CT perfusion imaging can detect residual lung tumor early after radiofrequency ablation: a preliminary animal study on both tumoral and peri-tumoral region assessment

Abstract

Background: Radiofrequency ablation (RFA) is a minimally invasive procedure to treat lung cancer.Timely evaluation on residual lung tumor after RFA is crucial to the prognosis, hence, our objective is to assess CT perfusion (CTP) on detection of residual lung tumor early after RFA. Methods: CTP imaging was performed in 24 lung VX2 tumor models 1 day before and within 1 hour after RFA. CTP maps with dual-input (n=24) and single-input [n=13, with predominant ground glass opacity (GGO) after RFA] models were generated using the maximal slope method. Regions of interest were independently placed on the maximal cross-sectional tumor before and after RFA and on GGO after RFA by two thoracic radiologists. The bronchial flow (BF), pulmonary flow (PF) and perfusion index (PI) were compared between pre-RFA and post-RFA images. The parameters (BF, PF and PI of tumor; PF of GGO) of the complete and incomplete RFA groups were compared based on NADH and TUNEL staining and were correlated with the microvascular density (MVD). Results: The BF and PF decreased after RFA (all P values <0.03). The decrease in BF and PF (ΔBF and ΔPF) in the complete RFA group was higher (P=0.01; 0.02). The areas under the curve (AUC) of ΔBF and ΔPF at 14.85 and 17.25 mL/min/100 mL in determination of tumor with complete ablation were 0.80 and 0.78, respectively. ΔBF was positively correlated with MVD (P=0.046, r=0.468). PF of GGO with incomplete RFA was higher (P=0.001). The AUC of PF ≤29.4 mL/min/100 mL in determination of tumor with complete ablation was 0.99. Conclusions: CTP could detect residual lung tumor early after RFA in a rabbit model, which might provide a clinical solution to early treatment assessment after RFA.

Diagnostic value of dual-layer spectral detector CT in differentiating lung adenocarcinoma from squamous cell carcinoma

“…The degree of tumor enhancement depends only on the amount of contrast medium in the tumor vessels. The central type of lung cancer is mainly SC, mainly supplied by bronchial artery, whereas the peripheral type of lung cancer is mainly AC with dual blood supply of bronchial artery and pulmonary artery (20,21). Because the blood supply from the bronchial artery is later than that from the pulmonary artery, the VP better reflects the blood supply of the tumor.…”

“…ID reflects intravascular blood flow distribution and vascular status by quantitative analysis of iodine content, but it is influenced by many factors, including cardiac output and blood volume of the patient, concentration and flow rate of the contrast medium, and dose and rate of injection (20). NID was defined as the ratio of tumor ID to that of the aorta or subclavian arteries at the same level, and most researchers (8,(21)(22)(23) state that NID can reduce the effect of individual circulatory variability on tumor iodine content and thus more accurately reflect the blood supply of the lesion. However, in this comparison of AC and SC, we found that ID is more effective than NID in both the AP and the VP, which is consistent with the results of the study by Li et al (10).…”

Complications Risk Assessment and Imaging Findings of Thermal Ablation Treatment in Liver Cancers: What the Radiologist Should Expect

“…Different diagnostic tools may be employed, alone or in association [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ]. Computed tomography (CT) and magnetic resonance imaging (MRI) represent the traditional imaging tools employed during the pre-treatment phase in order to identify and assess the target area [ 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 ], and in surveillance of the patient to evaluate treatment efficacy and post-procedural complications [ 87 , 88 , 89 , 90 , 91 , 92 , 93 ]. Ultrasound examination (US), without or with contrast medium (CEUS), is an innovative tool, utilized for problem solving during pre- and post-treatment phases [ 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 ], although the main use of interest is the possibility of assessing immediate effects during the procedure [ 60 , 61 ].…”