An Update on Randomized Clinical Trials in Hepatocellular Carcinoma

Paired conditional generative adversarial network for highly accelerated liver 4D MRI

Purpose.4D MRI with high spatiotemporal resolution is desired for image-guided liver radiotherapy. Acquiring densely sampling k-space data is time-consuming. Accelerated acquisition with sparse samples is desirable but often causes degraded image quality or long reconstruction time. We propose the Reconstruct Paired Conditional Generative Adversarial Network (Re-Con-GAN) to shorten the 4D MRI reconstruction time while maintaining the reconstruction quality.Methods.Patients who underwent free-breathing liver 4D MRI were included in the study. Fully- and retrospectively under-sampled data at 3, 6 and 10 times (3×, 6× and 10×) were first reconstructed using the nuFFT algorithm. Re-Con-GAN then trained input and output in pairs. Three types of networks, ResNet9, UNet and reconstruction swin transformer (RST), were explored as generators. PatchGAN was selected as the discriminator. Re-Con-GAN processed the data (3D +t) as temporal slices (2D +t). A total of 48 patients with 12 332 temporal slices were split into training (37 patients with 10 721 slices) and test (11 patients with 1611 slices). Compressed sensing (CS) reconstruction with spatiotemporal sparsity constraint was used as a benchmark. Reconstructed image quality was further evaluated with a liver gross tumor volume (GTV) localization task using Mask-RCNN trained from a separate 3D static liver MRI dataset (70 patients; 103 GTV contours).Results.Re-Con-GAN consistently achieved comparable/better PSNR, SSIM, and RMSE scores compared to CS/UNet models. The inference time of Re-Con-GAN, UNet and CS are 0.15, 0.16, and 120 s. The GTV detection task showed that Re-Con-GAN and CS, compared to UNet, better improved the dice score (3× Re-Con-GAN 80.98%; 3× CS 80.74%; 3× UNet 79.88%) of unprocessed under-sampled images (3× 69.61%).Conclusion.A generative network with adversarial training is proposed with promising and efficient reconstruction results demonstrated on an in-house dataset. The rapid and qualitative reconstruction of 4D liver MR has the potential to facilitate online adaptive MR-guided radiotherapy for liver cancer.

Magnetic Resonance-Guided Stereotactic Body Radiotherapy of Liver Tumors: Initial Clinical Experience and Patient-Reported Outcomes

PURPOSE/OBJECTIVE

Stereotactic body radiation therapy (SBRT) has emerged as a valid treatment alternative for non-resectable liver metastases or hepatocellular carcinomas (HCC). Magnetic resonance (MR) guided SBRT has a high potential of further improving treatment quality, allowing for higher, tumoricidal irradiation doses whilst simultaneously sparing organs at risk. However, data on treatment outcome and patient acceptance is still limited.

MATERIAL/METHODS

We performed a subgroup analysis of an ongoing prospective observational study comprising patients with liver metastases or HCC. Patients were treated with ablative MR-guided SBRT at the MRIdian Linac in the Department of Radiation Oncology at Heidelberg University Hospital between January 2019 and February 2020. Local control (LC) and overall survival (OS) analysis was performed using the Kaplan-Meier method. An in-house designed patient-reported outcome questionnaire was used to measure patients' experience with the MR-Linac treatment. Toxicity was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE v. 5.0).

RESULTS

Twenty patients (with n = 18 metastases; n = 2 HCC) received MR-guided SBRT for in total 26 malignant liver lesions. Median biologically effective dose (BED at α/β = 10) was 105.0 Gy (range: 67.2-112.5 Gy) and median planning target volume was 57.20 ml (range: 17.4-445.0 ml). Median treatment time was 39.0 min (range: 26.0-67.0 min). At 1-year, LC was 88.1% and OS was 84.0%. Grade I° gastrointestinal toxicity °occurred in 30.0% and grade II° in 5.0% of the patients with no grade III° or higher toxicity. Overall treatment experience was rated positively, with items scoring MR-Linac staff's performance and items concerning the breath hold process being among the top positively rated elements. Worst scored items were treatment duration, positioning and low temperature.

CONCLUSION

MR-guided SBRT of liver tumors is a well-tolerated and well-accepted treatment modality. Initial results are promising with excellent local control and only mildest toxicity. However, prospective studies are warranted to truly assess the potential of MR-guided liver SBRT and to identify which patients profit most from this new versatile technology.

Real-time Magnetic Resonance-guided Liver Stereotactic Body Radiation Therapy: An Institutional Report Using a Magnetic Resonance-Linac System

Background Stereotactic body radiation therapy (SBRT) is a proven and effective modality for treatment of hepatic primary and metastatic tumors. However, these lesions are challenging for planning and treatment execution due to natural anatomic changes associated with respiration. Magnetic resonance imaging (MRI) offers superior soft tissue contrast resolution and the ability for real-time image-guided treatment delivery and lesion tracking. Objective To evaluate the plan quality, treatment delivery, and tumor response of a set of liver SBRT cancer treatments delivered with magnetic resonance (MR)-guided radiotherapy on a MR-linear accelerator (MR-linac). Methods Treatment data from 29 consecutive patients treated with SBRT were reviewed. All treatments were performed using a step and shoot technique to one or more liver lesions on an MR-linac platform. Patients received 45 to 50 Gy prescribed to at least 95% of the planning target volume (PTV) in five fractions except for two patients who received 27-30 Gy in three fractions. Computed tomography and MRI simulation were performed in the supine position prior to treatment in the free-breathing, end exhalation, and end inhalation breath-hold positions to determine patient tolerability and potential dosimetric advantages of each technique. Immobilization consisted of using anterior and posterior torso MRI receive coils embedded in a medium-sized vacuum cushion. Gating was performed using sagittal cine images acquired at 4 frames/second. Gating boundaries were defined in the three major axes to be 0.3 to 0.5 cm. An overlapping region of interest, defined as the percentage volume allowed outside the boundary for beam-on to occur, was set between 1 and 10%. The contoured target was assigned a 5-mm PTV expansion. Organs at risk constraints adopted by the American Association of Physicists in Medicine Task Group 101 were used during optimization. Results Twenty-nine patients, with a total of 34 lesions, successfully completed the prescribed treatment with minimal treatment breaks or delays. Twenty-one patients were treated at end-exhale, and six were treated at end-inhale. Two patients were treated using a free-breathing technique due to poor compliance with breath-hold instructions. The reported mean liver dose was 5.56 Gy (1.39 - 10.43; STD 2.85) and the reported mean liver volume receiving the prescribed threshold dose was 103.1 cm3 (2.9 - 236.6; STD 75.2). Follow-up imaging at one to 12 months post treatment confirmed either stable or decreased size of treated lesions in all but one patient. Toxicities were mild and included nausea/vomiting, abdominal pain and one case of bloody diarrhea. Four patients died due to complications from liver cirrhosis unrelated to radiation effect. Conclusion SBRT treatment using a gated technique on an MR-linac has been successfully demonstrated. Potential benefits of this modality include decreased liver dose leading to decreased toxicities. Further studies to identify the benefits and risks associated with MR-guided SBRT are necessary.

Silence of Stomatin-Like Protein 2 Represses Migration and Invasion Ability of Human Liver Cancer Cells via Inhibiting the Nuclear Factor Kappa B (NF-κB) Pathway

BACKGROUND Liver cancer is the third leading cause of tumor-related deaths worldwide. Stomatin-like protein 2 (STOML2) is obviously upregulated in various tumors. In this study, we explored the potential roles and mechanisms of si-STOML2 in the migration and invasion of human hepatoma LM3 cells. MATERIAL AND METHODS The expression levels of STOML2 in tissues and cells were separately analyzed with quantitative real-time PCR (qRT-PCR) and Western blotting. The viability, migration, and invasion of cells were assessed by cell counting kit-8 (CCK-8), wound healing, and transwell analysis, respectively. The mRNA and protein levels of various factors were separately measured using qRT-PCR and Western blotting. Correlation analysis between the expression of STOML2 and the clinicopathological features of liver cancer patients was evaluated using the chi-square test. RESULTS Surprisingly, our results showed that STOML2 was upregulated in liver cancer tissue and cells, and this upregulation was linked to tumor size, histologic grade, and metastasis, but was not associated with sex, age, or TNM stage. The knockdown of STOML2 significantly repressed the viability, migration, and invasion of LM3 cells. We also observed that silencing STOML2 markedly downregulated the expression levels of matrix metalloproteinase-2 (MMP-2), MMP-9, metastatic tumor antigen 1 (MTA1), and nuclear factor kappa B (NF-κB), and upregulated levels of E-cadherin, tissue inhibitor of metalloproteinases 2 (TIMP2), and the inhibitor of kappa B (IκB). CONCLUSIONS STOML2 has a vital role in the progression of liver cancer. STOML2 silencing in LM3 cells obviously repressed the abilities of migration and invasion via suppressing the NF-κB pathway.

Long non-coding RNA KCNQ1OT1 mediates the growth of hepatocellular carcinoma by functioning as a competing endogenous RNA of miR-504

Accumulating evidence highlights the fact that long non‑coding RNAs (lncRNAs) serve as critical factors in the growth of hepatocellular carcinoma (HCC). The dysregulation of lncRNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) has been reported in numerous human benign diseases. However, the role of KCNQ1OT1 in human HCC remains poorly understood. In this study, we demonstrated that the expression of KCNQ1OT1 was abnormally increased in HCC tissues. The ectopic high expression of KCNQ1OT1 was associated with liver cirrhosis, a larger tumor size, an advanced TNM stage, and a worse overall survival and tumor‑free survival. For the first time, to the best of our knowledge, we report that KCNQ1OT1 knockdown results in a decreased cell viability and colony formation ability, and an increased rate of apoptosis in vitro. The results from our in vivo results demonstrated that KCNQ1OT1 silencing attenuated tumor growth by impairing cell proliferation. Additionally, we found that KCNQ1OT1 exerted its effects partly by relying on the microRNA‑504 (miR‑504)‑mediated regulation of cyclin‑dependent kinase 16 (CDK16), in addition to the regulation of the glycogen synthase kinase 3β (GSK3β)/β‑catenin/Bcl‑2 signaling pathway. The present study revealed the functions and mechanisms of action of lncRNA KCNQ1OT1 regarding its role in promoting the growth of HCC. Thus, lncRNA KCNQ1OT1 may prove to be a potential therapeutic target for human HCC.