Optimising the Use of Staging Computed Tomography of the Chest, Abdomen and Pelvis (CT CAP) in Newly Diagnosed Brain Lesions in Adults
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
Background Newly diagnosed brain lesions (NBLs) present a diagnostic challenge in distinguishing primary from secondary (metastatic) disease. Staging CT of the chest, abdomen and pelvis (CT CAP) is frequently used to identify an extracranial primary; however, in the absence of clear selection protocols, this investigation is often applied indiscriminately, exposing patients with primary brain tumours to unnecessary radiation, cost and delay. This study aimed to identify CT head-based predictors of a positive CT CAP to inform a selective staging protocol. Methods This retrospective cohort study included 184 patients reviewed at the Neurosurgery multidisciplinary team (MDT) at Queen Elizabeth Hospital, Birmingham (April 2022 to November 2022) with an NBL who underwent CT head imaging. Candidate predictors - lesion location (supratentorial/infratentorial), lesion number, lesion size, and previous history of cancer - were assessed against CT CAP outcome using univariable and multivariable logistic regression. Results A definitive CT CAP outcome was available for 106 patients, of whom 19 (18%; 95% confidence interval (CI), 11-27%) had a positive result. On univariable analysis, previous cancer history (odds ratio (OR), 17.8; 95% CI, 5.17-61.0), lesion size ≥4 cm (OR, 3.73; 95% CI, 1.01-13.8), and increasing lesion number (OR, 7.33 for ≥3 lesions; 95% CI, 1.94-27.7) were associated with a positive result, whereas lesion location was not (P = 0.50). After multivariable adjustment, o
Abstract
Background Newly diagnosed brain lesions (NBLs) present a diagnostic challenge in distinguishing primary from secondary (metastatic) disease. Staging CT of the chest, abdomen and pelvis (CT CAP) is frequently used to identify an extracranial primary; however, in the absence of clear selection protocols, this investigation is often applied indiscriminately, exposing patients with primary brain tumours to unnecessary radiation, cost and delay. This study aimed to identify CT head-based predictors of a positive CT CAP to inform a selective staging protocol. Methods This retrospective cohort study included 184 patients reviewed at the Neurosurgery multidisciplinary team (MDT) at Queen Elizabeth Hospital, Birmingham (April 2022 to November 2022) with an NBL who underwent CT head imaging. Candidate predictors - lesion location (supratentorial/infratentorial), lesion number, lesion size, and previous history of cancer - were assessed against CT CAP outcome using univariable and multivariable logistic regression. Results A definitive CT CAP outcome was available for 106 patients, of whom 19 (18%; 95% confidence interval (CI), 11-27%) had a positive result. On univariable analysis, previous cancer history (odds ratio (OR), 17.8; 95% CI, 5.17-61.0), lesion size ≥4 cm (OR, 3.73; 95% CI, 1.01-13.8), and increasing lesion number (OR, 7.33 for ≥3 lesions; 95% CI, 1.94-27.7) were associated with a positive result, whereas lesion location was not (P = 0.50). After multivariable adjustment, only previous cancer history remained independently associated with a positive CT CAP (adjusted OR, 14.6; 95% CI, 4.09-52.4; P < 0.001). Previous history of cancer is the dominant independent predictor of a positive staging CT CAP in patients with NBLs. Conclusion Previous history of cancer is the sole independent predictor of a positive staging CT CAP in patients with an LBN, whereas lesion number, size, and location are not. A risk-stratified staging pathway that prioritises cancer history rather than applying CT CAP indiscriminately could reduce unnecessary imaging while preserving diagnostic yield for metastatic disease.