Objective partial remission in another advanced Hodgkin lymphoma patient (HL2) induced by ¹³¹I-L19SIP radioimmunotherapy. (A) ¹⁸F-FDG PET scans show intense glucose metabolism in multiple enlarged lymph nodes, particularly in right and left axillary and supraclavicular nodes, in paratracheal, subcarinal, peritoneal, and iliacal nodes as well as in lymphoma lesions located in the basal lobes of both lungs (leftmost image). One (center) and 2 (rightmost image) months after application of therapeutic ¹³¹I-L19SIP (3.7 GBq), the number and size of active lymphoma lesions decreased substantially. (B) ¹⁸F-FDG PET scans and ¹³¹I-L19SIP SPECT-CT images from the same patient. Transaxial SPECT-CT images (top row) show selective ¹³¹I-L19SIP uptake to a pulmonary lymphoma lesion still detectable 12 days after injecting a therapeutic dose (3.7 GBq). Transaxial ¹⁸F-FDG PET scans captured prior to (second row), 1 month after (third row) and 2 months after (bottommost row) application of therapeutic ¹³¹I-L19SIP show a significant shrinkage in size and a complete disappearance of metabolic activity in the initially large pulmonary lymphoma lesion, indicative of lymphoma response to ¹³¹I-L19SIP radioimmunotherapy.