{"entity":{"id":"tumour-doubling-time","kind":"technology","name":"Tumour volume doubling time","aka":[],"tldr":"How long a tumour takes to double in volume, measured from two scans; it separates cancers from benign nodules in lung screening, sorts aggressive from indolent disease and estimates how long a tumour has been present.","summary":"Collins and colleagues introduced volume doubling time from serial chest radiographs in 1956. In lung cancer screening it is the main tool for managing indeterminate nodules: the NELSON trial used volume doubling time to classify growth, with faster than 400 days prompting work-up, and it underlies the British Thoracic Society and Lung-RADS pathways. Doubling time also grades kidney masses under surveillance, thyroid nodules and metastases, and, projected backwards, suggests that most cancers have grown for years before detection. Growth is Gompertzian rather than exponential, so a single doubling time is an approximation.","status":"established","asOf":"2026-09-17","links":[{"label":"NELSON volume-based management, van Klaveren 2009","url":"https://doi.org/10.1056/NEJMoa0906085"}],"tags":["mathematical-model"],"related":[],"cancers":["nsclc","rcc"],"sections":["ai-computation","drug-discovery"],"technologies":["radiomics","radiology-ai-screening","active-surveillance"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["nlst-nelson"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"principle":"Doubling time = t·ln2 / ln(V2/V1) for volumes V1 and V2 measured t days apart, assuming exponential growth over the interval.","strengths":["Simple and used in screening pathways","Separates aggressive from indolent lesions","Applies to any imaged tumour"],"limitations":["Assumes exponential growth","Measurement error dominates for small nodules","Growth rates change over time"],"since":1956},"route":"/technologies/tumour-doubling-time/","neighbours":{"cancer":[{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"},{"id":"rcc","kind":"cancer","name":"Renal cell carcinoma","route":"/cancers/rcc/"}],"section":[{"id":"ai-computation","kind":"section","name":"AI & Computation","route":"/fronts/ai-computation/"},{"id":"drug-discovery","kind":"section","name":"Drug Discovery Platforms","route":"/fronts/drug-discovery/"}],"technology":[{"id":"active-surveillance","kind":"technology","name":"Active surveillance","route":"/technologies/active-surveillance/"},{"id":"radiology-ai-screening","kind":"technology","name":"AI in radiology","route":"/technologies/radiology-ai-screening/"},{"id":"radiomics","kind":"technology","name":"Radiomics","route":"/technologies/radiomics/"}],"trial":[{"id":"nlst-nelson","kind":"trial","name":"NLST & NELSON (low-dose CT screening)","route":"/trials/nlst-nelson/"}]}}