Excellent Response to Lower Dose of 177Lu-PSMA-617 in a Metastatic Castration-Resistant Prostate Cancer Patient With a Transplanted Kidney.

A 68-year-old man with metastatic castration-resistant prostate cancer and widespread bone metastases as well as a history of kidney transplant, underwent 5 cycles of Lu-prostate-specific membrane antigen 617 therapies in our department. Being more cautious of the radiation burden imposed on the transplanted kidney, a lower average dose of 4 GBq per cycle was administered (instead of the more routine 6.0-7.4 GBq per cycle). However, excellent response was noted and serum creatinine level of 0.8 mg/dL remained stable.

Prostate-Specific Membrane Antigen in Low-Grade Fibromatosis.

We report a case of fibromatosis demonstrating prostate-specific membrane antigen (PSMA)-positive scan. A 76-year-old man was under assessment because of rising prostate-specific antigen level. Bone scan showed abnormal soft tissue uptake of Tc-MDP adjacent to the right scapula, compatible with a mass in MRI, thereafter. Because of the unavailability of Ga-PSMA scan in our department and also high cost in other centers, the patient underwent Lu-PSMA for more assessment, which revealed PSMA-avid mass. Pathologic examination confirmed the diagnosis of low-grade fibromatosis. This report demonstrates another false-positive result of PSMA scan and highlights the importance of pathologic examination.

Detection of Superior Vena Cava Obstruction on Dynamic 99mTc-DTPA Renal Transplant Scintigraphy.

We present an asymptomatic patient with a history of prolonged hemodialysis through a right internal jugular vein catheter who was diagnosed with superior vena cava (SVC) obstruction on 99mTechnetium-diethylenetriaminepentaacetic acid renal transplant scintigraphy. During the angiographic phase, an unusual vascular filling pattern was detected on the anterior view of the abdomen. Angioscintigraphic imaging of the chest wall was suggestive of SVC obstruction. The SVC obstruction in our patient was related to the long-term use of an indwelling catheter in the central venous system, which is a well-known complication of such a procedure. There is also evidence of a hypercoagulable state in dialyzed uremic cases; therefore, our patient may have been more susceptible to an SVC thrombosis. Acquired compensatory dilatation of the azygos vein is rather a rare finding. To the best of our knowledge, this is the first report describing an asymptomatic patient with SVC obstruction who was diagnosed by renal scintigraphy.