Stereotactic body radiation therapy as a bridge to transplantation and for recurrent disease in the transplanted liver of a patient with hepatocellular carcinoma

Stereotactic Body Radiotherapy and Liver Transplant for Liver Cancer: A Nonrandomized Controlled Trial

Importance

Whether stereotactic body radiotherapy (SBRT) as a bridge to liver transplant for hepatocellular carcinoma (HCC) is effective and safe is still unknown.

Objective

To investigate the feasibility of SBRT before deceased donor liver transplant (DDLT) for previously untreated unresectable HCC.

Design, Setting, and Participants

In this phase 2 nonrandomized controlled trial conducted between June 1, 2015, and October 18, 2019, 32 eligible patients within UCSF (University of California, San Francisco) criteria underwent dual-tracer (18F-fluorodeoxyglucose and 11C-acetate [ACC]) positron emission tomography with computed tomography (PET-CT) and magnetic resonance imaging (MRI) with gadoxetate followed by SBRT of 35 to 50 Gy in 5 fractions, and the same imaging afterward while awaiting DDLT. Statistical analysis was performed on an intention-to-treat basis between October 1 and 31, 2023.

Intervention

Patients received SBRT followed by DDLT when matched deceased donor grafts were available.

Main Outcomes and Measures

Coprimary end points were progression-free survival (PFS) and objective response rates (ORRs) by the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1), modified RECIST (mRECIST), and PET Response Criteria in Solid Tumors (PERCIST). Secondary end points were local control rate, overall survival (OS), and safety.

Results

A total of 32 patients (median age, 59 years [IQR, 54-63 years]; 22 men [68.8%]) with 56 lesions received SBRT. After a median follow-up of 74.6 months (IQR, 40.1-102.9 months), the median PFS was 17.6 months (95% CI, 6.6-28.6 months), and the median OS was 60.5 months (95% CI, 29.7-91.2 months). The 5-year PFS was 39.9% (95% CI, 19.9%-59.9%), and the 5-year OS was 51.3% (95% CI, 31.7%-70.9%). In terms of number of patients, ORRs were 62.5% ([n = 20] 95% CI, 54.2%-68.7%) by RECIST 1.1, 71.9% ([n = 23] 95% CI, 63.7%-79.0%) by mRECIST, and 78.1% ([n = 25] 95% CI, 73.2%-86.7%) by PERCIST. In terms of number of lesions, ORRs were 75.0% ([n = 42] 95% CI, 61.6%-80.8%) by RECIST 1.1, 83.9% ([n = 47] 95% CI, 74.7%-90.6%) by mRECIST, and 87.5% ([n = 49] 95% CI, 81.3%-98.6%) by PERCIST. Twenty patients with 36 lesions received DDLT, of whom 15 patients (75.0%) with 21 lesions (58.3%) exhibited pathologic complete response. Multivariable analyses revealed that pretreatment metabolic tumor volume (MTV) based on ACC (hazard ratio [HR], 1.06 [95% CI, 1.01-1.10]; P = .01) and complete metabolic response (CMR) by PERCIST (HR, 0.31 [95% CI, 0.10-0.96]; P = .04) were associated with PFS, while pretreatment MTV based on ACC (HR, 1.07 [95% CI, 1.03-1.16]; P = .01), total lesion activity based on ACC (HR, 1.01 [95% CI, 1.00-1.02]; P = .02), and CMR by PERCIST (HR, 0.21 [95% CI, 0.07-0.73]; P = .01) were associated with OS. Toxic effects associated with SBRT were reported for 9 patients (28.1%), with 1 grade 3 event.

Conclusions and Relevance

This phase 2 nonrandomized controlled trial demonstrated promising survival and safety outcomes of SBRT before DDLT for unresectable HCC. Future randomized clinical trials are warranted.

Impact of successful local ablative bridging therapy prior to liver transplantation on long-term survival in patients with hepatocellular carcinoma in cirrhosis

Background

It has been shown that local ablative procedures enable downsizing, reduce drop-out from the waiting list and improve prognosis after liver transplantation. It is still unclear whether a response to the local ablative therapy is due to a favorable tumor biology or if a real benefit in tumor stabilization exists, particularly in complete pathological response.

Method

Data of 163 HCC patients who underwent liver transplantation were extracted from our prospectively maintained registry. We analyzed the tumor load, pre-transplant α-fetoprotein levels, child stage aside the application and success of local ablative therapies as bridging procedures before transplantation.

Results

87 patients received multiple and/or combined local therapies. In 20 cases, this resulted in a complete remission of the tumor as observed in the explant histology. The other 76 patients underwent no bridging procedure. The observed 5- and 10-year survival rates for patients with bridging were 67% and 47% and without bridging 56% and 46%, respectively. Tumor-related 10-year survival showed a statistically significant difference between both groups (81% versus 59%). In the multivariate analyses bridging, number of lesions and α-fetoprotein level showed an independent statistically significant influence on tumor-related survival in these patients.

Conclusions

Successful local ablative therapy before liver transplantation is an independent statistically significant factor in long-term tumor-related survival for patients with HCC in cirrhosis and reduces tumor recurrences.

Does liver resection/transplantation affect respiratory induced liver motion in patients with hepatocellular carcinoma?

The purpose of this study was to evaluate the changes in magnitude of three-dimensional (3D) liver motion after liver resection/transplantation in patients with hepatocellular carcinoma (HCC) using four-dimensional (4D)-computed tomography (CT) images. From January 2012 to April 2016, 74 HCC patients underwent 4D-CT scans under a free-breathing state to assess respiratory liver motion. Of the 74 patients, 40 did not have a liver resection/transplantation (Group A), 34 with liver resection/transplantation. 15 underwent major or minor resection in the right liver lobe (Group B), 14 underwent major or minor resection in the left liver lobe (Group C), and five underwent liver transplantation (Group D). The 4D-CT images were sorted into 10 image series according to the respiratory phase from the end inspiration to the end expiration, and then transferred to treatment planning software. All liver contours were drawn by a single physician and confirmed by a second. Liver relative coordinates were automatically generated to calculate liver respiratory motion in different axial directions and compiled into a single composite image. Differences in respiratory liver motion were assessed using one-way ANOVA. The average liver respiratory motion in the cranial-caudal direction and 3D magnitude were 10.46 ± 2.78 mm (range, 5.60-18.80 mm) and 11.74 ± 2.65 mm (range, 7.45-20.79 mm) for patients without liver resection/transplantation, and 7.74 ± 2.79 mm (range, 2.20-12.90 mm) and 9.07 ± 2.38 mm (range, 4.79-14.08 mm) for posthepatectomy/post-transplant patients respectively. There were significant differences between Group A and B, Group A and C, Group A and D. However, there were no significant differences among Group B, C, and D. Liver resection/transplantation greatly affected respiratory-induced liver motion in patients with HCC. We, therefore, recommend discriminatory internal target volume (ITV) determination for patients with or without liver resection/transplantation undergoing external radiotherapy for hepatic tumors while respiratory motion management is unavailable.

Deep Inspiration Breath Hold-Based Radiation Therapy: A Clinical Review

Several recent developments in linear accelerator-based radiation therapy (RT) such as fast multileaf collimators, accelerated intensity modulation paradigms like volumeric modulated arc therapy and flattening filter-free (FFF) high-dose-rate therapy have dramatically shortened the duration of treatment fractions. Deliverable photon dose distributions have approached physical complexity limits as a consequence of precise dose calculation algorithms and online 3-dimensional image guided patient positioning (image guided RT). Simultaneously, beam quality and treatment speed have continuously been improved in particle beam therapy, especially for scanned particle beams. Applying complex treatment plans with steep dose gradients requires strategies to mitigate and compensate for motion effects in general, particularly breathing motion. Intrafractional breathing-related motion results in uncertainties in dose delivery and thus in target coverage. As a consequence, generous margins have been used, which, in turn, increases exposure to organs at risk. Particle therapy, particularly with scanned beams, poses additional problems such as interplay effects and range uncertainties. Among advanced strategies to compensate breathing motion such as beam gating and tracking, deep inspiration breath hold (DIBH) gating is particularly advantageous in several respects, not only for hypofractionated, high single-dose stereotactic body RT of lung, liver, and upper abdominal lesions but also for normofractionated treatment of thoracic tumors such as lung cancer, mediastinal lymphomas, and breast cancer. This review provides an in-depth discussion of the rationale and technical implementation of DIBH gating for hypofractionated and normofractionated RT of intrathoracic and upper abdominal tumors in photon and proton RT.

Management of recurrent hepatocellular carcinoma after liver transplant

Hepatocellular carcinoma (HCC) is the leading cause of deaths in patients with hepatitis B or C, and its incidence has increased considerably over the past decade and is still on the rise. Liver transplantation (LT) provides the best chance of cure for patients with HCC and liver cirrhosis. With the implementation of the MELD exception system for patients with HCC waitlisted for LT, the number of recipients of LT is increasing, so is the number of patients who have recurrence of HCC after LT. Treatments for intrahepatic recurrence after transplantation and after other kinds of surgery are more or less the same, but long-term cure of posttransplant recurrence is rarely seen as it is a “systemic” disease. Nonetheless, surgical resection has been shown to be effective in prolonging patient survival despite the technical difficulty in resecting graft livers. Besides surgical resection, different kinds of treatment are also in use, including transarterial chemoembolization, radiofrequency ablation, high-intensity focused ultrasound ablation, and stereotactic body radiation therapy. Targeted therapy and modulation of immunosuppressants are also adopted to treat the deadly disease.