Utility of the PET-CT in the evaluation of early response to treatment in the diffuse large B-cell lymphoma. Preliminary results.

OBJECTIVE: To assess the role of FDG-PET/CT performed after the first cycles of chemotherapy in the prediction of response to treatment in patients with diffuse large B-cell lymphoma. METHODS: Twenty patients (mean age: 48 years) were included, 16 initial staging and 4 relapse. All patients underwent PET/CT at 3 times: 1) Baseline, 2) After 1-3 cycles of chemotherapy (early response assessment), and 3) End of treatment (evaluation of final response). Early PET/CT findings were correlated to the end-treatment PET/CT and follow-up. The evaluation of the response was established according to the decrease in uptake of the lesions (SUVmax). In the early assessment, a good response indicator (GRI) was obtained when the lesion disappeared or had more than 50% reduction in SUVmax. At the end of the treatment, a complete metabolic response (CMR) was determined in negative PET scans. Follow-up was superior to 19 months and final outcome was established as progression/relapse or no evidence of disease (NED). RESULTS: At the early treatment evaluation, 16/16 patients of initial staging (100%) and 2/4 of relapse (50%) achieved GRI. At the end of treatment evaluation, 14/16 patients of initial staging with GRI achieved CMR and 1/16 PMR: 14 were alive with NED in the follow-up while 1 relapsed. In the second group, 2/2 patients with GRI achieved CMR (100%): 1 continued with NED in the follow-up and another relapsed. CONCLUSION: FDG-PET/CT after the first cycles of chemotherapy is useful to monitor treatment due to its high negative predictive value (87.5%), using it to modify treatment early in the non-responders.

[Calculation of the left ventricular ejection fraction. Comparison between 4 different instruments]. / Determinación de la fracción de eyección del ventrículo izquierdo realizada con 4 programas de cálculo distintos.

AIM: The aim of this study was to analyse the relationship between left ventricular ejection fractions (EF) obtained using four different instruments. MATERIAL AND METHODS: Eighty-five EF values were analysed. Gated acquisition was performed with the same gammacamera (SOPHA) using 99mTc-labelled red cells. Each EF was obtained using four processing systems: NXT (SOPHA), Entegra (Gems), Odyssey (Philips) and Esoft (Siemens), always working in automated mode. The paired student's t-test, Spearman correlation and Bland-Altman analysis were used to compare methods, and Deming regression was applied. RESULTS: Mean values and standard deviations for each program were: NXT: 61 +/- 9; Entegra: 60 +/- 10; Odyssey: 60 +/- 9; Esoft: 60 +/- 10. Although no significant differences were found as a whole and the values were linearly related, the methods are not interchangeable. CONCLUSIONS: The same program should be used in the follow-up of each patient, which is now easily achievable by means of the DICOM standard.