Geotemporal Fluorophore Biodistribution Mapping of Colorectal Cancer: Micro and Macroscopic Insights.

Fluorescence-guided oncology promises to improve both the detection and treatment of malignancy. We sought to investigate the temporal distribution of indocyanine green (ICG), an exogenous fluorophore in human colorectal cancer. This analysis aims to enhance our understanding of ICG's effectiveness in current tumour detection and inform potential future diagnostic and therapeutic enhancements. METHODS: Fifty consenting patients undergoing treatment for suspected/confirmed colorectal neoplasia provided near infrared (NIR) video and imagery of transanally recorded and ex vivo resected rectal lesions following intravenous ICG administration (0.25 mg/kg), with a subgroup providing tissue samples for microscopic (including near infrared) analysis. Computer vision techniques detailed macroscopic 'early' (<15 min post ICG administration) and 'late' (>2 h) tissue fluorescence appearances from surgical imagery with digital NIR scanning (Licor, Lincoln, NE, USA) and from microscopic analysis (Nikon, Tokyo, Japan) undertaken by a consultant pathologist detailing tissue-level fluorescence distribution over the same time. RESULTS: Significant intra-tumoural fluorescence heterogeneity was seen 'early' in malignant versus benign lesions. In all 'early' samples, fluorescence was predominantly within the tissue stroma, with uptake within plasma cells, blood vessels and lymphatics, but not within malignant or healthy glands. At 'late' stage observation, fluorescence was visualised non-uniformly within the intracellular cytoplasm of malignant tissue but not retained in benign glands. Fluorescence also accumulated within any present peritumoural inflammatory tissue. CONCLUSION: This study demonstrates the time course diffusion patterns of ICG through both benign and malignant tumours in vivo in human patients at both macroscopic and microscopic levels, demonstrating important cellular drivers and features of geolocalisation and how they differ longitudinally after exposure to ICG.

Acute colonic pseudo-obstruction post-cesarean section is not a benign entity: A case series and review of the literature.

Acute colonic pseudo-obstruction (ACPO) is an infrequent occurrence after cesarean section. Anecdotal evidence suggests that the clinical course of ACPO in the obstetric setting is different to that seen in non-pregnant adult patients with ACPO secondary to alternative causes, such as systemic illnesses, the use of certain medications, and after non-abdominal surgery. The risk of progression to ischemia and perforation, as well as the need for emergency surgery, appears to be higher after cesarean section. Here we describe the clinical course of ACPO in four patients after cesarean section from our institution, followed by a review of the literature and a discussion of the important issues surrounding this condition in the postpartum time period. The findings from our cohort of patients and the reports from the medical literature support a hands-on combined approach from a group of specialists including obstetricians, surgeons, radiologists, and enterostomal therapists. Immediate imaging followed by regular observation is mandatory for any patient being managed conservatively. Early use of endoscopic decompression should be considered for patients who are not resolving with a conservative approach. Clinical signs of peritonism or radiological signs of ischemia or perforation in patients with ACPO mandate immediate surgical intervention. Appropriate postoperative care is necessary to deal with the complex physiological and psychological consequences of emergency surgery and potential stoma formation so soon after cesarean section.

Real-time administration of indocyanine green in combination with computer vision and artificial intelligence for the identification and delineation of colorectal liver metastases.

Introduction: Fluorescence guided surgery for the identification of colorectal liver metastases (CRLM) can be better with low specificity and antecedent dosing impracticalities limiting indocyanine green (ICG) usefulness currently. We investigated the application of artificial intelligence methods (AIM) to demonstrate and characterise CLRMs based on dynamic signalling immediately following intraoperative ICG administration. Methods: Twenty-five patients with liver surface lesions (24 CRLM and 1 benign cyst) undergoing open/laparoscopic/robotic procedures were studied. ICG (0.05 mg/kg) was administered with near-infrared recording of fluorescence perfusion. User-selected region-of-interest (ROI) perfusion profiles were generated, milestones relating to ICG inflow/outflow extracted and used to train a machine learning (ML) classifier. 2D heatmaps were constructed in a subset using AIM to depict whole screen imaging based on dynamic tissue-ICG interaction. Fluorescence appearances were also assessed microscopically (using H&E and fresh-frozen preparations) to provide tissue-level explainability of such methods. Results: The ML algorithm correctly classified 97.2 % of CRLM ROIs (n = 132) and all benign lesion ROIs (n = 6) within 90-s of ICG administration following initial mathematical curve analysis identifying ICG inflow/outflow differentials between healthy liver and CRLMs. Time-fluorescence plots extracted for each pixel in 10 lesions enabled creation of 2D characterising heatmaps using flow parameters and through unsupervised ML. Microscopy confirmed statistically less CLRM fluorescence vs adjacent liver (mean ± std deviation signal/area 2.46 ± 9.56 vs 507.43 ± 160.82 respectively p < 0.001) with H&E diminishing ICG signal (n = 4). Conclusion: ML accurately identifies CRLMs from surrounding liver tissue enabling representative 2D mapping of such lesions from their fluorescence perfusion patterns using AIM. This may assist in reducing positive margin rates at metastatectomy and in identifying unexpected/occult malignancies.

Regressed testicular germ cell tumour in a post-pubertal male.

Testicular germ cell regression is a rare, generally metastatic phenomenon which describes the spontaneous, complete, or partial regression of a testicular germ cell tumour. As a result, studies have focused on defining specific histopathological criteria to establish if the resected testis is the primary source of the germ cell tumour. There are few publications which describe its presentation in the absence of distant metastases with elevated tumour markers and suspicious findings on testicular ultrasound. We present the clinical presentation and radiological features of a non-metastatic regressed testicular germ cell tumour following scrotal trauma in a post pubertal male.