An overview of stereotactic body radiation therapy for hepatocellular carcinoma

Acute Large Dose Irradiation Sensitizes Surviving Cells to Subsequent Irradiation; Implications for Stereotactic Body Radiation Therapy

To determine if the radiation sensitivity of cells that survive acute high-dose radiation exposure used in stereotactic body radiation therapy (SBRT), differs from the sensitivity of non-irradiated cells and cells that survive multiple 2 Gy doses of radiation. Isogenic rodent and two human tumor cell lines were exposed to 14 × 2 Gy of radiation, or a single acute dose of 12 Gy. The most resistant cell line was also exposed to an acute dose of 15 Gy. One week after 12 Gy, and 4 days after 14 × 2 Gy, surviving cells were exposed to 0-8 Gy in 2 Gy doses and cell survival was assessed by colony formation. In addition, the colony forming efficiency of 12 Gy survivors was evaluated for 1 month postirradiation. For cells exposed to 15 Gy, the response of surviving cells to 6 Gy was determined for up to 35 days postirradiation and compared to the 6 Gy surviving fraction of control cells. The radiation sensitivity of cells that survived 12 Gy exposure, and cells that survived 14 fractions of 2 Gy irradiation did not differ from the response of unirradiated control cells. However, the growth rate and colony forming efficiency of 12 Gy survivors was transiently reduced for greater than 2 weeks postirradiation. In contrast to the unchanged sensitivity of 12 Gy surviving cells at day 7 postirradiation, 15 Gy survivors exhibited enhanced sensitivity to radiation for up to 21 days postirradiation and suggests a biological basis for SBRT.

Oligo-Metastatic Cancers: Putative Biomarkers, Emerging Challenges and New Perspectives

Some cancer patients display a less aggressive form of metastatic disease, characterized by a low tumor burden and involving a smaller number of sites, which is referred to as "oligometastatic disease" (OMD). This review discusses new biomarkers, as well as methodological challenges and perspectives characterizing OMD. Recent studies have revealed that specific microRNA profiles, chromosome patterns, driver gene mutations (ERBB2, PBRM1, SETD2, KRAS, PIK3CA, SMAD4), polymorphisms (TCF7L2), and levels of immune cell infiltration into metastases, depending on the tumor type, are associated with an oligometastatic behavior. This suggests that OMD could be a distinct disease with specific biological and molecular characteristics. Therefore, the heterogeneity of initial tumor burden and inclusion of OMD patients in clinical trials pose a crucial methodological question that requires responses in the near future. Additionally, a solid understanding of the molecular and biological features of OMD will be necessary to support and complete the clinical staging systems, enabling a better distinction of metastatic behavior and tailored treatments.

Non-Surgical Locoregional Therapies Alone or in Combination with Systemic Therapy in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, representing the third-leading cause of cancer-related deaths worldwide. Curative intent treatment options for patients with HCC include liver transplantation, resection and ablation of small lesions. Other potentially curative therapies include cryoablation, microwave ablation and percutaneous alcohol injection. For locally advanced disease, different arterially directed therapies including transarterial chemoembolization and selective internal radiation therapy, plus external beam radiation including three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, stereotactic body radiation therapy and proton beam therapy, are available or studied. Systemic therapies based on checkpoint inhibitors and tyrosine kinase inhibitors are available for the management of metastatic HCC and sometimes for locally advanced disease. Combinations of locoregional therapies with systemic drugs are currently the subject of several clinical trials.

Salvage locoregional therapies for recurrent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related death worldwide. Despite the advent of screening efforts and algorithms to stratify patients into appropriate treatment strategies, recurrence rates remain high. In contrast to first-line treatment for HCC, which relies on several factors, including clinical staging, tumor burden, and liver function, there is no consensus or general treatment recommendations for recurrent HCC (R-HCC). Locoregional therapies include a spectrum of minimally invasive liver-directed treatments which can be used as either curative or neoadjuvant therapy for HCC. Herein, we provide a comprehensive review of recent evidence using salvage loco-regional therapies for R-HCC after failed curative-intent.

Life expectancy of patients with hepatocellular carcinoma according to the upfront treatment: A nationwide analysis

PURPOSE

The purpose of this study was to update the life expectancy of patients with hepatocellular carcinoma (HCC) in an exhaustive nationwide population according to the upfront treatment performed.

MATERIALS AND METHODS

From the French Program for the Medicalization of Information System database, all patients older than 18 years diagnosed with a de novo HCC from January 2011 to December 2018 were retrospectively selected. Five-year survival rates (95% confidence intervals [CI]) were computed according to the first surgical or interventional radiology procedures performed.

RESULTS

A total of 63,996 patients (80% men) with a median age of 68 years (Q₁, Q₃: 61, 77) were selected, including 24,007 patients who underwent at least one procedure (5-year survival of 45.5%; (95% CI: 44.8-46.2), and 39,989 with none (5-year survival, 9.6%; (95% CI: 9.3-10.0). Only 20.5% (13,101/63,996) of patients could undergo an upfront curative procedure. Liver transplantation achieved the best outcome, whether performed upfront (n = 791; 5-year survival, 79.0% [95% CI: 76.1-82.1]) or during subsequent steps (n = 2217; 5-year survival 80.9% [95% CI: 79.2-82.7]). Tumor ablation (n = 5306), open resection (n = 5171), and minimally-invasive resection (n = 1833) achieved 5-year survival rates of 53.8% (95% CI: 52.3-55.4), 54.1% (95% CI: 52.6-55.6), and 66.2% (95% CI: 63.7-68.7), respectively, with more patients with cirrhosis and subsequent procedures in the tumor ablation group. Patients with upfront transarterial (chemo)embolization (n = 10,247) and selective internal radiation therapy (n = 659) had 5-year survival rates of 31.3% (95% CI: 30.3-32.4) and 18.5% (95% CI: 15.2-22.5).

CONCLUSION

While HCC remains mostly diagnosed at an advanced stage associated with a poor prognosis, all the curative options provide 5-year survival rates above 50%.

LI-RADS treatment response assessment of combination locoregional therapy for HCC

HCC incidence continues to increase worldwide and is most frequently discovered at an advanced stage when limited curative options are available. Combination locoregional therapies have emerged to improve patient survival and quality of life or downstage patients to curative options. The increasing options for locoregional therapy combinations require an understanding of the expected post-treatment imaging appearance in order to assess treatment response. This review aims to describe the synergy between TACE combined with thermal ablation and TACE combined with SBRT. We will also illustrate expected imaging findings that determine treatment efficacy based on the mechanism of tissue injury using the LI-RADS Treatment Response Algorithm.

The impact of different setup methods on the dose distribution in proton therapy for hepatocellular carcinoma

Purpose

To investigate the impact of different setup methods, vertebral body matching (VM), diaphragm matching (DM), and marker matching (MM), on the dose distribution in proton therapy (PT) for hepatocellular carcinoma (HCC).

Materials and Methods

Thirty‐eight HCC lesions were studied retrospectively to assess changes in the dose distribution on two computed tomography (CT) scans. One was for treatment planning (1st‐CT), and the other was for dose confirmation acquired during the course of PT (2nd‐CT). The dose coverage of the clinical target volume (CTV‐D₉₈) and normal liver volume that received 30 Gy relative biological effectiveness (RBE) (liver‐V₃₀) were evaluated under each condition. Initial treatment planning on the 1st‐CT was defined as reference, and three dose distributions recalculated using VM, DM, and MM on the 2nd‐CT, were compared to it, respectively. In addition, the relationship between the CTV‐D₉₈ of each method and the distance between the center of mass (COM) of the CTV and the right diaphragm top was evaluated.

Results

For CTV‐D₉₈, significant differences were observed between the reference and VM and DM, respectively (P = 0.013, P = 0.015). There were also significant differences between MM and VM and DM, respectively (P = 0.018, P = 0.036). Regarding liver‐V₃₀, there was no significant difference in any of the methods, and there were no discernable difference due to the different setup methods. In DM, only two out of 34 cases with a distance from right diaphragm top to COM of CTV of 90 mm or less that CTV‐D₉₈ difference was 5% or more and CTV‐D₉₈ was worse than VM were confirmed.

Conclusion

Although MM is obviously the most effective method, it is suggested that DM may be particularly effective in cases where the distance from right diaphragm top to COM of CTV of 90 mm or less.