Imaging and therapy in prostate cancer using PSMA radioligands.

Prostate specific membrane antigen (PSMA)-directed PET imaging has rapidly transformed prostate cancer workup over the past decade and paved the way for a theranostic approach using 177Lu-labelled PSMA radioligand therapy. This review gives an overview of the underlying principles behind PSMA as a target; the current use of PSMA PET in prostate cancer imaging and benefits compared to conventional imaging; and therapeutic applications including optimisation of patient selection. It also explores the evidence base of PSMA PET for other indications not in routine clinical use and the future of PSMA-directed radioligand therapy.

The British nuclear medicine research strategy - the framework.

The British Nuclear Medicine Society (BNMS) has developed a Research Strategy framework led by the Research Champions of the BNMS and overseen by the BNMS Research and Innovation Committee. The objectives of the Research Strategy are to improve translation of cutting-edge nuclear medicine research from bench to bedside, the implementation of state-of-the-art multimodality technologies and to enhance multicentre radionuclide research in the UK. It strives to involve patients and the public in radionuclide research and to contribute to and work with the multi-professional national and international organisations involved in research with an ultimate aim to improve nuclear medicine services, and patients' outcomes and care.

Efficacy and safety of 177Lu­DOTATATE in patients with advanced pancreatic neuroendocrine tumours: data from the NETTER-R international, retrospective study.

PURPOSE: NETTER-R aimed to determine the efficacy, safety and tolerability of 177Lu-DOTATATE in patients with progressive, advanced pancreatic neuroendocrine tumours (panNETs) using retrospective real-world data from multiple sites. METHODS: This international study retrospectively included patients with panNETs treated with 177Lu-DOTATATE. The primary endpoint was progression-free survival (PFS) by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1). Secondary endpoints included overall survival (OS), safety and tumour response. RESULTS: In total, 110 patients with panNETs were studied; 65.5% received a cumulative dose of 177Lu-DOTATATE 29.6 GBq ± 10% (median: 7.4 GBq). In 62 patients with available RECIST v1.1 tumour response, the median PFS was 24.8 months (95% confidence interval [CI]: 17.5-34.5), and the objective response rate was 40.3% (95% CI: 28.1-53.6); all responses were partial. With a median follow up of 24.5 months (range: 2.0-123.4 months) after the first cycle of 177Lu-DOTATATE, the median OS in the full analysis set (n = 110) was 41.4 months (95% CI: 28.6-50.2). PFS (hazard ratio [HR]: 3.672; p = 0.0009) and OS (HR: 3.360; p < 0.0001) were longer in patients who received no chemotherapy prior to 177Lu-DOTATATE than those who did. No treatment-emergent adverse events (TEAEs) led to treatment discontinuation. Grade 3 anaemia, lymphopenia and thrombocytopenia occurred in 0.9%, 5.4% and 0.9% of patients, respectively. No acute leukaemia or myelodysplastic syndrome was reported. Six patients (5.5%) had renal TEAEs. All renal grade ≥ 3 events were transient and did not lead to treatment modification. CONCLUSIONS: These results reinforce the role of 177Lu-DOTATATE for the treatment of patients with advanced, somatostatin receptor-positive panNETs.

Striatal Dopaminergic Deficit and Sleep in Idiopathic Rapid Eye Movement Behaviour Disorder: An Explorative Study.

INTRODUCTION: Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is increasingly recognised as an important precursor disease state of alpha-synucleinopathies. This parasomnia is characterized by a history of recurrent nocturnal dream enactment behaviour, loss of skeletal muscle atonia, and increased phasic muscle activity during REM sleep. Neuroimaging studies of striatal dopamine transporter uptake tracer signaling suggest increasing dopaminergic deficit across the continuum of the alpha-synucleinopathies, with early sleep dysfunction suggestive of early caudate dysfunction. Henceforth, we set out to investigate the relationship between early sleep changes and the striatal dopaminergic availability in iRBD. METHODS: Twelve patients with iRBD, who had undergone a video polysomnography and a neuroimaging assessment of striatal dopamine transporter (DaT) uptake tracer signaling, and 22 matched controls who had similarly undergone a video polysomnography were retrospectively identified. Data were statistically analyzed to identify altered sleep parameters and correlate them with striatal dopamine transporter uptake tracer signaling. RESULTS: The iRBD patients exhibited an increased number of periodic limb movements during sleep (P=0.001), compared to 22 age-matched healthy subjects. In addition, several significant links were found between regional DaT-uptakes and sleep architecture. Correlational analyses suggested a strong positive association between sleep fragmentation and dopamine deficiency in left caudate (r=-0.630, P=0.028), whilst an increased uptake in the whole striatum was strongly linked to the sleep efficiency, and to a lesser degree to the length of sleep duration. DISCUSSION: To the best of our knowledge, this is the first demonstration of a close relationship between dopaminergic availability in striatum and the quality of sleep in iRBD. Taken together, our exploratory findings suggest that subtle but functionally significant striatal changes in early stages of iRBD may contribute to the further shaping of sleep architecture.

Thyroid lymphoma incidentally detected by 18F-fluorocholine (FCH) PET/CT.

A 63-year-old man underwent a (18)F-fluorocholine ((18)F-FCH) PET/CT for staging assessment of a high-risk locally advanced prostate cancer with an equivocal node on conventional workup (Gleason 4 + 5, PSA 11.1; T3b, N(0/1), M(0) on standard staging investigations). (18)F-FCH-avid disease was demonstrated in the prostate and several non-enlarged pelvic nodes. An incidental focus of tracer uptake was reported within the left lobe of the thyroid gland, with subtle enlargement of the left thyroid lobe on the CT component of the study. A diagnosis of diffuse large B-cell lymphoma was confirmed following thyroid ultrasound and cytology.