The joint IAEA, EANM, and SNMMI practical guidance on peptide receptor radionuclide therapy (PRRNT) in neuroendocrine tumours

Peptide receptor radionuclide therapy (PRRNT) is a molecularly targeted radiation therapy involving the systemic administration of a radiolabelled peptide designed to target with high affinity and specificity receptors overexpressed on tumours. PRRNT employing the radiotagged somatostatin receptor agonists (90)Y-DOTATOC ([(90)Y-DOTA(0),Tyr(3)]-octreotide) or (177)Lu-DOTATATE ([(177)Lu-DOTA(0),Tyr(3),Thr(8)]-octreotide or [(177)Lu-DOTA(0),Tyr(3)]-octreotate) have been successfully used for the past 15 years to target metastatic or inoperable neuroendocrine tumours expressing the somatostatin receptor subtype 2. Accumulated evidence from clinical experience indicates that these tumours can be subjected to a high absorbed dose which leads to partial or complete objective responses in up to 30 % of treated patients. Survival analyses indicate that patients presenting with high tumour receptor expression at study entry and receiving (177)Lu-DOTATATE or (90)Y-DOTATOC treatment show significantly higher objective responses, leading to longer survival and improved quality of life. Side effects of PRRNT are typically seen in the kidneys and bone marrow. These, however, are usually mild provided adequate protective measures are undertaken. Despite the large body of evidence regarding efficacy and clinical safety, PRRNT is still considered an investigational treatment and its implementation must comply with national legislation, and ethical guidelines concerning human therapeutic investigations. This guidance was formulated based on recent literature and leading experts’ opinions. It covers the rationale, indications and contraindications for PRRNT, assessment of treatment response and patient follow-up. This document is aimed at guiding nuclear medicine specialists in selecting likely candidates to receive PRRNT and to deliver the treatment in a safe and effective manner. This document is largely based on the book published through a joint international effort under the auspices of the Nuclear Medicine Section of the International Atomic Energy Agency

Prevalence, birth incidence, and penetrance of von Hippel–Lindau disease (vHL) in Denmark

Von Hippel–Lindau disease (vHL) is a rare hereditary tumour predisposition with multiorgan involvement that is not always easily recognized. The disease is reported to be almost fully penetrant at age 60 years. Previous estimates of vHL prevalence and incidence are all regional and vary widely. Most are >20 years old and prone to selection bias because of inclusion of only clinically affected vHL patients who were diagnosed before genetic testing was available. In an unselected cohort of all known Danish carriers of a disease-causing VHL variant, we assessed vHL penetrance on a national basis. We further used national health registers to identify individuals who fulfilled the clinical diagnostic vHL criteria based on their registered diagnostic codes, but had not been diagnosed with vHL. We also assessed the medical histories of first-degree relatives to identify familial cases. This study gives the first national estimates of vHL prevalence (1 in 46 900 individuals) and birth incidence (1 in 27 300 live births). vHL has been underdiagnosed in Denmark, and as many as 25% of the overall vHL cohort (diagnosed+undiagnosed patients) have a missed diagnosis in spite of fulfilling the international diagnostic criteria. We found an overall penetrance of 87% at age 60 years. When considering only vHL patients who have not attended surveillance, 20% will still be asymptomatic at age 60 years. This should be considered in the context of genetic counselling, especially when assessing the risk of vHL in asymptomatic adult first-degree relatives who are often not genetically tested