Determination of split renal function by PSMA imaging: comparison of Ga-PSMA-11 PET with Tc-MAG3 scintigraphy.

MAG3 scintigraphy with determination of split renal function (SRF) is a standard procedure in patients with metastasized castration-resistant prostate carcinoma (mCRPC) undergoing PSMA radioligand therapy (PSMA-RLT). These patients also receive frequent PSMA PET/CT scans for staging and follow up. PSMA is not only overexpressed in prostate cancer epithelial cells, but also physiologically overexpressed in the proximal tubular cells of the kidney.

Neuron-specific enolase has potential value as a biomarker for [F]FDG/[Ga]Ga-PSMA-11 PET mismatch findings in advanced mCRPC patients.

Background: PSMA-targeted radioligand therapy (PSMA-RLT) yielded impressive results in the metastasized castration-resistant prostate carcinoma (mCRPC) setting. High expression of PSMA is essential for successful PSMA-RLT. However, some patients develop [F]FDG-avid lesions with low or no PSMA expression ([F]FDG/[Ga]Ga-PSMA-11 mismatch findings on PET/CT) in the course of treatment.

Response and outcome of liver metastases in patients with metastatic castration-resistant prostate cancer (mCRPC) undergoing Lu-PSMA-617 radioligand therapy.

Purpose: Little is known about the efficacy of prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) against liver metastases of metastatic castration-resistant prostate cancer (mCRPC). We retrospectively analyzed efficacy-related outcomes of Lu-PSMA-617 RLT in this setting and potential predictors of those outcomes.

Methods: Twenty-eight consecutive mCRPC patients with liver metastases given Lu-PSMA-617 RLT were analyzed retrospectively.

Benefit of including CT urography in [68Ga]PSMA-11 PET/CT with low-dose CT: first results from a larger prostate cancer cohort analysis.

Background: Accuracy of [Ga]PSMA-11 PET/CT may be hampered by ureter accumulation, mimicking lymph node metastases depending on localization and configuration. The benefit of CT urography for differentiation of lymph node metastasis from urinary tract activity was evaluated in a "PET/CT with low-dose CT" setting.

Methods: Retrospective analysis of PET/CT for primary staging, biochemical recurrence or local treatment planning in patients with prostate cancer.

Remember the Pitfall: Intrapancreatic Accessory Spleen Mimicking Neuroendocrine Neoplasm.

We report of a 71-year-old woman with a 2-cm somatostatin receptor-positive intrapancreatic lesion almost misdiagnosed as neuroendocrine neoplasm. By additional red blood cell scintigraphy with heat-damaged erythrocytes, the lesion was identified as an intrapancreatic accessory spleen, and unnecessary operation (which was already planned) could be avoided. This case report reminds colleagues to consider accessory spleen as differential diagnosis for somatostatin receptor-positive lesions even when located inside the pancreas.

New insights in the paradigm of upregulation of tumoral PSMA expression by androgen receptor blockade: Enzalutamide induces PSMA upregulation in castration-resistant prostate cancer even in patients having previously progressed on enzalutamide.

Purpose: There is preliminary evidence for prostate-specific membrane antigen (PSMA) upregulation effects of androgen receptor blockade in prostate cancer. In an attempt to find the best condition for PSMA radioligand therapy in metastatic castration-resistant prostate cancer (mCRPC) patients, we evaluated the effect of oral enzalutamide in patients, predominantly having previously progressed on enzalutamide treatment.

Methods: Ten patients with advanced mCRPC scheduled for PSMA radioligand therapy were examined with Ga-PSMA-11 PET/CT before and after a mean of 11.

Ac-PSMA-617/Lu-PSMA-617 tandem therapy of metastatic castration-resistant prostate cancer: pilot experience.

Purpose: Up to 30% of patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) never respond or develop resistance to Lu-labeled PSMA-targeted radioligand monotherapy. Single-agent PSMA-targeted radioligand therapy (PRLT) with the alpha-emitter Ac showed promise against mCRPC but may cause severe and/or persistent xerostomia, which may substantially impair patients' quality-of-life. We hypothesized that when Lu-PSMA ligand alone is ineffective, tandem therapy with low-activity Ac-PSMA ligand plus full activity of the beta emitter may enhance efficacy while minimizing xerostomia severity.

Recovery of Renal Function Under PSMA Mediated Radioligand Therapy of Advanced Metastasized Castration Resistant Prostate Cancer.

Radioligand therapy targeting prostate specific membrane antigen (PSMA-RLT) is becoming increasingly important in palliative care of metastasized castration resistant prostate cancer (mCRPC) as a highly effective and low toxicity therapy option. In addition to its overexpression in prostate cancer cells, PSMA is also physiologically expressed in the kidneys which is raising concerns over dose related nephrotoxicity of PSMA-RLT. We describe potential positive short-term effects of PSMA-RLT on renal function with marked recovery of a pretreatment compromised kidney.

Early metabolic response assessment of breast cancer liver metastases: 4-week posttreatment FDG PET predicts survival after 90Y microsphere radioembolization.

Aim: To evaluate the feasibility of early metabolic response assessment with F-FDG PET/CT in patients with breast cancer liver metastases 4 weeks after radioembolization with Yttrium-90 labeled microspheres.

Methods: 25 patients (mean age 58y, range 40-74) with advanced stage liver metastases of breast cancer were treated with 1.9 ± 0.

Large Paraesophageal Schwannoma With Intense Prostate-Specific Membrane Antigen Expression on 68Ga-PSMA-PET/CT Mimicking Lymph Node Metastasis in a Patient With Prostate Cancer.

Prostate-specific membrane antigen (PSMA)-PET/CT as an emerging modality in molecular imaging will lead to earlier detection and localization of relapse in prostate cancer but will undoubtedly also lead to false-positive findings, as it becomes clear that this new tracer is not as specific as its name would suggest. In this context, we present a case of a large PSMA-expressing schwannoma, a rare nerve sheath tumor mimicking paraesophageal lymph node metastasis in a patient with a history of prostate cancer and biochemical recurrence.

Influence of soluble fibrin on reaction kinetics of plasmin type 1 and type 2 with alpha2-antiplasmin.

This study investigates, by slow binding kinetics methods, reaction kinetics of both plasmin types 1 and 2 with alpha -antiplasmin in the presence of increasing concentrations of either epsilon-amino-caproic acid (EACA) or soluble fibrin. All curves of plasmin-alpha -antiplasmin interaction followed the same pattern, indicating reversible slow binding inhibition with an initial loose complex and a following tight complex. Without soluble fibrin or EACA, differences between plasmin types 1 and 2 could be seen in the initial loose complex formation.

Differences between neonates and adults in carbohydrate sequences and reaction kinetics of plasmin and alpha(2)-antiplasmin.

This study investigates reaction kinetics by slow-binding kinetics methods of both adult and fetal plasmin (Types 1 and 2) with adult and fetal alpha(2)-antiplasmin. In addition, carbohydrate sequences of Fetal and Adult Plasminogen Types 1 and 2, as well as fetal and adult alpha(2)-antiplasmin, were determined by mass spectrometric analysis. All curves of plasmin-alpha(2)-antiplasmin interaction followed the same pattern, indicating reversible slow-binding inhibition with an initial loose complex and a following tight complex.