PET/MR in the Staging and Efficacy Evaluation of Newly Diagnosed NK/T-cell Lymphoma

This study evaluates whether a combined PET/MRI scan (a powerful imaging tool that shows both structure and activity in the body) is more accurate than standard PET/CT scans at diagnosing and tracking treatment response in people with NK/T-cell lymphoma, a rare type of blood cancer. **You may be eligible if...** - You are 14–70 years old - You have been newly diagnosed with NK/T-cell lymphoma confirmed by biopsy - You have not yet received any treatment for this lymphoma - You are in reasonably good health (ECOG 0–2) with a life expectancy of at least 6 months **You may NOT be eligible if...** - You have been diagnosed with aggressive NK cell leukemia (a different condition) - You are pregnant or breastfeeding - You have significant liver or kidney problems - You have a pacemaker, metal implants in the head, or other devices that make MRI unsafe - You are claustrophobic or unable to cooperate with the scan Talk to your doctor to see if this trial is right for you.