Biologically effective dose (BED) of stereotactic body radiation therapy (SBRT) was an important factor of therapeutic efficacy in patients with hepatocellular carcinoma (≤5 cm)

Stereotactic body radiation therapy in primary liver tumor: Local control, outcomes and toxicities

Objective

Stereotactic body radiation therapy (SBRT) is a therapeutic option in the guidelines for liver primaries after standard strategies like surgery or thermoablation have failed. To assess its efficacy and safety, we reviewed all patients treated by SBRT for a hepatocellular carcinoma (HCC) over a six-year period.

Methods and materials

The study included all patients treated by SBRT for HCC between April 2015 and November 2021 in the University Cancer Institute at Toulouse-Oncopole. All patients were inoperable and not eligible for thermoablation, or after a failure. All tumor sizes were included and cirrhosis up to Child-Pugh B was accepted. Local control (LC), overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Treatment response was assessed using mRECIST criteria. Toxicity was graded using CTCAE (v4.0).

Results

One hundred and nine patients with 118 lesions were treated. Half underwent prior standard treatment. Median dose was 50 Grays in five fractions for most patients. Chronic liver disease represented 90.8 % of cases with a median age of 69 years. Median tumor size was 4.0 cm. Median follow-up was 22.2 months [95 %CI: 15.1-30.4]. LC, OS and PFS at two years were 82.4 % [95 %CI: 71.3; 89.5], 73.2 % [95 %CI: 61.5; 81.8] and 35.8 % [95 %CI: 25.1; 46.7], respectively. Acute toxicities occurred in 20.2 % of patients, including 10.1 % grade 3-4 and 1.8 % grade 5. Late toxicities occurred in 5.5 % of patients including 4.6 % grade 3-4. Grade ≥ 3 toxicity was related to digestive perforation or liver failure.

Conclusion

SBRT provides good LC with an acceptable safety profile. It can be used in several settings such as salvage therapy or in combination with validated treatment. Prospective randomized trials are needed to validate SBRT as a standard alternative.

Exploring the Evolving Landscape of Stereotactic Body Radiation Therapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) carries significant morbidity and mortality. Management of the HCC requires a multidisciplinary approach. Surgical resection and liver transplantation are the gold standard options for the appropriate settings. Stereotactic body radiation therapy (SBRT) has emerged as a promising treatment modality in managing HCC; its use is more studied and well-established in advanced HCC (aHCC). Current clinical guidelines universally endorse SBRT as a viable alternative to radiofrequency ablation (RFA), transarterial chemoembolisation (TACE), and transarterial radioembolisation (TARE), a recommendation substantiated by literature demonstrating comparable efficacy among these modalities. In early-stage HCC, SBRT primarily manages unresectable tumours unsuitable for ablative procedures such as microwave ablation and RFA. SBRT has been incorporated as a modality to downstage tumours or as a bridge to transplant. In the case of intermediate or advanced HCC, SBRT offers excellent results either as a single modality or adjunct to other locoregional modalities such as TACE/TARE. Recent data from late-stage HCC patients illustrate the effectiveness of SBRT in achieving local tumour control while minimising damage to surrounding healthy liver tissue. It has promising local control of approximately 80-90% in managing HCC. Additional prospective data comparing the efficacy of SBRT with the first-line recommended therapies such as RFA, TACE, and surgery are essential. The standard of care for patients with advanced/metastatic disease is systemic therapy (immunotherapy/tyrosine kinase inhibitors). SBRT, in combination with immune-checkpoint inhibitors, has an immune-modulatory effect that results in a synergistic effect. Recent findings indicate that the combination of immunotherapy and SBRT in HCC is well-tolerated and exhibits synergistic effects. Further exploration of diverse immunotherapy and radiotherapy strategies is essential to identify the appropriate time for combination treatments and to optimise dose and fraction regimens. Prospective, randomised studies are imperative to establish SBRT as the primary treatment for HCC.

Comparative analysis of clinical treatment outcomes: Breath-hold vs. free-breathing techniques in liver stereotactic body radiotherapy

INTRODUCTION

The aim of this study was to clarify the safety and efficacy of breath-hold irradiation in liver stereotactic body radiotherapy (SBRT).

METHODS

A retrospective analysis was conducted on 57 consecutive patients who received SBRT for hepatocellular carcinoma or liver metastases between 2013 and 2021. Breath-hold irradiation was implemented for patients treated after April 2020.

RESULTS

The median follow-up period for all patients was 16.4 months (IQR: 7.36-20.9). The 2-year overall survival rate was 64.4% (95% CI: 47.4-77.2), and the local control rate was 84.3% (95% CI: 69.7-92.3) for all patients. The 1-year overall survival was 80.0% (95% CI: 60.8-90.5) versus 82.0% (95% CI: 53.5-93.9) in the free-respiratory (FR) group versus the breath-hold (BH) group, respectively (P = 0.60). The 1-year local control rates were 78.1% (95% CI: 57.5-89.5) in the FR group and 95.7% (95% CI: 72.9-99.4) in the BH group, respectively (P = 0.16). Radiation-induced liver injury, defined by an escalation of ≥2 in Child-Pugh score, was observed in four patients within each group (FR 13% vs. BH 15%). There were no gastrointestinal adverse events of Grade 3 or higher.

CONCLUSION

Breath-hold irradiation can be safely administered and has demonstrated clinical potential in improving local control. Further research into dose escalation using breath-hold techniques is warranted.

Cancer-specific dose and fractionation schedules in stereotactic body radiotherapy for oligometastatic disease: An interim analysis of the EORTC-ESTRO E2-RADIatE OligoCare study

BACKGROUND AND INTRODUCTION

Optimal dose and fractionation in stereotactic body radiotherapy (SBRT) for oligometastatic cancer patients remain unknown. In this interim analysis of OligoCare, we analyzed factors associated with SBRT dose and fractionation.

MATERIALS AND METHODS

Analysis was based on the first 1,099 registered patients. SBRT doses were converted to biological effective doses (BED) using α/β of 10 Gy for all primaries, and cancer-specific α/β of 10 Gy for non-small cell lung and colorectal cancer (NSCLC, CRC), 2.5 Gy for breast cancer (BC), or 1.5 Gy for prostate cancer (PC).

RESULTS

Of the interim analysis population of 1,099 patients, 999 (99.5 %) fulfilled inclusion criteria and received metastasis-directed SBRT for NSCLC (n = 195; 19.5 %), BC (n = 163; 16.3 %), CRC (n = 184; 18.4 %), or PC (n = 457; 47.5 %). Two thirds of patients were treated for single metastasis. Median number of fractions was 5 (IQR, 3-5) and median dose per fraction was 9.7 (IQR, 7.7-12.4) Gy. The most frequently treated sites were non-vertebral bone (22.8 %), lung (21.0 %), and distant lymph node metastases (19.0 %). On multivariate analysis, the dose varied significantly for primary cancer type (BC: 237.3 Gy BED, PC 300.6 Gy BED, and CRC 84.3 Gy BED), and metastatic sites, with higher doses for lung and liver lesions.

CONCLUSION

This real-world analysis suggests that SBRT doses are adjusted to the primary cancers and oligometastasis location. Future analysis will address safety and efficacy of this site- and disease-adapted SBRT fractionation approach (NCT03818503).

Optimal hypofractionated radiation therapy schemes for early-stage hepatocellular carcinoma

PURPOSE

Stereotactic body radiation therapy (SBRT) has been emerging as an efficacious and safe treatment modality for early-stage hepatocellular carcinoma (HCC), but optimal fractionation regimens are unknown. This study aims to analyze published clinical tumor control probability (TCP) data as a function of biologically effective dose (BED) and to determine radiobiological parameters and optimal fractionation schemes for SBRT and hypofractionated radiation therapy of early-stage HCC.

MATERIAL AND METHODS

Clinical 1- to 5-year TCP data of 4313 patients from 41 published papers were collected for hypofractionated radiation therapy at 2.5-4.5 Gy/fraction and SBRT of early-stage HCC. BED was calculated at isocenter using three representative radiobiological models developed per the Hypofractionated Treatment Effects in the Clinic (HyTEC) initiative. Radiobiological parameters were determined from a fit to the TCP data using the least χ2 method with one set of model parameters regardless of tumor stages or Child-Pugh scores A and B.

RESULTS

The fits to the clinical TCP data for SBRT of early-stage HCC found consistent α/β ratios of about 14 Gy for all three radiobiological models. TCP increases sharply with BED and reaches an asymptotic maximal plateau, which results in optimal fractionation schemes of least doses to achieve asymptotic maximal tumor control for SBRT and hypofractionated radiation therapy of early-stage HCC that are found to be model-independent.

CONCLUSION

From the fits to the clinical TCP data, we presented the first determination of radiobiological parameters and model-independent optimal fractionation regimens in 1-20 fractions to achieve maximal tumor control whenever safe for SBRT and hypofractionated radiation therapy of early-stage HCC. The determined optimal fractionation schemes agree well with clinical practice for SBRT of early-stage HCC. However, most existing hypofractionated radiation therapy schemes of 3-5 Gy/fraction are not optimal, higher doses are required to maximize tumor control, further validation of these findings is essential with clinical TCP data.

Applications of Machine Learning (ML) and Mathematical Modeling (MM) in Healthcare with Special Focus on Cancer Prognosis and Anticancer Therapy: Current Status and Challenges

The use of data-driven high-throughput analytical techniques, which has given rise to computational oncology, is undisputed. The widespread use of machine learning (ML) and mathematical modeling (MM)-based techniques is widely acknowledged. These two approaches have fueled the advancement in cancer research and eventually led to the uptake of telemedicine in cancer care. For diagnostic, prognostic, and treatment purposes concerning different types of cancer research, vast databases of varied information with manifold dimensions are required, and indeed, all this information can only be managed by an automated system developed utilizing ML and MM. In addition, MM is being used to probe the relationship between the pharmacokinetics and pharmacodynamics (PK/PD interactions) of anti-cancer substances to improve cancer treatment, and also to refine the quality of existing treatment models by being incorporated at all steps of research and development related to cancer and in routine patient care. This review will serve as a consolidation of the advancement and benefits of ML and MM techniques with a special focus on the area of cancer prognosis and anticancer therapy, leading to the identification of challenges (data quantity, ethical consideration, and data privacy) which are yet to be fully addressed in current studies.

Therapeutic Outcome of Stereotactic Body Radiotherapy for Small Hepatocellular Carcinoma Lesions - A Systematic Review and Network Meta-analysis

Surgical resection, stereotactic body radiotherapy (SBRT) and radiofrequency ablation (RFA) have seldom been compared for small hepatocellular carcinoma (HCC). We explored the treatment outcomes of SBRT for small HCC by conducting a network meta-analysis (NMA). We compared the efficacy and safety of surgical resection, RFA and SBRT for liver-confined small HCC (three or fewer lesions with a diameter ≤5 cm). The study endpoint included the odds ratios of the 1-, 3- and 5-year progression/recurrence/disease-free survival (disease progression-free survival; DPFS) and overall survival rates, as well as severe complications. Forty-five studies included 21 468 patients. In the NMA with comparable data, SBRT had comparable 1-, 3- and 5-year DPFS but significantly worse pooled long-term overall survival (3- and 5-year overall survival) than surgical resection (odds ratio 1.39, 95% confidential interval 1.3-1.89; odds ratio 1.33, 95% confidence interval 1.06-1.69, respectively). SBRT was associated with significantly better pooled 1-year DPFS compared with RFA (odds ratio 0.39, 95% confidence interval 0.15-0.97), with the remaining outcomes being comparable. SBRT had significantly less incidence of severe complications compared with surgical resection (odds ratio 0.62, 95% confidence interval 0.42-0.88) and RFA (odds ratio 0.2, 95% confidence interval 0.03-0.94). In conclusion, for small HCCs (≤5 cm) with one to three nodules, SBRT may be favourable to reduce the risks of severe complications. In terms of DPFS, SBRT may be recommended as an alternative first-line therapy for RFA and surgical resection. The results regarding overall survival should be interpreted with caution, considering the potentially uneliminated bias. There is a clear need for well-designed randomised trials to conclusively identify real differences in efficacy between these treatments, especially SBRT and surgical resection.

Online verification of breath-hold reproducibility using kV-triggered imaging for liver stereotactic body radiation therapy

PURPOSE

To introduce a new technique for online breath-hold verification for liver stereotactic body radiation therapy (SBRT) based on kilovoltage-triggered imaging and liver dome positions.

MATERIAL AND METHODS

Twenty-five liver SBRT patients treated with deep inspiration breath-hold were included in this IRB-approved study. To verify the breath-hold reproducibility during treatment, a KV-triggered image was acquired at the beginning of each breath-hold. The liver dome position was visually compared with the expected upper/lower liver boundaries created by expanding/contracting the liver contour 5 mm in the superior-inferior direction. If the liver dome was within the boundaries, delivery continued; otherwise, beam was held manually, and the patient was instructed to take another breath-hold until the liver dome fell within boundaries. The liver dome was delineated on each triggered image. The mean distance between the delineated liver dome to the projected planning liver contour was defined as liver dome position error edome . The mean and maximum edome of each patient were compared between no breath-hold verification (all triggered images) and with online breath-hold verification (triggered images without beam-hold).

RESULTS

Seven hundred thirteen breath-hold triggered images from 92 fractions were analyzed. For each patient, an average of 1.5 breath-holds (range 0-7 for all patients) resulted in beam-hold, accounting for 5% (0-18%) of all breath-holds; online breath-hold verification reduced the mean edome from 3.1 mm (1.3-6.1 mm) to 2.7 mm (1.2-5.2 mm) and the maximum edome from 8.6 mm (3.0-18.0 mm) to 6.7 mm (3.0-9.0 mm). The percentage of breath-holds with edome >5 mm was reduced from 15% (0-42%) without breath-hold verification to 11% (0-35%) with online breath-hold verification. online breath-hold verification eliminated breath-holds with edome >10 mm, which happened in 3% (0-17%) of all breath-holds.

CONCLUSION

It is clinically feasible to monitor the reproducibility of each breath-hold during liver SBRT treatment using triggered images and liver dome. Online breath-hold verification improves the treatment accuracy for liver SBRT.

Radiation dose is associated with improved local control for large, but not small, hepatocellular carcinomas

BACKGROUND

With advances in understanding liver tolerance, conformal techniques, image guidance, and motion management, dose-escalated radiotherapy has become a potential treatment for inoperable hepatocellular carcinoma (HCC). We aimed to evaluate the possible impact of biologically effective dose (BED) on local control and toxicity among patients with HCC.

METHODS AND MATERIALS

Patients treated at our institution from 2009 to 2018 were included in this retrospective analysis if they received definitive-intent radiotherapy with a nominal BED of at least 60 Gy. Patients were stratified into small and large tumors using a cutoff of 5 cm, based on our clinical practice. Toxicity was assessed using ALBI scores and rates of clinical liver function deterioration.

RESULTS

One hundred and twenty-eight patients were included, with a mean follow-up of 16 months. The majority of patients (90.5%) had a good performance status (ECOG 0-1), with Child-Pugh A (66.4%) and ALBI Grade 2 liver function at baseline (55.4%). Twenty (15.6%) patients had a local recurrence in the irradiated field during the follow-up period. Univariate and multivariate Cox proportional hazard analyses showed that only BED significantly predicted local tumor recurrence. Higher BED was associated with improved local control in tumors with equivalent diameters over 5 cm but not in smaller tumors. There was no difference in liver toxicity between the low and high-dose groups.

CONCLUSIONS

Higher radiotherapy dose is associated with improved local control in large tumors but not in tumors smaller than 5 cm in diameter. High-dose radiotherapy was not associated with increased liver toxicity.

Cleaning the dose falloff with low modulation in SBRT lung plans

Purpose.This dosimetric study is intended to lower the modulation factor in lung SBRT plans generated in the Eclipse TPS that could replace highly modulated plans that are prone to the interplay effect.Materials and methods.Twenty clinical lung SBRT plans with high modulation factors (≥4) were replanned in Varian Eclipse TPS version 15.5 utilizing 2 mm craniocaudal and 1 mm axial block margins followed by light optimization in order to reduce modulation. A unique plan optimization methodology, which utilizes a novel shell structure (OptiForR₅₀) for R_50%optimization in addition to five consecutive concentric 5 mm shells, was utilized to control dose falloff according to RTOG 0813 and 0915 recommendations. The prescription varied from 34-54 Gy in 1-4 fractions, and the dose objectives were PTV D_95%= Rx, PTV D_max< 140% of Rx, and minimizing the modulation factor. Plan evaluation metrics included modulation factor, CI_RTOG, homogeneity index (HI), R_50%, D_2cm, V_105%, and lung V_8-12.8Gy(Timmerman Constraint). A random-intercept linear mixed effects model was used with a p ≤ 0.05 threshold to test for statistical significance.Results.The retrospectively generated plans had significantly lower modulation factors (3.65 ± 0.35 versus 4.59 ± 0.54; p < 0.001), lower CI_RTOG(0.97 ± 0.02 versus 1.02 ± 0.06; p = 0.001), higher HI (1.35 ± 0.06 versus 1.14 ± 0.04; p < 0.001), lower R_50%(4.09 ± 0.45 versus 4.56 ± 0.56; p < 0.001), and lower lungs V_8-12.8Gy(Timmerman) (4.61% ± 3.18% versus 4.92% ± 3.37%; p < 0.001). The high dose spillage V_105%was borderline significantly lower (0.44% ± 0.49% versus 1.10% ± 1.64%; p = 0.051). The D_2cmwas not statistically different (46.06% ± 4.01% versus 46.19% ± 2.80%; p = 0.835).Conclusion.Lung SBRT plans with significantly lower modulation factors can be generated that meet the RTOG constraints, using our planning strategy.

Study of hepatic toxicity in small liver tumors after photon or proton therapy based on factors predicting the benefits of proton

OBJECTIVES

In a previous study of hepatic toxicity, the following three factors were identified to predict the benefits of proton beam therapy (PBT) for hepatocellular carcinomas (HCCs) with a maximum diameter of ≤5 cm and Child-pugh grade A (CP-A): number of tumors (1 vs ≥2), the location of tumors (hepatic hilum or others), and the sum of the diameters of lesions. The aim of this study is to analyze the association between these three factors and hepatic toxicity.

METHODS

We retrospectively reviewed patients of CP-A treated with PBT or photon stereotactic body radiotherapy (X-ray radiotherapy, XRT) for HCC ≤5 cm. For normal liver dose, the V5, V10, V20 (volumes receiving 5, 10, and 20 Gy at least), and the mean dose was evaluated. The albumin-bilirubin (ALBI) and CP score changes from the baseline were evaluated at 3 and 6 months after treatment.

RESULTS

In 89 patients (XRT: 48, PBT: 41), those with two or three (2-3) predictive factors were higher normal liver doses than with zero or one (0-1) factor. In the PBT group, the ALBI score worsened more in patients with 2-3 factors than those with 0-1 factor, at 3 months (median: 0.26 vs 0.02, p = 0.032) and at 6 months (median: 0.35 vs 0.10, p = 0.009). The ALBI score change in the XRT group and CP score change in either modality were not significantly different in the number of predictive factors.

CONCLUSION

The predictive factor numbers predicted the ALBI score change in PBT but not in XRT.

ADVANCES IN KNOWLEDGE

This study suggest that the number of predictive factors previously identified (0-1 vs 2-3) were significantly associated with dosimetric parameters of the normal liver in both modalities. In the proton group, the number of predictive factors was associated with a worsening ALBI score at 3 and 6 months, but these associations were not found in the photon SBRT group.

For Hepatocellular Carcinoma Treated with Yttrium-90 Microspheres, Dose Volumetrics on Post-Treatment Bremsstrahlung SPECT/CT Predict Clinical Outcomes

In transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC) with Yttrium-90 (Y-90) microspheres, recent studies correlate dosimetry from bremsstrahlung single photon emission tomography (SPECT/CT) with treatment outcomes; however, these studies focus on measures of central tendency rather than volumetric coverage metrics commonly used in radiation oncology. We hypothesized that three-dimensional (3D) isodose coverage of gross tumor volume (GTV) is the driving factor in HCC treatment response to TARE and is best assessed using advanced dosimetry techniques applied to nuclear imaging of actual Y-90 biodistribution. We reviewed 51 lobar TARE Y-90 treatments of 43 HCC patients. Dose prescriptions were 120 Gy for TheraSpheres and 85 Gy for SIR-Spheres. All patients underwent post-TARE Y-90 bremsstrahlung SPECT/CT imaging. Commercial software was used to contour gross tumor volume (GTV) and liver on post-TARE SPECT/CT. Y-90 dose distributions were calculated using the Local Deposition Model based on post-TARE SPECT/CT activity maps. Median gross tumor volume (GTV) dose; GTV receiving less than 100 Gy, 70 Gy and 50 Gy; minimum dose covering the hottest 70%, 95%, and 98% of the GTV (D70, D95, D98); mean dose to nontumorous liver, and disease burden (GTV/liver volume) were obtained. Clinical outcomes were collected for all patients by chart and imaging review. HCC treatment response was assessed according to the modified response criteria in solid tumors (mRECIST) guidelines. Kaplan-Meier (KM) survival estimates and multivariate regression analyses (MVA) were performed using STATA. Median survival was 22.5 months for patients achieving objective response (OR) in targeted lesions (complete response (CR) or partial response (PR) per mRECIST) vs. 7.6 months for non-responders (NR, stable disease or disease progression per mRECIST). On MVA, the volume of underdosed tumor (GTV receiving less than 100 Gy) was the only significant dosimetric predictor for CR (p = 0.0004) and overall survival (OS, p = 0.003). All targets with less than CR (n = 39) had more than 20 cc of underdosed tumor. D70 (p = 0.038) correlated with OR, with mean D70 of 95 Gy for responders and 60 Gy for non-responders (p = 0.042). On MVA, mean dose to nontumorous liver trended toward significant association with grade 3+ toxicity (p = 0.09) and correlated with delivered activity (p < 0.001) and burden of disease (p = 0.05). Dosimetric models supplied area under the curve estimates of > 0.80 predicting CR, OR, and ≥grade 3 acute toxicity. Dosimetric parameters derived from the retrospective analysis of post-TARE Y-90 bremsstrahlung SPECT/CT after lobar treatment of HCC suggest that volumetric coverage of GTV, not a high mean or median dose, is the driving factor in treatment response and that this is best assessed through the analysis of actual Y-90 biodistribution.

Biologically Equivalent Dose Comparison Between Magnetic Resonance-Guided Adaptive and Computed Tomography-Guided Internal Target Volume-Based Stereotactic Body Radiotherapy for Liver Tumors

Background and aim Magnetic resonance (MR) imaging has been increasingly adopted in the field of radiotherapy, and the most advanced MR image-guided radiotherapy is known as MR-guided online adaptive radiotherapy (MRgOART), which integrates MRI and linac systems. Few attempts have yet been made to directly compare treatment outcomes between the MRgOART and standard computed tomography (CT)-guided radiotherapy (CTgRT). Besides, it is reported that the biologically equivalent dose (BED) may be a good predictor of the local control (LC) and the overall survival (OS) for liver tumors. The purpose of this study is to compare the BEDs between the MRgOART and the CTgRT by way of virtual isotoxic planning for liver tumors. The hypothesis of this study is therefore that the MRgOART increases LC and OS as compared to the CTgRT. Materials and methods Using the five patient cases available, isotoxic planning was performed. For CTgRT, an internal target volume (ITV) was defined, and the planning target volume (PTV) was created by adding an isotropic margin of 10 mm. For MRgRT, a gross tumor volume (GTV) was defined, and the PTV was created by adding an isotropic margin of 5 mm. Each tumor size was virtually adjusted so that the CTgRT plans resulted in BED <100 Gy under the condition that the nearest organs at risk receive maximum tolerated doses. Subsequently, the BED was recalculated for MRgOART plans with the adjusted tumor size. Results and discussion It was found that the BEDs of the MRgOART plans always exceeded 100 Gy and were approximately 20 Gy larger than those of the corresponding CTgRT plans. Literature shows that superior overall survival rates for liver tumors were observed when BED was >100 Gy as compared to BED <100 Gy, suggesting that MR-guided adaptive planning may potentially lead to better treatment outcomes for liver tumors. We have also observed a case where the duodenum largely moved and abutted the liver after the CT images were acquired, indicating a significant disadvantage of the standard CTgRT because such abutting is not observable by the cone-beam CT immediately before treatment. Conclusion A highly accelerated evidence-creation procedure to suggest the clinical superiority of MRgOART has been arguably proposed with promising results. The sample size is small and limits the extent to which the findings in this study can be generalized. Further virtual clinical trials within the radiotherapy community are awaited with more clinical outcomes data.

Prognosis and Risk Factors of Recurrence in HBV-Related Small Hepatocellular Carcinoma After Stereotactic Body Radiation Therapy

Objective

The role of stereotactic body radiation therapy (SBRT) for treating small hepatocellular carcinoma (sHCC) has gained increasing recognition. However, the prognosis and risk factors for recurrence in patients with sHCC remain unclear. This study investigated the risk factors for the recurrence of hepatitis B virus (HBV)-related sHCC after SBRT.

Methods

A total of 240 HBV-related sHCC patients treated with SBRT between March 2011 and March 2020 were retrospectively analyzed. The cumulative probability of recurrence was calculated according to the Kaplan–Meier method. Univariate and multivariate analyses were performed with Cox proportional hazard models.

Results

Recurrent hepatocellular carcinoma developed in 134 (55.8%) patients at a median time of 27 months after SBRT. The one- and two-year rates of recurrence were 20.9 and 45.0%, respectively. The median follow-up time was 30 months. The Cox multivariate analysis indicated that age (P = 0.029, HR [1.019, 1.002–1.037]), tumor size (P = 0.012, HR [1.227, 1.045–1.440]), and aspartate aminotransferase-to-platelet ratio index (APRI) (P = 0.005, HR [1.911, 1.221–2.989]) were independent risk factors for recurrence.

Conclusion

Patients receiving SBRT for HBV-related sHCC may be at greater risk of recurrence if they have a high APRI score combined with advanced age and large tumor size.

A study on predicting cases that would benefit from proton beam therapy in primary liver tumors of less than or equal to 5 cm based on the estimated incidence of hepatic toxicity

•

An advantage of PBT is reducing the liver receiving low doses of radiation.

•

The factors predicting the benefit in PBT are different among NTCP models.

•

The tumor size, number, and location are useful in estimating the benefits of PBT.

Background

Materials and methods

Results

Conclusions

Hypofractionation in Hepatocellular Carcinoma - The Effect of Fractionation Size

The use of stereotactic body radiotherapy (SBRT) in hepatocellular carcinoma (HCC) has increased over the years. Several prospective studies have demonstrated its safety and efficacy, and randomised trials are underway. The advancement in technology has enabled the transition from three-dimensional conformal radiotherapy to highly focused SBRT. Liver damage is the primary limiting toxicity with radiation, with the incidence of grade 3 varying from 0 to 30%. The reported radiotherapy fractionation schedule for HCC, and in practice use, ranges from one to 10 fractions, based on clinician preference and technology available, tumour location and tumour size. This review summarises the safety and efficacy of various SBRT fractionation schedules for HCC.

External Beam Radiation Therapy for Primary Liver Cancers: An ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides evidence-based recommendations for the indications and technique-dose of external beam radiation therapy (EBRT) in hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC).

METHODS

The American Society for Radiation Oncology convened a task force to address 5 key questions focused on the indications, techniques, and outcomes of EBRT in HCC and IHC. This guideline is intended to cover the definitive, consolidative, salvage, preoperative (including bridge to transplant), and adjuvant settings as well as palliative EBRT for symptomatic primary lesions. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

Strong recommendations are made for using EBRT as a potential first-line treatment in patients with liver-confined HCC who are not candidates for curative therapy, as consolidative therapy after incomplete response to liver-directed therapies, and as a salvage option for local recurrences. The guideline conditionally recommends EBRT for patients with liver-confined multifocal or unresectable HCC or those with macrovascular invasion, sequenced with systemic or catheter-based therapies. Palliative EBRT is conditionally recommended for symptomatic primary HCC and/or macrovascular tumor thrombi. EBRT is conditionally recommended as a bridge to transplant or before surgery in carefully selected patients. For patients with unresectable IHC, consolidative EBRT with or without chemotherapy should be considered, typically after systemic therapy. Adjuvant EBRT is conditionally recommended for resected IHC with high-risk features. Selection of dose-fractionation regimen and technique should be based on disease extent, disease location, underlying liver function, and available technologies.

CONCLUSIONS

The task force has proposed recommendations to inform best clinical practices on the use of EBRT for HCC and IHC with strong emphasis on multidisciplinary care. Future studies should focus on further defining the role of EBRT in the context of liver-directed and systemic therapies and refining optimal regimens and techniques.

Treatment outcomes of stereotactic body radiation therapy using a real-time tumor-tracking radiotherapy system for hepatocellular carcinomas

AIM

To report the outcomes of stereotactic body radiotherapy using a real-time tumor-tracking radiotherapy system for hepatocellular carcinoma patients.

METHODS

From January 2005 to July 2018, 63 patients with 74 lesions with a maximum diameter ≤52 mm were treated by stereotactic body radiotherapy using a real-time tumor-tracking radiotherapy system. No patient with a Child-Pugh Score ≥9 was included, and 85.6% had a score of 5 or 6. Using the biological effective dose (BED) with an α/β ratio of 10 (BED₁₀ ), the median dose in BED₁₀ at the reference point was 76.8 Gy (range 60-122.5 Gy). Overall survival (OS) and local control rates were assessed using the Kaplan-Meier method.

RESULTS

With a median follow-up period of 24.6 months (range 0.9-118.4 months), the 1-year and 2-year OS rates were 86.8% (95% confidence interval [95% CI] 75.8-93.3) and 71.1% (57.8-81.6), respectively. The 2-year OS was 89.6% in patients with the baseline modified albumin-bilirubin (mALBI) grade =1, and 61.7% in patients with grade ≥2a. In the multivariate analysis, the mALBI grade (=1 vs. ≥2a) was a significant factor for OS (p = 0.028, 95% CI 1.11-6.18). The 1-year and 2-year local control rates were 100% (100-100%) and 92.0% (77.5-97.5%). The local control rates were significantly higher in the BED₁₀ ≥100 Gy group than in the BED₁₀ <100 Gy group (2-year 100% vs. 86.5%, p = 0.049) at the reference point.

CONCLUSION

This retrospective study of stereotactic body radiotherapy using real-time tumor-tracking radiotherapy for hepatocellular carcinoma showed favorable outcomes with lower incidence of toxicities, especially in patients treated with BED₁₀ ≥100 Gy to the reference point.

Optimal stereotactic body radiotherapy dosage for hepatocellular carcinoma: a multicenter study

BACKGROUND

The optimal dose and fractionation scheme of stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) remains unclear due to different tolerated liver volumes and degrees of cirrhosis. In this study, we aimed to verify the dose-survival relationship to optimize dose selection for treatment of HCC.

METHODS

This multicenter retrospective study included 602 patients with HCC, treated with SBRT between January 2011 and March 2017. The SBRT dosage was classified into high dose, moderate dose, and low dose levels: SaRT (BED10 ≥ 100 Gy), SbRT (EQD2 > 74 Gy to BED10 < 100 Gy), and ScRT (EQD2 < 74 Gy). Overall survival (OS), progression-free survival (PFS), local control (LC), and intrahepatic control (IC) were evaluated in univariable and multivariable analyses.

RESULTS

The median tumor size was 5.6 cm (interquartile range [IQR] 1.1-21.0 cm). The median follow-up time was 50.0 months (IQR 6-100 months). High radiotherapy dose correlated with better outcomes. After classifying into the SaRT, SbRT, and ScRT groups, three notably different curves were obtained for long-term post-SBRT survival and intrahepatic control. On multivariate analysis, higher radiation dose was associated with improved OS, PFS, and intrahepatic control.

CONCLUSIONS

If tolerated by normal tissue, we recommend SaRT (BED10 ≥ 100 Gy) as a first-line ablative dose or SbRT (EQD2 ≥ 74 Gy) as a second-line radical dose. Otherwise, ScRT (EQD2 < 74 Gy) is recommended as palliative irradiation.

Therapeutic outcome and related predictors of stereotactic body radiotherapy for small liver-confined HCC: a systematic review and meta-analysis of observational studies

Background and purpose

Stereotactic body radiotherapy (SBRT) is a promising ablative modality for hepatocellular carcinoma (HCC) especially for those with small-sized or early-stage tumors. This study aimed to synthesize available data to evaluate efficacy and explore related predictors of SBRT for small liver-confined HCC (≤ 3 lesions with longest diameter ≤ 6 cm).

Materials and methods

A systematic search were performed of the PubMed and Cochrane Library databases. Primary endpoints were overall survival (OS) and local control (LC) of small HCC treated with SBRT, meanwhile, to evaluate clinical parameters associated with treatment outcome by two methods including subgroup comparisons and pooled HR meta-analysis. The secondary endpoint was treatment toxicity.

Results

After a comprehensive database review, 14 observational studies with 1238 HCC patients received SBRT were included. Pooled 1-year and 3-year OS rates were 93.0% (95% confidence interval [CI] 88.0–96.0%) and 72.0% (95% CI 62.0–79.0%), respectively. Pooled 1-year and 3-year LC rates were 96.0% (95% CI 91.0–98.0%) and 91.0% (95% CI 85.0–95.0%), respectively. Subgroup comparisons regarding Child–Pugh class (stratified by CP-A percentage 100%, 75–100%, 50–75%) showed there were statistically significant differences for both 1-year and 3-year OS rate (p < 0.01), while that regarding number of lesions, pretreatment situation, age (median/mean age of 65), macrovascular invasion, tumor size, and radiation dose (median BED₁₀ of 100 Gy), there were no differences. In subgroup comparisons for LC rate, it showed number of lesions (1 lesion vs. 2–3 lesions) was significantly associated with 1-year LC rate (p = 0.04), though not associated with 3-year LC rate (p = 0.72). In subgroup comparisons categorized by other factors including pretreatment situation, age, CP-A percentage, macrovascular invasion, tumor size, and radiation dose, there were no significant differences for 1- or 3-year LC rate. To further explore the association between CP class and OS, the second method was applied by combining HR and 95% CIs. Results indicated CP-A was predictive of better OS (p = 0.001) with pooled HR 0.31 (95% CIs 0.11–0.88), which was consistent with subgroup comparison results. Concerning adverse effect of SBRT, pooled rates of grade ≥ 3 hepatic complications and RILD were 4.0% (95% CI 2.0–8.0%) and 14.7% (95% CI 7.4–24.7%), respectively.

Conclusion

The study showed that SBRT was a potent local treatment for small liver-confined HCC conferring excellent OS and LC persisting up to 3 years, even though parts of included patients were pretreated or with macrovascular invasion. CP-A class was a significant predictor of optimal OS, while number of lesions might affect short term tumor control (1-year LC). Tumor size and radiation dose were not vital factors impacting treatment outcome for such small-sized HCC patients. Because of the low quality of observational studies and heterogeneous groups of patients treated with SBRT, further clinical trials should be prospectively investigated in large sample sizes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01761-1.

Stereotactic body radiotherapy versus intensity-modulated radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis

BACKGROUND

It is unclear whether robotic stereotactic body radiotherapy (SBRT) is superior to intensity-modulated radiotherapy (IMRT) in advanced hepatocellular carcinoma (HCC). This study aimed to compare the long-term outcomes of SBRT with those of IMRT in HCCs with portal vein tumor thrombosis (PVTT).

METHODS

We retrospectively evaluated 287 HCC patients with PVTT who underwent radiotherapy between January 2000 and January 2017. Of them, 154 and 133 patients were treated with IMRT and SBRT, respectively. Overall survival (OS), progression-free survival (PFS), intrahepatic control (IC), and local control (LC) were evaluated in univariable and propensity-score matched analyses.

RESULTS

After matching, 102 well-paired patients were selected. There was no significant difference in the 6-, 12-, 24-, and 60-month cumulative OS (73.5, 42.9, 23.6, 7.6% vs. 72.4, 45.1, 29.8, 13.2%, p = 0.151), PFS (53.9, 29.3, 21.8, 7.5% vs. 54.5, 19.3, 12.0, 9.6%, p = 0.744), IC (61.4, 45.7, 39.0, 26.8% vs. 75.1, 45.8, 35.9, 28.7%, p = 0.144), and LC (85.2, 56.5, 52.1, 47.4% vs. 87.4, 65.2, 62.1, 62.1%, p = 0.191) between the IMRT and SBRT groups. A biologically effective dose assumed at an a/b ratio of 10 (BED₁₀) of ≥ 100 Gy was the optimal cutoff for predicting the OS, PFS, IC, and LC in the patients who received SBRT.

CONCLUSIONS

When high-precision tracking technology is available, SBRT appears to be a safe and more time-efficient treatment, achieving comparable OS, PFS, IC and LC to IMRT for local advanced HCC with PVTT. A BED₁₀ ≥ 100 Gy is recommended if tolerated by normal tissue.

Radiation treatment planning study to investigate feasibility of delivering Immunotherapy in Combination with Ablative Radiosurgery to Ultra-High DoSes (ICARUS)

PURPOSE

Immune checkpoint inhibitors improve survival in metastatic diseases for some cancers. Multisite SBRT with pembrolizumab (SBRT + Pembro) was shown to be safe with promising local control using biologically effective doses (BEDs) = 95-120 Gy. Increased BED may improve response rate; however, SBRT doses are limited by surrounding organs at risk (OARs). The purpose of this work was to develop and validate methods for safe delivery of ultra-high doses of radiation (BED₁₀  > 300) to be used in future clinical trials.

METHODS AND MATERIALS

The radiation plans from 15 patients enrolled on a phase I trial of SBRT + pembro were reanalyzed. Metastatic disease sites included liver (8/15), inguinal region (1/15), pelvis (2/15), lung (1/15), abdomen (1/15), spleen (1/15), and groin (1/15). Gross tumor volumes (GTVs) ranged from 80 to 708 cc. Following the same methodology used in the Phase I trial on which these patients were treated, GTVs > 65 cc were contracted to a 65 cc subvolume (SubGTV) resulting in only a portion of the GTV receiving prescription dose. Volumetric modulated arc therapy (VMAT) was used to plan treatments BED₁₀  = 360 Gy. Plans utilizing both 6FFF and 10FFF beams were compared to clinical plans delivering BED₁₀  = 112.50 Gy. The target primary goal was V100% > 95% with a secondary goal of V70% > 99% and OAR objectives per the trial. To demonstrate feasibility, plans were delivered to a diode array phantom and evaluated for fidelity using gamma analysis.

RESULTS

All 30 plans met the secondary coverage goal and satisfied all OAR constraints. The primary goal was achieved in 12/15 of the 6FFF plans and 13/15 of the 10FFF plans. Average gamma analysis passing rate using criteria of 3% dose difference and 3, 2, and 1 mm were 99.1  ±  1.0%, 98.5  ±  1.6%, and 95.1  ±  3.8%, respectively.

CONCLUSION

Novel VMAT planning approaches with clinical treatment planning software and linear accelerators prove capable of delivering radiation doses in excess of 360 Gy BED₁₀ to tumor subvolumes, while maintaining safe OAR doses.

External beam radiation therapy in a centenarian with primary liver cancer: A case report

RATIONALE

Due to unprecedented global aging, the number of elderly and super-elderly patients with cancer is increasing. However, restricted by comorbidities or fragility, many elderly patients are considered ineligible to receive invasive therapies. A centenarian with primary liver cancer (PLC) was treated by external beam radiation therapy (EBRT). This rare case deserves our attention.

PATIENT CONCERNS

We present a rare case of a centenarian with PLC. The super-elderly male patient complained that 2 liver lesions were found by abdominal ultrasonography in June 2016.

DIAGNOSES

The Segment 7 (S7) lesion and the Segment 5/8 (S5/8) lesion were clinically diagnosed as PLC successively.

INTERVENTIONS

The S7 lesion was considered PLC initially and treated by EBRT in October 2016. In the 1-year follow-up after EBRT, the S7 lesion was well controlled. Unfortunately, the S5/8 lesion had increased in size, was diagnosed as PLC and subsequently treated by CyberKnife in another hospital. However, local failure of the S5/8 lesion was suggested 15 months after CyberKnife. At the age of 102 years, the patient received re-irradiation for the S5/8 lesion.

OUTCOMES

Three months after re-irradiation, des-γ-carboxy-prothrombin decreased to normal; no significant change in the S5/8 lesion was found in Magnetic Resonance Imaging. No severe acute or late toxicities were reported after each course of EBRT. Unfortunately, the patient died of respiratory failure caused by severe pneumonia in mid-March 2020.

CONCLUSION

Advanced age is not a contraindication for elderly patients with cancer to receive radiotherapy and even re-irradiation.

Adjuvant apatinib treatment after resection of hepatocellular carcinoma with portal vein tumor thrombosis: a phase II trial

Background

Survival after resection of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) still remains poor. Apatinib, a vascular endothelial cell growth factor receptor 2 inhibitor, has been shown to be safe and effective in patients with advanced HCC, so in the present study its efficacy and safety in the adjuvant setting was explored.

Methods

In this single-center, open-label phase II trial, the patients received apatinib (500 mg/day) until they experienced disease recurrence or intolerable toxicity. The primary endpoint was recurrence-free survival (RFS); the secondary endpoints included overall survival (OS) and safety.

Results

From a total of 49 patients who were screened between August 2017 and December 2018, 30 study participants received apatinib. According to the Liver Cancer Study Group of Japan classification of PVTT, there were 7, 11, and 12 participants with Vp1, Vp2, and Vp3, respectively. The median duration of treatment was 4.8 months [interquartile range (IQR): 2.0-8.8], and the median dose of apatinib was 339.7 mg/day (IQR: 267.7-500 mg/day). The median follow-up was 14.3 months (IQR: 12.3-19.3). The median RFS was 7.6 months [95% confidence interval (CI): 5.7-9.5 months]. The 1-year RFS rate and the 1-year OS rate were 36.1% and 93.3%, respectively. A total of 29 (96.7%) patients experienced adverse events, and 14 (46.7%) had grade 3 or 4 adverse events. No treatment-related deaths occurred.

Conclusions

Apatinib was well tolerated in patients after resection of HCC with PVTT. The median RFS in this group was improved compared with that previously reported.

Trial registration

No.: NCT03261791 (ClinicalTrials.gov).

Stereotactic body radiotherapy in hepatocellular carcinoma: patient selection and predictors of outcome and toxicity

INTRODUCTION

Stereotactic Body Radiotherapy (SBRT) emerged as a valuable option in early to advanced-stage Hepatocellular Carcinoma (HCC) as defined by Barcelona Clinic Liver Cancer (BCLC) system. The aim of our study is to evaluate SBRT in HCC patients and to identify predictors of outcome and toxicity.

MATERIALS AND METHODS

A retrospective review of HCC patients treated at our Institution between November 2011 and December 2018 was carried out. SBRT was delivered in 3-10 fractions to a median Biologically Effective Dose (BED¹⁰) of 103 Gy¹⁰.

RESULTS

SBRT was performed in 128 patients to 217 HCC localizations, accounting for 142 treatment courses. BCLC stage was A, B, C in, respectively, 40 (31%), 72 (56%) and 16 (13%) patients. Local Control (LC), Progression Free Survival (PFS) and Overall Survival (OS) at 2 years were, respectively: 78%, 15% and 58%. LC was influenced by BED10 > 120 Gy¹⁰ (Hazard Ratio, HR: 0.08, 95% CI 0.01-0.59; p = 0.013) and size ≥ 3 cm (HR: 2.71, 95% CI 1.10-6.66; p = 0.03). BCLC stage was correlated to PFS (median 14 vs 12 vs 5 months, p = 0.012). In BCLC stage A-B disease (n = 112), LC was associated with improved survival (median 30 months vs not reached, p = 0.036). Acute and late toxicity rate was 26% (n = 37) and 8% (n = 11). Patients with BCLC B-C stage disease showed increased acute toxicity (HR: 2.9, 95% CI 1.10-7.65; p = 0.032).

CONCLUSION

Delivery of ablative doses > 120 Gy¹⁰ and tumor size are determinants of LC. Prolonged PFS and improved OS can be obtained in BCLC A-B patients. Grade 3 liver dysfunction is infrequent.

Biologically effective dose (BED) escalation of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma patients (≤5 cm) with CyberKnife: protocol of study

BACKGROUND

There is a lack of data on the biologically effective dose and the efficacy of stereotactic body radiotherapy in hepatocellular carcinoma patients, and this study was conducted to explore the relation between BED and efficacy.

METHODS

This study is designed as a mono-center study. The participants are randomized into three group, and received the following recommended schedule: 49Gy/7f, 54Gy/6f and 55Gy/5f with BED₁₀ in correspondence to 83.3Gy, 102.6Gy and 115.5Gy. The primary outcome measures are to calculate local control rates (LC), overall survival rates (OS) and progression-free survival rates (PFS). The secondary outcome measures are to observe radiation-induced liver injury (RILD) rates, Child-Pugh score and indocyanine green retention rate at 15 min (ICG-R15) value before and after CK-SBRT. Moreover, gastrointestinal toxicities are also observed.

DISCUSSION

There is no uniform standard for CK-SBRT dose schedule of hepatocellular carcinoma. We propose to conduct a study determining the optimal CK-SBRT schedule of hepatocellular carcinoma patients (≤5 cm). The trial protocol has been approved by the Institutional Review Board of 302 Hospital of PLA (People's Liberation Army). The Ethics number is 2017111D.

TRAIL REGISTRATION

Clinical trails number: NCT03295500. Date of registration: November, 2017.

Repeated CyberKnife stereotactic body radiation therapy in hepatocellular carcinoma

Background

To explore the survival and side effects of repeated CyberKnife stereotactic body radiation therapy (CK-SBRT) on hepatocellular carcinoma patients.

Methods

24 HCC patients were collected at The Fifth Medical Center of PLA General Hospital from November 2011 to July 2016. They received second-course CK-SBRT with a prescribed dose of 50(48–55) Gy/5-8fx, and a single dose of 10 (7–11) Gy/fx. Cumulative overall survival rates (OS), progression-free survival rates (PFS) and local control rates (LC) were calculated by Kaplan-Meier method.

Results

All patients finished their radiotherapy plans. The 1-,2- and 3-year cumulative OS rate were 95.8,81.1 and 60.8%. The 1-,2- and 3-year LC rate were 95.5,90.7 and 90.7%, respectively. The 1-, 2- and 3-year PFS were 74.8, 49.2 and 39.4%, respectively. 16 patients complained of fatigue during second-course therapy, 2 patients showed Grade 2 gastrointestinal reaction, 1 patient was diagnosed radiation-induced liver disease and none died. PFS was significantly higher in the interval time < 12 months group than in the interval time ≥ 12 months group (p = 0.030).

Conclusions

It is preliminarily believed that re-CK-SBRT is an effective and safe treatment for HCC patients, but the treatment criteria should be strictly controlled.