Evaluation of Multisource Adaptive MRI Fusion for Gross Tumor Volume Delineation of Hepatocellular Carcinoma

Abstract

PurposeTumor delineation plays a critical role in radiotherapy for hepatocellular carcinoma (HCC) patients. The incorporation of MRI might improve the ability to correctly identify tumor boundaries and delineation consistency. In this study, we evaluated a novel Multisource Adaptive MRI Fusion (MAMF) method in HCC patients for tumor delineation.MethodsTen patients with HCC were included in this study retrospectively. Contrast-enhanced T1-weighted MRI at portal-venous phase (T1WPP), contrast-enhanced T1-weighted MRI at 19-min delayed phase (T1WDP), T2-weighted (T2W), and diffusion-weighted MRI (DWI) were acquired on a 3T MRI scanner and imported to in-house-developed MAMF software to generate synthetic MR fusion images. The original multi-contrast MR image sets were registered to planning CT by deformable image registration (DIR) using MIM. Four observers independently delineated gross tumor volumes (GTVs) on the planning CT, four original MR image sets, and the fused MRI for all patients. Tumor contrast-to-noise ratio (CNR) and Dice similarity coefficient (DSC) of the GTVs between each observer and a reference observer were measured on the six image sets. Inter-observer and inter-patient mean, SD, and coefficient of variation (CV) of the DSC were evaluated.ResultsFused MRI showed the highest tumor CNR compared to planning CT and original MR sets in the ten patients. The mean ± SD tumor CNR was 0.72 ± 0.73, 3.66 ± 2.96, 4.13 ± 3.98, 4.10 ± 3.17, 5.25 ± 2.44, and 9.82 ± 4.19 for CT, T1WPP, T2W, DWI, T1WDP, and fused MRI, respectively. Fused MRI has the minimum inter-observer and inter-patient variations as compared to original MR sets and planning CT sets. GTV delineation inter-observer mean DSC across the ten patients was 0.81 ± 0.09, 0.85 ± 0.08, 0.88 ± 0.04, 0.89 ± 0.08, 0.90 ± 0.04, and 0.95 ± 0.02 for planning CT, T1WPP, T2W, DWI, T1WDP, and fused MRI, respectively. The patient mean inter-observer CV of DSC was 3.3%, 3.2%, 1.7%, 2.6%, 1.5%, and 0.9% for planning CT, T1WPP, T2W, DWI, T1WDP, and fused MRI, respectively.ConclusionThe results demonstrated that the fused MRI generated using the MAMF method can enhance tumor CNR and improve inter-observer consistency of GTV delineation in HCC as compared to planning CT and four commonly used MR image sets (T1WPP, T1WDP, T2W, and DWI). The MAMF method holds great promise in MRI applications in HCC radiotherapy treatment planning.

Pixelwise Gradient Model for Image Fusion (PGMIF): a multi-sequence magnetic resonance imaging (MRI) fusion model for tumor contrast enhancement of nasopharyngeal carcinoma

“…As depicted in the results section, PGMIF outperforms other state-of-the-art fusion algorithms, as validated by both qualitative and quantitative analysis. Compared with studies like Cheung et al 2022 ( 25 ), our method does not require error and trial and in principle produce sharp image contrast. However, it should be noted that the study is limited to one dataset from one institution and no external testing was done to evaluate generalizability beyond the given dataset.…”

Advances in gross tumor target volume determination in radiotherapy for patients with hepatocellular carcinoma

“…Irrespective of the RT method used, precise determination of GTV is an essential prerequisite for successful treatment. Separating the border of the tumor from the adjacent normal tissue is crucial for accurate GTV determination ( 25 ). The development of a Fibrous Capsule (FC) is a distinctive pathological characteristic of HCC, which occurs due to the interaction between the tumor and the liver.…”

Review of functional magnetic resonance imaging in the assessment of nasopharyngeal carcinoma treatment response

“…Due to inflammation and scarring after RT, accurate biopsy sampling is challenging and not reliable 3 . Instead, multiparametric magnetic resonance imaging (MRI) has been used for treatment assessment 10 . In the past, the application of MRI in oncology was limited to conventional morphological images only.…”

“…3 Instead, multiparametric magnetic resonance imaging (MRI) has been used for treatment assessment. 10 In the past, the application of MRI in oncology was limited to conventional morphological images only.…”