Impact of PET-CT imaging on staging and conformal radiotherapy treatment planning for non small cell carcinoma of lung

Introduction: Lung cancer is the most common cancer in the world and accounts for nearly 13% of all new cancer diagnoses in both sexes combined and currently is the leading cause of cancer related deaths worldwide. Due to dismal overall survival, all efforts should be made to improve the diagnosis and treatment to lung cancer patients. So the aim of this study is to explore the possibility of using fused CT-PET images for accuracy of staging and three dimensional radiation treatment planning in regard delineation of target in patients of carcinoma lung (NSCLC) who are referred to us for radical radiotherapy. Materials and Methods: It's a hospital based prospective study in which 16(n) cancer patients who had biopsy proven NSCLC and were referred to us for radical radiotherapy. Results: The mean age was 65 yrs, 81.25% (13) patients are male and 18.75 % (3) are female. PET-CT imaging changed the staging in 4 patients (25%), metastatic disease found in 2 patients (12.5%). The registration of fused images of PET with planning CT scan decreased the gross tumor volume (GTV) in 10 patients (71.42%), decreased volume in 4 patients (28.58%). The 3D-CRT planes were modified in 5patients (35%). Conclusion: Our findings extend the conclusion of observational studies in which FDG-PET has already been used to improve cancer staging and the definition of GTV for radiation treatment planning. It showed 25% change in staging, 12% detecting distant metastasis and 35% alteration in radiotherapy treatment plan. PET-CT should be routinely used for staging and if feasible it should be incorporated in radiotherapy treatment planning.