Checkpoint inhibitors, cancer immunotherapies, are the new forms of treatment for gray zone lymphoma, a rare subtype that combines the characteristics of both Hodgkin and non-Hodgkin disease forms. Programmed cell death protein 1/ programmed cell death ligand 1 (PD-L1/PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) modulate the immune system function. Immunological checkpoints can be stimulatory or inhibitory, and tumors can use these checkpoints to protect against immune system attacks. This is a case report of a difficult diagnosis and describes the most current treatment using checkpoint inhibitors, through the review of the clinical record of a patient diagnosed with gray area lymphoma in August 2019, using a descriptive and cross-sectional analysis of the clinical history and disease evolution. The case showed that pembrolizumab therapy is an effective treatment option for patients with rare gray zone lymphoma refractory to different lines of treatment. Both the diagnosis and treatment of gray area lymphoma remain a challenge for the medical and multiprofessional teams, and collaboration between them ensured effective treatment for the patient.

Background: This work aims to present a nuclear medicine imaging service's data regarding applying positron emission–computing tomography (PET/CT) scans with the radiopharmaceutical 68Ga-PSMA-HBED-CC (68Ga-PSMA-11) to diagnose prostate cancer clinical relapse. Methods: Eighty patients with a mean age of 68.26 years with an average prostatic-specific antigen blood level of 7.49 ng/ml (lower concentration = 0.17 ng/ml) received 68Ga-PSMA-11 intravenously, and full-body images of PT-CT scanning were obtained. Of the total of patients admitted to the imaging service, 87.5% were examined for disease's biochemical recurrence and clinical relapse, and 70.0% had a previous radical prostatectomy (RP). Results: Of the patients without RP, 95.8% had detection of intra-glandular disease. The 68Ga-PSMA-11 PET/CT imaging results revealed small lesions, even in patients with low blood levels of prostatic-specific antigen, mainly in metastatic cancer cases in lymph nodes and bones. Conclusion: The 68Ga-PSMA-11 PET/CT imaging was essential in detecting prostate cancer, with significantly high sensitivity in detecting recurrent cases. Due to its inherent reliability and sensitivity, PET/CT scanning with 68Ga-PSMA-11 received an increasing number of medical requests throughout the present follow-up study, confirming the augmented demand for this clinical imaging procedure in the regional medical community.