Escalated focal liver radiation and concurrent hepatic artery fluorodeoxyuridine for unresectable intrahepatic malignancies

Hypofractionated Radiotherapy-Related Lymphopenia Is Associated With Worse Survival in Unresectable Intrahepatic Cholangiocarcinoma

OBJECTIVE

The aim of this study was to evaluate the incidence of radiotherapy (RT)-related lymphopenia, its predictors, and association with survival in unresectable intrahepatic cholangiocarcinoma (ICC) treated with hypofractionated-RT (HF-RT).

METHODS

Retrospective analysis of 96 patients with unresectable ICC who underwent HF-RT (median 58.05 Gy in 15 fractions) between 2009 and 2022 was performed. Absolute lymphocyte count (ALC) nadir within 12 weeks of RT was analyzed. Primary variable of interest was severe lymphopenia, defined as Grade 3+ (ALC <0.5 k/μL) per CTCAE v5.0. Primary outcome of interest was overall survival (OS) from RT.

RESULTS

Median follow-up was 16 months. Fifty-two percent of patients had chemotherapy pre-RT, 23% during RT, and 40% post-RT. Pre-RT, median ALC was 1.1 k/μL and 5% had severe lymphopenia. Post-RT, 68% developed RT-related severe lymphopenia. Patients who developed severe lymphopenia had a significantly lower pre-RT ALC (median 1.1 vs. 1.5 k/μL, P =0.01) and larger target tumor volume (median 125 vs. 62 cm 3 , P =0.02). In our multivariable Cox model, severe lymphopenia was associated with a 1.7-fold increased risk of death ( P =0.04); 1-year OS rates were 63% vs 77% ( P =0.03). Receipt of photon versus proton-based RT (OR=3.50, P =0.02), higher mean liver dose (OR=1.19, P <0.01), and longer RT duration (OR=1.49, P =0.02) predicted severe lymphopenia.

CONCLUSIONS

HF-RT-related lymphopenia is an independent prognostic factor for survival in patients with unresectable ICC. Patients with lower baseline ALC and larger tumor volume may be at increased risk, and use of proton therapy, minimizing mean liver dose, and avoiding treatment breaks may reduce RT-related lymphopenia.

Case report: Massive hepatocellular carcinoma with complete response to the non-surgical systematic treatment strategy

Background

The five-year recurrence rate of hepatocellular carcinoma (HCC) remains as high as 70%. A complete clinical response has not been observed without surgical resection. Here, we report a rare case of clinical complete response and long-term survival in a patient with massive HCC receiving treatment with immunotherapy, anti-angiogenic therapy, and radiotherapy.

Case description

A 38-year-old woman presented to our hospital for abdominal pain that persisted for 3 months. She was diagnosed as Barcelona Clinic Liver Cancer(BCLC) stage A, with a Cancer of the Liver Italian Program (CLIP) score of 3, American Joint Committee on Cancer (AJCC) Tumor-Node-Metastasis (TNM) staging systems stage IB. She refused surgical resection and trans-arterial chemoembolization and accepted a non-invasive systematic treatment strategy involving immunotherapy, anti-angiogenic therapy, and radiotherapy. Her tumor burden decreased, and she experienced partial response before radiotherapy. Following radiotherapy, she experienced a complete clinical response and has been alive for more than 36 months after her initial presentation. She is currently alive.

Conclusion

A non-invasive systematic treatment strategy is a potential radical treatment option for patients with massive HCC.

Proton Beam Therapy for Intrahepatic Cholangiocarcinoma: A Multicenter Prospective Registry Study in Japan

Introduction

Intrahepatic cholangiocarcinoma (ICC) can be treated with chemotherapy in unresectable cases, but outcomes are poor. Proton beam therapy (PBT) may provide an alternative treatment and has good dose concentration that may improve local control.

Methods

Fifty-nine patients who received initial PBT for ICC from May 2016 to June 2018 at nine centers were included in the study. The treatment protocol was based on the policy of the Japanese Society for Radiation Oncology. Forty patients received 72.6-76 Gy (RBE) in 20-22 fr, 13 received 74.0-76.0 Gy (RBE) in 37-38 fr, and 6 received 60-70.2 Gy (RBE) in 20-30 fr. Overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan-Meier analysis.

Results

The 59 patients (35 men, 24 women; median age: 71 years; range: 41-91 years) had PS of 0 (n = 47), 1 (n = 10), and 2 (n = 2). Nine patients had hepatitis and all 59 cases were considered inoperable. The Child-Pugh class was A (n = 46), B (n = 7), and unknown (n = 6); the median maximum tumor diameter was 5.0 cm (range 2.0-15.2 cm); and the clinical stage was I (n = 12), II (n = 19), III (n = 10), and IV (n = 18). At the last follow-up, 17 patients were alive (median follow-up: 36.7 months; range: 24.1-49.9 months) and 42 had died. The median OS was 21.7 months (95% CI: 14.8-34.4 months). At the last follow-up, 37 cases had recurrence, including 10 with local recurrence. The median PFS was 7.5 months (95% CI: 6.1-11.3 months). In multivariable analyses, Child-Pugh class was significantly associated with OS and PFS, and Child-Pugh class and hepatitis were significantly associated with local recurrence. Four patients (6.8%) had late adverse events of grade 3 or higher.

Conclusion

PBT gives favorable treatment outcomes for unresectable ICC without distant metastasis and may be particularly effective in cases with large tumors.

Impact of radiation therapy and alpha-fetoprotein level on survival outcomes for patients with hepatocellular carcinoma: A population-based study

BACKGROUND

The use of radiation therapy (RT) in hepatocellular carcinoma (HCC) remains a matter for debate. Recently published research indicate that advanced RT techniques may improve survival in patients with HCC. This study aimed to evaluate this hypothesis in a large-scale retrospective cohort. The effect of alpha-fetoprotein (AFP) was taken into account because of its important role in the prognosis of HCC.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for adults patients diagnosed 2010-2019 with HCC (≥ 18 years). The study population was divided into four groups: Non-radiation & AFP-positive (reference), Non-radiation & AF-negative, Radiation & AFP-positive, Radiation & AFP-negative. Distant metastasis (DM) was used as a stratification factor. Differences in 5-year overall survival (OS) of the four groups were assessed using the Kaplan-Meier method. Univariate and multivariable Cox proportional hazards model were used to estimate unadjusted and adjusted hazard ratios (HR).

RESULTS

A total of 34,656 patients were eligible for this analysis, including 21,084 (60.8%), 8,449 (24.4%), 3,810 (11.0%) and 1,313 (3.8%) in the Non-radiation & AFP-positive, Non-radiation & AF-negative, Radiation & AFP-positive and Radiation & AFP-negative groups, respectively. Median OSs of the four groups were 3, 4, 5 and 11 months in the DM cohort, and 12, 28, 15, and 28 months in the Non-DM cohort. Patients in the Radiation & AFP - group had the best OS and patients in the Non-radiation & AFP + group had the worst OS (adjusted HR [95% confidence interval (CI)]: 0.497 [0.399-0.619] in the DM cohort, and 0.405 [0.372-0.441] in the Non-DM cohort). Radiation & AFP + also showed improved survival compared with the reference group (adjusted HR [95%CI]: 0.725 [0.657-0.801] in the DM cohort, and 0.630 [0.600-0.661] in the Non-DM cohort).

CONCLUSIONS

This population-based cohort study confirmed a significant improvement in overall survival with radiation therapy in HCC. AFP-negative patients benefit the most from RT. Superior OS of radiation therapy and AFP-negative status persisted even in patients with complex metastasis patterns. Our data suggest that radiation may provide an alternative modality for unresectable HCC.

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.

Clinical Efficacy of Hypofractionated Proton Beam Therapy for Intrahepatic Cholangiocarcinoma

Forty-seven patients with intrahepatic cholangiocarcinoma (IHCC) who received proton beam therapy (PBT) were analyzed to evaluate the clinical efficacy and safety of hypofractionated PBT in patients with inoperable or recurrent IHCC. The median prescribed dose of PBT was 63.3 GyE (range: 45-80 GyE) in 10 fractions, and the median duration of follow-up in all the patients was 18.3 months (range: 2.4-89.9 months). Disease progression occurred in 35 of the 47 (74.5%) patients; local, intrahepatic, and extrahepatic progression occurred in 5 (10.6%), 20 (42.6%), and 29 (61.7%) patients, respectively. The 2-year freedom from local progression (FFLP), progression-free survival (PFS), overall survival (OS) rates, and median time of OS were 86.9% (95% confidence interval [CI], 74.4-99.4%), 16.8% (95% CI, 4.3-29.3%), 42.7% (95% CI, 28.0-57.4%), and 21.9 months (95% CI, 16.2-28.3 months), respectively; grade ≥ 3 adverse events were observed in four (8.5%) patients. In selected patients with localized disease (no viable tumors outside of the PBT sites), the median time of OS was 33.8 months (95% CI, 5.4-62.3). These findings suggest that hypofractionated PBT is safe and could offer a high rate of FFLP and promising OS in patients with inoperable or recurrent IHCC.

The evolving role of radiation therapy as treatment for liver metastases

Liver metastases occur commonly in many solid malignancies. With advances in systemic therapies and increased life expectancy, the role of using local therapies in oligo-metastases is rapidly increasing. Stereotactic body radiotherapy (SBRT) is an emerging precision therapy that is being used more frequently in the treatment for unresectable liver metastases. This review focuses on the role of SBRT for liver metastases, principles of treatment, clinical outcomes, toxicity, and optimal patient selection.

Cost-effectiveness analysis of personalised versus standard dosimetry for selective internal radiation therapy with TheraSphere in patients with hepatocellular carcinoma

Aims

To perform a cost-effectiveness analysis (CEA) comparing personalised dosimetry with standard dosimetry in the context of selective internal radiation therapy (SIRT) with TheraSphere for the management of adult patients with locally advanced hepatocellular carcinoma (HCC) from the Italian Healthcare Service perspective.

Materials and methods

A partition survival model was developed to project costs and the quality-adjusted life years (QALYs) over a lifetime horizon. Clinical inputs were retrieved from a published randomised controlled trial. Health resource utilisation inputs were extracted from the questionnaires administered to clinicians in three oncology centres in Italy, respectively. Cost parameters were based on Italian official tariffs.

Results

Over a lifetime horizon, the model estimated the average QALYs of 1.292 and 0.578, respectively, for patients undergoing personalised and standard dosimetry approaches. The estimated mean costs per patient were €23,487 and €19,877, respectively. The incremental cost-utility ratio (ICUR) of personalised versus standard dosimetry approaches was €5,056/QALY.

Conclusions

Personalised dosimetry may be considered a cost-effective option compared to standard dosimetry for patients undergoing SIRT for HCC in Italy. These findings provide evidence for clinicians and payers on the value of personalised dosimetry as a treatment option for patients with HCC.

Radiation Oncology: Future Vision for Quality Assurance and Data Management in Clinical Trials and Translational Science

The future of radiation oncology is exceptionally strong as we are increasingly involved in nearly all oncology disease sites due to extraordinary advances in radiation oncology treatment management platforms and improvements in treatment execution. Due to our technology and consistent accuracy, compressed radiation oncology treatment strategies are becoming more commonplace secondary to our ability to successfully treat tumor targets with increased normal tissue avoidance. In many disease sites including the central nervous system, pulmonary parenchyma, liver, and other areas, our service is redefining the standards of care. Targeting of disease has improved due to advances in tumor imaging and application of integrated imaging datasets into sophisticated planning systems which can optimize volume driven plans created by talented personnel. Treatment times have significantly decreased due to volume driven arc therapy and positioning is secured by real time imaging and optical tracking. Normal tissue exclusion has permitted compressed treatment schedules making treatment more convenient for the patient. These changes require additional study to further optimize care. Because data exchange worldwide have evolved through digital platforms and prisms, images and radiation datasets worldwide can be shared/reviewed on a same day basis using established de-identification and anonymization methods. Data storage post-trial completion can co-exist with digital pathomic and radiomic information in a single database coupled with patient specific outcome information and serve to move our translational science forward with nimble query elements and artificial intelligence to ask better questions of the data we collect and collate. This will be important moving forward to validate our process improvements at an enterprise level and support our science. We have to be thorough and complete in our data acquisition processes, however if we remain disciplined in our data management plan, our field can grow further and become more successful generating new standards of care from validated datasets.

Regional Therapy for Colorectal Cancer Liver Metastases: Which Modality and When?

For patients with unresectable colorectal liver metastases (uCRLM), regional therapies leverage the unique, dual blood supply to the liver; the hepatic artery is the main blood supply for liver tumors, whereas the portal vein supplies most normal hepatic parenchyma. Infusion of cancer therapies via the hepatic artery allows selective delivery to the tumors with relative sparing of normal liver tissue and little extrahepatic exposure, thus limiting systemic side effects. There is a paucity of randomized controlled trial evidence to inform the optimal integration of regional therapies into the management of CRLM. Hepatic arterial infusion pump (HAIP) chemotherapy has a potential survival benefit when used in the adjuvant setting after resection of CRLM. HAIP chemotherapy can be safely given with contemporary systemic therapies and is associated with a high objective response and rate of conversion to resectability in patients with uCRLM. Drug-eluting beads coated with irinotecan transarterial chemoembolization is associated with high objective response rates within the liver and has a well-established safety profile in patients with uCRLM. Transarterial radioembolization achieves high rates of response within the liver but is not associated with improvements in overall survival or quality of life in the first- or second-line setting for uCRLM. The best treatment approach is the one that most aligns with a given patients' values, preferences, and philosophy of care. In the first-line setting, HAIP could be offered to motivated patients who hope to achieve conversion to resectability. After progression on chemotherapy, HAIP, transarterial chemoembolization, and transarterial radioembolization are valuable treatment options to consider for patients with liver-limited or liver-predominant CRLM who seek to optimize response rates and regional control.

Selective Internal Radiation Therapy with Yttrium-90 for Intrahepatic Cholangiocarcinoma: A Systematic Review on Post-Treatment Dosimetry and Concomitant Chemotherapy

Selective internal radiation therapy (SIRT) with yttrium-90 (90Y)-loaded microspheres is increasingly used for the treatment of Intrahepatic Cholangiocarcinoma (ICC). Dosimetry verifications post-treatment are required for a valid assessment of any dose-response relationship. We performed a systematic review of the literature to determine how often clinics conducted post-treatment dosimetry verification to measure the actual radiation doses delivered to the tumor and to the normal liver in patients who underwent SIRT for ICC, and also to explore the corresponding dose-response relationship. We also investigated other factors that potentially affect treatment outcomes, including the type of microspheres used and concomitant chemotherapy. Out of the final 47 studies that entered our study, only four papers included post-treatment dosimetry studies after SIRT to quantitatively assess the radiation doses delivered. No study showed that one microsphere type provided a benefit over another, one study demonstrated better imaging-based response rates associated with the use of glass-based TheraSpheres, and two studies found similar toxicity profiles for different types of microspheres. Gemcitabine and cisplatin were the most common chemotherapeutic drugs for concomitant administration with SIRT. Future studies of SIRT for ICC should include dosimetry to optimize treatment planning and post-treatment radiation dosage measurements in order to reliably predict patient responses and liver toxicity.

Stereotactic body radiation therapy for primary liver tumors: An effective liver-directed therapy in the toolbox

The use of radiation for primary liver cancers has historically been limited because of the risk of radiation-induced liver disease. Treatment fields have become more conformal because of several technical advances, and this has allowed for dose escalation. Stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy, is now able to safely treat liver tumors to ablative doses while sparing functional liver parenchyma by using highly conformal therapy. Several retrospective and small prospective studies have examined the use of SBRT for liver cancers; however, there is a lack of well-powered randomized studies to definitively guide management in these settings. Recent advances in systemic therapy for primary liver cancers have improved outcomes; however, the optimal selection criteria for SBRT as a local therapy remain unclear among other liver-directed options such as radiofrequency ablation, transarterial chemoembolization, and radioembolization.

Optimizing Loco Regional Management of Oligometastatic Colorectal Cancer: Technical Aspects and Biomarkers, Two Sides of the Same Coin

Colorectal cancer (CRC) is the third most common cancer worldwide and has a high rate of metastatic disease which is the main cause of CRC-related death. Oligometastatic disease is a clinical condition recently included in ESMO guidelines that can benefit from a more aggressive locoregional approach. This review focuses the attention on colorectal liver metastases (CRLM) and highlights recommendations and therapeutic locoregional strategies drawn from the current literature and consensus conferences. The different percutaneous therapies (radiofrequency ablation, microwave ablation, irreversible electroporation) as well as trans-arterial approaches (chemoembolization and radioembolization) are discussed. Ablation margins, the choice of the imaging guidance as well as characteristics of the different ablation techniques and other technical aspects are analyzed. A specific attention is then paid to the increasing role of biomarkers (in particular molecular profiling) and their role in the selection of the proper treatment for the right patient. In conclusion, in this review an up-to-date state of the art of the application of locoregional treatments on CRLM is provided, highlighting both technical aspects and the role of biomarkers, two sides of the same coin.

Magnetic Resonance Imaging-Guided Adaptive Radiotherapy for Colorectal Liver Metastases

Technological advances have enabled well tolerated and effective radiation treatment for small liver metastases. Stereotactic ablative radiation therapy (SABR) refers to ablative dose delivery (>100 Gy BED) in five fractions or fewer. For larger tumors, the safe delivery of SABR can be challenging due to a more limited volume of healthy normal liver parenchyma and the proximity of the tumor to radiosensitive organs such as the stomach, duodenum, and large intestine. In addition to stereotactic treatment delivery, controlling respiratory motion, the use of image guidance, adaptive planning and increasing the number of radiation fractions are sometimes necessary for the safe delivery of SABR in these situations. Magnetic Resonance (MR) image-guided adaptive radiation therapy (MRgART) is a new and rapidly evolving treatment paradigm. MR imaging before, during and after treatment delivery facilitates direct visualization of both the tumor target and the adjacent normal healthy organs as well as potential intrafraction motion. Real time MR imaging facilitates non-invasive tumor tracking and treatment gating. While daily adaptive re-planning permits treatment plans to be adjusted based on the anatomy of the day. MRgART therapy is a promising radiation technology advance that can overcome many of the challenges of liver SABR and may facilitate the safe tumor dose escalation of colorectal liver metastases.

Radiosensitizing Chemotherapy (Irinotecan) with Stereotactic Body Radiation Therapy for the Treatment of Inoperable Liver and/or Lung Metastases of Colorectal Cancer

Simple Summary

Stereotactic body radiotherapy (SBRT) is a recognized treatment for liver or lung metastases, but radiosensitivity of colorectal cancer could be lower than other primary cancers. We postulated that local responses could be improved by SBRT with a concomitant radiosensitizing agent (irinotecan). RADIOSTEREO-CAMPTO was a prospective multi-center phase 2 trial conducted between 2008 and 2013. We confirmed that SBRT-Irinotecan was a short, effective and well-tolerated treatment, with no worsening of the quality of life. It allowed for several months of chemotherapy-free periods despite most patients receiving multiple prior lines of treatment. Radiosensitizing irinotecan was able to compensate for lower SBRT dose than nowadays used for liver and lung metastases and could be an interesting regimen in case of tumour-surrounding healthy tissues requiring limited radiation dose.

Abstract

Background: Stereotactic body radiotherapy (SBRT) is a recognized treatment for colorectal cancer (CRC) metastases. We postulated that local responses could be improved by SBRT with a concomitant radiosensitizing agent (irinotecan). Methods: RADIOSTEREO-CAMPTO was a prospective multi-center phase 2 trial investigating SBRT (40–48 Gy in 4 fractions) for liver and/or lung inoperable CRC oligometastases (≤3), combined with two weekly intravenous infusions of 40 mg/m² Irinotecan. Primary outcome was the objective local response rate as per RECIST. Secondary outcomes were early and late toxicities, EORTC QLQ-C30 quality of life, local control and overall survival. Results: Forty-four patients with 51 lesions (liver = 39, lungs = 12) were included. Median age was 69 years (46–84); 37 patients (84%) had received at least two prior chemotherapy treatments. Median follow-up was 48.9 months. One patient with two lung lesions was lost during follow-up. Assuming maximum bias hypothesis, the objective local response rate in ITT was 86.3% (44/51—95% CI: [76.8–95.7]) or 82.4% (42/51—95% CI: [71.9–92.8]). The observed local response rate was 85.7% (42/49—95% CI: [75.9–95.5]). The 1 and 2-year local (distant) progression-free survivals were 84.2% (38.4%) and 67.4% (21.3%), respectively. The 1 and 2-year overall survivals were 97.5% and 75.5%. There were no severe acute or late reactions. The EORTC questionnaire scores did not significantly worsen during or after treatment. Conclusions: SBRT with irinotecan was well tolerated with promising results despite heavily pretreated patients.

Radiofrequency ablation and stereotactic body radiotherapy for hepatocellular carcinoma: should they clash or reconcile?

Until a few decades ago, surgical resection was the only valid option for treating hepatocellular carcinoma (HCC). However, various locoregional modalities including arterial-directed therapy, radiofrequency ablation (RFA), and radiotherapy have been recently shown to be effective. RFA is now established as a standard treatment for small localized HCCs, showing oncological results comparable to those of surgical resection in randomized studies. Stereotactic body radiotherapy (SBRT) is a modern radiotherapeutic modality that targets tumors with precision and delivers high radiation doses over a short period of time; it has particularly attracted clinical interest after its therapeutic efficacy was found to be similar to that of surgery in early-stage lung cancer. Given its potent disease control capability, SBRT has also been applied to early HCCs and demonstrated promising results in recent studies. It has also been noted for its suitability to treat tumors located in anatomical locations where RFA would be challenging. However, since its effectiveness has not been compared to that of RFA in randomized studies of patients eligible for RFA, the use of SBRT has been debated. This review was conducted to guide physicians from all fields involved in the treatment of early HCC. The therapeutic characteristics and indications of both SBRT and RFA are described, and recent comparative studies between the two modalities are discussed. In addition, we examined the factors that should be considered when selecting the appropriate treatments, and offer our recommendations.

Long-Term Results of a Phase 1 Dose-Escalation Trial and Subsequent Institutional Experience of Single-Fraction Stereotactic Ablative Radiation Therapy for Liver Metastases

PURPOSE

We report long-term outcomes from our phase 1 dose-escalation study to determine the maximum tolerated dose of single-fraction liver SABR pooled with our subsequent single institutional experience with patients treated postprotocol at the highest dose level (40 Gy) established from the phase 1 study.

METHODS AND MATERIALS

Patients with liver metastases from solid tumors located outside of the central liver zone were treated with single-fraction SABR on a phase 1 dose escalation trial. At least 700 cc of normal liver had to receive <9.1 Gy. Seven patients with 10 liver metastases received the initial prescription dose of 35 Gy, and dose was then escalated to 40 Gy for 7 more patients with 7 liver metastases. An additional 19 postprotocol patients with 22 liver metastases were treated to 40 Gy in a single fraction. Patients were followed for toxicity and underwent serial imaging to assess local control.

RESULTS

Median imaging follow-up for the combined cohort (n = 33, 39 lesions) was 25.9 months; 38.9 months for protocol patients and 20.2 months for postprotocol patients. Median lesion size was 2.0 cm (range, 0.5-5.0 cm). There were no dose-limiting toxicities observed for protocol patients, and only 3 grade 2 toxicities were observed in the entire cohort, with no grade ≥3 toxicities attributable to treatment. Four-year actuarial local control of irradiated lesions in the entire cohort was 96.6%, 100% in the protocol group and 92.9% in the subsequent patients. Two-year overall survival for all treated patients was 82.0%.

CONCLUSIONS

For selected patients with liver metastases, single-fraction SABR at doses of 35 and 40 Gy was safe and well-tolerated, and shows excellent local control with long-term follow-up; results in subsequent patients treated with single-fraction SABR doses of 40 Gy confirmed our earlier results.

Hypofractionated proton beam radiotherapy in patients with unresectable liver tumors: multi-institutional prospective results from the Proton Collaborative Group

Background

Recent advances in radiotherapy techniques have allowed ablative doses to be safely delivered to inoperable liver tumors. In this setting, proton beam radiotherapy (PBT) provides the means to escalate radiation dose to the target volume while sparing the uninvolved liver. This study evaluated the safety and efficacy of hypofractionated PBT for liver tumors, predominantly hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC).

Methods

We evaluated the prospective registry of the Proton Collaborative Group for patients undergoing definitive PBT for liver tumors. Demographic, clinicopathologic, toxicity, and dosimetry information were compiled.

Results

To date, 63 patients have been treated at 9 institutions between 2013 and 2019. Thirty (48%) had HCC and 25 (40%) had ICC. The median dose and biological equivalent dose (BED) delivered was 58.05 GyE (range 32.5–75) and 80.5 GyE (range 53.6–100), respectively. The median mean liver BED was 13.9 GyE. Three (4.8%) patients experienced at least one grade ≥ 3 toxicity. With median follow-up of 5.1 months (range 0.1–40.8), the local control (LC) rate at 1 year was 91.2% for HCC and 90.9% for ICC. The 1-year LC was significantly higher (95.7%) for patients receiving BED greater than 75.2 GyE than for patients receiving BED of 75.2 GyE or lower (84.6%, p = 0.029). The overall survival rate at 1 year was 65.6% for HCC and 81.8% for ICC.

Conclusions

Hypofractionated PBT results in excellent LC, sparing of the uninvolved liver, and low toxicity, even in the setting of dose-escalation. Higher dose correlates with improved LC, highlighting the importance of PBT especially in patients with recurrent or bulky disease.

Clinical outcomes of stereotactic body radiation therapy for small hepatocellular carcinoma

BACKGROUND AND AIM

The purpose of this study was to investigate the long-term oncologic outcomes after stereotactic body radiation therapy (SBRT) for small hepatocellular carcinoma (HCC).

METHODS

A total of 290 patients with HCC were registered between March 2007 and July 2013. A dose of 10-15 Gy per fraction was given over three to four consecutive days, resulting in a total dose of 30-60 Gy. Overall and recurrence-free survivals were estimated from the date of the start of SBRT to the date of death, the last follow-up examination, or to the date of tumor recurrence.

RESULTS

The median follow-up period of all patients was 38.2 months, and the median tumor size was 1.7 cm. Overall survival (OS) rate at 5 years was 44.9%. Multivariate analyses revealed that age, Child-Pugh class, tumor size, and albumin levels were significant factors for OS. The 5-year local control rate was 91.3%. In multivariate analysis, tumor size and albumin were significantly associated with local tumor control. However, there was a negative correlation between total dose and tumor size in Pearson's correlation analysis (r = -0.111, P = 0.046).

CONCLUSIONS

Stereotactic body radiation therapy was an excellent ablative treatment option for patients with small HCC. Tumor size was a significant factor for local tumor control after SBRT, although the total dose was negatively correlated with tumor size. Considering the low OS rates and the high local tumor control rates, the combined SBRT and systemic therapies may be beneficial for improving survival outcomes.

External Beam Radiation Therapy for Liver Metastases

Stereotactic ablative radiotherapy (SABR) commonly is used for small liver metastases. Modern conformal radiotherapy techniques, including 3-dimensional conformal radiotherapy and intensity-modulated radiation therapy, enable the safe delivery of SABR to small liver volumes. For larger tumors, the safe delivery of SABR can be challenging due to a more limited volume of healthy normal liver parenchyma and the proximity of the tumor to radiosensitive organs, such as the stomach, duodenum, and large intestine. Controlling respiratory motion, the use of image guidance, and increasing the number of radiation fractions sometimes are necessary for the safe delivery of SABR in these situations.

Phase I Radiation Dose-Escalation Study to Investigate the Dose-Limiting Toxicity of Concurrent Intra-Arterial Chemotherapy for Unresectable Hepatocellular Carcinoma

Concurrent intra-arterial chemotherapy and radiotherapy (iA-CCRT) can increase the response rate in hepatocellular carcinoma (HCC), but may cause a higher toxicity. We conducted this Phase I study to investigate the dose-limiting toxicity of iA-CCRT for HCC. In total, 52.5 Gy in 25 fractions was prescribed as planning target volume (PTV) 1 at dose level 1. The dose escalation was 0.2 Gy per fraction and up to 2.5 Gy, with 62.5 Gy at level 3. Concurrent intra-arterial 5-fluorouracil was administered during the first and fifth weeks of radiotherapy (RT). Toxicities were graded using the Common Toxicity Criteria for Adverse Events, version 4.0. Results: Seventeen patients with HCC were analyzed: four at dose level 1, 6 at level 2, and 7 at level 3. The mean irradiated dose administered to the uninvolved liver at each dose level was 21.3, 21.6, and 18.2 Gy, respectively. There was no grade ≥3 gastrointestinal toxicity; two patients experienced grade 3 hyperbilirubinemia. All patients had Child-Pugh class A disease, but 3 patients developed class B disease after iA-CCRT. During a median follow-up of 13 months, the median progression-free survival (PFS) and overall survival (OS) were 10 and 22 months, respectively. Patients treated at dose level 3 showed improved PFS and OS. Conclusions: Radiation dose escalation of iA-CCRT did not cause any significant toxicities in patients with advanced HCC. Further large-scale studies with long-term follow-up are needed to determine the efficacy and feasibility of higher doses of iA-CCRT.

Stereotactic Body Radiotherapy as a Salvage Therapy after Incomplete Radiofrequency Ablation for Hepatocellular Carcinoma: A Retrospective Cohort Study

Residual tumor tissue after radiofrequency ablation (RFA) is inevitable in clinical practice, and the optimal management of residual tumor after RFA has not been established. To evaluate the efficiency and toxicity of stereotactic body radiotherapy (SBRT) as a salvage therapy after incomplete RFA for hepatocellular carcinoma (HCC), we retrospectively included 32 HCC patients with an initial incomplete response (iIR) to RFA from May 2011 to August 2018. An iIR was defined as the presence of residual enhancement on CT or MRI one month after RFA treatment. The primary endpoint was local tumor control (LTC); the secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. All patients fulfilled 6 fractions of SBRT as planned, with dosages ranging from 30 Gy to 54 Gy. The objective response rate (ORR) was 50.0%. The 1- and 2-year LTC rates were 86.6% (95% CI, 74.3% to 98.9%) and 74.7% (95% CI, 55.9% to 93.5%), respectively. Fewer times of prior treatments was associated with better LTC (HR = 11.7, P=0.026). The 1- and 2-year PFS rate were 69.9% (95% CI, 53.4% to 86.4%) and 52.7% (95% CI, 33.1% to 72.3%), respectively. A higher Child-Pugh score was the only independent risk factor for tumor progression (HR = 5.17, P=0.012). The 1- and 3-year OS rate were 85.6% and 67.1%, respectively. Only two patients suffered grade 3 adverse events, and none experienced grade 4 or 5 events. In conclusion, for HCC patients confirmed to have an iIR to prior RFA, with compensated liver function, SBRT provided favorable LTC and OS along with acceptable toxicity.

Targeting therapeutic vulnerabilities with PARP inhibition and radiation in IDH-mutant gliomas and cholangiocarcinomas

Mutations in isocitrate dehydrogenase (IDH) genes occur in multiple cancer types, lead to global changes in the epigenome, and drive tumorigenesis. Yet, effective strategies targeting solid tumors harboring IDH mutations remain elusive. Here, we demonstrate that IDH-mutant gliomas and cholangiocarcinomas display elevated DNA damage. Using multiple in vitro and preclinical animal models of glioma and cholangiocarcinoma, we developed treatment strategies that use a synthetic lethality approach targeting the reduced DNA damage repair conferred by mutant IDH using poly(adenosine 5'-diphosphate) ribose polymerase inhibitors (PARPis). The therapeutic effects are markedly enhanced by cotreatment with concurrent, localized radiation therapy. PARPi-buttressed multimodality therapies may represent a readily applicable approach that is selective for IDH-mutant tumor cells and has potential to improve outcomes in multiple cancers.

Circular RNA TUBD1 Acts as the miR-146a-5p Sponge to Affect the Viability and Pro-Inflammatory Cytokine Production of LX-2 Cells through the TLR4 Pathway

The functions and molecular mechanism of circRNAs in the development of radiation-induced liver disease (RILD) remain largely unknown. The goal of this study was to explore the expression and potential role of a new circular RNA, named circTUBD1, in irradiated and lipopolysaccharide (LPS)-stimulated human hepatic stellate cell (HSC) line LX-2 cells. The expression of circTUBD1 was significantly upregulated in irradiated and LPS-stimulated LX-2 cells compared to non-treated LX-2 cells. To explore the functions of circTUBD1, small interfering RNAs targeting circTUBD1 were designed. Silencing circTUBD1 inhibited proliferation, promoted apoptosis of LX-2 cells, and significantly decreased the expression level of pro-inflammatory cytokines, including IL-1β, IL-6 and TNF-α in irradiated and LPS-stimulated LX-2 cells. Mechanistic analysis suggested that circTUBD1 acted as the miR-146a-5p sponge to affect pro-inflammatory cytokine production through regulating expression of Toll-like receptor 4 (TLR4), interleukin receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor-6 (TRAF6), and phosphorylation of nuclear factor-kappa B (pNF-κB) in irradiated and LPS-stimulated LX-2 cells. To our knowledge, this is the first study to show that circTUBD1 acts as a miR-146a-5p sponge to affect the viability and pro-inflammatory cytokine production of LX-2 cells through the TLR4 pathway, suggesting that circTUBD1 is a potential target for RILD therapy.

Radiation dose escalation for locally advanced unresectable intrahepatic and extrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (IHCC) and extrahepatic cholangiocarcinoma (EHCC) remain challenging diseases to treat. The majority of patients present with advanced disease, and the tumors often cause life-threatening biliary obstruction and vascular compromise of the liver. Local control (LC) of these tumors has the potential to prolong life for patients. While escalated-dose radiation therapy (EDRT) has been demonstrated to be an effective, safe option to achieve LC of IHCC, data for EHCC suggest that EDRT with current techniques has limitations, often due to dose-limiting bowel structures in close proximity to the extrahepatic biliary system. Here we review the results of EDRT for IHCC and EHCC and point to potential directions to combine radiotherapy with novel agents. The molecular characterization of cholangiocarcinoma has particularly opened new avenues for clinical investigations of targeted therapies with EDRT and may point to ways to achieve both systemic and LC benefits for patients.

Indications of external radiotherapy for hepatocellular carcinoma from updated clinical guidelines: Diverse global viewpoints

The etiology and disease patterns of hepatocellular carcinoma (HCC) significantly vary among regions. Modern standard treatments commonly require multidisciplinary approaches, including applications of up-to date medicine and advanced procedures, and necessitate the support of socioeconomic systems. For these reasons, a number of clinical guidelines for HCC from different associations and regions have been presented. External beam radiation therapy was contraindicated for HCC until a few decades ago, but with the development of new technologies, its application has rapidly increased as selective irradiation for tumorous lesions became possible. Most of the guidelines had been opposed or indifferent to radiotherapy in the past, but several guidelines have introduced indications and recommendations for radiotherapy in their updated versions. This review will discuss the characteristics of important guidelines and their contents regarding radiotherapy and will also provide guidance to physicians who are considering applications of locoregional modalities that include radiotherapy.

Lymphopenia Is Associated with Gross Target Volumes and Fractions in Hepatocellular Carcinoma Patients Treated with External Beam Radiation Therapy and Also Indicates Worse Overall Survival

PURPOSE

To investigate whether lymphocyte nadir induced by radiation is associated with survival and explore its underlying risk factors in patients with hepatocellular carcinoma (HCC).

METHODS

Total lymphocyte counts were collected from 184 HCC patients treated by radiotherapy (RT) with complete follow-up. Associations between gross tumor volumes (GTVs) and radiation-associated parameters with lymphocyte nadir were evaluated by Pearson/Spearman correlation analysis and multiple linear regression. Kaplan-Meier analysis, log-rank test, as well as univariate and multivariate Cox regression were performed to assess the relationship between lymphocyte nadir and overall survival (OS).

RESULTS

GTVs and fractions were negatively related with lymphocyte nadir (p < 0.001 and p=0.001, respectively). Lymphocyte nadir and Barcelona Clinic Liver Cancer (BCLC) stage were independent prognostic factors predicting OS of HCC patients (all p < 0.001). Patients in the GTV ≤55.0 cc and fractions ≤16 groups were stratified by lymphocyte nadir, and the group with the higher lymphocyte counts (LCs) showed longer survival than the group with lower LCs (p < 0.001 and p=0.006, respectively). Patient distribution significantly differed among the RT fraction groups according to BCLC stage (p < 0.001). However, stratification of patients in the same BCLC stage by RT fractionation showed that the stereotactic body RT (SBRT) group achieved the best survival. Furthermore, there were significant differences in lymphocyte nadir among patients in the SBRT group.

CONCLUSIONS

A lower lymphocyte nadir during RT was associated with worse survival among HCC patients. Smaller GTVs and fractions reduced the risk of lymphopenia.

Radiotherapy for HCC: Ready for prime time?

Stereotactic body radiation therapy (SBRT) has an evolving role in the management of hepatocellular carcinoma (HCC), largely due to recent advances in imaging technology. Often utilized in situations where other locoregional therapies are not feasible, SBRT has been demonstrated to be an effective treatment that confers high rates of durable local control. However, there is limited evidence to firmly establish its place in the treatment paradigm for HCC. In this article, we review the current evidence and highlight specific considerations in the multiple settings where SBRT may be used, including for primary HCC treatment and bridging/downstaging, as well as exploring the potential for SBRT in the treatment of extrahepatic oligo-metastatic HCC.

Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma: Current State and Future Opportunities

Hepatocellular carcinoma is a rising cause of morbidity and mortality in the USA and around the world. Surgical resection and liver transplantation are the preferred management strategies; however, less than 30% of patients are eligible for surgery. Stereotactic body radiation therapy is a promising local treatment option for non-surgical candidates. Local control rates between 95 and 100% have been reported at 1-2 years post-treatment, and classical radiation-induced liver disease described with conventional radiation is an unlikely complication from stereotactic radiotherapy. Enrollment in randomized trials will be essential in establishing the role of stereotactic radiation in treatment paradigms for hepatocellular carcinoma.

Stereotactic body radiation therapy for hepatocellular carcinoma: Practice patterns, dose selection and factors impacting survival

Background

Stereotactic body radiation therapy (SBRT) is an emerging option for unresectable hepatocellular carcinoma (HCC) without consensus regarding optimal dose schemas. This analysis identifies practice patterns and factors that influence dose selection and overall survival, with particular emphasis on dose and tumor size.

Materials/Methods

Query of the National Cancer Database (NCDB) identified patients with unresectable, nonmetastatic HCC who received SBRT from 2004 to 2013. Biological Effective Dose (BED) was calculated for each patient in order to uniformly analyze different fractionation regimens.

Results

A total of 456 patients met the inclusion criteria. The median BED was 100 Gy (22.5‐208.0), which corresponded to the most common dose fractionation (50 Gy in five fractions). Various factors influenced dose selection including tumor size (P < 0.001), tumor stage (P = 0.002), and facility case volume (<0.001). On multivariate analysis, low BED (<75 Gy, HR 2.537, P < 0.001; 75‐100 Gy, HR 1.986, P = 0.007), increasing tumor size (HR 1.067, P = 0.032), elevated AFP (HR 1.585, P = 0.019), stage 3 (HR 1.962, P < 0.001), low‐volume facilities (1‐5 cases HR 1.687, P = 0.006), and a longer time interval from diagnosis to SBRT (>2 to ≤4 months, HR 1.456, P = 0.048; >4 months, HR 2.192, P < 0.001) were associated with worse survival.

Conclusion

SBRT use is increasing for HCC, and multiple regimens are clinically employed. Although high BED was associated with improved outcomes, multiple factors contributed to the dose selection with favorable patients receiving higher doses. Continued efforts to enhance radiation planning and delivery may help improve utilization, safety, and efficacy.

Prognosticators of hepatocellular carcinoma with intrahepatic vascular invasion

Objective:

The prognosis of intrahepatic vascular invasion, including unilateral or main portal vein tumor thrombosis (PVTT) and hepatic vein thrombosis, is still poor. Many patients with intrahepatic vascular invasions never receive radiotherapy (RT). In recent years, more conformal RT techniques such as intensity-modulated RT (IMRT) have been developed and applied to treat other cancers and have significantly improved treatment results and decreased side effects. The purpose of this study is to evaluate the treatment results in patients with intrahepatic vascular invasion and explore the role of IMRT in these treatments.

Materials and Methods:

There were a total of 73 patients with newly diagnosed AJCC stage IIIB hepatocellular carcinoma (HCC), with either PVTT or hepatic vein tumor thrombosis between 2007 and 2015 in our hospital. IMRT was used for all patients who received RT. Prognostic factors, including treatment modalities, liver function, and comorbidities, were analyzed using univariate and multivariate analysis with the Cox model. Survival time was analyzed using the Kaplan–Meier method.

Results:

The longest follow-up time was 45.3 months. The median age was 67 years. Univariate analyses indicated that IMRT, transarterial chemoembolization (TACE), target therapy (sorafenib), tumor size, Child-Pugh class, and ascites were significantly associated with overall survival (OS). In multivariate analysis, IMRT (hazard ratio [HR], 0.495; P = 0.019), sorafenib (HR, 0.340; P = 0.013), tumor size (HR, 2.085; P = 0.020), and Child-Pugh class (P = 0.004), were independent prognostic predictors for patients with intrahepatic vessel invasion, but TACE and ascites were not. The outcomes of patients who had different treatment modalities were significantly different (P < 0.001). Patients who received IMRT with TACE had the best outcomes. Patients who received an RT dose above 5400 cGy had better outcomes than those who with a dose below 5400 cGy, although the results were not significantly different (P = 0.248).

Conclusion:

IMRT is an important treatment component for patients with intrahepatic vascular invasion. Combined treatment modalities, such as IMRT with TACE, could improve the outcomes of HCC patients with intrahepatic vessel invasion.

Proton beam therapy outcomes for localized unresectable hepatocellular carcinoma

BACKGROUND AND PURPOSE

This study documents the utilization and efficacy of proton beam therapy (PBT) in western patients with localized unresectable hepatocellular carcinoma (HCC).

METHODS AND METHODS

Forty-six patients with HCC, Child-Pugh class of A or B, no prior radiotherapy history, and ECOG performance status 0-2 received PBT at our institution from 2007 to 2016. Radiographic control within the PBT field (local control, LC) and overall survival (OS) were calculated from the start of PBT.

RESULTS

Most (83%) patients had Child-Pugh class A. Median tumor size was 6 cm (range, 1.5-21.0 cm); 22% of patients had multiple tumors and 28% had tumor vascular thrombosis. Twenty-five (54%) patients received prior treatment. Median biologically effective dose (BED) was 97.7 GyE (range, 33.6-144 GyE) administered in 15 fractions. Actuarial 2-year LC and OS rates were 81% and 62% respectively; median OS was 30.7 months. Out-of-field intrahepatic failure was the most common site of disease progression. Patients receiving BED ≥90 GyE had a significantly better OS than those receiving BED <90 GyE (49.9 vs. 15.8 months, p = 0.037). A trend toward 2-year LC improvement was observed in patients receiving BED ≥90 GyE compared with those receiving BED <90 GyE (92% vs. 63%, p = 0.096). On multivariate analysis, higher BED (p = 0.023; hazard ratio = 0.308) significantly predicted improved OS. Six (13%) patients experienced acute grade 3 toxicity.

CONCLUSIONS

High-dose PBT is associated with high rates of LC and OS for unresectable HCC. Dose escalation may further improve outcomes.

Radiotherapy for Hepatocellular Carcinoma

For patients with unresectable or medically inoperable hepatocellular carcinoma, there are many local and regional therapies available, including stereotactic body radiotherapy, radiofrequency ablation, and transcatheter embolic approaches. This article will describe these treatment options and review the current comparative literature, suggesting that stereotactic body radiotherapy provides similar or better tumor control and a favorable side effect profile.

Correlation of radiation dose and activity with clinical outcomes in metastatic colorectal cancer after selective internal radiation therapy using yttrium-90 resin microspheres

PURPOSE

Yttrium-90 (Y)-resin microspheres are prescribed using activity. We evaluated overall survival (OS) and radiographic tumor response after selective internal radiation therapy (SIRT) with resin microspheres in patients with liver metastases from colorectal cancer.

PATIENTS AND METHODS

We retrospectively reviewed 60 metastatic colorectal cancer patients treated at our institution with SIRT using Y-resin microspheres. Each patient underwent pre-SIRT MRI or computed tomography imaging of the liver with intravenous contrast. Patients underwent post-treatment imaging at 2-3-month intervals with response assessed according to unidimensional Response Evaluation Criteria in Solid Tumors (RECIST) criteria as well as published three-dimensional volumetric criteria. We then related the prescribed activity established by the body surface area method and the corresponding prescribed dose to radiographic treatment response and OS.

RESULTS

The median follow-up after the first SIRT treatment was 8.9 months. The mean prescribed activity and the prescribed dose were 26.6 mCi and 52.8 Gy, respectively. OS was not significantly associated with either prescribed activity or prescribed dose. Prescribed dose was also not related to response. However, a significant relationship was found between a higher prescribed activity and an improved radiographic response by RECIST (P=0.04) at the second follow-up.

CONCLUSION

The prescribed activity of Y-resin microspheres may be correlated with radiographic response by RECIST criteria at 4-6 months post-treatment. For a more accurate prediction of response, a valid dose calculation model based on post-Y PET dosimetry is likely needed given the heterogeneous dose delivery seen in SIRT.

Leaflet manual of external beam radiation therapy for hepatocellular carcinoma: a review of the indications, evidences, and clinical trials

The use of external beam radiation therapy (EBRT) in the treatment of hepatocellular carcinoma (HCC), which was rarely performed due to liver toxicity with a previous technique, has increased. Palliation of portal vein thrombosis, supplementation for insufficient transarterial chemoembolization, and provision of new curative opportunities using stereotactic body radiotherapy are the potential indications for use of EBRT. The mechanism of EBRT treatment, with its radiobiological and physical perspectives, differs from those of conventional medical treatment or surgery. Therefore, understanding the effects of EBRT may be unfamiliar to physicians other than radiation oncologists, especially in the field of HCC, where EBRT has recently begun to be applied. The first objective of this review was to concisely explain the indications for use of EBRT for HCC for all physicians treating HCC. Therefore, this review focuses on the therapeutic outcomes rather than the detailed biological and physical background. We also reviewed recent clinical trials that may extend the indications for use of EBRT. Finally, we reviewed the current clinical practice guidelines for the treatment of HCC and discuss the current recommendations and future perspectives.

Radiotherapy of Liver Malignancies. From Whole Liver Irradiation to Stereotactic Hypofractionated Radiotherapy

Aims and background

Until recently radiotherapy of hepatic malignancies has played a limited role due to the well-known limited radiotolerance of the liver. The aim of this paper is to review the available data on the risk of radiation-induced liver disease (RILD) and to define the modern role of radiotherapy in the management of patients with metastatic or primary liver malignancies.

Methods

The advent of three-dimensional conformal treatment planning with dose-volume histogram analysis has made the study of partial liver irradiation possible. Limited portions of the liver may withstand high doses of radiation with minimal risk of RILD. Patients with solitary unresectable liver tumors may be treated with high-dose radiotherapy with curative intent. Recently, the feasibility of stereotactically guided treatment techniques with a single fraction or few treatment sessions has been explored in numerous institutions.

Results

The radiation tolerance of the whole liver found by several investigations is in the order of approximately 30 Gy, which seriously restricts its clinical application. The role of whole liver irradiation therefore appears of limited benefit in the palliation of patients with multiple liver metastases. The use of three-dimensional conformal techniques has made partial liver irradiation possible to doses in the 70–80 Gy range with conventional fractionation. At least two published series have reported improved local control and survival rates with dose escalation with three-dimensional conformal radiotherapy in patients with unresectable liver metastases. Similar outcomes have been recently reported with single dose (or hypofractionated) stereotactic radiotherapy both in metastatic and primary hepatic malignancies with minimal morbidity. Accurate target delineation and treatment reproducibility are the key to the success of this novel treatment approach, and specific treatment planning techniques and patient setup procedures must be developed to implement it.

Conclusions

Stereotactic high-dose radiotherapy is technically feasible for the treatment of inoperable liver malignancies, with the potential of high local control and low morbidity. Definitive evidence on the clinical advantages of this technique over other more established treatments can only be gathered from well-designed clinical studies.

Local Control After Stereotactic Body Radiation Therapy for Liver Tumors

PURPOSE

To quantitatively evaluate published experiences with hepatic stereotactic body radiation therapy (SBRT), to determine local control rates after treatment of primary and metastatic liver tumors and to examine whether outcomes are affected by SBRT dosing regimen.

METHODS AND MATERIALS

We identified published articles that reported local control rates after SBRT for primary or metastatic liver tumors. Biologically effective doses (BEDs) were calculated for each dosing regimen using the linear-quadratic equation. We excluded series in which a wide range of BEDs was used. Individual lesion data for local control were extracted from actuarial survival curves, and data were aggregated to form a single dataset. Actuarial local control curves were generated using the Kaplan-Meier method after grouping lesions by disease type and BED (<100 Gy₁₀ vs >100 Gy₁₀). Comparisons were made using log-rank testing.

RESULTS

Thirteen articles met all inclusion criteria and formed the dataset for this analysis. The 1-, 2-, and 3-year actuarial local control rates after SBRT for primary liver tumors (n = 431) were 93%, 89%, and 86%, respectively. Lower 1- (90%), 2- (79%), and 3-year (76%) actuarial local control rates were observed for liver metastases (n = 290, log-rank P = .011). Among patients treated with SBRT for primary liver tumors, there was no evidence that local control is influenced by BED within the range of schedules used. For liver metastases, on the other hand, outcomes were significantly better for lesions treated with BEDs exceeding 100 Gy₁₀ (3-year local control 93%) than for those treated with BEDs of ≤100 Gy₁₀ (3-year local control 65%, P < .001).

CONCLUSIONS

Stereotactic body radiation therapy for primary liver tumors provides high rates of durable local control, with no clear evidence for a dose-response relationship among commonly utilized schedules. Excellent local control rates are also seen after SBRT for liver metastases when BEDs of >100 Gy₁₀ are utilized.

Cumulative dose of radiation therapy of hepatocellular carcinoma patients and its deterministic relation to radiation-induced liver disease

This study aimed to investigate the relationship between dose and radiation-induced liver disease (RILD) in patients with hepatocellular carcinoma (HCC) receiving 3-dimensional conformal radiotherapy (3DCRT). Twenty-three patients with HCC who received conventional fractionated 3DCRT, including 7 who were diagnosed with classic RILD, were enrolled in this retrospective investigation. Cone-beam computed tomography (CBCT) scans were acquired at the time of treatment for each patient. The beams from each patient's treatment plan were applied to each pretreatment CBCT (the modified CBCT or mCBCT) to construct the delivered dose distribution of the day considering inter-treatment anatomy changes. The daily doses were summed together with the help of deformable image registration (DIR) to obtain the adjusted cumulative dose (D_adjusted). The dose changes to the normal liver between the original planned dose (D_plan) and D_adjusted were evaluated by V20, V30, V40, and the mean dose to normal liver (MDTNL). Univariate analysis was performed to identify the significant dose changes. Among the 23 patients, the liver V20, V30, V40, and MDTNL showed significant differences between D_plan and D_adjusted, with average values of these parameters increased by 4.1%, 4.7%, 4.5%, and 3.9 Gy, respectively (p < 0.05). The adjusted liver dose in 21 patients (91%) was higher than the planned value. For patients without and with RILD,the MDTNL was increased on average by 3.5 Gy and 4.7 Gy, and normal tissue complication probability (NTCP) increased on average by 2.8% and 7.5%, respectively. Our study found that the adjusted cumulative dose based on calculations using pretreatment mCBCT differs significantly from planned dose; the use of the dosimetric results of the initial plan was found to be less predictive of RILD as compared with D_adjusted. Determination of a reconstructed D_adjusted using the mCBCT scans are more accurate in predicting RILD and has the potential to reduce the risk of RILD.

[Stereotactic body radiotherapy for liver tumors: State of the art]

Thanks to the improvement in radiotherapy physics, biology, computing and imaging, patients presenting with liver tumors can be efficiently treated by radiation. Radiotherapy has been included in liver tumors treatment guidelines at all disease stages. Liver stereotactic radiotherapy has to be preferred to standard fractionated radiotherapy whenever possible, as potentially more efficient because of higher biological equivalent dose. Liver stereotactic radiotherapy planning and delivery require extensive experience and optimal treatment quality at every step, thus limiting its availability to specialized centres. Multicentre studies are difficult to develop due to a large technical heterogeneity. Respiratory management, image guidance and immobilization are considerations as important as machine type. The use of multimodal planning imaging is compulsory to achieve expected contouring quality. Treatment efficacy is difficult to assess following liver stereotactic radiotherapy, but local control is high and toxicity unusual. As a consequence, liver stereotactic radiotherapy is part of multimodal and multidisciplinary management of liver tumors.

Efficacy and safety of ultrasound-guided implantation of fiducial markers in the liver for stereotactic body radiation therapy

Objective

Stereotactic body radiation therapy (SBRT) for the treatment of a malignancy in the liver requires the perilesional implantation of fiducial markers for lesion detection. The purpose of this study is to evaluate the efficacy and safety of ultrasound (US) -guided marker implantation for SBRT.

Methods

We retrospectively reviewed 299, US–guided, intrahepatic fiducial markers implanted in 101 patients between November 2013 and September 2014. SBRT-planning CT images were analyzed to determine the technical success of the implantation, the mean distance between the tumor margin and the marker, with the ideal location of fiducials defined as the distance between a marker and a tumor less than 3 cm and the distance between markers greater than 2 cm according to the tumor conspicuity seen on gray-scale US and the artifact obscuring tumor margins. We also evaluated procedure-related major and minor complications.

Results

Technical success was achieved in 291 (97.3%) fiducial marker implantations. The mean distance between the tumor and the marker was 3.1 cm (S.D., 2.1 cm; range, 0–9.5 cm). Of 101 patients, 72 lesions (71.3%, 2.2 ± 1.0 cm; range, 0–3.0 cm) had fiducial markers located in an ideal location. The ideal location of fiducials was more common in visible lesions than in poorly conspicuous lesions (90.2% vs. 52.0%, P < 0.001). Seventeen markers (5.8%) developed beam-hardening artifacts obscuring the tumor margins. There were no major complications, although 12 patients (11.9%) developed minor complications.

Conclusions

US-guided implantation of fiducial markers in the liver is an effective and safe procedure with only rare complications.

Transarterial Radioembolization Versus Concurrent Chemoradiation Therapy for Locally Advanced Hepatocellular Carcinoma: A Propensity Score Matching Analysis

PURPOSE

It is unclear whether the efficacy and safety of concurrent chemoradiation therapy (CCRT) and transarterial radioembolization (TARE) with ⁹⁰Y are comparable in patients with locally advanced hepatocellular carcinoma.

METHODS AND MATERIALS

In total, 209 treatment-naive patients with stage B or C cancer according to the Barcelona Clinic Liver Cancer classification who were treated with TARE or CCRT were analyzed. Propensity scores were calculated and matched at a 1:1 ratio for TARE versus CCRT using age, tumor size, tumor number, portal vein thrombosis, and Barcelona Clinic Liver Cancer staging. In the CCRT group, concurrent hepatic arterial infusion chemotherapy with 5-fluorouracil was delivered at a dosage of 500 mg/d during the first and last 5 days of radiation therapy (median, 45 Gy). Overall survival, freedom from progression, tumor response, and complication rate were compared between the TARE and CCRT groups.

RESULTS

Among 209 patients, 124 (62 undergoing TARE and 62 undergoing CCRT) were selected after propensity score matching. Overall survival (TARE vs CCRT, 14.0 months vs 13.2 months, P=.435) and freedom from progression (6.9 months vs 7.8 months, P=.437) were comparable between the 2 groups. Objective response rates at 1 month after treatment were higher for CCRT than for TARE (46.8% vs 16.1%, P<.001), while objective response rates at 3 months were significantly higher for TARE than for CCRT (39.3% vs 21.4%, P=.04). There was no significant difference in long-term response rates (at 6 months and 1 year) between the 2 groups. The CCRT group experienced a higher rate of curative resection or liver transplantation after treatment than the TARE group, although the statistical significance was marginal (24.2% vs 11.3%, P=.060). Treatment-related complications were less frequent after TARE than after CCRT.

CONCLUSIONS

Both treatments yielded comparable survival rates and long-term response rates in patients with intermediate- or advanced-stage hepatocellular carcinoma. The role of these modalities as a bridge to curative therapy requires further investigation.

Decision Making: Intra-arterial Therapies for Cholangiocarcinoma-TACE and TARE

The incidence of intrahepatic cholangiocarcinoma (ICC) has been increasing in recent years and now represents the second most common primary hepatic cancer in the United States. The prognosis is dismal without surgical resection. In patients ineligible to receive curative treatments, locoregional therapies represent a diverse array of techniques that can stabilize or reverse tumor progression to improve overall survival and reduce tumor-related symptoms. Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) have been demonstrated to be efficacious methods for this patient population. Deciding between these two options is challenging. This article reviews the differences in patient selection, preprocedural evaluation, financial considerations and availability, quality of life, and rates of complications and overall survival.

Radiation therapy for hepatobiliary malignancies

Hepatobiliary malignancies represent a heterogeneous group of diseases, which often arise in a background of underlying hepatic dysfunction complicating their local management. Surgical resection continues to be the standard of care for hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC); unfortunately the majority of patients are inoperable at presentation. The aggressiveness of these lesions makes locoregional control of particular importance. Historical experience with less sophisticated radiotherapy resulted in underwhelming efficacy and oftentimes prohibitive liver toxicity. However, with the advent of extremely conformal and precise radiotherapy delivery, dose escalation to the tumor with sparing of surrounding normal tissue has yielded notable improvements in efficacy for this modality of treatment. Dose escalation has come in a variety of forms most notably as stereotactic body radiation therapy (SBRT) and hypofractionated proton therapy. As radiation techniques continue to improve, their proper incorporation into the local management of hepatobiliary malignancies will be paramount in improving the prognosis of what is a grave diagnosis.

Impact of the activity calculation method used in transarterial radioembolization: a dosimetric comparison between 90Y-SIRSphere and 90Y-TheraSphere therapy

PURPOSE

Transarterial radioembolization is used to treat primary and secondary liver malignancies. Two commercially available drugs are utilized for the purpose. The aim of our study is to compare the radiation dose delivered to the tumor by these drugs.

MATERIALS AND METHODS

This study included 86 patients (M : F - 7.6 : 1, median age=50.5 years), 46 patients were treated by Y-TheraSphere and 42 patients were treated by Y-SIRSphere. Activity administered in Y-TheraSphere and Y-SIRSphere was calculated using a modified partition model and a modified body surface area model, respectively. The radiation dose delivered by two drugs was calculated and compared in our study.

RESULT

Activity administered in Y-TheraSphere was significantly higher than that of Y-SIRSphere. Hence, the radiation dose delivered to the tumor by Y-SIRSphere was significantly lower (58.4%) than that of Y-TheraSphere (P=0.000).

CONCLUSION

As the radiation dose delivered by Y-SIRSphere was lower than Y-TheraSphere, we believe that the formula for Y-SIRSphere activity calculation needs to be modified so that the optimal dose can be delivered to the tumor.