Imaging Modalities for Preoperative Staging of Rectal Cancer in Developing Countries: A Comparative Study of F-FDG PET/CT and MRI

Abstract

Rectal cancer represents a significant health care challenge globally, demanding accurate pre-operative staging to guide therapeutic interventions and prognostic estimations.This study aims to compare the efficacy and use of F-FDGPET/CT and MRI in preoperative staging of rectal cancer in developing countries such as india. Using a cross-sectional study design, a total of 70 patients diagnosed with rectal cancer were prospectively enrolled and equally divided Into group A and group B. For group A f- fdg PET/CT and for group B MRI was conducted. The primary outcome measures were accuracy, sensitivity, and specificity of each imaging modalityin detecting local tumor extent (T stage), lymph nodeinvolvement (N stage), and distant metastasis (M stage). Histopathological biopsy was taken for each patient and considered as reference standard. Data were analyzed using descriptive statistics and diagnostic accuracy measures.Results showed that both F-FDG PET/CT (71.4%) and MRI(75..5%) had high accuracy in T staging, with comparablesen sitivity (F -FDG PET/CT - 59.6%, MRI - 72.0%) and specificity ( F -FDG- 94.8% , MRI - 82.2%). MRI showed higher sensitivity ( 78.6%) in detecting lymph node involvement than F-FDG PET/CT (72.2%) .F-FDG PET/xCT demonstrated higher sensitivity in detecting distant metastasis compared to MRI. Conclusion: F-FDG PET/CT and MRI are comparable for preoperative staging of rectal cancer, with their own limitations and benifits . MRI provides detailed information about the local tissue involvement, and presence of lymph node metastases where as F-FDG PET/CT is more helpful in detecting distant metastases. But as MRI is more readily available and is more cost effective than F-FDG PET/CT in developing countries such as india, it should be used as the imaging modality of choice for pre - operative staging of rectal cancer.