Subnodal Correspondence of PSMA Expression and USPIO-MRI in Metastatic Pelvic Lymph Nodes in Prostate Cancer.

OBJECTIVES: Two advanced imaging modalities used to detect lymph node (LN) metastases in prostate cancer patients are prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography and ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI). As these modalities use different targets, a subnodal comparison is needed to interpret both their correspondence and their differences. The aim of this explorative study was to compare ex vivo 111In-PSMA µSPECT images with high-resolution 7 T USPIO µMR images and histopathology of resected LN specimens from prostate cancer patients to assess the degree of correspondence at subnodal level. MATERIALS AND METHODS: Twenty primary prostate cancer patients who underwent pelvic LN dissection were included and received USPIO contrast and 111In-PSMA. A total of 41 LNs of interest (LNOIs) were selected for ex vivo imaging based on γ-probe detection or palpation. µSPECT and µMRI acquisition were performed immediately after resection. Overlay of µSPECT images on MR images was performed, and the level of correspondence (LoC) between µSPECT and µMR findings was assessed according to a 4-point Likert classification scheme. RESULTS: Forty-one LNOIs could be matched to an LN on ex vivo µMRI. Coregistration of µSPECT and USPIO-enhanced water-selective multigradient echo MR images was successful for all 41 LNOIs. Ninety percent of the lesions showed excellent correspondence regarding the presence of metastatic tissue and affected subnodal site (LoC 4; 37/41). In only 1 of 41 LNOIs, a small metastasis was misclassified by both techniques. Three LNOIs were classified as LoC 3 (7%) and 1 LNOI as LoC 2. All LoC 2 and LoC 3 lesions had PSMA-expressing metastases on final histopathology. CONCLUSIONS: Coregistration of µSPECT and USPIO-µMRI showed excellent subnodal correspondence in the majority (90%) of LNs. Ex vivo imaging may thus help localize small cancer deposits within resected LNs and could contribute to improved interpretation of in vivo imaging of LNs.

An Updated Systematic Review on Focal Therapy in Localized Prostate Cancer: What Has Changed over the Past 5 Years?

CONTEXT: Focal therapy is a promising, minimally invasive strategy to selectively treat localized prostate cancer. A previous systematic review indicated that there is growing evidence for favorable functional outcomes, but that oncological effectiveness was yet to be defined. OBJECTIVE: To assess the effectiveness of focal therapy in patients with localized prostate cancer in terms of functional and oncological outcomes. EVIDENCE ACQUISITION: PubMed, Embase, and The Cochrane Library were searched for studies between October 2015 and December 31, 2020. In addition, the research stages were acquired according to the Idea, Development, Exploration, Assessment, Long-term study (IDEAL) recommendations. Ongoing studies were identified through clinical trial registries. EVIDENCE SYNTHESIS: Seventy-two studies were identified exploring eight different sources of energy to deliver focal therapy in 5827 patients. Twenty-seven studies reported on high-intensity focused ultrasound (HIFU), nine studies on irreversible electroporation, 11 on cryoablation, eight on focal laser ablation and focal brachytherapy, seven on photodynamic therapy (PDT), two on radiofrequency ablation, and one on prostatic artery embolization. The majority of studies were prospective development stage 2a studies (n = 357). PDT and HIFU, both in stage 3, showed promising results. Overall, HIFU studies reported a median of 95% pad-free patients and a median of 85% patients with no clinically significant cancer (CSC) in the treated area. For PDT, no changes in continence were reported and a median of 90% of patients were without CSC. Both treatments were well tolerated. CONCLUSIONS: Over the past 5 yr, focal therapy has been studied for eight different energy sources, mostly in single-arm stage 2 studies. Although a first randomized controlled trial in focal therapy has been performed, more high-quality evaluations are needed, preferably via multicenter randomized controlled trials with long-term follow-up and predefined assessment of oncological and functional outcomes and health-related quality-of-life measures. PATIENT SUMMARY: Focal treatment (FT) of prostate cancer has potential, considering that it has less impact on continence and potency than radical treatment. Our systematic review indicates that despite the method being studied extensively over the past half decade, the majority of studies remain in an early research stage. The techniques high-intensity focused ultrasound and photodynamic therapy have shown most progression toward advanced research stages and show favorable results. However, more high-quality evidence is required before FT can become available as a standard treatment.

How can robot-assisted surgery provide value for money?

OBJECTIVES: To develop an interactive tool that estimates what potential benefits are needed for the robot to provide value for money when compared with endoscopic or open surgical interventions. DESIGN: A generic online interactive tool was developed to analyze the (health) effects needed to compensate for the additional costs of using a surgical robotic system from a healthcare perspective. The application of the tool is illustrated with a hypothetical new surgical robotic platform. A synthesis of evidence from different sources was used combined with interviews with surgeons. SETTING: Flexible tool that can be adapted to flexible settings. PARTICIPANTS: Any hospital patient group for which robotic, endoscopic or open surgical procedures may be considered as appropriate treatment alternatives (eg, urology, gynecology, and so on). INTERVENTION: Robotically assisted surgical interventions. COMPARATOR: Endoscopic or open surgical interventions. MAIN OUTCOME MEASURES: Thresholds of how much (health) effect is needed for robot-assisted surgery to provide value for money and to become cost-effective. RESULTS: The utilization rate of the surgical robotic system and a reduction in complications appeared to be important aspects in determining the value for money. To become cost-effective, it was deemed important for new surgical robotic systems to have added clinical benefit and become less costly than the current system. CONCLUSIONS: This paper and its assisting interactive tool can be used by clinicians, researchers, and policymakers to gain insight in the benefit needed to provide value for money when using a (new) surgical robotic system or, when the effects are known or can be estimated, to assess the value for money for a specific indication. For robotic surgery to provide most value for money, we recommend assessing for each indication whether the necessary effects seem achievable.

Prior PSMA PET-CT Imaging and Hounsfield Unit Impact on Tumor Yield and Success of Molecular Analyses from Bone Biopsies in Metastatic Prostate Cancer.

Developing and optimizing targeted therapies in metastatic castration-resistant prostate cancer (mCRPC) necessitates molecular characterization. Obtaining sufficient tumor material for molecular characterization has been challenging. We aimed to identify clinical and imaging variables of imaging-guided bone biopsies in metastatic prostate cancer patients that associate with tumor yield and success in obtaining molecular results, and to design a predictive model: Clinical and imaging data were collected retrospectively from patients with prostate cancer who underwent a bone biopsy for histological and molecular characterization. Clinical characteristics, imaging modalities and imaging variables, were associated with successful biopsy results. In our study, we included a total of 110 bone biopsies. Histological conformation was possible in 84 of all biopsies, of which, in 73 of the 84, successful molecular characterization was performed. Prior use of PSMA PET-CT resulted in higher success rates in histological and molecular successful biopsies compared to CT or MRI. Evaluation of spine biopsies showed more often successful results compared to other locations for both histological and molecular biopsies (p = 0.027 and p = 0.012, respectively). Low Hounsfield units (HUs) and deviation (Dev), taken at CT-guidance, were associated with histological successful biopsies (p = 0.025 and p = 0.023, respectively) and with molecular successful biopsies (p = 0.010 and p = 0.006, respectively). A prediction tool combining low HUs and low Dev resulted in significantly more successful biopsies, histological and molecular (p = 0.023 and p = 0.007, respectively). Based on these results, we concluded that site selection for metastatic tissue biopsies with prior PSMA PET-CT imaging improves the chance of a successful biopsy. Further optimization can be achieved at CT-guidance, by selection of low HU and low Dev lesions. A prediction tool is provided to increase the success rate of bone biopsies in mCRPC patients, which can easily be implemented in daily practice.

Multiparametric magnetic resonance imaging and follow-up to avoid prostate biopsy in 4259 men.

OBJECTIVE: To determine the proportion of men avoiding biopsy because of negative multiparametric magnetic resonance imaging (mpMRI) findings in a prostate MRI expert centre, and to assess the number of clinically significant prostate cancers (csPCa) detected during follow-up. PATIENTS AND METHODS: Retrospective study of 4259 consecutive men having mpMRI of the prostate between January 2012 and December 2017, with either a history of previous negative transrectal ultrasonography-guided biopsy or biopsy naïve. Patients underwent mpMRI in a referral centre. Lesions were classified according to Prostate Imaging Reporting And Data System (PI-RADS) versions 1 and 2. Negative mpMRI was defined as an index lesion PI-RADS ≤2. Follow-up until 13 October 2018 was collected by searching the Dutch Pathology Registry (PALGA). Gleason score ≥3 + 4 was considered csPCa. Kaplan-Meier analysis and univariable logistic regression models were used in the cohort of patients with negative mpMRI and follow-up. RESULTS: Overall, in 53.6% (2281/4259) of patients had a lesion classified as PI-RADS ≤2. In 320 patients with PI-RADS 1 or 2, follow-up mpMRI was obtained after a median (interquartile range) of 57 (41-63) months. In those patients, csPCa diagnosis-free survival (DFS) was 99.6% after 3 years. Univariable logistic regression analysis revealed age as a predictor for csPCa during follow-up (P < 0.05). In biopsied patients, csPCa was detected in 15.8% (19/120), 43.2% (228/528) and 74.5% (483/648) with PI-RADS 3, 4 and 5, respectively. CONCLUSION: More than half of patients having mpMRI of the prostate avoided biopsy. In those patients, csPCa DFS was 99.6% after 3 years.