Lokal İleri Evre Meme Kanserlerinde 18-Fdg Pet/Bt Parametrelerinin Neoadjuvan Kemoterapi Cevabı Öngörüsündeki Yeri ve Manyetik Rezonans Görüntüleme ile Karşılaştırılması
Abstract
Several studies have shown promising results for the prediction of pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer (LABC) using 18 FDG PET/CT. Dynamic contrast enhanced magnetic resonance imaging (dCE-MRI) can assess the response to NAC by providing information on the angiogenesis and morphology of the tumor. This study was planned to compare the predictive value of semi-quantitative paratemers obtained by dCE-MRI, dynamic and dual-phase 18FDG-PET/CT in LABC patients receiving NAC. Fortysix patients with LABC underwent dCE-MRI and 18FDG-FDG/PET at baseline and after 2-3 cycles of NAC (interim). Tumor diameter, spherical (SV), angiographic volumes (AV), peak signal intensity (PSI), rapid and medium component of initial rise, percentage of Type I, Type II, Type III curves were calculated. Dynamic 18FDG and dual phase images were recorded in the prone position. Using 18FDG dynamic data, SUVmax values for 2nd, 5th and 30th minutes were measured. In addition, SUL2peak, metabolik volume (Per2V) and total lesion glycolysis (Per2TLG) values were measured for the first 2 minutes data. For early (E) and late (L) images, SUVmax, SUVmean and SUVpeak, TLG and metabolic tumor volume (MTV) was measured using adaptive (adp) and 42% thresholding method. Baseline and interim studies were used to calculate percentage changes and compared according to the surgery results; pCR vs non-pCR. ROC curves were obtained to calculate the AUCs for the prediction of pCR. Optimal treshold values to discriminate between pCR and non-pCR were calculated. Late prone images had higher sensitivity and specificity to detect the residual tumor (91%, 71.4%) and residual lymph node (62.5%, 87.5%) compared to MRI (84%, 37.5%, LN: 37.5%, 57.5%) and early prone images (84.5%, 75%, LN: 50%, 83%). PET/CT parameters were significantly different between pCR and non-pCR groups, except MTV-42 values. Higher AUC values were obtained for SV% (0.83), Per2V% (0.826), MTV (% 0.79), TLG% (0.785), and TTLG % (0.828). Optimal cut-off values (sens, spec.and acc.) values were -65% for SV% ( 80%, 73%, 75%), -67.6% for Per2V% (87%, 78%, 80.7%), -73% for MTV% (78%, 86%, 84%), -88% for TLG% (78%, 81%, 80%), and -88% for TTLG (78%, 86%, 84%), respectively. Semi-quantitavite parameters for 18 FDG PET/CT and volumetric changes obtained with dCE-MRI can predict response to NAC. Percentage changes in MTV, TLG and Per2V can identify nonresponding patients better than other parameters.