Objectives: To systematically assess the current available literature concerning advanced optical imaging methods for the detection and diagnosis of bladder cancer (BCa), focusing particularly on the sensitivity and specificity of these techniques. Methods: First a scoping search was performed to identify all available optical techniques for BCa detection and diagnosis. The optical imaging techniques used for detecting BCa are: the Storz professional image enhancement system (IMAGE1 S), narrow‐band imaging (NBI), photoacoustic imaging (PAI), autofluorescence imaging (AFI), photodynamic diagnosis (PDD), and scanning fibre endoscopy (SFE). The staging and grading techniques for BCa are: optical coherence tomography (OCT), confocal laser endomicroscopy (CLE), Raman spectroscopy, endocytoscopy, and non‐linear optical microscopy (NLO). Then a systematic literature search was conducted using MEDLINE, EMBASE and Web of Science from inception to 21 November 2023. Articles were screened and selected by two independent reviewers. Inclusion criteria were: reporting on both the sensitivity and specificity of a particular technique and comparison to histopathology, and in the case of a detection technique comparison to white light cystoscopy (WLC). Results: Out of 6707 articles, 189 underwent full‐text review, resulting in 52 inclusions. No articles met criteria for IMAGE1 S, PAI, SFE, Raman spectroscopy, and endocytoscopy. All detection techniques showed higher sensitivity than WLC, with NBI leading (87.8–100%). Overall, detection technique specificity was comparable to WLC, with PDD being most specific (23.3–100%). CLE and OCT varied in sensitivity and specificity, with OCT showing higher specificity for BCa diagnosis, notably for carcinoma in situ (97–99%) compared to CLE (62.5–81.3%). NLO demonstrated high sensitivity and specificity (90–97% and 77–100%, respectively) based on limited data from two small ex vivo studies. Conclusions: Optical techniques with the most potential are PDD for detecting and OCT for staging and grading BCa. Further research is crucial to validate their integration into routine practice and explore the value of other imaging techniques.

State-of-the-art research in bladder cancer (BC) diagnosis is being driven by advances in optical technologies, biomarker discovery, non-invasive imaging, and the integration of artificial intelligence into clinical workflows. The goal is to detect BC earlier, more accurately, and with fewer invasive procedures. Our viewpoint is that research and development of optics and photonics will be key to improving outcomes for patients.

Radical cystectomy is the recommended treatment in muscle-invasive bladder cancer patients with hydronephrosis. However, there is no literature on the impact of chemoradiotherapy on pre-existing hydronephrosis or the development of new hydronephrosis. This study aims to assess the incidence, aetiology, and management of hydronephrosis before and after chemoradiotherapy (CRT). Retrospective cohort study, including patients with muscle-invasive bladder cancer (MIBC) treated with CRT between 1 January 2014 and 5 December 2022. Patients with urethral urothelial carcinoma and with stage T1 were included if they received total bladder irradiation. Exclusion criteria were renal transplantation, ureteral reimplantation, sequential chemotherapy and radiotherapy, CRT as preoperative treatment, urinary diversion before CRT, transitioning to palliative radiotherapy, and sarcomatoid or signet ring cell carcinoma type. Patients were also excluded if no follow-up data was available. In this period 181 patients received CRT, after applying the exclusion criteria a total of 146 patients were eligible for evaluation. The main outcome was hydronephrosis, defined as any grade of dilatation of the renal pelvis with or without ureter dilatation, identified on any form of imaging. 146 patients were included, 27 with pre-existing hydronephrosis before CRT and 119 without. The mean age of the patients was 73 years (Standard deviation (SD): 8.59) and 74% was male. Hydronephrosis in patients with pre-existing hydronephrosis persisted after CRT in 74% (n = 20), with 44% (n = 12) receiving drainage. Of the patients without pre-existing hydronephrosis, 21% (n = 25) developed hydronephrosis, and 52% (n = 13) of the patients that developed hydronephrosis required drainage. Tumour was responsible for pre-existing hydronephrosis in 93% (n = 25) and for hydronephrosis after CRT in 22% (n = 6) with pre-existing hydronephrosis. In patients without pre-existing hydronephrosis, hydronephrosis was caused by a tumour in 11 out of 25 patients. Pre-existing hydronephrosis persists after CRT for MIBC in ~ 75% of patients and ~ 20% of patients without pre-existing hydronephrosis develops hydronephrosis after CRT. Around half of these patients receive drainage. These findings may assist in counselling patients with pre-existing hydronephrosis regarding the potential outcomes following CRT.

A technique that enables real-time diagnosis of bladder cancer is needed. Optical coherence tomography (OCT) is a promising technique, but a forward-looking OCT catheter is necessary for OCT to enable bladder cancer diagnosis. This study aims to describe the design of a novel forward-looking microelectromechanical systems (MEMS)-based OCT catheter, assess the performance characteristics, and evaluate its ability to identify histopathological characteristics of bladder specimens. A description of the OCT catheter and systems used is provided. Performance characteristics were measured with a beam profiler and microscopy slide (mirror for dispersion and thickness for lateral calibration). Ex vivo measurements were performed on resected bladder tissue from patients undergoing a radical cystectomy. A forward-looking OCT probe with an outer diameter of 2.52 mm and a rigid length of 17 mm was designed and evaluated. The focus position was measured as 10.9 mm from the MEMS mirror, with a Rayleigh length of 2.55 mm. Several histopathological features could be correlated to OCT features of the ex vivo measurements. In conclusion, a forward-looking OCT probe that can be inserted in the working channel of a rigid cystoscope was designed and evaluated. Performance characteristics were overall in line with simulated expectations.

Objectives: To evaluate the effect of metformin on non‐muscle‐invasive bladder cancer (NMIBC) marker lesions. Patients and methods: A phase II, open‐label, multicentre, marker lesion trial using oral metformin in patients with primary or recurrent, multiple, low‐grade Ta‐T1 NMIBC was conducted. After transurethral resection for histological confirmation, leaving one tumour as a marker lesion, 11 patients were treated with oral metformin up to 3000 mg per day for 3 months. Reported outcomes included response of the marker lesion, safety of metformin, quality of life and pharmacological and immunohistochemical examinations of the mechanism of action of metformin. Results: One complete response and one partial response were observed. In the other nine patients, the marker lesion remained, while five of these patients also developed new Ta low‐grade lesions. Diarrhoea grade ≤ 2 was the most common adverse event (AE), observed in nine out of 11 patients. No serious AEs related to study treatment occurred. Metformin concentrations in the urine were significantly higher than metformin levels in the blood. Immunohistochemical analysis before and after treatment showed no difference in expression of markers associated with the mechanism of metformin. Conclusion: We did not find conclusive evidence for the hypothesis of an antitumour effect of metformin in bladder cancer.