<prompt> A lady with CA ovary in follow up with raised CA 125 level, Next step :CTPETMRIClinical exam and serial follow up of CA 125  <response>: Ans. is b i.e. PET In a case of treated ovarian cancer - Treatment assessment is done by : Tumor marker CA 125 - It is a reliable indicator of disease response or progression. - If CA 125 levels decreases after treatment - It indicates response to treatment. - If CA 125 levels increase after treatement - It indicates relapse after treatment. - A review of the literature suggests that an elevated Ca 125 level predicts persistent disease at second look surgery in 97 of the cases but CA 125 is not sensitive enough to exclude subclinical disease in many patients. - Follow up in a patients of ovarian cancer is done by physical and pelvic examination along with estimation of CA 125 levels. Patient is advised to visit every 3-4 months for the first 2 years and then 6 monthly for 5 years. Clinical examination and CA 125 together can detect 90 of recurrences. Radiological procedures are not required in all cases. But since here CA 125 is elevated and we have to choose one option - the best is PET as : - CT scan cannot distinguish between a relapsed tumour and fibrosis where as PET scan will exactly demonstrate whether it is a relapsed tumour or a fibrosis. - In a patient treated with chemotherapy or radiotherapy fibrosis is common. It can present as a mass. 