Rapid Lymphatic Clearance After Subcutaneous Extravasation of 177 Lu-PSMA-I&T Radioligand Therapy.
Fakkert RK, van Nierop BJ, van Rooij R, Lam MGEH, de Keizer B.
Abstract
Extravasation of therapeutic radiopharmaceuticals during radioligand therapy is uncommon. We report the first published case of subcutaneous extravasation of 177 Lu-PSMA-I&T, presenting with acute upper-arm swelling, pain, and transient autonomic symptoms. Early planar scintigraphy and SPECT/CT demonstrated intense radiotracer accumulation in the left upper arm, with rapid redistribution and near-complete clearance by 20 hours. Dosimetric analysis estimated an absorbed dose of ~8 Gy at the injection site. Conservative management resulted in no radiation-induced tissue injury. The clinical course was comparable to previously reported cases of 177 Lu-PSMA-617 extravasation. This case highlights the value of early imaging in the case of extravasation for evaluating the extent of the extravasation and enabling absorbed dose estimation.