Aim The aim of this study was to evaluate the impact of ¹⁸F-fluorodeoxyglucose (¹⁸F-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 ¹⁸F-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.

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 ¹⁸F-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 ¹⁸F-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.

Aim: We aimed to analyze the prognostic factors affecting disease-specific survival in patients with recurrent and/or metastatic differentiated thyroid carcinoma. Methods: Seventy-seven patients with recurrent/metastatic differentiated thyroid carcinoma who were previously treated with total thyroidectomy followed by radioactive iodine therapy were enrolled. Recurrent/metastatic disease was detected by positron emission tomography/computed tomography. At the time of last follow-up (mean 4.8±1.3 years), patients were grouped as having (i) clinical remission ( n =17), (ii) stable disease ( n =22), or (iii) progressive disease ( n =38). We retrospectively examined the prognostic impact of clinical factors (age, sex, TNM stage), histopathological factors of the primary tumor (tumor size, histology, the presence of vascular invasion, extrathyroidal spread, and lymph node metastasis), serum thyroglobulin levels, and metabolic parameters of recurrent/metastatic disease such as radioactive iodine avidity, F18-fluorodeoxyglucose uptake (SUV _max ) in metastatic deposits, number and location of F18-fluorodeoxyglucose–avid lesions (locoregional vs. distant), and the impact of surgery on disease-specific survival. Results: Lack of vascular invasion ( p =0.04), presence of surgically amenable recurrence/metastasis ( p =0.0001), and suppressible on-therapy serum thyroglobulin levels at the time of recurrent/metastatic disease ( p =0.01) were strong predictors of clinical remission and good prognosis on multivariate analysis. Lesional SUV _max , number or location of F18-fluorodeoxyglucose–avid lesions, and TNM stage did not correlate with clinical outcome. Clinical remission could only be achieved by curative surgery. Patients without curative surgery for recurrence/metastasis had a 43 times higher risk to develop progressive disease than patients with disease amenable to surgery. Conclusions: Curative surgery is an essential therapeutic modality to achieve clinical remission in metastatic/recurrent differentiated thyroid carcinoma. Positron emission tomography/computed tomography is a powerful method to detect surgically resectable disease for the selection of patients who may benefit from curative surgery.