BACKGROUND: The objective of this study was to evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) as a local salvage treatment after incomplete transarterial chemoembolization (TACE) for inoperable hepatocellular carcinoma (HCC). METHODS: The main eligibility criteria were a greatest tumor dimension (LD sum) <10 cm, inoperable HCC, and incomplete response after TACE. Prescribed SBRT doses were up to 60 gray (Gy) in 3 fractions, but doses were reduced until normal tissue constraints were allowed. RESULTS: Between May 2008 and February 2011, 50 patients were enrolled in this phase 2 trial, of which 47 patients were evaluable. Forty‐one patients had Child‐Pugh class A disease (A5/A6 were 32/9), 6 patients had class B7 disease, and 5 patients had portal vein tumor thrombosis. All patients underwent TACE 1 to 5 times before SBRT. SBRT doses ranged from 42 to 60 Gy in 3 fractions (median dose, 57 Gy), and the median LD sum was 29 mm (range, 13‐78 mm). Eighteen patients (38.3%) achieved complete remission within 6 months of completing of SBRT, and 18 patients (38.3%) had a partial response. The 2‐year local control rate was 94.6%, the overall survival rate was 68.7%, and the progression‐free survival rate was 33.8%. Three patients (6.4%) experienced grade 3 gastrointestinal toxicity, and 2 patients (4.3%) experienced grade 4 gastric ulcer perforation. CONCLUSIONS: This trial demonstrated that SBRT after incomplete TACE for inoperable HCC achieves promising rates of response and local control. On the basis of these study results, a modified, multi‐institutional, phase 2 trial to reduce gastrointestinal toxicity is recommended. Cancer 2012. © 2012 American Cancer Society.

BackgroundRecent studies using stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) have reported high tumor response and local control. However, the optimal SBRT dose remains unknown, and it is still not clear whether a dose response relationship for local control (LC) and overall survival (OS) exist or not. We performed this study to determine whether a dose response relationship for LC and OS is observed in SBRT for inoperable HCC.MethodsBetween 2003 and 2011, 108 patients with HCC were treated with SBRT. All patients were unsuitable for surgery or local ablation and had incomplete response to transarterial chemoembolization. Eighty-two patients with a longest tumor diameter (LD) less than or equal to 7.0 cm who were treated with 3-fraction SBRT and were analyzed. This cohort comprised 74 Child-Turcotte-Pugh (CTP) class A patients and 8 CTP class B7 patients. The median LD was 3.0 cm (range, 1.0–7.0 cm), and the median dose was 51 Gy (range, 33–60 Gy).ResultsLC and OS rates at 2 years after SBRT were 87% and 63%, respectively, with a median follow-up duration of 30 months for all patients. The 2-year LC/OS rates for patients treated with doses of > 54, 45–54, and < 45 Gy were 100/71, 78/64, and 64%/30%, respectively (p = .009/p < .001). Multivariate analysis revealed that the SBRT dose (p = .005) and Barcelona Clinic Liver Cancer stage (p = .015) were significant prognostic factors for OS. Correlation analysis revealed a positive linear relationship between the SBRT dose and LC (p = .006, R = .899)/OS (p = .002, R = .940) at 2 years. Based on the tumor-control probability model, a dose of 54.8 Gy provides 2-year LC with a 90% probability. Five patients experienced grade 3 or higher gastrointestinal toxicity, and 6 had deteriorating of CTP score by greater than or equal to 2 within 3 months of SBRT.ConclusionsThis study demonstrated a dose response relationship for LC and OS with SBRT for HCC. Higher LC rates resulting from an increased dose may translate into survival benefits for patients with HCC.

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We previously demonstrated that the phytosphingosine-induced apoptosis was accompanied by the concomitant induction of both the caspase-8-mediated and mitochondrial activation-mediated apoptosis pathways. In the present study, we investigated the role of mitogen-activated protein kinases (MAPKs) in the activation of these two distinct cell death pathways induced by phytosphingosine in human cancer cells. Phytosphingosine caused strong induction of caspase-8 activity and caspase-independent Bax translocation to the mitochondria. A rapid decrease of phosphorylated ERK1/2 and a marked increase of p38 MAPK phosphorylation were observed within 10 min after phytosphingosine treatment. Activation of ERK1/2 by pretreatment with phorbol 12-myristate 13-acetate or forced expression of ERK1/2 attenuated phytosphingosine-induced caspase-8 activation. However, Bax translocation and caspase-9 activation was unaffected, indicating that down-regulation of the ERK activity is specifically required for the phytosphingosine-induced caspase-8-dependent cell death pathway. On the other hand, treatment with SB203580, a p38 MAPK-specific inhibitor, or expression of a dominant negative form of p38 MAPK suppressed phytosphingosine-induced translocation of the proapoptotic protein, Bax, from the cytosol to mitochondria, cytochrome c release, and subsequent caspase-9 activation but did not affect caspase-8 activation, indicating that activation of p38 MAPK is involved in the mitochondrial activation-mediated cell death pathway. Our results suggest that phytosphingosine can utilize two different MAPK signaling pathways for amplifying the apoptosis cascade, enhancing the understanding of the molecular mechanisms utilized by naturally occurring metabolites to regulate cell death. Molecular dissection of the signaling pathways that activate the apoptotic cell death machinery is critical for both our understanding of cell death events and development of cancer therapeutic agents.

The use of chemical modifiers as radiosensitizers in combination with low-dose irradiation may increase the therapeutic effect on cancer by overcoming a high apoptotic threshold. Here, we showed that phytosphingosine treatment in combination with ␥-radiation enhanced apoptotic cell death of radiation-resistant human T-cell lymphoma in a caspase-independent manner. Combination treatment induced an increase in intracellular reactive oxygen species ( results demonstrate that enhancement of cell death of radiation-resistant cancer cells by phytosphingosine treatment in combination with ␥-radiation is mediated by nuclear translocation of AIF, which is in turn mediated both by ROS-dependent Bax relocalization and ROS-independent PARP-1 activation. The molecular signaling pathways that we elucidated in this study may provide potential drug targets for radiation sensitization of cancers refractive to radiation therapy.

PurposeTo report the results of stereotactic body radiotherapy (SBRT) for unresectable primary or recurrent cholangiocarcinoma.Materials and MethodsFrom January 2005 through August 2013, 58 patients with unresectable primary (n = 28) or recurrent (n = 30) cholangiocarcinoma treated by SBRT were retrospectively analyzed. The median prescribed dose was 45 Gy in 3 fractions (range, 15 to 60 Gy in 1-5 fractions). Patients were treated by SBRT only (n = 53) or EBRT + SBRT boost (n = 5). The median tumor volume was 40 mL (range, 5 to 1,287 mL).ResultsThe median follow-up duration was 10 months (range, 1 to 97 months). The 1-year, 2-year overall survival rates, and median survival were 45%, 20%, and 10 months, respectively. The median survival for primary group and recurrent group were 5 and 13 months, respectively. Local control rate at 1-year and 2-year were 85% and 72%, respectively. Disease progression-free survival rates at 1-year and 2-year were 26% and 23%, respectively. In univariate analysis, ECOG performance score (0-1 vs. 2-3), treatment volume (<50 vs. ≥50 mL), and pre-SBRT CEA level (<5 vs. ≥5 ng/mL) were significant in overall survival rate. In multivariate analysis, ECOG score (p = 0.037) and tumor volume (p = 0.030) were statistically significant. In the recurrent tumor group, patients with >12 months interval from surgery to recurrence showed statistically significant higher overall survival rate than those with ≤12 months (p = 0.026). Six patients (10%) experienced ≥grade 3 complications.ConclusionSBRT can be considered as an effective local modality for unresectable primary or recurrent cholangiocarcinoma.

This study showed that SBRT can be safely administered to select HCC patients, and these results suggest that this technique should be considered a salvage treatment. A further well-controlled large-scale study and longer follow-up are needed to determine optimal dose-fraction schedules and characterize late complications.

Objective: To investigate the clinical applications of stereotactic body radiation therapy (SBRT) using the CyberKnife system for pelvic recurrence from rectal cancer with a focus on survival and toxicity. Methods: Between 2002 and 2006, 23 patients with recurrent rectal cancer were treated with SBRT at our institution. The median follow-up was 31 months. Sites of recurrence were presacral in seven patients and the pelvic wall in 16. SBRT doses ranged from 30 to 51 Gy (median 39 Gy) and were delivered in three fractions. Response to treatment was assessed by computed tomography. Overall and local progression-free survival and toxicities were recorded. Results: Four-year overall survival and local control rates were 24.9 and 74.3%, respectively. No prognostic factor was found to affect patient survival or local progression. One patient developed a severe radiation-related toxicity, but recovered completely after treatment. Conclusions: SBRT for pelvic recurrence was found to be comparable with other modalities with respect to overall survival and complication rates. Further studies are needed to confirm these preliminary results.