(1) Background: As outcome of patients with metastatic melanoma treated with anti-PD1 immunotherapy can vary in success, predictors are needed. We aimed to predict at the patients’ levels, overall survival (OS) and progression-free survival (PFS) after one year of immunotherapy, based on their pre-treatment 18F-FDG PET; (2) Methods: Fifty-six metastatic melanoma patients—without prior systemic treatment—were retrospectively included. Forty-five 18F-FDG PET-based radiomic features were computed and the top five features associated with the patient’s outcome were selected. The analyzed machine learning classifiers were random forest (RF), neural network, naive Bayes, logistic regression and support vector machine. The receiver operating characteristic curve was used to compare model performances, which were validated by cross-validation; (3) Results: The RF model obtained the best performance after validation to predict OS and PFS and presented AUC, sensitivities and specificities (IC95%) of 0.87 ± 0.1, 0.79 ± 0.11 and 0.95 ± 0.06 for OS and 0.9 ± 0.07, 0.88 ± 0.09 and 0.91 ± 0.08 for PFS, respectively. (4) Conclusion: A RF classifier, based on pretreatment 18F-FDG PET radiomic features may be useful for predicting the survival status for melanoma patients, after one year of a first line systemic treatment by immunotherapy.

Background: The co-infusion of amino acid solutions during peptide receptor radionuclide therapy reduces the tubular reabsorption of ¹⁷⁷Lu-oxodotreotide, thus minimizing nephrotoxicity. In our nuclear medicine department, the patients received two different types of amino acid perfusion over time: a commercial solution (CS) containing 10% amino acids, and a 2.5% lysine–arginine (LysArg) hospital preparation, produced by a referral laboratory. The aim of the present study was to analyze the tolerance of the two amino acid solutions. Methods: The patient files were analyzed and double-checked. The study parameters comprised the gender, age, primary tumor site, type of amino acid perfusion, adverse events (AE) and WHO AE grades, antiemetic premedication, creatinine, and serum potassium level. Results: From February 2016 to February 2019, 76 patients were treated, for a total 235 cycles. AEs occurred in 71% of the CS cycles (n = 82/116), versus 18% (n = 21/119) in the LysArg group (p < 0.0001). In the CS group, the AEs were mostly WHO grade 4 (n = 24/82), and mostly grade 1 in the LysArg group (n = 13/21). Poisson regression showed a higher risk of AE overall and of grades 3 and 4 in the females and with CS. The mean creatinine clearance was identical before and after the PRRT cycles, whichever amino acid perfusion was used. Conclusions: The lysine–arginine preparation showed better tolerance than the commercial solution. The change to LysArg reduced the antiemetic premedication from four molecules to one.

We report the case of a 64-year-old woman with musculoskeletal pain and elevated serum parathyroid hormone who had undergone parathyroidectomy for primary hyperparathyroidism 4 years earlier. An ¹⁸F-choline PET/CT scan was performed and incidentally showed an intense uptake in a right upper lobe pulmonary nodule and in the right hilar, mediastinal, and cervical lymph nodes. Histopathological analysis confirmed the diagnosis of a small cell lung cancer. Clinical symptoms and recurrent hyperparathyroidism were therefore consistent with a paraneoplastic syndrome. A complete metabolic response was achieved on ¹⁸F-FDG PET/CT scan after chemotherapy.

18F-FDG PET-CT used to lack of resolution to detect vasculitis in the superficial cranial and cervical arteries. Very few cases, for which some of these arteries were visualized, are published, and the images were acquired using a dedicated PET protocol. We present a case, acquired using a routine whole-body protocol, with increased tracer uptake detected in vertebral arteries, internal and external carotid arteries, superficial temporal arteries, occipital arteries, maxillary arteries, facial arteries, and lingual arteries. It underlines the potential for newer-generation PET-CT system to assess vasculitis. 18F-FDG PET-CT may have an important role to detect and follow vasculitis in the future.

We report a case of a 23-year-old woman with concomitant Takayasu arteritis and nodular sclerosis classic Hodgkin lymphoma, both diagnosed by ¹⁸ F-FDG PET/CT. Treatment with ABVD chemotherapy, corticosteroids, and radiotherapy (without additional immunosuppressive therapy) led to parallel remission of both conditions. PET/CT after 2 chemotherapy cycles confirmed a complete metabolic response, sustained over 4 years. This case underscores the key role of ¹⁸ F-FDG PET/CT in diagnosing and monitoring both diseases and highlights the rare coexistence and concurrent evolution of large-vessel vasculitis and Hodgkin lymphoma, suggesting a possible paraneoplastic or indirect association that is seldom reported.