-DT >6 months. Around 3/4 of patients (75.9%) with a positive 68Ga-PSMA-11 PET/CT initiated treatment, including surgery (2.4%), stereotactic radiotherapy ± androgen deprivation therapy (ADT) (22%) or external conformational radiotherapy ± ADT (46.3%). Patient management changed in 43 cases (39.8%). CONCLUSION: Our study confirmed the ability of 68Ga-PSMA-11 PET/CT to detect occult biochemical recurrence, even in a selected population of CaP patients with negative 18F-choline PET/CT, even at low PSA levels.

Impact of Multiparametric MRI and PSA Density on the Initial Indication or the Maintaining in Active Surveillance During Follow-Up in low-Risk Prostate Cancer.

INTRODUCTION: A greater selection of candidates for active surveillance (AS) of prostate cancer (PCa) may decrease the rate of delayed treatment. We aimed to study: 1) the impact of MRI and PSA density (PSAd) at baseline on the final status, and 2) the impact of bio-clinical features during the follow-up on pursuing AS. MATERIALS AND METHODS: This retrospective, monocentric study between June 2013 and July 2020, included 99 patients in AS (median follow-up: 19 months [18-92]). All MRI were reviewed by a single radiologist. Lost to follow-up were 17 patients and 6 patients chose treatment by themselves. Treatment was proposed in case of upgrading (≥ GG2) or increasing PCa volume. RESULTS: Impact of MRI and PSAd at baseline:  Combining PSAd ≤ 0.15 and PIRADS ≤ 3, the probability to remain in AS was 72%. This rate reached 83% when PSAd ≤ 0.10 was associated to normal MRI.  During follow-up:  One hundred fifty-seven prostatic biopsies (PBx) were performed and 38 (24%) found PCa upgrading. The association between negative MRI and PSAd ≤ 0.10, during follow-up, had an excellent NPV to predict treatment (95%). This combination concerned 25% (37/151) of surveillance biopsies that could have been avoided at the cost of delaying upgrading in 3% (1/37). In multivariate analysis, only PIRADS ≥ 4 before PBx was associated to a risk of treatment during follow-up (OR, 10.4 [95% CI, 4.2-25.8]; P < .0001). CONCLUSION: Using PSAd and MRI at baseline to select patients showed excellent performances to predict the maintenance in AS. During follow-up, MRI PIRADS ≥ 4 was associated to an increased risk of treatment.

A machine-learning approach based on 409 treatments to predict optimal number of iodine-125 seeds in low-dose-rate prostate brachytherapy.

PURPOSE: Low-dose-rate brachytherapy is a key treatment for low-risk or favorable intermediate-risk prostate cancer. The number of radioactive seeds inserted during the procedure depends on prostate volume, and is not easy to predict without pre-planning. Consequently, a large number of unused seeds may be left after treatment. The objective of the present study was to predict the exact number of seeds for future patients using machine learning and a database of 409 treatments. MATERIAL AND METHODS: Database consisted of 18 dosimetric and efficiency parameters for each of 409 cases. Nine predictive algorithms based on machine-learning were compared in this database, which was divided into training group (80%) and test group (20%). Ten-fold cross-validation was applied to obtain robust statistics. The best algorithm was then used to build an abacus able to predict number of implanted seeds from expected prostate volume only. As an evaluation, the abacus was also applied on an independent series of 38 consecutive patients. RESULTS: The best coefficients of determination R 2 were given by support vector regression, with values attaining 0.928, 0.948, and 0.968 for training set, test set, and whole set, respectively. In terms of predicted seeds in test group, mean square error, median absolute error, mean absolute error, and maximum error were 2.55, 0.92, 1.21, and 7.29, respectively. The use of obtained abacus in 38 additional patients resulted in saving of 493 seeds (393 vs. 886 remaining seeds). CONCLUSIONS: Machine-learning-based abacus proposed in this study aims at estimating the necessary number of seeds for future patients according to past experience. This new abacus, based on 409 treatments and successfully tested in 38 new patients, is a good alternative to non-specific recommendations.

Development of a Radiomic-Based Model Predicting Lymph Node Involvement in Prostate Cancer Patients.

Significant advances in lymph node involvement (LNI) risk modeling in prostate cancer (PCa) have been achieved with the addition of visual interpretation of magnetic resonance imaging (MRI) data, but it is likely that quantitative analysis could further improve prediction models. In this study, we aimed to develop and internally validate a novel LNI risk prediction model based on radiomic features extracted from preoperative multimodal MRI. All patients who underwent a preoperative MRI and radical prostatectomy with extensive lymph node dissection were retrospectively included in a single institution. Patients were randomly divided into the training (60%) and testing (40%) sets. Radiomic features were extracted from the index tumor volumes, delineated on the apparent diffusion coefficient corrected map and the T2 sequences. A ComBat harmonization method was applied to account for inter-site heterogeneity. A prediction model was trained using a neural network approach (Multilayer Perceptron Network, SPSS v24.0©) combining clinical, radiomic and all features. It was then evaluated on the testing set and compared to the current available models using the Receiver Operative Characteristics and the C-Index. Two hundred and eighty patients were included, with a median age of 65.2 y (45.3-79.6), a mean PSA level of 9.5 ng/mL (1.04-63.0) and 79.6% of ISUP ≥ 2 tumors. LNI occurred in 51 patients (18.2%), with a median number of extracted nodes of 15 (10-19). In the testing set, with their respective cutoffs applied, the Partin, Roach, Yale, MSKCC, Briganti 2012 and 2017 models resulted in a C-Index of 0.71, 0.66, 0.55, 0.67, 0.65 and 0.73, respectively, while our proposed combined model resulted in a C-Index of 0.89 in the testing set. Radiomic features extracted from the preoperative MRI scans and combined with clinical features through a neural network seem to provide added predictive performance compared to state of the art models regarding LNI risk prediction in PCa.

Minimal channel GreenLight photovaporization before permanent implant prostate brachytherapy for patients with obstructive symptoms: Technically feasible and safe.

PURPOSE: Brachytherapy (BrT) is a standard treatment for low-risk to favorable-intermediate-risk prostate cancer but is a relative contraindication for patients with obstructive symptoms. We aimed to assess the feasibility and urinary toxicity of a minimal photovaporization (mPVP) before implantation. MATERIALS AND METHODS: Between 04/2009 and 08/2016, 50 patients candidates for BrT but with International Prostate Symptom Score (IPSS)>15, uroflowmetry <15 mL/s, obstructive prostate or large median lobe underwent a mPVP (GreenLight Laser) at least 6 weeks (median 8.5) before permanent seed implantation (loose seeds, 125I, 160 Gy). RESULTS: Two patients (4%) did not have sufficient improvement and did not undergo BrT, although it would have been possible at 3 months. For the 48 (96%) other patients, at the baseline, mean IPSS was 15.5 (±5.3), vs. 8.6 (±4.4) after mPVP (p = 1 × 10-6), and uroflowmetry 11.7 mL/s (±4), vs. 17.4 (±5.4) (p = 1.4 × 10-5). We did not experience any difficulty for BrT. Mean IPSS did not significantly increase 1, 3, or 6 months after BrT. With a median followup of 60 months [30-120], (92% assessed at last followup), only 4 patients (4/48 = 8.3%) experienced urinary retention and 5 (10.4%) needed surgery for urinary toxicity. In addition, only 2 patients (4%) needed medical treatment at last followup. Considering the 8 patients with de novo incontinence at 1 year, only 2 (4%) had persistent mild symptoms at last followup (36 months) (ICS1-2). CONCLUSIONS: These results suggest that a two-step approach with an mPVP at least 6 weeks before BrT is feasible, with no excessive urinary toxicity, and may be a good strategy for obstructive patients seeking BrT.

Toxicity in patients treated with permanent prostate brachytherapy using intraoperatively built custom-linked seeds versus loose seeds.

PURPOSE: Low-dose-rate brachytherapy (BT) with permanent iodine-125 radioactive seeds is a highly effective treatment option for low- and favorable intermediate-risk prostate cancer. However, optimal implantation is not always achieved due to edema or seeds loss. One way to improve seed placement is the use of stranded seeds called "intraoperatively built custom-linked seeds (IBCLS)" in an opposition to loose seeds (LS). To date, there are few data comparing toxicity rates between these two techniques. The aim of this study was to compare dosimetric parameters and toxicity rates at 2 years between both procedures in a matched-paired population. MATERIAL AND METHODS: Patients were considered for BT according to European guidelines. Among 548 patients treated at our institution, 105 patients in the loose seeds cohort were individually matched to 105 patients in the IBCLS group according to age, prostate volume, pre-operative international prostate symptom score (IPSS), clinical stage, and Gleason score. Erectile function was scored using the five-item international index of erectile function (IIEF-5) score. A multivariable linear mixed-effects model was applied to examine the association between total and individual scores (repeated measures) and covariates. RESULTS: Overall, 61 (29%) patients presented with a favorable intermediate-risk prostate cancer. There were no significant changes in IPSS over time (p = 0.57). During follow-up, the IIEF-5 was similar in the two groups, except at one month, where it was lower in the IBCLS group (10.9 vs. 6.9, p = 0.029). Also, there was no difference in grade ≥ 2 rectal toxicity. At 1 month, D90Gy, V150%, and V100% were higher in the LS group compared to the IBCLS group. CONCLUSIONS: Low-dose-rate prostate brachytherapy using IBCLS is a safe technique, with comparable toxicity profiles at 2 years compared to LS brachytherapy.

Prospective four years of evaluation of erectile function after low-dose-rate prostate brachytherapy using baseline IIEF-5 > 16.

PURPOSE: Prostate brachytherapy (BT) is a validated treatment for localized prostate cancer (CaP) and an attractive therapy option for patients seeking to preserve erectile function (EF). The aim of this paper is to prospectively assess EF evolution during 4 years after BT. MATERIAL AND METHODS: Between February 2007 and July 2012, 179 patients underwent an exclusive Iodine-125 BT, for low-intermediate favorable risk CaP of whom, 102 had an initial international index of erectile function 5 score (IIEF-5) > 16 and were included in the study. Of those, 12.7% received neo-adjuvant hormonotherapy (HT) to decrease the prostate volume. Post-BT intake of phosphodiesterase inhibitors (PDE5i) was not an exclusion criterion. Erectile function was prospectively assessed using a validated questionnaire IIEF-5 before treatment and annually for 4 years. RESULTS: At 1-year follow-up, 54% of patients preserved an IIEF-5 > 16 and only 8% suffered from severe ED. During the next 3 years, the results were not statistically different. The mean IIEF-5 lost 4 points during the first year, 17 vs. 21, and remained stable during the following 3 years. We did not find any significant differences in the proportion of patients treated by PDE5i (18-20%). As for patients with a normal preoperative IIEF-5 (> 21) (n = 52), 35-42% preserved a normal EF and 71-77% maintained an IIEF-5 > 16, including 13-19% of patients who needed PDE5i. Those results were stable for over 4 years. CONCLUSIONS: During the first 4 years after BT, more than half of patients maintained an IIEF-5 > 16, and EF results remained stable. Severe erectile dysfunction (ED) was very rare.

Dose to the penile bulb and individual patient anatomy are predictive of erectile dysfunction in men treated with 125I low dose rate brachytherapy for localized prostate cancer.

Background: To evaluate the occurrence of erectile dysfunction at 3 years (3yED) after prostate brachytherapy (BT) and to predict 3yED after treatment based on patients and treatments characteristics. Material and methods: From September 2007 to July 2015, 117 men with mild or no ED [International Index of Erectile Function (IIEF-5) > 16] underwent 125Iodine real-time ultrasound-guided low-dose rate BT to a total dose of 160 Gy for low-risk or favorable intermediate-risk prostate adenocarcinoma, and were followed prospectively during 3 years. Median age was 63 years (51-79). The post-implant dosimetric parameters on the postoperative computer tomography were derived from the dose-volume histogram of the prostate and the penile bulb (PB), crura, neurovascular bundles (NVBs) and internal pudendal arteries (IPAs). Potential clinical confounding factors were collected. Additionally, anatomical indexes reflecting the prostate anatomical location within the pelvis were studied. These variables were compared between patients with and without 3yED. 3yED was defined as an IIEF-5 score change to the lower category between baseline, with or without medication. Results: The 3yED rate was 59% (62% maintained an IIEF-5 > 16). On multivariate analysis, prostate D90% (p > .5) and pretreatment characteristics including age (p > .5), pre-implant potency (p > .5), diabetes (p = .08) and high cardiovascular risk rates (p = .1) did not influence the occurrence of 3yED. Only the PB dose especially the D10% > 51 Gy was associated with 3yED (p = .005). Conversely, dose to the crura, IPAs or NVBs did not seem to impact the erectile function. The prostate position, especially the apex location varied significantly between potent and impotent patients and 3yED was significantly associated with close position of the prostate apex to PB (p = .008). Conclusion: The most predictive factor of 3yED was the dose to the PB. This may be explained by variation in individual patients' anatomy and this could allow for the development of better strategies to prevent ED.

Long-term Patient-reported Clinical Outcomes and Reoperation Rate after Photovaporization with the XPS-180W GreenLight Laser.

OBJECTIVE: To evaluate the long-term reported clinical outcomes after photovaporization of the prostate (PVP) with the XPS-GreenLight laser in patients with symptomatic benign prostatic enlargement (BPE). DESIGN, SETTING, AND PARTICIPANTS: A prospective longitudinal study was performed for all consecutive patients with BPE who underwent PVP at our institution between 2010 and 2012. Patient-reported clinical outcomes were assessed at 1 mo, 3 mo, 12 mo, and 57 mo using International Prostate Symptoms Score, International Continence Society, and International Index of Erectile Function short-form questionnaires. Maximum flow rate (Qmax), postvoid residual urine measurements were assessed at 3 mo and 12 mo. Long-term satisfaction, complications, and reoperation rates were assessed by questionnaires. Prostate-specific antigen was measured at 3 mo, 12 mo, and 57 mo. INTERVENTION: A single surgeon (GF) has practiced photovaporization with a Moxy fiber, under transrectal ultrasonography monitoring. Long-term clinical outcomes were evaluated using questionnaires. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary measurement was the reoperation. RESULTS AND LIMITATIONS: Eighty-four patients of 102 answered the long-term questionnaire. The mean age was 68±7.2 yr. The mean follow-up was 57.4±6.8 mo. The mean prostate volume was 73±38ml. After treatment, the mean International Prostate Symptoms Score decreased significantly from 19.9±6.4 to 6.1±5.6, 3.9±3.4, and 5.9±5.8, respectively, at 3 mo, 12 mo, and 57 mo. The mean prostate-specific antigen level decreased significantly (-56%) from 4.5±4.3ng/ml preoperatively to 2.0±2.0ng/ml and 2.6±2.2ng/ml, respectively, at 12 mo and 57 mo. The mean Qmax increased from 9.6±3.8ml/s preoperatively to 23.9±11.5ml/s and 25.2±9.2ml/s, respectively, at 3 mo and 12 mo. Overall reoperation rate was 4.8%(4/84). Limitations include the single surgeon single center design study and the lack of long-term objectives data such as urodynamic parameters (postvoid residual urine and Qmax). CONCLUSIONS: Photovaporization of the prostate with the XPS-GreenLight laser is an effective technique able to durably improve reported clinical outcomes in patients with BPE. PATIENT SUMMARY: In this study we looked at the long-term outcomes after laser therapy with XPS-GreenLight laser for benign prostatic enlargement. We found a few reoperation rates and good stable reported clinical outcomes after a mean follow-up of 57 mo. We conclude that this laser technique can offer durably good reported clinical outcomes.

Prostate Volume Segmentation in TRUS Using Hybrid Edge-Bhattacharyya Active Surfaces.

OBJECTIVE: We present a new hybrid edge and region-based parametric deformable model, or active surface, for prostate volume segmentation in transrectal ultrasound (TRUS) images. METHODS: Our contribution is threefold. First, we develop a new edge detector derived from the radial bas-relief approach, allowing for better scalar prostate edge detection in low contrast configurations. Second, we combine an edge-based force derived from the proposed edge detector with a new region-based force driven by the Bhattacharyya gradient flow and adapted to the case of parametric active surfaces. Finally, we develop a quasi-automatic initialization technique for deformable models by analyzing the profiles of the proposed edge detector response radially to obtain initial landmark points toward which an initial surface model is warped. RESULTS: We validate our method on a set of 36 TRUS images for which manual delineations were performed by two expert radiation oncologists, using a wide variety of quantitative metrics. The proposed hybrid model achieved state-of-the-art segmentation accuracy. CONCLUSION: Results demonstrate the interest of the proposed hybrid framework for accurate prostate volume segmentation. SIGNIFICANCE: This paper presents a modular framework for accurate prostate volume segmentation in TRUS, broadening the range of available strategies to tackle this open problem.

Evaluation of the "Quadrella" at 3 years: New index to assess functional and oncological performance specific to prostate brachytherapy.

PURPOSE: "Quadrella" index has been recently developed to assess oncological and functional outcomes after prostate brachytherapy (PB). We aimed to evaluate this index at 1, 2, and 3 years, using validated questionnaires, assessed prospectively. METHODS AND MATERIALS: From 08/2007 to 01/2013, 193 patients underwent 125Iodine PB for low-risk or favorable intermediate-risk prostate adenocarcinoma. Inclusion criteria were as follows: no incontinence (International Continence Society Index initial score = 0) and good erectile function (International Index of Erectile Function-5 items: >16). One hundred patients were included (mean age: 64 y). Postimplantation intake of phosphodiesterase inhibitors was not considered as failure. The "Quadrella" index was defined by the absence of biochemical recurrence (Phoenix criteria), significant erectile dysfunction (ED) (Index of Erectile Function-5 items: >16), urinary toxicity (UT) (International Prostate Score Symptom [IPSS] <15 or IPSS> 15 with ΔIPSS <5), and rectal toxicity (RT) (Radiation Therapy Oncology Group = 0). RESULTS: At 12 months, 90 patients were evaluable: 42/90 (46.7%) achieved Quadrella. The main criteria for failure were as follows: ED in 77.1% (37/48) of cases, RT in 20.8% (10/48) of cases, and UT in 12.5% (9/57) of cases. At 24 and 36 months, 59.3% (48/81) and 61.1% (44/72) of patients achieved Quadrella, respectively. The main cause of failure was ED in 69.7% (23/33) and 85.7% (24/28) of cases, while RT was involved in 21.2% (7/33) and in 3.6% (1/28) of cases, and UT in 9.1% (3/33) and 3.6% (1/28) of cases. Only one case of biochemical recurrence was observed (i.e., 1/28 = 3.6% at 3 y). CONCLUSIONS: The Quadrella can be used at 1, 2, and 3 years after PB. It allows to take into account the urinary and RT specific to PB. ED was the main cause of failure. This index will be useful to assess midterm and long-term results.

The combination of targeted and systematic prostate biopsies is the best protocol for the detection of clinically significant prostate cancer.

OBJECTIVE: Compared with standard systematic transrectal ultrasound (TRUS)-guided biopsies (SBx), targeted biopsies (TBx) using magnetic resonance imaging (MRI)/TRUS fusion could increase the detection of clinically significant prostate cancer (PCa-s) and reduce non-significant PCa (PCa-ns). This study aimed to compare the performance of the two approaches. MATERIALS AND METHODS: A prospective, single-center study was conducted on all consecutive patients with PCa suspicion who underwent prebiopsy multiparametric MRI (mpMRI) using the Prostate Imaging Reporting and Data System (PI-RADS). All patients underwent mpMRI/TRUS fusion TBx (two to four cores/target) using UroStation™ (Koelis, Grenoble, France) and SBx (10-12 cores) during the same session. PCa-s was defined as a maximal positive core length ≥4 mm or Gleason score ≥7. RESULTS: The study included 191 patients (at least one suspicious lesion: PI-RADS ≥3). PCa was detected in 55.5% (106/191) of the cases. The overall PCa detection rate and the PCa-s detection rate were not significantly higher in TBx alone versus SBx (44.5% vs 46.1%, p = .7, and 38.2% vs 33.5%, p = .2, respectively). Combined TBx and SBx diagnosed significantly more PCa-s than SBx alone (45% vs 33.5%, p = .02). PCa-s was detected only by TBx in 12% of cases (23/191) and only by SBx in 7.3% (14/191). Gleason score was upgraded by TBx in 16.8% (32/191) and by SBx in 13.6% (26/191) of patients (p = .4). CONCLUSIONS: The combination of TBx and SBx achieved the best results for the detection and prognosis of PCa-s. The use of SBx alone would have missed the detection of PCa-s in 12% of patients.

Target definition in salvage postoperative radiotherapy for prostate cancer: 18F-fluorocholine PET/CT assessment of local recurrence.

PURPOSE: Inadequate clinical target volume (CTV) definition is likely to be a major contributing factor to local recurrence (LR) rate after radiotherapy. Our aims were to identify sites of prostate cancer LR in biochemical recurrence post-prostatectomy using 18F-Fluorocholine (18F-FCH) positron emission tomography/computed tomography (PET/CT) and to compare different CTV-delineation guidelines in a cohort of postoperative patients. MATERIAL AND METHODS: Thirty-six patients presenting with LR within the prostatic bed on 18F-FCH PET/CT between 10/2011 and 06/2016 were included in this retrospective study. Median PSA at the time of 18F-FCH PET/CT was 2.7 ng/mL (0.8-9.4) and median PSA doubling time was 11 months (3-28). For each patient, the CTVRTOG, CTVFROGG and CTVEORTC following the corresponding guidelines were outlined and compared. Forty-one LR were delineated using a gradient-based method and the percentage of FCH uptake included in each CTV was evaluated. RESULTS: The anastomosis was the most common recurrence site (52.8%), followed by the retrovesical region (31.7%) and the bladder neck (7%). The median SUV max value was 4.8 (2.3-16.1). The percentage of LR entirely included in the CTVRTOG was not significantly different from that included in the CTVFROGG (84% versus 83%, p = .5). Significantly more recurrences were included in the CTVRTOG volume compared to the CTVEORTC (84% versus 68%, p=.006), due to a better coverage of the bladder neck and retrovesical regions. Six out of 10 relapses occurring in the posterior region of the anastomosis were not covered by any of the CTVs. CONCLUSIONS: In our study, the CTVRTOG and CTVFROGG ensured the best coverage of LR seen on 18F-FCH PET/CT. When outlining the prostatic fossa, greater coverage of the posterior vesico-urethral region may allow better coverage of potential microscopic disease.

Fully automatic deformable registration of pretreatment MRI/CT for image-guided prostate radiotherapy planning.

PURPOSE: In prostate radiotherapy, dose distribution may be calculated on CT images, while the MRI can be used to enhance soft tissue visualization. Therefore, a registration between MR and CT images could improve the overall treatment planning process, by improving visualization with a demonstrated interobserver delineation variability when segmenting the prostate, which in turn can lead to a more precise planning. This registration must compensate for prostate deformations caused by changes in size and form between the acquisitions of both modalities. METHODS: We present a fully automatic MRI/CT nonrigid registration method for prostate radiotherapy treatment planning. The proposed registration methodology is a two-step registration process involving both a rigid and a nonrigid registration step. The registration is constrained to volumes of interest in order to improve robustness and computational efficiency. The method is based on the maximization of the mutual information in combination with a deformation field parameterized by cubic B-Splines. RESULTS: The proposed method was validated on eight clinical patient datasets. Quantitative evaluation, using Hausdorff distance between prostate volumes in both images, indicated that the overall registration errors is 1.6 ± 0.2 mm, with a maximum error of less than 2.3 mm, for all patient datasets considered in this study. CONCLUSIONS: The proposed approach provides a promising solution for an effective and accurate prostate radiotherapy treatment planning since it satisfies the desired clinical accuracy.

Correlation between prostate volume and single nucleotide polymorphisms implicated in the steroid pathway.

OBJECTIVES: A few preliminary studies have suggested a link between some genetics variants and benign prostatic hyperplasia (BPH). Our goal was to study the link between a set of single nucleotide polymorphisms (SNPs) implicated in the steroid pathway and accurate measurement of prostate volume in a cohort of men who underwent radical prostatectomy. METHODS: Clinical and pathological data including prostate weight were obtained from 611 Caucasian patients with small volume, localized prostate cancer treated by radical prostatectomy. Patients were genotyped for 90 SNPs located inside or nearby genes implicated in the steroid pathway (Sequenom iPLEX). Correlation between prostate weight and genotypes from each SNP was studied by analysis of covariance, adjusted on age and tumor stage. A Bonferroni correction was applied, and the SNPs implicated were then incorporated in a multivariable model. RESULTS AND LIMITATIONS: Seven SNPs located in or nearby genes implicated in steroid hormone metabolism were significantly associated with prostate volume: HSD17B2 (rs1119933), ESR2 (rs8006145), SULT2B1 (rs279451), NQO1 (rs2917670), ESR1 (rs1569788), GSTP1 (rs1138272), and CYP19A1 (rs17523880). Significant association was maintained after multivariate analysis for four SNPs, indicating their independent association with prostate volume. The power of the association of each SNP with prostate volume was comparable to the effect of age. The strongest associations were found with variants in ESR1, ESR2, HSD17B2, and CYP19A1 genes, indicating a potential role of the estrogen signaling pathway in genesis of BPH. CONCLUSIONS: Our results are in favor of an implication of estrogen biotransformation and signaling pathways in the pathophysiology of BPH.