Ocena radiološko neopredeljivih pljučnih nodulov z dinamično pozitronsko emisijsko tomografijo združeno z računalniško tomografsko preiskavo in perfuzijskimi parametri

Marin, Aleksander (author), Salapura, Vladka (mentor), Mirsadraee, Saeed (comentor)

Izhodišče Razvoj novih slikovnih diagnostičnih tehnologij nam omogoča funkcionalno sledenje radiofarmakov in kontrastnih sredstev v pljučnih nodulih. Namen doktorske naloge je bil oceniti vlogo dinamične pozitronske emisijske tomografije in računalniške tomografije z radioizotopom 18-fluordeoksiglukozo (18F-FDG PET/CT) in perfuzijske CT pri karakterizaciji pljučnih nodulov. Bolniki in metode V raziskavo smo vključili 20 zaporednih preiskovancev z naključno odkritim pljučnimi noduli, ki so opravili dinamično 18F-FDG PET/CT preiskavo in perfuzijski CT. V nodulih smo izmerili vrednost ‘standardised uptake value’ (SUVmax), na dinamičnem 18F-FDG PET/CT smo s Patlakovo metodo določili konstanto fosforilacije (Ki). Na perfuzijskem CT smo s Patlakovim modelom izračunali parameter volumen krvi ‘blood volume’ (BV), z metodo maksimalnega naklona smo določili perfuzijski parameter arterijskega pretoka ‘arterial flow’. Nodule smo razdelili v benigno in maligno skupino na osnovi histološke diagnoze ali 2-letnega sledenja s CT. Parametre smo statistično primerjali med skupinama z neparemtričnim Mann-Whitney testom, p<0.05 je veljal kot statistično pomemben. Rezultati Analizirali smo 21 pljučnih nodulov (povprečen premer ± SD: 20,1±7,5 mm; 9-29 mm) pri 20 bolnikih (11 moških, 9 žensk, povprečna starost 65,3 leta, starostni razpon 50-76 let). Povprečna SUVmax ±SD v benigni skupini je bila 2.2±1.7, v maligni 7.0±4.5, p=0.0148. Ki parameter v benigni skupini je bil 0.0057±0.0071 min-1, v maligni skupini 0.0230±0.0155 min-1, p=0.0311. Povprečen BV med benignimi noduli je bil 11.6857±6.7347 ml/100ml ter 28.3400±15.9672 ml/100ml med malignimi noduli, p=0.0250. Povprečen AF v maligni skupini je bil 74.4571±89.0321 ml/100g/min, v maligni skupini 89.200±49.8883 ml/100g/min, p=0.1613. Zaključki Potrdili smo hipotezo, da je metabolični parameter dinamične 18F-FDG PET/CT različnen v benignih in malignih pljučnih nodulih. Hipotezo, da so parametri perfuzijske CT različni v benignih in malignih pljučnih nodulih, smo delno potrdili in delno zavrgli. Potrdili smo, da je parameter BV perfuzijske CT različen v benignih in malignih pljučnih nodulih. Parameter AF perfuzijske CT ni bil različen v benignih in malignih pljučnih nodulih.

• Language: Slovenian
• Keywords: pljučni nodul, CT, PET/CT, dinamični, perfuzija
• Work type: Doctoral dissertation
• Organization: MF - Faculty of Medicine
• Year: 2021
• PID: 20.500.12556/RUL-133313
• COBISS.SI-ID: 102029059
• Publication date in RUL: 21.11.2021

Secondary language

• Language: English
• Title: Evaluation of the radiologically indeterminate lung nodules with dynamic positron emission tomography with computed tomography and perfusion parameters

Abstract

Background Advances in imaging technology now enable evaluation of lung nodule perfusion. We aimed to derive metabolic parameters relating to pulmonary nodules using dynamic 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG PET/CT), and nodule perfusion parameters derived through perfusion computed tomography (CT), and to determine whether these factors can differentiate benign from malignant pulmonary nodules. Materials and Methods Twenty patients with 21 pulmonary nodules incidentally detected on CT were recruited to undergo a dynamic 18F-FDG PET/CT and a perfusion CT. For each nodule the maximum standardised uptake value (SUVmax) was measured on conventional 18F-FDG PET/CT images. The net FDG phosphorylation rate or influx constant (Ki) was calculated from the dynamic 18F-FDG PET/CT data sets by using Patlak plot model. Arterial flow (AF) using the maximum slope model and blood volume (BV) using the Patlak plot method for each nodule were calculated from the perfusion CT. All nodules were characterised as malignant or benign based on histopathology or 2 year follow up CT. SUVmax, Ki and perfusion indices were statistically compared between the two groups using the nonparametric Mann-Whitney test. Results Twelve malignant and nine benign pulmonary nodules were analysed (median size 20.1 mm, 9–29 mm) in 21 patients (male/female=11/9; mean age±SD: 65.3±7.4; age range: 50–76 years). The average SUVmax±SD of the benign and malignant nodules were 2.2±1.7 vs 7.0±4.5, respectively (p=0.0148). The dynamic 18F-FDG PET/CT average Ki values in benign and malignant nodules were 0.0057±0.0071 and 0.0230±0.0155 min-1, respectively (p=0.0311). Average BV parameters for the benign and malignant nodules were 11.6857±6.7347 and 28.3400±15.9672 ml/100ml, respectively (p=0.0250). Average values of AF for the benign and malignant nodules were 74.4571±89.0321 and 89.200±49.8883 ml/100g/min, respectively (p=0.1613). Conclusion Dynamic 18F-FDG PET/CT and perfusion CT can both differentiate benign from malignant lung nodules. Perfusion CT derived BV proved the most accurate parameter at making this differentiation.

• Keywords: lung nodule, CT, PET/CT, dynamic, perfusion