Radiation Dosimetry in Lu-PSMA-617 Therapy.

Radionuclide therapy using the small molecule PSMA bound to the beta-emitting radionuclide, Lutetium-177 (Lu-PSMA) has demonstrated efficacy and survival benefit castrate resistant metastatic disease and represents a novel new line of therapy. Whilst dosimetry was critical for early development, it was not incorporated into either the TheraP or VISION randomized studies, highlighting the difficulty of adopting dosimetry in routine clinical practice. Accumulated clinical experience has also shown that the common (and generally low grade) toxicities such as nausea, xerostomia, and cytopenias are not readily predicted on the basis of dosimetry estimates.

68Ga-DOTATATE Uptake in Ischemic Stroke.

A 76-year-old man known to have a pancreatic neuroendocrine tumor with hepatic and lymph nodes metastasis had a follow-up Ga-DOTATATE PET/CT before Lu-DOTATATE therapy. A new cerebral lesion expressing somatostatin receptors was discovered in the right temporal lobe, suggestive of an ischemic stroke territory. This was later confirmed from the hospital chart where an ischemic stroke was described a month ago.