Feasibility of split-course stereotactic ablative radiotherapy for oligometastases.

BACKGROUND: There is growing interest in the use of stereotactic ablative radiotherapy (SABR) for oligometastases. However, extreme caution should be exercised in treating tumors closely located to organs at risk (OARs) with SABR. To reduce complications, we have applied split-course SABR to oligometastases closely located to OARs or to those being retreated with radiotherapy. METHODS: We retrospectively reviewed the records of patients with oligometastases who were treated with planned split-course SABR between January 2012 and December 2016. RESULTS: A total of 23 patients with 29 oligometastatic lesions were enrolled. The primary diagnoses were bone and soft tissue cancers in 13 lesions, liver cancers in 12 lesions, and colorectal cancers in four lesions. The median tumor volume was 78 cm3 (range, 4-1781 cm3). The lesions were treated with 1-3 fractions in the first stage of SABR (first SABR), and one or two fractions in the second stage of SABR (second SABR). The time interval between the two stages was about 4 weeks. A partial response was noted in 16 lesions (55%) after the first SABR, and practical reductions in the doses to OARs were observed in the second SABR compared with the first SABR. The 1-, 2- and 3-year local control rates were 92%, 65% and 43%, respectively. No Grade 4 or 5 toxicities were observed during or after treatment. CONCLUSION: Split-course SABR appeared to be feasible for the treatment of oligometastases closely located to OARs.

Stereotactic body radiotherapy for oligometastases confined to the para-aortic region: clinical outcomes and the significance of radiotherapy field and dose.

We retrospectively reviewed 88 patients with oligometases in the para-aortic region from any controlled primary tumor site who were treated with stereotactic body radiotherapy (SBRT). The 5-year local control, disease-free survival, and overall survival rates were 83%, 31%, and 41%, respectively. A 90% tumor-control probability was predicted at a biological effective dose of 90 Gy. Severe gastrointestinal toxicities (grade ≥3) were observed in 2 of 88 patients (1%). The results of this study are limited by the retrospective nature of the study but could serve as the background and rationale for future prospective trials on SBRT-based treatment for oligometastses.

Low Hepatic Toxicity in Primary and Metastatic Liver Cancers after Stereotactic Ablative Radiotherapy Using 3 Fractions.

This study evaluated the incidence of hepatic toxicity after stereotactic ablative radiotherapy (SABR) using 3 fractions to the liver, and identified the predictors for hepatic toxicity. We retrospectively reviewed 78 patients with primary and metastatic liver cancers, who underwent SABR using 3 fractions between 2003 and 2011. To examine the incidence of hepatic toxicity, we defined newly developed hepatic toxicity≥grade 2 according to the National Cancer Institute Common Terminology Criteria for Adverse Events v4.0 within 3 months after the end of SABR as a significant adverse event. To identify the predictors for hepatic toxicity, we analyzed several clinical and dosimetric parameters (rV5Gy-rV35Gy: normal liver volume receiving

Severe intestinal toxicity after stereotactic ablative radiotherapy for abdominopelvic malignancies.

PURPOSE: The purpose of this study is to identify the predictors for severe intestinal toxicity (IT) in patients with abdominopelvic malignancies treated with three fractions of stereotactic ablative radiotherapy (SABR). METHODS: From 2001 to 2011, 202 patients with abdominopelvic malignancies were treated with curative-intent SABR. Among these, we retrospectively reviewed the clinical records of 55 patients with the presence of the intestine that received a dose ≥20 % of the prescribed dose. The total dose ranged from 33 to 60 Gy in three fractionations (median dose, 45 Gy). We analyzed the clinical and dosimetric parameters for severe IT ≥ grade 3 according to the National Cancer Institute Common Toxicity Criteria v4.0: V(20-35) (volume of the intestine that received xGy) and D(max) (maximum point dose). RESULTS: Severe IT was found in six patients (the median time, 3 months). V(25) was the best dosimetric predictor for severe IT (P = 0.004). With V(25) ≤ 20 ml, severe IT decreased from 50 to 4 %. SABR duration was the best clinical predictor. Severe IT decreased in patients who received SABR at 4-8 days than on three consecutive days (0 vs. 18 %, P = 0.037). CONCLUSIONS: Following three fractions of SABR, V(25) is a valuable predictor of severe IT. And SABR would be conducted with a treatment interval of at least 48 h if possible.

Feasibility and efficacy of stereotactic ablative radiotherapy for Barcelona Clinic Liver Cancer-C stage hepatocellular carcinoma.

The purpose of this study was to assess the feasibility and efficacy of stereotactic ablative radiotherapy (SABR) for liver tumor in patients with Barcelona Clinic Liver Cancer (BCLC)-C stage hepatocellular carcinoma (HCC). We retrospectively reviewed the medical records of 35 patients between 2003 and 2011. Vascular invasion was diagnosed in 32 patients, extrahepatic metastases in 11 and both in 8. Thirty-two patients were categorized under Child-Pugh (CP) class A and 3 patients with CP class B. The median SABR dose was 45 Gy (range, 30-60 Gy) in 3-5 fractions. The median survival time was 14 months. The 1- and 3-yr overall survival (OS) rate was 52% and 21%, respectively. On univariate analysis, CP class A and biologically equivalent dose ≥ 80 Gy(10) were significant determinants of better OS. Severe toxicity above grade 3, requiring prompt therapeutic intervention, was observed in 5 patients. In conclusion, SABR for BCLC-C stage HCC showed 1-yr OS rate of 52% but treatment related toxicity was moderate. We suggest that patients with CP class A are the best candidate and at least SABR dose of 80 Gy(10) is required for BCLC-C stage.

Stereotactic body radiation therapy for inoperable hepatocellular carcinoma as a local salvage treatment after incomplete transarterial chemoembolization.

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.

High dose stereotactic body radiotherapy using three fractions for colorectal oligometastases.

BACKGROUND AND OBJECTIVES: This study evaluated the treatment result of high dose stereotactic body radiation therapy (SBRT) for colorectal oligometastases. METHODS: Between 2003 and 2009, 41 patients with 50 lesions confined to one organ from colorectal cancer (CRC) and treated with high dose SBRT ≥45 Gy were retrospectively reviewed. Lymph nodes (LNs) (18 patients) were the most frequent sites followed in order by lung (12) and liver (11). SBRT doses ranged from 45 to 60 Gy in three fractions (median 48 Gy). The cumulative gross tumor volume (GTV) ranged from 2 to 123 ml (median 13 ml). RESULTS: The median follow-up period from the SBRT date was 28 months (range, 6-65 months). The 3-year local control and overall survival rates were 64 and 60%, and the respective 5-year rates were 57 and 38%. Cumulative GTV and SBRT dose were statistically significant prognostic factors for local control. The grade 3 or 4 complications occurred in three patients (7%). CONCLUSIONS: High dose SBRT for colorectal oligometastases was found to produce results comparable with surgical series. To improve local control, dose higher than 48 Gy are recommend when possible, but further study will be required to define the optimal normal tissue constraints and acceptable toxicity.

Local tumor control after retreatment of spinal metastasis using stereotactic body radiotherapy; comparison with initial treatment group.

BACKGROUND: The aim of this study is to evaluate local control rates after stereotactic body radiotherapy (SBRT) in recurrent spinal metastasis after external beam radiotherapy (EBRT) and new spinal metastatic lesions. MATERIAL AND METHODS: Retrospective review of medical records and radiological data was performed on 54 retreatment and 131 initial SBRT patients. To compare various fractionation schedules, the biologically effective dose (BED) was applied. SBRT dose was calculated with linear-quadratic model and normalized to a 2-Gy equivalent dose (nBED, α/ß =2 Gy for spinal cord, α/ß =10 Gy for tumor). Doses to a point within the spinal cord that received the maximum dose (Pmax) were checked. Local control failure was defined as progression by imaging study. Overall survival, progression free survival, delivered radiation dose to tumor and spinal cord, and spinal cord Pmax nBED were compared in two groups. RESULTS: The mean delivered radiation doses to tumor margin during SBRT were 51.1 Gy2/10 (retreatment) and 50.7 Gy2/10 (initial treatment). Mean survival was 29.6 months (overall)/20.7 months (retreatment)/ 32.4 months (initial treatment). Mean progression free period was 23.9 months (overall)/18.0 months (retreatment)/ 26.0 months (initial treatment). Radiological control rates of retreatment and initial treatment group were 96%/95% at six months, 81%/89% at 12 months and 79%/90% at 24 months. Among 54 retreatment lesions, 13 lesions showed local control failure during follow-up. With regard to spinal cord radiation dose during SBRT, Spinal cord Pmax nBED was 46.2 Gy2/2 (retreatment) and 48.7 Gy2/2 (initial treatment). In retreatment group, total nBED to spinal cord was a mean of 83.4 Gy2/2. There was no case of radiation myelopathy detected. CONCLUSIONS: Retreatment of spinal metastases using SBRT provided effective local control without neurological complications.

Bilateral orbital metastases from breast cancer: a case report of successful palliation using stereotactic radiotherapy.

Of ophthalmic involvement from metastatic breast cancer, extraocular/intraorbital metastases are extremely rare. External beam radiotherapy has been a mainstay palliation for symptomatic orbital metastases. We present a case of bilateral orbital metastases from breast cancer successfully treated with stereotactic radiotherapy (SRT). A 38-year-old woman presented with decreased vision in the right eye for 3 weeks. Eight months previously, she underwent whole-brain radiotherapy for multiple brain metastases from breast cancer. Visual acuity was hand motion, and the eyelid closed incompletely in the affected eye. Computed tomography scans showed a 3-cm extraconal mass in the right orbit. She underwent temporary tarsorrhaphy followed by SRT. A total dose of 39 Gy was delivered to the right orbital mass in three daily fractions. Four months later, her visual function was normal in both eyes and the right orbital mass disappeared. A new lesion was detected in the left orbit. She underwent SRT for the left orbital lesion using the same dose-fractionation schedule. No radiation-related toxicities were observed. She died 19 months after the first SRT. Our case suggests that SRT may be an effective and safe treatment option in patients with orbital metastases from breast cancer.

Image-guided stereotactic body radiation therapy for localized prostate cancer.

PURPOSE: We report the results of a retrospective study of stereotactic body radiation therapy (SBRT) using CyberKnife for localized prostate cancer. The study focused on the safety and feasibility of this treatment modality. MATERIALS AND METHODS: Between October 2002 and December 2007, 44 patients suffering from localized adenocarcinoma of the prostate were treated with SBRT using CyberKnife at the Korea Cancer Center Hospital. The patients were divided into 3 groups: a low-risk group (5 patients), an intermediate-risk group (10 patients), and a high-risk group (29 patients). Five patients received 32 Gy in 4 fractions, 28 patients received 34 Gy in 4 fractions, and 11 patients received 36 Gy in 4 fractions. RESULTS: The median age of the patients was 69 years (range, 53-79 years) and the median duration of follow-up 40 months (range, 12-78 months). There were 6 acute and 3 late grade 2 urinary toxicities, and 4 acute and 5 late grade 2 rectal toxicities, but there were no grade 3 or higher treatment-related toxicities. The 5-year cause-specific survival rate and progression-free survival rate were both 100%. At last follow-up, the biochemical failure-free rate of the low-risk, intermediate-risk and high-risk patients was 100%, 100% and 90.8%, respectively. CONCLUSION: SBRT using CyberKnife for localized prostate cancer is safe and well tolerated. We obtained promising results with 34 Gy in a 4-fraction regimen especially for the high-risk patients.

Preliminary result of stereotactic body radiotherapy as a local salvage treatment for inoperable hepatocellular carcinoma.

BACKGROUND AND OBJECTIVES: To evaluate the toxicity and efficacy of stereotactic body radiotherapy (SBRT) for the treatment of localized hepatocellular carcinoma (HCC) in the absence of another standard treatment option. METHODS: The authors reviewed the details of 38 patients with inoperable HCC (diameter <10 cm) treated by SBRT in a prospectively registered database at their institution. All patients had been treated by transcatheter arterial chemoembolization before SBRT, which had been finally deemed ineffective. SBRT dosages (33-57 Gy in three or four fractions) were administered according to tumor volumes, which ranged from 11 to 464 ml (median, 40.5 ml). RESULTS: Two-year overall survival and local progression-free survival rates were 61.4% and 66.4%, respectively. The local response rate was 63% at 3 months after SBRT. A high radiation dose was found to be independently related to survival. A decline in liver function was observed in six patients (16%) and Grade 3 musculoskeletal toxicity in one patient (2.7%). CONCLUSIONS: 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.

Trends for the past 10 years and international comparisons of the structure of Korean radiation oncology.

OBJECTIVE: Study aims include determination of nationwide structural characteristics of radiation oncology facilities, types of radiation therapy equipment, availability of human resources and trends and comparisons with previous surveys. METHODS: An annual nationwide survey was conducted to collect the statistics of infrastructure since 1997. All requested questionnaires have been identical for 10 years. The questionnaires included status on basic radiation therapy facilities, human resources and radiation therapy equipment. Journal and statistical data reviews were performed to evaluate the structure of other countries. RESULTS: Radiation oncology facilities have steadily increased for 10 years and reached 60 sites in 2006. Also a steady increase of 1.5 times for linear accelerators, 5.8 times for computed tomography simulators and 3.0 times for radiation treatment planning systems was noted. Meanwhile, cobalt-60 teletherapy units and hyperthermia equipment had steadily deceased for 10 years. The number of human resources has steadily increased for the past 10 years, especially for radiation therapy technologists. However, radiation therapy equipment and human resources per population are relatively low compared with advanced countries. CONCLUSIONS: This study will assist preparation of the administrative planning policy of radiation oncology and should be useful to indicate the direction of future development and educational training programs in Korea and possibly in other countries.

Pilot study of stereotactic body radiotherapy for huge hepatocellular carcinoma unsuitable for other therapies.

AIMS: To determine the feasibility and efficacy of stereotactic body radiotherapy (SBRT) for huge hepatocellular carcinoma unsuitable for other therapies. METHODS: Six patients with very large hepatocellular carcinomas (>10 cm) unsuitable for surgical resection or that failed to respond to transcatheter arterial chemoembolization (TACE) were treated by SBRT. Doses ranged from 32 Gy to 40 Gy in four fractions. Survival, response, and toxicities were evaluated. RESULTS: After a median follow-up of 25.9 months (range 8.1-56 months), three patients had died and three were alive. Overall, treatment was well tolerated and no dose-limiting toxicity or radiation-induced liver disease was observed. The median survival was 10 months (range 3-56 months) and the median progression-free duration was 6 months (range, 2-21 months). Partial response was achieved by four patients, stable disease by one, and one patient had disease progression. One patient with a partial response who underwent lobectomy after SBRT was alive 56 months post-SBRT. CONCLUSION: This study suggests that SBRT can be delivered safely at 32-40 Gy in four fractions to huge hepatocellular carcinoma. Furthermore, combinations of SBRT with other modalities such as surgery or TACE might prolong survival.

Clinical utilization of radiation therapy in Korea, 2016.

Radiotherapy (RT) is one of the primary cancer treatment modalities. To estimate the actual utilization of RT and infrastructure in Korea, the current study was performed. Data from 2012 to 2016 were extracted from the Health Insurance Review and Assessment Service. In addition, a nationwide survey was conducted to collect the statistics of RT facilities, equipment and human resources in Korea. The total number of patients treated with RT was 72 563 in 2016. The five cancers that were most commonly treated with RT in 2016 were breast, lung, colorectal, liver and prostate cancer. According to analyses of specific treatment modalities, the number of patients treated with intensity-modulated radiotherapy (IMRT), stereotactic radiation therapy (SRT) and proton therapy increased from 6670, 6306 and 50 in 2012 to 21584, 9048 and 703 in 2016, respectively. Ninety radiation oncology centers were working in 2015 and there were a total of 213 megavoltage teletherapy machines. In 2015, 310 patients were treated per megavoltage RT machine, 246 patients per radiation oncologist, 501 patients per medical physicist and 111 patients per radiotherapy technologist. In conclusion, the number of patients who underwent RT in Korea has increased steadily from 2012 to 2016. The IMRT utilization rate remarkably increased in 2016, and the number of patients treated with advanced treatment modalities such as IMRT, SRT and proton therapy is expected to increase.

Preliminary survey of 3D image-guided brachytherapy for cervical cancer at representative hospitals in Asian countries.

3D image-guided brachytherapy (3D-IGBT) has become a standard therapy for cervical cancer. However, the use of 3D-IGBT is limited in East and Southeast Asia. This study aimed to clarify the current usage patterns of 3D-IGBT for cervical cancer in East and Southeast Asia. A questionnaire-based survey was performed in 11 countries within the framework of the Forum for Nuclear Cooperation in Asia. The questionnaire collected the treatment information of patients with cervical cancer who underwent 3D-IGBT. The cumulative external beam radiotherapy and 3D-IGBT doses were summarized and normalized to a biological equivalent dose of 2 Gy per fraction (EQD2) using a linear-quadratic model. Of the 11 institutions representing the participating countries, six (55%) responded to the questionnaire. Overall, data of 36 patients were collected from the six institutions. Twenty-one patients underwent whole-pelvic irradiation and 15 underwent whole-pelvic irradiation with central shielding. Patients received a median of four treatment sessions of 3D-IGBT (range, 2-6). All 3D-IGBT sessions were computed tomography (CT)-based and not magnetic resonance image-based. The median doses to the high-risk clinical target volume D90, bladder D2cc, rectum D2cc and sigmoid colon D2cc were 80.9 Gy EQD2 (range, 58.9-105.9), 77.7 Gy EQD2 (range, 56.9-99.1), 68.0 Gy EQD2 (range, 48.6-90.7) and 62.0 Gy EQD2 (range, 39.6-83.7), respectively. This study elucidated the current patterns of 3D-IGBT for the treatment of cervical cancer in East and Southeast Asia. The results indicate the feasibility of observational studies of CT-based 3D-IGBT for cervical cancer in these countries.

Stereotactic body radiation therapy using three fractions for isolated lung recurrence from colorectal cancer.

OBJECTIVE: To determine the feasibility of stereotactic body radiotherapy (SBRT) using 3 fractions for isolated colorectal lung metastases. METHODS: From June 2003 to December 2006, 13 cases of isolated pulmonary metastasis from colorectal cancer were treated by SBRT due to an inoperable state (7 patients), or the patient's refusal to undergo surgical excision (6 patients). All patients underwent chemotherapy for salvage treatment. SBRT doses ranged from 39 to 51 Gy in 3 fractions. Nine patients had a solitary lesion, 3 patients had 2 lesions, and 1 patient had 3 lesions. Median tumor volume for the 18 lesions was 5.9 ml (range 1.6-45 ml). RESULTS: Follow-up duration was 15-57 months. Three-year overall survival, local control and progression-free survival rates were 64.7, 52.7 and 11.5%, respectively.Univariate analysis showed that total internal target volume was a significant prognostic factor for local control. During the follow-up, 11 of the 13 patients experienced local recurrence, distant metastasis or both. The most frequent site of failure was in a nontargeted lung region. No severe complication was attributed to SBRT. CONCLUSION: Our study suggests the potential feasibility of SBRT for selected patients with 1-3 small metastatic nodules. A further larger-scale study is required to define the indications for SBRT in cases with isolated pulmonary metastasis from colorectal cancer.

Clinical characteristics of radiation oncology in Korea during past 10 years.

To understand trends in the clinical characteristics of radiation oncology over the last 10 yr in Korea, annual survey questionnaires were sent to all of Korean radiation oncology facilities since 1990. Questionnaires addressed basic radiation therapy facilities and the clinical information. Responses were obtained from all facilities, and data collected from 1997 to 2006 was analyzed. The numbers of new patients that have undergone radiation therapy and the numbers of hospitals with a department of radiation oncology have steadily increased over the past 10 yr, and totaled 37,215 patients and 60 hospitals, respectively, in 2006. However, the proportion of patients irradiated among total cancer patients has remained below 30% over the last 10 yr. The numbers of prostate cancer, breast cancer, and hepatoma have increased by more than 3 fold over the past 10 yr. Moreover, the percentage of irradiated patients treated by brachytherapy was 10.3% in 1997, but this gradually fell to only 4.2% in 2006. The information collected described the role played by radiation oncology in Korea. Continuous surveys are required to enable trends to be detected.

Stereotactic body radiotherapy for isolated para-aortic lymph node recurrence after curative resection in gastric cancer.

The aim of this study was to investigate whether stereotactic body radiotherapy (SBRT) can salvage gastric cancer patients with para-aortic lymph node (PALN) recurrence. From January 2003 to December 2006, 7 patients were treated for isolated PALN recurrence from gastric cancer after curative resection. Follow up durations ranged from 19 to 33 months (median; 26 months), and SBRT doses from 45 Gy to 51 Gy (median 48 Gy) in 3 fractions. Disease progression-free and overall survivals and toxicities were recorded. Response to treatment was assessed by computed tomography. Final patient outcomes were as follows: 2 were alive without evidence of disease, 3 remained alive with disease, and 2 patients died of disease. Five of 7 patients showed complete response and 2 patients partial response between 3 and 11 months after SBRT. Three-year overall and disease progression-free survival rates post-SBRT were 43% and 29%, respectively. No severe complication was detected during follow-up. Selected patients with isolated PALN recurrence can be salvaged by SBRT without severe complications.

Feasibility of image-guided robotic radiotherapy using three fractions for uveal melanoma.

AIMS: A retrospective study was performed to demonstrate the feasibility and efficacy of 3-fraction image-guided robotic stereotactic radiotherapy (fSRT) for uveal melanoma. MATERIALS AND METHODS: Six patients with medium-sized or large tumors, who declined enucleation, were enrolled. The gross tumor volume (GTV) ranged from 454 to 2185 mm3. The total doses included 36 or 39 Gy in 3 fractions. RESULTS: Follow-up ranged from 19 to 40 months. In 5 patients, the tumor mass gradually underwent an average 24.5% size reduction. All 3 patients with a GTV <1000 mm3 had a functional eye, while 3 patients with a GTV > or = 1000 mm3 did not have a functional eye. Radiation-induced complications occurred to some degree in all patients. However, complications that required enucleation were not detected. CONCLUSION: We suggest that image-guided robotic radiotherapy using 3 fractions is a feasible and safe treatment option for patients with uveal melanoma. In cases of medium-sized and large tumors, fSRT could be used as an alternative treatment for cases ineligible for brachytherapy, but a longer follow-up and a larger number of patients are required to confirm the suitability of the method.

Three-fraction stereotactic body radiation therapy for isolated liver recurrence from colorectal cancer.

AIMS: To determine the feasibility and efficacy of 3-fraction stereotactic body radiation therapy for isolated colorectal cancer liver metastases. MATERIALS AND METHODS: Ten patients with isolated inoperable liver metastasis from colorectal cancer with progression after salvage chemotherapy underwent stereotactic body radiation therapy. Follow-up was 7-49 months (median, 12). Six patients had a solitary lesion and 4 patients had 2 lesions. Internal target volumes of metastatic liver tumors ranged from 3.4 to 271 ml. Stereotactic body radiation therapy doses ranged from 36 to 51 Gy and were administered in three fractions. All patients demonstrated disease progression despite chemotherapy prior to stereotactic body radiation therapy. RESULTS: Three-year overall survival and local control rates were 40% and 60%, respectively. Tumors with an internal target volume < 100 ml showed better local control rate than larger tumors. No severe complication was attributed to the therapy. CONCLUSION: Our study suggests the potential feasibility of stereotactic body radiation therapy for selected patients with colorectal cancer liver metastasis and no treatment option. The study showed that excellent local control was achieved in patients with a total tumor volume of < 100 ml but failed to clarify the role of stereotactic body radiation therapy for larger tumors. Further large scale studies are needed to define the indications of such therapy.