Radiotherapy for hepatocellular carcinoma: an overview

Risk of second malignant neoplasm following proton versus intensity-modulated photon radiotherapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the sixth most common cancer in the world, is a global health concern. Radiotherapy for HCC is uncommon, largely because of the likelihood of radiation-induced liver disease, an acute side effect that is often fatal. Proton beam therapy (PBT) and intensity-modulated radiation therapy (IMRT) may offer HCC patients a better option for treating the diseased liver tissue while largely sparing the surrounding tissues, especially the non-tumor liver. However, even advanced radiotherapies carry a risk of late effects, including second malignant neoplasms (SMNs). It is unclear whether PBT or IMRT confers less risk of an SMN than the other. The purpose of this study was to compare the predicted risk of developing an SMN for a patient with HCC between PBT and IMRT. For both treatments, radiation doses in organs and tissues from primary radiation were determined using a treatment planning system; doses in organs and tissues from stray radiation from PBT were determined using Monte Carlo simulations and from IMRT using thermo-luminescent dosimeter measurements. Risk models of SMN incidence were taken from the literature. The predicted absolute lifetime attributable risks of SMN incidence were 11.4% after PBT and 19.2% after IMRT. The results of this study suggest that using proton beams instead of photon beams for radiotherapy may reduce the risk of SMN incidence for some HCC patients.

Current role of selective internal irradiation with yttrium-90 microspheres in the management of hepatocellular carcinoma: a systematic review

PURPOSE

This article reviews the role of selective internal irradiation (SIR) with yttrium-90 ((90)Y) microspheres for hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Studies were identified by searching Medline and PubMed databases for articles from 1990 to 2009 using the keywords "selective internal irradiation," "hepatocellular carcinoma," "therapeutic embolization," and "yttrium-90."

RESULTS

(90)Y microspheres are a safe and well-tolerated therapy for unresectable HCC (median survival range, 7 -21.6 months). The evidence was limited to cohort studies and comparative studies with historical control. (90)Y microspheres have been reported to downstage unresectable HCC to allow for salvage treatments with curative intent, act as a bridging therapy before liver transplantation, and treat HCC with curative intent for patients who are not surgical candidates because of comorbidities.

CONCLUSIONS

(90)Y microsphere is recommended as an option of palliative therapy for large or multifocal HCC without major portal vein invasion or extrahepatic spread. It can also be used for recurrent unresectable HCC, as a bridging therapy before liver transplantation, as a tumor downstaging treatment, and as a curative treatment for patients with associated comorbidities who are not candidates for surgery.

Dose-volume histogram analysis of the safety of proton beam therapy for unresectable hepatocellular carcinoma

PURPOSE

To evaluate the safety and efficacy of radiotherapy using proton beam (PRT) for unresectable hepatocellular carcinoma.

METHODS AND MATERIALS

Sixty consecutive patients who underwent PRT between May 1999 and July 2007 were analyzed. There were 42 males and 18 females, with a median age of 70 years (48-92 years). All but 1 patient had a single lesion with a median diameter of 45 mm (20-100 mm). Total PRT dose/fractionation was 76-cobalt Gray equivalent (CGE)/20 fractions in 46 patients, 65 CGE/26 fractions in 11 patients, and 60 CGE/10 fractions in 3 patients. The risk of developing proton-induced hepatic insufficiency (PHI) was estimated using dose-volume histograms and an indocyanine-green retention rate at 15 minutes (ICG R15).

RESULTS

None of the 20 patients with ICG R15 of less than 20% developed PHI, whereas 6 of 8 patients with ICG R15 values of 50% or higher developed PHI. Among 32 patients whose ICG R15 ranged from 20% to 49.9%, PHI was observed only in patients who had received 30 CGE (V30) to more than 25% of the noncancerous parts of the liver (n = 5) Local progression-free and overall survival rates at 3 years were 90% (95% confidence interval [CI], 80-99%) and 56% (95% CI, 43-69%), respectively. A gastrointestinal toxicity of Grade ≥2 was observed in 3 patients.

CONCLUSIONS

ICG R15 and V30 are recommended as useful predictors for the risk of developing PHI, which should be incorporated into multidisciplinary treatment plans for patients with this disease.

Nonoperative therapies for combined modality treatment of hepatocellular cancer: expert consensus statement

Although surgical resection and liver transplantation are the only treatment modalities that enable prolonged survival in patients with hepatocellular carcinoma (HCC), the majority of HCC patients presents with advanced disease and do not undergo resective or ablative therapy. Transarterial chemoembolization (TACE) is indicated in intermediate/advanced stage unresectable HCC even in the setting of portal vein involvement (excluding main portal vein). Sorafenib has been shown to improve survival of patients with advanced HCC in two controlled randomized trials. Yttrium 90 is a safe microembolization treatment that can be used as an alternative to TACE in patients with advanced liver only disease or in case of portal vein thrombosis. External beam radiation can be helpful to provide local control in selected unresectable HCC. These different treatment modalities may be combined in the treatment strategy of HCC and also used as a bridge to resection or liver transplantation. Patients should undergo formal multidisciplinary evaluation prior to initiating any such treatment in order to individualize the best available options.

Regenerative capacity of normal and irradiated liver following partial hepatectomy in rats

PURPOSE

To investigate the regenerative capacity and proliferation related to cell cycle modulators in irradiated livers after partial hepatectomy (PH) in rats.

METHODS AND MATERIALS

Two experimental groups were given a single dose of either 4-Gy or 8-Gy photon radiation to the whole liver following PH. The control group underwent only PH, without irradiation. The liver specimens were analysed for apoptosis, proliferation and cell cycle related genes between 0.5 and 12 days.

RESULTS

Mean change in weight of the remnant liver in the 8-Gy group was significantly lower than in the control and 4-Gy groups. The apex of proliferating cell nuclear antigen labelling and bromodeoxyuridine incorporation index in two irradiated groups were also apparently lower than that in control group. After PH, transforming growth factor beta-1 (TGFbeta1), and the type II receptor of TGFbeta (TGFbetaR-II), anti-tumour protein 53(p53) and anti-tumour protein21(p21) protein expression in the irradiated livers was higher than in unirradiated ones. Significant apoptosis was noted in 8-Gy group. However, the maximal value of hepatocyte growth factor (HGF) mRNA and protein expression in the irradiated group was suppressed and restoration of liver function was delayed.

CONCLUSION

Whole liver lower dose irradiation can attenuate regenerative capacity following partial hepatectomy in rats.

Accelerated treatment using intensity-modulated radiation therapy plus concurrent capecitabine for unresectable hepatocellular carcinoma

BACKGROUND

: Patients with unresectable hepatocellular carcinoma (HCC) have limited treatment options. In this study, the authors investigated the feasibility, toxicity, and efficacy associated with intensity-modulated radiation therapy (IMRT) and concurrent, chronomodulated capecitabine in the treatment of unresectable HCC.

METHODS

: Twenty patients underwent treatment planning for HCC confined to the liver with helical tomotherapy-based IMRT. Fifty-five percent of patients had Child-Pugh Class A disease, and 45% of patients had Class B disease. Ninety-five percent of patients were prescribed 50 gray (Gy) of radiotherapy to the planning target volume delivered in 20 fractions with concurrent, chronomodulated capecitabine. Transcatheter arterial chemoembolization preceded radiotherapy in 11 patients, and 9 patients received IMRT alone because of portal vein thrombosis, esophageal varices, or tumor size.

RESULTS

: The mean greatest tumor dimension was 9 cm (range, 1.3-17.4 cm), the mean dose to normal liver was 22.6 Gy (range, 10-29.2 Gy), and the average volume of liver that received >30 Gy (V30) was 27.2% (range, 12%-43%). Eighteen patients (90%) completed the prescribed treatment of 50 Gy. There was no increase from baseline in acute or late toxicity greater than 2 grades. Partial response or disease stability was achieved at 3 months to 6 months after treatment in 15 of 16 patients (94%). The median survival (+/-standard deviation) for patients who had Child-Pugh Class A and B disease was 22.5 +/- 5.1 months and 8 +/- 3.3 months, respectively.

CONCLUSIONS

: In this initial experience with accelerated IMRT plus capecitabine for patients who had large HCC lesions, the results demonstrated acceptable toxicity with promising local control. The relatively low acute and late toxicity observed with this program suggested that dose intensification can be incorporated into the treatment regimen if needed. Cancer 2009. (c) 2009 American Cancer Society.

Stereotactic Radiotherapy of the Liver: A Bridge to Transplantation

Patients with hepatocellular carcinoma (HCC) have limited curative therapeutic options. In North America, liver transplantation is one of the most commonly used curative therapies. Many potential transplant patients will be treated with another therapeutic modality to prevent local disease progression while awaiting organ donation.

We present the case of 60-years old male diagnosed with HCC and awaiting liver transplantation. Prior to registration on the transplant list, the patient had a significant increase of his serum alpha-fetoprotein level. Due to his vascular anatomy and tumor location, he was not a candidate for more standard local ablative therapies. He was thus offered stereotactic radiotherapy as a bridge to liver transplantation. He received 50Gy in 5 fractions using respiratory gating. Following this, he had a complete radiological and serological response without worsening of his baseline Child-Pugh class C cirrhosis. Following transplant, 13 months later, pathological examination of the liver explant revealed only scarring at the site of radiation. This case illustrated the fact that hepatic stereotactic radiotherapy is a promising and safe treatment for patients with HCC. In selected patients, it can be a bridge to transplantation and, on its own, has the potential to induce complete pathological response in non-surgical candidates.

Combination of transarterial chemoembolization and three-dimensional conformal radiotherapy for hepatocellular carcinoma with inferior vena cava tumor thrombus

PURPOSE

To evaluate the effects of transarterial chemoembolization (TACE) and three-dimensional conformal radiotherapy (CRT) in patients with hepatocellular carcinoma (HCC) and inferior vena cava tumor thrombus (IVCTT).

METHODS AND MATERIALS

A total of 42 consecutive patients who underwent TACE and CRT (TACE+CRT group) for the treatment of HCC with IVCTT were prospectively enrolled from July 2004 to October 2006. As historical controls, 29 HCC patients with IVCTT who received TACE alone (TACE group) between July 2003 and June 2004 were included. CRT was designed to target only the IVCTT and to deliver a median total dose of 45 Gy (range, 28-50 Gy).

RESULTS

Most baseline characteristics of the two groups were similar (p > 0.05). The response and progression-free rates of IVCTT were significantly higher in the TACE+CRT group than in the TACE group (42.9% and 71.4% vs. 13.8% and 37.9%, respectively; p < 0.01 for both rates). Overall, patient survival was significantly higher in the TACE+CRT group than in the TACE group (p < 0.01), with a median survival time of 11.7 months and 4.7 months, respectively. Treatment with TACE+CRT (hazard ratio [HR] = 0.38; 95% confidence interval [CI], 0.20-0.71), progression of IVCTT (HR = 4.05; 95% CI, 2.00-8.21), Child-Pugh class B (HR = 3.44; 95% CI, 1.79-6.61), and portal vein invasion (HR = 2.31; 95% CI, 1.19-4.50) were identified as independent predictors of mortality by multivariable analysis.

CONCLUSIONS

The combination of TACE and CRT is more effective in the control of IVCTT associated with HCC and improves patient survival compared with TACE alone.

Clinical study of recombinant adenovirus-p53 combined with fractionated stereotactic radiotherapy for hepatocellular carcinoma

OBJECTIVE

The purpose of our study was to evaluate the feasibility and treatment outcomes of recombinant adenovirus-p53 (rAd-p53, trademarked as Gendicine) combined with fractionated stereotactic radiotherapy (fSRT) in treatment of primary hepatocellular carcinoma (HCC).

METHODS

We randomly enrolled 40 patients with HCC treated by fSRT alone (fSRT group) or rAd-p53 combined with fSRT (combined group). Tumor size was 2-5.2 cm (average 3.2 cm). We prescribed 50 Gy in 10 fractions at the 50%-80% isodose line of the planning target volume for 2 weeks in two groups. The combined group was treated with two intratumoral injections of rAd-p53 on day 1 and 8 while fSRT started on day 3. Tumor response was assessed after treatment using modified WHO criteria. The follow-up period was 11-44 months (median 35 months).

RESULTS

The overall response rate of fSRT group was 70%, with 4 patients showing complete response (20%), 10 partial response (50%) and 6 stable disease (30%). Correspondingly the overall response rate of combined group was 85%, with 7 patients showing complete response (35%), 10 partial response (50%) and 3 stable disease (15%). The 1-year survival rates of fSRT group and combined group were 70.0% and 90.0%, respectively. The 1-year disease-free survival rates of fSRT group and combined group were 65% and 85%, respectively. These treatments were well tolerated, because grade 3 or 4 toxicity was not observed.

CONCLUSION

These results suggest that rAd-p53 combined with fSRT is a relatively safe and effective method for treating primary hepatocellular carcinoma compared with only fSRT. Thus, rAd-p53 combined with fractionated SRT may be preferred as a choice of local treatment for primary HCC when the patients are inoperable or when the patients refuse operation.

Effect of tumour necrosis factor-alpha and irradiation alone or in combination on the viability of hepatocellular and biliary adenocarcinoma cell lines in vitro

BACKGROUND

Tumour necrosis factor alpha (TNF-alpha) may exhibit antitumoral activity and can influence the reaction of both tumour and normal tissue to radiation.

AIMS

To test the effect of TNF-alpha and/or irradiation on hepatocellular (HepG2, Hep3B, Sk-Hep1, HuH7) and cholangiocellular (Sk-chA1, Mz-chA1) tumour cell lines.

METHODS

Colony formation, apoptosis analysis and trypan blue exclusion were used to assess cell viability. Doses of radiation (2-25 Gy) and TNF-alpha (100-50,000 U) as well as their respective sequencing were varied (24 and 12 h before and 6 h after). The expression of TNF-alpha and TNF receptors 1/2 was determined using real-time polymerase chain reaction and IkappaBalpha protein expression was detected by Western blot.

RESULTS

Sole irradiation induced a reduction in colony formation in all cell lines and sole TNF-alpha in HepG2 and Sk-chA1 cells only. No difference in apoptosis induction after TNF-alpha or irradiation was observed. Cellular death induced by the combination of TNF-alpha and radiation was not superior to the use of any of the two agents alone. All cell lines revealed that radiation induced upregulation of TNF-alpha whereas the extent of TNF receptor-specific transcription did not change. Furthermore, radiation-induced changes in IkappaBalpha expression were not detectable.

CONCLUSIONS

Our data suggest that both TNF-alpha and radiation may be treatment options for hepatocellular and cholangiocellular carcinomas. Because TNF-alpha and radiation do not interact in terms of radiosensitization, anti-TNF-alpha treatment may have the potential to protect against hepatocellular injury after abdominal irradiation. However, further in vivo studies are needed to confirm that anti-TNF-alpha treatment does not compromise tumour control and actually attenuates radiation-induced liver injury.

Effective Dose from Stray Radiation for a Patient Receiving Proton Therapy for Liver Cancer

Because of its advantageous depth-dose relationship, proton radiotherapy is an emerging treatment modality for patients with liver cancer. Although the proton dose distribution conforms to the target, healthy tissues throughout the body receive low doses of stray radiation, particularly neutrons that originate in the treatment unit or in the patient. The aim of this study was to calculate the effective dose from stray radiation and estimate the corresponding risk of second cancer fatality for a patient receiving proton beam therapy for liver cancer. Effective dose from stray radiation was calculated using detailed Monte Carlo simulations of a double-scattering proton therapy treatment unit and a voxelized human phantom. The treatment plan and phantom were based on CT images of an actual adult patient diagnosed with primary hepatocellular carcinoma. For a prescribed dose of 60 Gy to the clinical target volume, the effective dose from stray radiation was 370 mSv; 61% of this dose was from neutrons originating outside of the patient while the remaining 39% was from neutrons originating within the patient. The excess lifetime risk of fatal second cancer corresponding to the total effective dose from stray radiation was 1.2%. The results of this study establish a baseline estimate of the stray radiation dose and corresponding risk for an adult patient undergoing proton radiotherapy for liver cancer and provide new evidence to corroborate the suitability of proton beam therapy for the treatment of liver tumors.