Naoto Kamiya

Endourological stone surgery frequently relies on intraoperative X-ray fluoroscopy for guidewire and access sheath placement, retrograde pyelography, stent positioning, and percutaneous renal access. Although radiation exposure from an uncomplicated procedure is usually limited, recurrent imaging and interventions contribute to cumulative patient exposure, and repeated procedures result in occupational exposure among operating-room personnel. This narrative review examines fluoroscopic workflows in ureteroscopy, retrograde intrarenal surgery, percutaneous nephrolithotomy, and endoscopic combined intrarenal surgery, with particular emphasis on dose metrics, determinants of exposure, and practical optimization. Readily implementable measures consistent with the as-low-as-reasonably-achievable (ALARA) principle include low-dose and pulsed fluoroscopy, reduced pulse rates, collimation, last-image hold, optimized C-arm geometry, protective equipment, dosimetry, feedback, and team training. Evidence also supports fluoroscopy-free or fluoroscopy-minimized ureteroscopy and retrograde intrarenal surgery in selected patients, as well as ultrasound-guided percutaneous nephrolithotomy, including hybrid ultrasound-fluoroscopy workflows. Endoscopically assisted puncture, three-dimensional reconstruction, image fusion, navigation, augmented reality, and computer vision span different stages of clinical maturity; AI-assisted dose optimization remains experimental and lacks endourology-specific clinical validation. Standardized multidimensional reporting of patient and staff dosimetry, evidence-based technology classification, and procedure- and complexity-specific benchmarks are needed. Prospective multicenter studies should evaluate integrated image-guided workflows using clinically relevant outcomes, including radiation dose, stone-free outcomes, complications, operative time, usability, and cost.

Prostate-specific membrane antigen (PSMA) has become a central molecular target in prostate cancer because it enables both high-performance imaging and targeted radioligand therapy. PSMA positron emission tomography/computed tomography (PET/CT) is now used across several clinical settings, including primary staging of higher-risk localized disease, localization of biochemical recurrence, salvage radiotherapy planning, and assessment of oligometastatic disease. In metastatic castration-resistant prostate cancer, PSMA-targeted radioligand therapy (RLT), particularly lutetium-177-labeled PSMA-617, has established therapeutic value and is moving into earlier disease states. From an applied science perspective, the clinical performance of PSMA theranostics depends not only on target expression and trial efficacy, but also on radiopharmaceutical design, radionuclide selection, radiochemical quality, PET acquisition and reconstruction, standardized reporting, dosimetry, and quantitative response assessment. This narrative review summarizes the biological, radiochemical, and technical foundations of PSMA theranostics, the clinical evidence supporting PSMA PET/CT in key disease states, and the pivotal data for PSMA-targeted RLT. It also discusses imaging-based treatment eligibility, dosimetry, post-therapy imaging, Response Evaluation Criteria in PSMA Imaging, and next-generation beta- and alpha-emitting platforms. PSMA theranostics should be understood as an integrated clinical and technological platform that links molecular imaging, treatment selection, radionuclide delivery, and longitudinal response assessment across the prostate cancer care pathway.

Systemic therapy for metastatic prostate cancer is increasingly defined by upfront intensification and biomarker-guided mechanism switching. This narrative review synthesizes pivotal randomized trials, guideline recommendations, and implementation-focused literature across metastatic castration-sensitive prostate cancer (mCSPC) and metastatic castration-resistant prostate cancer (mCRPC). Evidence was organized around decision points at mCSPC diagnosis and at mCRPC transition, while incorporating biological mechanisms of resistance, including AR-axis reactivation, AR splice variants, lineage plasticity, DNA repair–hormone signaling interactions, and PSMA expression heterogeneity. In mCSPC, androgen deprivation therapy plus docetaxel and/or androgen receptor signaling inhibitors (ARSIs) improves survival, with triplet regimens favored for selected chemotherapy-fit patients with aggressive de novo disease. In mCRPC, cross-resistance limits routine ARSI-to-ARSI switching, and randomized data support mechanism-distinct options, including taxanes, PARP-based therapy in homologous recombination repair (HRR)-altered disease, and PSMA-targeted radioligand therapy (RLT) in selected PSMA-positive patients. As RLT moves earlier, PSMA heterogeneity, renal function, bone marrow reserve, and emerging dosimetry-based optimization should inform practical implementation. Ongoing trials are evaluating earlier theranostics, alpha-emitting radioligands, and biomarker-enriched combinations. An implementation-first approach that intensifies treatment when appropriate, tests early and acts on HRR results, uses PSMA PET to guide RLT, and preserves hematologic reserve may maximize access to multiple life-prolonging mechanisms.

Precision medicine in prostate cancer (PCa) is increasingly best understood as a continuum linking risk-adapted detection, multimodal diagnosis and phenotyping, and implementation-ready decision pathways. Contemporary clinical guidelines emphasize structured diagnostic strategies, appropriate use of advanced imaging, and selective deployment of biomarkers when results can alter management. Upstream risk enrichment using polygenic risk scores and multivariable prediction models may improve the yield of clinically significant disease while mitigating harms related to overdiagnosis. At the point of suspicion, magnetic resonance imaging-first pathways and reflex biomarker testing provide practical tools to reduce unnecessary biopsy while maintaining safeguards for the detection of clinically important disease. Beyond diagnosis, prostate-specific membrane antigen positron emission tomography refines disease-state phenotyping in initial staging, biochemical recurrence, and limited-burden presentations, while standardized acquisition and reporting improve reproducibility and multidisciplinary communication. Germline and tumor-based molecular profiling should be operationalized as a longitudinal care process with clear consent, turnaround targets, and test-to-action rules that define what each result enables at specific decision nodes. Finally, longitudinal monitoring approaches, including liquid biopsy and artificial intelligence-enabled pathology, are evolving rapidly and require transparent reporting and rigorous risk-of-bias appraisal before broad clinical adoption. This narrative review synthesizes key evidence across the precision continuum and outlines a decision-node-based, test-to-action framework for maximizing clinical benefit, maintaining quality, and ensuring equitable access.

Urinary stone disease is common, recurrent, and increasingly managed through imaging-driven pathways, yet standard-dose CT of the kidneys, ureters, and bladder (CT KUB) raises concerns about cumulative radiation exposure and the limited use of quantitative imaging information for risk stratification. This review synthesizes contemporary evidence on dose-optimized CT, advanced spectral technologies, and artificial intelligence (AI)-enabled analytics that are reshaping diagnosis, treatment selection, and triage. This review summarizes data supporting low-dose and ultra-low-dose CT protocols that preserve diagnostic accuracy while substantially reducing dose, and discusses how dual-energy CT, photon-counting CT, and radiomics facilitate noninvasive stone characterization and extraction of imaging biomarkers beyond size and location. It also reviews AI approaches for automated detection, segmentation, and volumetric quantification across CT, KUB, and ultrasounds, highlighting their potential to standardize stone-burden metrics. It further examines predictive models, including logistic regression, nomograms, and machine learning, for perioperative infectious complications, emergency department admission or intervention, procedure success, and long-term recurrence, and outlines reporting and validation frameworks and implementation considerations, including software as a medical device regulation and human oversight. In contrast to prior reviews that consider imaging and AI separately, this review integrates dose reduction, spectral characterization, and AI-driven analytics within real-world clinical pathways to distinguish established clinical applications from those that remain investigational. Integrating advanced CT and AI outputs into well-validated prediction models embedded in real-world workflows may enable safer imaging, more consistent triage, and more personalized follow-up for urinary stone disease.

Taxane chemotherapy remains a durable backbone in advanced prostate cancer, but its clinical value is increasingly determined by timing, sequencing, and deliverability. We synthesize pivotal randomized trials and contemporary guidance to provide a chemotherapy-forward framework spanning metastatic castration-sensitive prostate cancer (mCSPC) and metastatic castration-resistant prostate cancer (mCRPC). In mCSPC, early docetaxel added to androgen deprivation therapy—often as part of triplet intensification with an androgen receptor pathway inhibitor (ARPI)—offers the greatest absolute benefit in fit patients with high disease burden or aggressive clinical tempo. In mCRPC, docetaxel remains foundational, while cabazitaxel is preferred over ARPI switching after prior docetaxel and one ARPI, supporting mechanism-based sequencing. Practical implementation requires proactive toxicity prevention (especially neutropenia), dose and schedule individualization, and preservation of functional status to maintain eligibility for subsequent life-prolonging therapies. Immunotherapy has a limited but important niche: sipuleucel-T may benefit selected patients with low symptom burden, whereas immune checkpoint inhibitors are best reserved for biomarker-defined subsets such as microsatellite instability-high or mismatch repair-deficient tumors; tumor mutational burden should be interpreted cautiously in prostate cancer. Ongoing trials and emerging antigen-directed platforms will clarify whether chemotherapy can act as an immune-enabling partner in defined settings.

Background: In high-risk non-muscle-invasive bladder cancer (NMIBC), adjuvant therapies, such as intravesical Bacillus Calmette–Guérin (BCG) instillation, are widely employed; however, BCG treatment poses challenges due to potential adverse effects and ongoing supply limitations. This study aimed to evaluate treatment patterns, therapeutic efficacy, incidence of adverse events, and clinical predictors of recurrence and progression in patients with high-grade pT1 urothelial carcinoma (HG-T1 UC) of the bladder. Methods: This retrospective cohort study included 204 patients diagnosed with HG-pT1 UC who underwent transurethral resection of bladder tumor (TURBT) at Toho University Sakura Medical Center between 2010 and 2021. Clinical data encompassing treatment modalities (BCG or intravesical chemotherapy), complications, and oncological outcomes were collected. Recurrence-Free Survival (RFS), Progression-Free Survival, and Cancer-Specific Survival were analyzed using Kaplan–Meier analyses and multivariate regression models. Results: Maintenance BCG therapy was significantly associated with prolonged RFS compared to other treatments, including among ‘very high-risk’ patients. However, 52.4% of patients receiving BCG maintenance experienced adverse events, with dose reductions required in 59% of cases. Notably, recurrence rates did not significantly differ based on dose reduction or the total number of BCG instillations. Tumor multiplicity emerged as an independent risk factor for recurrence. Conclusions: Although maintenance BCG therapy remains essential for managing HG-T1 UC, especially in high-risk patients, treatment should be individualized due to concerns about tolerability and availability. The study results support the importance of personalized strategies based on risk stratification as outlined in clinical guidelines for preventing recurrence in NMIBC.

Hereditary predisposition substantially shapes prevention and management across urologic oncology. This narrative review synthesizes contemporary, practice-oriented guidance on whom to test, what to test, how to act on results, and how to implement care equitably for hereditary forms of prostate cancer, renal cell carcinoma (RCC), urothelial carcinoma, pheochromocytoma/paraganglioma (PPGL), and adrenocortical carcinoma (ACC). We delineate between forms of indication-driven germline testing (e.g., universal testing in metastatic prostate cancer; early-onset, bilateral/multifocal, or syndromic RCC; reflex tumor mismatch repair (MMR)/microsatellite instability (MSI) screening in upper-tract urothelial carcinoma (UTUC); universal testing in PPGL; universal TP53 testing in ACC) and pair these strategies with minimum actionable gene sets and syndrome-specific surveillance frameworks. Key points include targeted prostate-specific antigen screening in BRCA2 carriers and the impact of BRCA/ATM variants on reclassification during active surveillance; major hereditary RCC syndromes with genotype-tailored surveillance and pathway-directed therapy (e.g., HIF-2α inhibition for von Hippel–Lindau disease); UTUC/bladder cancer in Lynch syndrome with tumor MMR/MSI screening, annual urinalysis (selective cytology), and immunotherapy opportunities in deficient MMR disease/MSI-H; PPGL management emphasizing universal germline testing, intensified surveillance for SDHB, cortical-sparing adrenalectomy, and emerging HIF-2α inhibition; and ACC care modified by Li–Fraumeni syndrome (minimization of radiation/genotoxic therapy with whole-body imaging surveillance). Testicular germ cell tumor remains largely polygenic, with no routine germline testing in typical presentations. Finally, we provide pre-/post-test genetic-counseling checklists and mainstreamed workflows with equity metrics to operationalize precision care and close real-world access gaps.

Lymphovascular invasion (LVI) is a potent yet underutilized prognostic marker in bladder cancer, particularly in non–muscle-invasive disease (NMIBC). We aimed to develop and internally validate a predictive nomogram to estimate the probability of LVI at initial transurethral resection of bladder tumors (TURBT), utilizing preoperative clinical parameters. In this retrospective cohort study, 413 patients with histologically confirmed urothelial carcinoma who underwent initial TURBT were included. LVI was identified histologically in 9.2% of cases. Univariate and multivariate logistic regression, in conjunction with the least absolute shrinkage and selection operator modeling, revealed eight significant predictors: papillary architecture, Box–Cox–transformed tumor size, urinary cytology classification, age ≥ 75 years, pedunculated morphology, gender, hydronephrosis, and tumor multiplicity. The resulting nomogram demonstrated excellent discriminative performance, with an AUC of 0.888 in the training cohort and 0.827 in the validation cohort, and exhibited good calibration based on weighted plots. This model facilitates individualized prediction of LVI using routinely available clinical data. Early detection of LVI may inform risk-adapted management strategies, including repeat resection, or intensified surveillance in patients with bladder cancer. The model complements existing predictive frameworks and can contribute to more personalized and effective bladder cancer care.

Background/Objectives: The therapeutic landscape of advanced or metastatic urothelial carcinoma (UC) has shifted from platinum chemotherapy to precision immuno-oncology. Immune checkpoint inhibitors (ICIs)—pembrolizumab, nivolumab, and avelumab—show efficacy across platinum-refractory, maintenance, and adjuvant settings, yet benefit is limited to subsets, underscoring the need for biomarkers. Antibody–drug conjugates (ADCs), notably enfortumab vedotin(EV), and targeted agents such as FGFR inhibitors further expand options. This review synthesizes current evidence and emerging paradigms to guide combinations and sequencing. Methods: We performed a narrative synthesis of peer-reviewed trials (emphasizing pivotal phase III studies), key translational investigations, and contemporary guidelines on ICIs, ADCs, HER2-directed therapies, FGFR inhibitors, molecular subtyping, and genomic profiling in UC, integrating efficacy signals, biomarker associations, and practical implications for sequencing. Results: ICIs now occupy multiple settings, but heterogeneous benefit highlights the importance of molecularly informed selection. EV alone and with pembrolizumab has produced unprecedented first-line activity, prompting a strategic shift. Molecular subtyping and genomic profiling delineate phenotypes with variable immune responsiveness and targetable vulnerabilities, enabling rational combinations and refined sequencing. Ongoing trials are evaluating next-generation ADCs, HER2-directed approaches, and dual checkpoint blockade to achieve durable, personalized disease control. Conclusions: Management of locally advanced or metastatic UC is converging on precision immuno-oncology, wherein biomarker-driven selection, molecular subtyping, and thoughtful sequencing of ICIs, ADCs, and targeted agents are central to optimizing outcomes. Active trials and translational advances are expected to refine personalized strategies and embed molecular guidance into routine care.