This article provides a review of the major clinically available PET tracers for the imaging of prostate cancer, describing their mechanisms of action, scan acquisition protocols, role in the clinical setting, and commonly encountered technical and imaging pearls and pitfalls. Prostate cancer is the second most common cancer in men worldwide, with a wide spectrum of biologic behavior ranging from indolent low-risk disease to highly aggressive castration-resistant prostate cancer. Conventional imaging with computed tomography, magnetic resonance imaging, and bone scintigraphy is limited for the detection of nodal disease and distant bone metastases. In addition, advances in the available therapeutic options, both localized and systemic, drive the requirement for precise diagnostic and prognostic tools to refine the individual therapeutic approach at various times in the management of patients with prostate cancer. Positron emission tomography (PET) has a rapidly evolving role in the assessment of prostate cancer, particularly in the scenario of biochemical relapse. Fluorine 18 (18F) fluorodeoxyglucose, the most widely available PET tracer, has limitations, particularly in indolent prostate cancer. In the past decade, several PET tracers with specific molecular targets have reach...

18F-Fluorodeoxyglucose positron emission tomography/CT imaging plays a key role in oncological imaging including in staging, radiotherapy planning, treatment response and recurrence assessment. Immunotherapies represent a major advance in cancer therapy for a number of tumours with resulting survival benefit. However, a wide range of immune related adverse events (irAEs), some of which can be apparent on imaging, have been reported. These involve many organ systems but particularly endocrine, cutaneous and gastrointestinal systems. Early detection of irAEs is essential to aid diagnosis and management of patients and to reduce associated morbidity. In addition, it is important to not mistake treatment related effects for disease. This pictorial review aims to identify common irAEs and changes seen on 18F-fluorodeoxyglucose positron emission tomography/CT.

We conducted the first-in-human study of ¹⁸F-fluoroethyl triazole [Tyr3] octreotate (¹⁸F-FET-βAG-TOCA) in patients with neuroendocrine tumors (NETs) to evaluate biodistribution, dosimetry, and safety. Despite advances in clinical imaging, detection and quantification of NET activity remains a challenge, with no universally accepted imaging standard. Methods Nine patients were enrolled. Eight patients had sporadic NET and one had multiple endocrine neoplasia type 1 (MEN1) syndrome. Patients received 137-163MBq (mean 155.7± 8 MBq) of ¹⁸F-FET-βAG-TOCA. Safety data were obtained during and 24 h after radioligand administration. Patients underwent detailed whole body PET-CT multi-bed scanning over 4 h with sampling of venous bloods for radioactivity and radioactive metabolite quantification. Regions of interest were defined to derive individual and mean organ residence times; effective dose (ED) was calculated with OLINDA 1.1. Results All patients tolerated ¹⁸F-FET-βAG-TOCA with no adverse events. Over 60% parent radioligand was present in plasma at 60 min. High tumor (primary and metastases)-to-background contrast images were observed. Physiological distribution was seen in pituitary, salivary, thyroid and spleen, with low background distribution in liver, an organ where metastases commonly occur. The organs receiving highest absorbed dose were gallbladder, spleen, stomach, liver, kidneys and bladder. The calculated ED over all subjects (mean ± SD) was 0.029 ± 0.004 mSv/MBq. Conclusion The favorable safety, imaging and dosimetric profile makes ¹⁸F-FET-βAG-TOCA a promising candidate radioligand for staging and management of NETs. Clinical studies in an expanded cohort are ongoing to clinically qualify this agent.

Effective anticancer therapy is thought to involve induction of tumour cell death through apoptosis and/or necrosis. [¹⁸F]ICMT-11, an isatin sulfonamide caspase-3/7-specific radiotracer, has been developed for PET imaging and shown to have favourable dosimetry, safety, and biodistribution. We report the translation of [¹⁸F]ICMT-11 PET to measure chemotherapy-induced caspase-3/7 activation in breast and lung cancer patients receiving first-line therapy.

Background: Angiogenesis is a driver of platinum resistance in ovarian cancer. We assessed the effect of combination pazopanib and paclitaxel followed by maintenance pazopanib in patients with platinum-resistant/refractory ovarian cancer. Integrins α_vβ₃ and α_vβ₅ are both upregulated in tumor-associated vasculature. [¹⁸F]Fluciclatide is a novel PET tracer that has high affinity for integrins α_vβ_3/5, and was used to assess the anti-angiogenic effect of pazopanib. Patients and methods: We conducted an open-label, phase Ib study in patients with platinum-resistant/refractory ovarian cancer. Patients received 1 week of single-agent pazopanib (800 mg daily) followed by combination therapy with weekly paclitaxel (80 mg/m²). Following completion of 18 weeks of combination therapy, patients continued with single-agent pazopanib until disease progression. Dynamic [¹⁸F]fluciclatide-PET imaging was conducted at baseline and after 1 week of pazopanib. Response (RECIST 1.1), toxicities, and survival outcomes were recorded. Circulating markers of angiogenesis were assessed with therapy. Results: Fourteen patients were included in the intention-to-treat analysis. Complete and partial responses were seen in seven patients (54%). Median progression-free survival (PFS) was 10.63 months, and overall survival (OS) was 18.5 months. Baseline [¹⁸F]fluciclatide uptake was predictive of long PFS. Elevated baseline circulating angiopoietin and fibroblast growth factor (FGF) were predictive of greater reduction in SUV_60,mean following pazopanib. Kinetic modeling of PET data indicated a reduction in K₁ and K_i following pazopanib indicating reduced radioligand delivery and retention. Conclusions: Combination therapy followed by maintenance pazopanib is effective and tolerable in platinum-resistant/refractory ovarian cancer. [¹⁸F]Fluciclatide-PET uptake parameters predict clinical outcome with pazopanib therapy indicating an anti-angiogenic response.