The incidence of secondary central nervous system involvement in patients with non-Hodgkin's lymphoma as detected by 18F-FDG PET/CT.

AIM: Secondary central nervous system (CNS) involvement is a devastating and usually fatal complication of non-Hodgkin's lymphoma (NHL). We aimed to evaluate the incidence of secondary CNS involvement and the value of (18)F-FDG PET/computed tomography (CT) imaging in the detection of secondary CNS involvement in patients with NHL. METHODS: A total of 123 immunocompetent patients (58 men, 65 women; mean age: 56.5±19.2) with biopsy-proven NHL who underwent (18)F-FDG PET/CT for primary staging (n=68) and restaging (n=55) of recurrent disease were reviewed retrospectively. Those with secondary CNS involvement as diagnosed on PET/CT were identified. CNS involvement was confirmed by MRI and cerebrospinal fluid cytology. RESULTS: The clinical Ann Arbor stages of the patient population were as follows: stage I - 10 patients; stage II - 44 patients; stage III - 32 patients, and stage IV - 37 patients. PET/CT detected CNS involvement in six patients. The ages of patients with CNS disease ranged from 23 to 68 (mean: 47.2) years. Three patients presented with CNS involvement associated with systemic disease manifestation at initial diagnosis; one patient had isolated CNS relapse and two had relapsed systemic NHL with progression to CNS involvement. Relapse interval was 8-12 months following initial diagnosis. The types of CNS involvement in patients were as follows: parenchymal (n=2), leptomeningeal (n=2), both parenchymal and leptomeningeal (n=1), and pituitary gland involvement (n=1), which is an uncommon manifestation. Median duration of survival was 2.5 months after the diagnosis of CNS involvement. CONCLUSION: The incidence of secondary CNS involvement was 4.4% at initial diagnosis and 5.4% among patients with relapse of lymphoma in our study. PET/CT is a sensitive, objective, and valuable method for the diagnosis of secondary CNS involvement in patients with NHL. In addition, pituitary gland involvement, as a very rare manifestation of secondary CNS lymphoma, has been shown.

Clinical impact of ¹8F-FDG PET/CT in the pretreatment evaluation of patients with locally advanced cervical carcinoma.

AIM: The aim of this study was to evaluate the impact of F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) on the pretreatment evaluation of patients with locally advanced cervical carcinoma. METHOD: Forty-seven patients with stage 2b-4a cervical carcinoma underwent F-FDG PET/CT for initial staging and pretreatment evaluation. Concomitant pelvic/abdominal MRI was performed in 38 patients. The contribution of PET/CT to treatment planning was evaluated, and the prognostic performance of PET/CT was compared with that of MRI. Lymph node (LN) status on PET/CT was correlated with patient follow-up data. RESULTS: PET/CT detected hypermetabolic LNs in 39/47 patients. In 24/39 patients (62%), PET/CT was found to be superior to MRI. In 13/24 patients (54%), PET/CT detected para-aortic ± pelvic LNs, which were not found on MRI. PET/CT successfully detected distant metastases in 10 patients and peritonitis carcinomatosa in one patient; these patients were upstaged clinically. Overall, PET/CT has led to modifications in the extent of the radiotherapy field in 34% of patients and to major alterations in treatment plans in 23% of patients with widespread disease. The frequency of PET-positive LNs was significantly lower in patients who were alive without disease at the time of last follow-up (60%) compared with patients with persistent disease and nonsurvivors (100%, P=0.012). CONCLUSION: The presence of PET-positive LNs has prognostic significance in patients with cervical carcinoma. PET/CT has the potential to show both lymphatic and distant metastases, which results in modifications to the chemoradiotherapeutic regimen. The use of PET/CT must be included in the initial workup of patients with locally advanced cervical carcinoma.