CT (computed tomography)
A CT scan is a fast 3D X-ray that shows the size and shape of tumours and whether they have spread.
Workhorse of staging and response assessment (RECIST). Fast, widely available, excellent for lung, liver, bone, and lymph nodes. Limited soft-tissue contrast and no biological information; ionising radiation. Photon-counting CT improves resolution at lower dose.
How it works
A rotating X-ray source and detector measure attenuation, which is reconstructed into cross-sectional images. Iodinated contrast highlights vasculature.
- Fast, ubiquitous
- Sub-millimetre resolution
- Standard for RECIST response
- Anatomic only; cannot distinguish scar from live tumour
- Radiation dose
- Poor for brain, marrow, and small peritoneal disease
Lung screening works when it uses volumetric nodule management, and it works against a no-screening control. The protocol underpins the UK Targeted Lung Health Check programme and European recommendations. Benefit in women remains less precisely estimated.
For people with a heavy smoking history, an annual low-dose CT scan is one of the few screening tests proven to reduce cancer deaths. Most abnormal scans are not cancer, so screening must be paired with careful nodule management. It does not apply to never-smokers or light smokers.
Latest papers
topQuery for this technology: (TITLE:"computed tomography" OR ABSTRACT:"computed tomography" OR TITLE:"photon-counting CT" OR ABSTRACT:"photon-counting CT") AND (cancer OR tumor OR tumour OR oncology OR carcinoma OR lymphoma OR leukemia OR leukaemia OR myeloma OR sarcoma OR melanoma OR glioma) AND (staging OR screening OR response). Results are unfiltered search hits about CT (computed tomography), not a curated reading list.