Objectives: To evaluate the physical properties of seven ureteroscopes (URSs) and compare the maximal angle of deflection (MAD) when used with flexible and navigable suction access sheaths (FANSs) of varying sizes. Materials and Methods: Seven commercial URSs (ranging from 6.3 to 9.5 F in size) were evaluated for outer diameter, irrigation flow rate, image resolution, colour reproduction and MAD. MAD was measured under three conditions: standalone URS deflection without the FANS; standard deflection of the FANS while positioned at the URS tip; and advanced FANS deflection, with the URS fully deflected beyond the FANS, and the FANS advanced. For each URS type, standalone deflection was repeated five times, and FANS deflections were repeated four times to calculate an average. FANS sizes of 10/12 F, 11/13 F and 12/14 F (ClearPetra) were tested. Results: The HugeMed URS had the smallest scope diameter (6.3 F) and the lowest flow (20 mL/min), while the Endoso URS had the highest flow (32 mL/min). All the URSs had similar resolutions except the MacroLux, Seegen and Endoso URSs, which were noticeably superior in this respect. Colour reproduction was best with the MacroLux and Endoso URSs. Without a FANS, the standalone mean MAD across all URS types was 293°. Standard deflection with FANS significantly decreased the MAD (up to a 49% reduction), whereas advanced deflection maintained the MAD (up to 269°). Larger FANS, especially the 12/14‐F size, tended to reduce deflection. The MacroLux URS maintained the highest MAD across all FANS sizes, followed by the Seegen and Urotech devices. Conclusion: Ureteroscope deflection significantly varied by model. Use of a FANS reduced deflection angles, especially with larger sheaths. However, advancing the FANS over a deflected scope preserved deflection angles. Overall, the MacroLux URS showed the best deflection with FANS, whereas the Seegen, Endoso and Urotech URSs showed a balance between flow rate, optics and deflection. These findings could inform clinicians in their selection of a URS for endourology procedures.

Stereotactic ablative radiotherapy (SABR) has revolutionized the management of patients with oligometastatic and selected primary cancers due to its ability to deliver highly conformal, high-dose radiation in few fractions with minimal toxicity. However, the biological heterogeneity among patients treated with SABR results in variable outcomes, emphasizing the need for predictive and prognostic biomarkers to guide patient selection and post-treatment management. This narrative review discusses the current landscape of biomarker development in the context of SABR across tumor types. Key classes include circulating tumor DNA (ctDNA), extracellular vesicles (EVs), radiomic features, and immunological markers. We highlight the role of each biomarker category in refining therapeutic approaches, their integration into ongoing clinical trials, and future directions for personalized SABR paradigms. Translating these promising biomarker strategies into clinical SABR workflows will require further standardisation, validation, and regulatory alignment.

Colorectal cancer (CRC) is a major cause of cancer mortality worldwide, with metastatic disease remaining the main driver of poor prognosis. In recent years, the concept of oligometastatic disease, where patients present with a limited number of metastases, has created an opportunity to use local therapies with curative intent. Stereotactic ablative radiotherapy (SABR) has become increasingly important in this setting, as it allows the delivery of high, ablative doses with excellent local control and generally low toxicity. Notably, randomised data such as SABR-COMET, alongside large prospective series including SABR-5, have demonstrated improvements in survival outcomes in the context of oligometastatic disease across mixed primary tumour types, with CRC patients making up a relatively small proportion in these trials. This has presented SABR as a practical treatment option for patients with oligometastatic CRC, although more CRC-specific phase III trials are needed. Other challenges include the radioresistance of CRC metastases, and treatment outcomes that vary depending on the anatomical site, tumour biology, and prior therapies. Technical issues such as motion management and organ-at-risk constraints also continue to limit dose escalation. Emerging strategies—including MR-guided radiotherapy, proton-based SABR, integration with systemic agents such as immunotherapy, and the use of biomarkers and artificial intelligence to refine patient selection—are beginning to address these limitations. This review summarises the current evidence and emerging advancements to highlight how SABR may evolve as part of an integrated approach to oligometastatic CRC.