Testicular tumors account for 1% of all cancers in males and germ cell tumors comprise 95% of all testicular cancers. Seminomas consist of around 50% of cases. However,adequate information is not there as 60- 80% residual disease is seen even after with the standard management of chemotherapy.

With the advent of functional imaging there was hope that it could aid in more accurately targeting these tumors to systematically evaluate the role of PET-CT imaging in identifying patients diagnosed with stage IIB-IIIC seminomatous germ cell tumor, with residual visible tumor post chemotherapy who would benefit with loco regional radiotherapy.

The therapeutic research in Seminomashas been relatively slow and such structured studies can allow analysis of large number of patients to report on acute and late effect of treatment outcomes using CTCAE and QOL (EORTC QLQ C-30) in these cancers. We hope that we will get help in identifying thrust areas for future research through this study.

Inclusion Criteria:

1. Histological diagnosis of classical seminoma
2. Primary site - testis, mediastinum or retroperitoneum
3. Stage IIB-IIIC (AJCC 8th edition)
4. Age>18 years
5. Karnofsky Performance Status at least 70
6. A response assessment FDG PETCT scan done at least twelve weeks after the first line chemotherapy, showing a persistent measurable residual mass
7. Patient willing and reliable for follow up and QOL.

Exclusion Criteria:

1. Histology other than classical seminoma
2. Non completion of planned first-line chemotherapy
3. Prior history of radiotherapy to the involved region
4. Inability to deliver adequate radiotherapy dose safely based on assessment by radiation oncologist