Eruption of Metastatic Paraganglioma After Successful Therapy with 177 Lu/ 90 Y-DOTATOC and 177 Lu-DOTATATE

We present two cases of marked progression of metastatic paraganglioma following initial partial response to PRRT. Given their positivity on68Ga-DOTATATE PET/CT and111In-octreotide SPECT, they underwent PRRT. Imaging following treatment revealed significant improvement in size and intensity, with some foci nearly completely resolved in one patient, and disease regression with a decrease in the number and size of bone and liver lesions in the second patient. Within months, repeat imaging in both patients revealed extensive metastatic disease with new lesions, which eventually lead to their deaths. The mechanism for rapid disease progression after partial response is not well understood, although it could be related to initially high Ki-67 levels or18F-FDG PET/CT SUVmax values. However, naturally rapid disease progression despite PRRT response cannot be excluded. This finding warrants the importance of proper patient counseling along with early and accurate pre-PRRT assessment, taking into consideration the above potential risk factors for therapy response in order to personalize treatment regimens and achieve maximum patient benefit.ClinicalTrials.gov IdentifierNCT00004847
Source: Nuclear Medicine and Molecular Imaging - Category: Nuclear Medicine Source Type: research