Clinical behaviour of papillary thyroid cancer oncocytic variant: stage-matched comparison versus classical and tall cell variant papillary thyroid cancer.

OBJECTIVE: Papillary thyroid cancer (PTC) has many variants and most of them are mild tumors. Oncocytic variant (OV) is a rare subtype of PTC. There are controversial results about its prognosis in the literature. We investigated its aggressivity and clinical course by comparing it with classical variant (CV) and tall cell variant (TV) of PTC over a stage-matched design. MATERIAL AND METHODS: Pure 100 OV, 71TV and 1219 CV were included in this retrospective cohort study. OV was compared with CV and TV according to independent prognostic parameters. OV was also compared stage by stage with CV and TV for recurrence. RESULTS: Mean age was 46,8 years and male/female ratio 25/75 for OV. The recurrence rates in our study were 16% in OV, 13,5% in CV and 56% in TV. There is a statistically significant difference according to recurrence between stage I and stage IV OV and CV (p=0.023, p=0.03, respectively). There is also a statistically significant difference between stage I and stage IV OV and TV according to recurrence (p=0.001, p=0.024, respectively). OV can be supposed to behave between CV and TV, but very closer to CV. CONCLUSIONS: OV seems to be slightly more aggressive than CV. Despite an inadequate sample size for stage II and III, our findings imply an increased recurrence risk for OV than CV at the advanced stages (stage III and IV) and CV has an unfavorable prognosis than OV at early stages (stage I and II) according to stage-matched model.

Can metabolic tumor parameters on primary staging 18F-FDG PET/CT aid in risk stratification of primary central nervous system lymphomas for patient management as a prognostic model? / ¿Pueden contribuir los parámetros tumorales metabólicos, establecidos mediante 18F-FDG PET/TC para estadificación primaria, a la estratificación del riesgo de los linfomas del sistema nervioso central, para el tratamiento del paciente como modelo pronóstico?

OBJECTIVE: Primary central nervous system (CNS) lymphoma is an aggressive and fatal extranodal non-Hodgkin lymphoma jailed in CNS at initial diagnosis. Its prognosis is poor and the disease has a fatal outcome when compared with systemic non-Hodgkin lymphoma. A few baseline risk stratification scoring systems have been suggested to estimate the prognosis mainly based on serum lactate dehydrogenase level,age, Karnofsky performance score, involvement of deep brain structures and cerebrospinal fluid protein concentration. 18F-FDG PET/CT has a high prognostic value with respect to overall survival and disease-free survival in many cancers and lymphomas. We aimed to investigate metabolic tumor indexes on primary staging 18F-FDG PET/CT as prognostic markers in primary CNS lymphoma. MATERIAL AND METHODS: Fourteen patients with primary CNS diffuse large B-cell lymphoma (stage i) were enrolled in this retrospective cohort study. Primary staging 18F-FDG PET/CT was performed and quantitative parameters like maximum standardized uptake value, average standardized uptake value, metabolic tumor volume and total lesion glycolysis (TLG) were calculated for all patients before the treatment. Cox regression models were performed to determine their relation with survival time. RESULTS: In the evaluation of all potential risk factors impacting recurrence/metastases (age, sex, serum lactate dehydrogenase, involvement of deep brain structures, maximum standardized uptake value, average standardized uptake value, metabolic tumor volume, and TLG) with univariate analysis, TLG remained statistically significant (P=.02). CONCLUSION: Metabolic tumor parameters are useful in prognosis estimation of primary CNS lymphomas, especially TLG, which is the most important one and may play a role in patient management.

Post-surgical ablation of thyroid remnants with high-dose (131)I in patients with differentiated thyroid carcinoma.

The aims of this study were to evaluate the efficacy of an empirically determined "fixed" high ablative dose of radioiodine ((131)I) therapy and to determine the utility of ultrasonography (US) in dose determination. A retrospective analysis was performed of 242 thyroid cancer cases treated with "fixed" high-dose (131)I for ablation of thyroid remnants without a pre-ablative (131)I diagnostic scintigraphy or radioiodine uptake study. Treatment doses ranged from 1850 MBq (50 mCi) to 7.4 GBq (200 mCi). The selection of the treatment dose was based on the surgical and pathological findings as well as the remnant thyroid volume calculated by US. A successful ablation was defined as the absence of activity in the thyroid bed on subsequent imaging studies. Successful ablation was obtained in 218 of the 242 patients (90%). In 162 of the 218 patients (74.3%), successful ablation was achieved after a single (131)I treatment. The remnant thyroid volume calculated by US was significantly different (P=0.04) between those who were successfully ablated and those who were not. The total (131)I dose needed for successful ablation was significantly higher in males (P=0.003). Patients with higher post-operative thyroglobulin (Tgb) levels and patients with a higher stage of disease required higher doses (P=0.036 and P=0.021 respectively). Serum Tgb levels were under 10 ng.ml(-1) in 220 of the 242 patients (90%) following radioiodine ablation while not receiving L-thyroxine suppression. Nineteen patients (7.8%) showed metastases on post-therapy scan and successful treatment was achieved in 11 of 19 (57.8%). Four of the 19 patients with distant metastases (revealed on post-treatment scan) were found to have been given a treatment dose of less than 200 mCi based on the proposed empirical approach. These results indicate that "fixed" high-dose (131)I treatment is clinically feasible with an acceptable dose underestimation rate, and the utilization of US in the determination of the thyroid remnant volume provides more accurate and reproducible results.