Diagnosis of Chemotherapy-induced Peripheral Neurotoxicity: A Scoping Review

Background/Aim: Chemotherapy-induced peripheral neuropathy (CIPN) is a common and disabling side-effect of various chemotherapeutic agents. This scoping review aimed to systematically map the existing literature on diagnostic methods used to identify, assess, and monitor CIPN. The review was guided by the research question: “What diagnostic methods have been used in the literature to identify, assess, or monitor chemotherapy-induced peripheral neuropathy in adult cancer patients?" Materials and Methods: We searched PubMed, Web of Science, Scopus, and the Cochrane Library from 2000 to 2024. Studies were included if they evaluated diagnostic methods for CIPN such as clinical assessments, patient-reported outcomes, biomarkers, neurophysiological tests, or digital tools. Data were extracted and narratively synthesized by diagnostic method type. The methodological quality of each included study was assessed using the Joanna Briggs Institute Critical Appraisal Tools. Results: Twenty-nine studies met the inclusion criteria. The most frequently used tools were patient-reported questionnaires, notably the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Chemotherapy-Induced Peripheral Neuropathy 20 (EORTC QLQ-CIPN20) and the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE). Biomarkers such as neurofilament light chain and microRNAs, neurophysiological tests including nerve conduction studies, diffusion tensor imaging, functional magnetic resonance imaging, as well as digital technologies, such as mobile applications and wearable sensors, were also employed. Studies showed considerable heterogeneity in design, population, timing of assessments, and tool validation. Conclusion: Despite growing interest in multimodal approaches that integrate subjective and objective tools, a lack of standardization and validation limits the clinical applicability of many diagnostic methods. There is an urgent need to develop and validate reliable, reproducible, and feasible tools for the diagnosis and monitoring of CIPN in routine practice.