DIAGNOSTIC ACCURACY OF CT NECK CHEST ABDOMEN PELVIS WITH BONE SCAN FOR SKELETAL METASTASIS AMONG MALIGNANT CANCER PATIENTS

Abstract

Background: Skeletal metastasis is a common complication of advanced solid malignancies and is associated with pain, fractures, neurological deficits, and reduced quality of life. Early detection is important for accurate staging, treatment planning, and prevention of serious complications. In many resource-limited settings, computed tomography (CT) and bone scintigraphy remain widely used imaging modalities for the evaluation of suspected bone metastases. Objective: To determine the diagnostic accuracy of computed tomography of the neck, chest, abdomen, and pelvis for detecting skeletal metastases in patients with solid malignancies using bone scintigraphy as the reference comparator. Methods: This cross-sectional validation study was conducted at the Department of Radiology, Shifa International Hospital Islamabad from October 2025 to April 2025. A total of 255 patients aged 18 to 70 years with histologically confirmed solid organ cancers underwent both CT scanning and bone scintigraphy. CT findings were classified as lytic, sclerotic, or mixed lesions. Diagnostic performance measures including sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were calculated using a 2 × 2 contingency table. Statistical association between CT and bone scan findings was assessed using the chi-square test. Results: Bone metastases were detected in 104 patients (40.8%) on bone scintigraphy and in 91 patients (35.7%) on CT. CT demonstrated a sensitivity of 81.7%, specificity of 96.1%, positive predictive value of 93.4%, negative predictive value of 88.5%, and overall diagnostic accuracy of 90.6%. A significant association was observed between CT and bone scan findings (p < 0.001). The spine and pelvis were the most frequently involved skeletal sites. Conclusion: Computed tomography shows high specificity and moderate sensitivity for detecting skeletal metastases in patients with solid malignancies. CT may serve as a useful imaging modality for identifying established bone lesions and supporting clinical decision making, particularly in healthcare settings where access to advanced imaging is limited.