The Effect of Metabolic PET Parameters on Survival Outcome in Malignant Pleural Mesothelioma

Abstract

Objective: 18-Fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) is one of the most valuable imaging types and tumor metabolic volume is another parameter that can be obtained from PET-CT. Our primary objective is to evaluate the effect of PET-CT metabolic parameters on survival in patients with malignant pleural mesothelioma (MPM). Methods:A total of 29 patients with MPM had been evaluated with 18F-FDG PET-CT between January 2016 and December 2017. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized uptake values (SUVmax) and TLG/liver SUVmean values were calculated. Also, effects of these parameters on survival rates were evaluated.Results: Histological subtypes of the disease were determined as epithelioid (n=24), biphasic (n=3), sarcomatoid (n=2). Median overall survival was 255 days (21-903). Median MTV was 225 cm³ (10-1879), median TLG was 1056 g/ml*cm³ (36-18927), median SUVmax was 7.7 (1.5-20) and TLG/liver SUVmean ratio was 561.2 (14.9-8113.7). Sensitivity and specificity for MTV 113 cut-off value were 86.4% and 85.7%, respectively. Determined cut-off value for TLG was 419.5, sensitivity and specificity of the value were 81.8% and 85.7%, respectively. Additionally, determined cut-off value for TLG/liver SUVmean ratio was 107.4, the rate of sensitivity and specificity for this value were 95.5% and 71.4%, respectively. The patients with higher MTV, TLG and TLG/liver SUVmean had worse survival rate. Conclusion:We confirmed significant association between MTV, TLG and TLG/liver SUVmean values and patients survival. These promising PET derived parameters can be used for evaluating treatment response and prognosis in MPM. ÖzAmaç: 18-Florodeoksiglukoz pozitron emisyon bilgisayarlı tomografi (18F-FDG PET-BT) en değerli görüntüleme yöntemlerinden biridir ve metabolik tümör volümü de PET-BT'den elde edilebilecek başka bir parametredir. Bu çalışmada MPM'de metabolik PET-BT parametrelerinin sağkalım üzerine etkisini değerlendirmeyi amaçladık.Yöntemler: Çalışmaya Ocak 2016 -Aralık 2017 tarihleri arasında tedavi öncesi 18F-FDG PET-BT çekimi yapılan 29 hasta dahil edildi. Tüm hastaların metabolik tümör volümü (MTV), total lezyon glikolizi (TLG), standardize tutulum değerleri (SUVmax) ve total lezyon glikolizi/karaciğer SUVmean (TLG/KC SUVmean) değerleri hesaplandı. Ayrıca bu parametrelerin sağkalım üzerine etkileri değerlendirildi.Bulgular: Histolojik alt tip olarak epitelioid (n=24), bifazik (n=3) ve sarkomatoid (n=2) alt gruplardan oluşmaktaydı. Ortanca sağkalım 255 (21 -903) gün idi. Median MTV değeri 225 cm³ (10-1675), median TLG değeri 1056 g/ml*cm³ (36-1776), median SUVmax değeri 7.7 (1.5-20) ve median TLG/KC SUVmean değeri 561,2 (14.9-8113.7) idi. MTV için cut off değer olarak 113 alındığında sensitivite %86,4 ve spesifite %85,7 idi. TLG için cut off değer olarak 419.5 alındığında sensitivite %81,8 ve spesifite %85,7 idi. Ayrıca TLG/KC SUVmean için cut off değer olarak 107.4 alındığında sensitivite %95,5 ve spesifite %71,4 idi. Yüksek MTV, TLG ve TLG/KC SUV...

Effects of the changes between preand post-treatment 18F-FDG PET-CT volumetric parameters on overall survival in pleural mesothelioma

“…In the study by Klabatsa et al [14], median OS was reported as 6.4 months in patients with MTV > 755 compared to 14.4 months in those with MTV < 755 (p = 0.001). Akdeniz et al [11] also found OS of 24.6 ± 4.1 months in patients with MTV1 < 113 compared to 8.2 ± 1.3 months in those with MTV > 113 (p = 0.002).…”

“…The same study also determined TLG1 levels of 389.2 ± 492.9 in responsive patients compared to levels of 2666.7 ± 4122.7 in unresponsive patients (p = 0.093) [15]. In the study by Akdeniz et al [11], patients with TLG1 < 419.5 had OS of 22.4 ± 4.2 and patients with TLG > 419.5 had overall survival of 8.5 ± 1.3 (p = 0.008).…”

“…The evaluation of post-chemotherapy treatment response is also quite critical in terms of treatment continuation or treatment change. Metabolic tumor parameters measured on PET-CT, such as SUVmax and SUVmean, are useful in the evaluation of treatment response [11]. In addition to conventional imaging methods, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) parameters are utilized to assess the efficacy of treatment in tumor response evaluation.…”

The benefit of surgery on survival for patients with stage 1 and 2 malignant pleural mesothelioma

“…The contrast-enhanced thorax tomography and 18-Fluorodeoxyglucose positron emission tomography-computed tomography are used to identify pleural abnormalities, pleural effusion, parenchymal lesions, and the stage of the disease, guide pleural biopsy, and predict survival 3 . Video-assisted thoracoscopic surgery (VATS) or an open thoracotomy provides sufficient tissue for diagnosis 4 .…”