Stereotactic body radiotherapy in pancreatic adenocarcinoma

Background:Stereotactic body radiotherapy(SBRT)in pancreatic cancer allows high delivery of radiation doses on tumors without affecting surrounding tissue.This review aimed at the SBRT application in the treatment of pancreatic cancer.Data sources:We retrieved articles published in MEDLINE/PubMed from January 2017 to December 2022.Keywords used in the search included:“pancreatic adenocarcinoma”OR“pancreatic cancer”AND“stereotactic ablative radiotherapy(SABR)”OR“stereotactic body radiotherapy(SBRT)”OR“chemoradiotherapy(CRT)”.English language articles with information on technical characteristics,doses and fractionation,indications,recurrence patterns,local control and toxicities of SBRT in pancreatic tumors were included.All articles were assessed for validity and relevant content.Results:Optimal doses and fractionation have not yet been defined.However,SBRT could be the standard treatment in patients with pancreatic adenocarcinoma in addition to CRT.Furthermore,the combination of SBRT with chemotherapy may have additive or synergic effect on pancreatic adenocarcinoma.Conclusions:SBRT is an effective modality for patients with pancreatic cancer,supported by clinical practice guidelines as it has demonstrated good tolerance and good disease control.SBRT opens a possibility of improving outcomes for these patients,both in neoadjuvant treatment and with radical intent.

Uninvolved liver dose prediction in stereotactic body radiation therapy for liver cancer based on the neural network method

BACKGROUND The quality of a radiotherapy plan often depends on the knowledge and expertise of the plan designers.AIM To predict the uninvolved liver dose in stereotactic body radiotherapy(SBRT)for liver cancer using a neural network-based method.METHODS A total of 114 SBRT plans for liver cancer were used to test the neural network method.Sub-organs of the uninvolved liver were automatically generated.Correlations between the volume of each sub-organ,uninvolved liver dose,and neural network prediction model were established using MATLAB.Of the cases,70%were selected as the training set,15%as the validation set,and 15%as the test set.The regression R-value and mean square error(MSE)were used to evaluate the model.RESULTS The volume of the uninvolved liver was related to the volume of the corresponding sub-organs.For all sets of Rvalues of the prediction model,except for D_(n0)which was 0.7513,all R-values of D_(n10)-D_(n100)and D_(nmean)were>0.8.The MSE of the prediction model was also low.CONCLUSION We developed a neural network-based method to predict the uninvolved liver dose in SBRT for liver cancer.It is simple and easy to use and warrants further promotion and application.

Treatment for paraganglioma with stereotactic radiotherapy

BACKGROUND Paragangliomas(PG)are rare neoplasms of neuroendocrine origin that tend to be highly vascularized,slow-growing,and usually sporadic.To date,common treatment options are surgical resection(SR),with or without radiation therapy(RT),and a watch-and-wait approach.AIM To evaluate the local control and effectiveness of exclusive fractionated stereotactic RT(FSRT)treatment in unresectable PG(uPG).METHODS We retrospectively evaluated patients with uPG(medically inoperable or refused SR)treated with FSRT with a Cyberknife System(Accuray Incorporated,Sunnyvale,California).Toxicity and initial efficacy were evaluated.RESULTS From May 2009 to January 2023,6 patients with a median age of 68(range 20-84)were treated with FSRT.The median delivered dose was 21 Gy(range 20-30 Gy)at a median isodose line of 75.5%(range 70%-76%)in 4 fractions(range 3-5 fractions).The median volume was 13.6 mL(range 12.4-65.24 mL).The median cumulative biological effective dose and equivalent dose in 2-Gy fractions were 70 Gy and 37.10 Gy respectively.Site of origin involved were the timpa-nojugular glomus(4/6),temporal bone,and cervical spine.In 1 of the 6 patients,the follow-up was insufficient;5 of 6 patients showed a 5-year overall survival and 5-year progression-free survival of 100%.We observed negligible toxicities during and after RT.The majority of patients showed stable symptoms during follow-up.Only 1 patient developed spine metastases.CONCLUSION Our preliminary results on this small cohort of patients suggest that FSRT could be an effective and safe alternative to SR.

Stereotactic body radiotherapy combined with sintilimab in patients with recurrent or oligometastatic hepatocellular carcinoma: A phase Ⅱ clinical trial

BACKGROUND Stereotactic body radiotherapy(SBRT)and programmed cell death 1 inhibitors have shown potential in treating hepatocellular carcinoma(HCC)in retrospective studies.AIM To evaluate the efficacy of combining SBRT with sintilimab for patients with recurrent or oligometastatic HCC.METHODS This trial involved patients with recurrent or oligometastatic HCC intravenously treated with SBRT plus sintilimab every 3 wk for 12 mo or until disease progression.The primary endpoint was progression-free survival(PFS).RESULTS Twenty-five patients were enrolled from August 14,2019,to August 23,2021.The median treatment duration was 10.2(range,0.7-14.6)months.SBRT was delivered at a median dose of 54(range,48-60)Gy in 6(range,6-10)fractions.The median follow-up time was 21.9(range,10.3-39.7)mo,and 32 targeted lesions among 25 patients were evaluated for treatment response according to the Response Evaluation Criteria in Solid Tumors version 1.1.The median PFS was 19.7 mo[95%confidence interval(CI):16.9-NA],with PFS rates of 68%(95%CI:52-89)and 45.3%(95%CI:28-73.4)at 12 and 24 mo,respectively.The median overall survival(OS)was not reached,with OS rates of 91.5%(95%CI:80.8-100.0)and 83.2%(95%CI:66.5-100.0)at 12 and 24 mo,respectively.The 1-and 2-year local control rate were 100%and 90.9%(95%CI:75.4%-100.0%),respectively.The confirmed objective response rate and disease control rate was 96%,and 96%,respectively.Most adverse events were graded as 1 or 2,and grade 3 adverse events were observed in three patients.CONCLUSION SBRT plus sintilimab is an effective,well-tolerated treatment regimen for patients with recurrent or oligometastatic HCC.

Effect of Stereotactic Body Radiation Therapy on Diverse Organ Lesions in Advanced Non-Small Cell Lung Cancer Patients Receiving Immune Checkpoint Inhibitors

Objective The combination of stereotactic body radiation therapy(SBRT)and immune checkpoint inhibitors(ICIs)is actively being explored in advanced non-small-cell lung cancer(NSCLC)patients.However,little is known about the optimal fractionation and radiotherapy target lesions in this scenario.This study investigated the effect of SBRT on diverse organ lesions and radiotherapy dose fractionation regimens on the prognosis of advanced NSCLC patients receiving ICIs.Methods The medical records of advanced NSCLC patients consecutively treated with ICIs and SBRT were retrospectively reviewed at our institution from Dec.2015 to Sep.2021.Patients were grouped according to radiation sites.Progression-free survival(PFS)and overall survival(OS)were recorded using the Kaplan-Meier method and compared between different treatment groups using the log-rank(Mantel-Cox)test.Results A total of 124 advanced NSCLC patients receiving ICIs combined with SBRT were identified in this study.Radiation sites included lung lesions(lung group,n=43),bone metastases(bone group,n=24),and brain metastases(brain group,n=57).Compared with the brain group,the mean PFS(mPFS)in the lung group was significantly prolonged by 13.3 months(8.5 months vs.21.8 months,HR=0.51,95%CI:0.28–0.92,P=0.0195),and that in the bone group prolonged by 9.5 months with a 43%reduction in the risk of disease progression(8.5 months vs.18.0 months,HR=0.57,95%CI:0.29–1.13,P=0.1095).The mPFS in the lung group was prolonged by 3.8 months as compared with that in the bone group.The mean OS(mOS)in the lung and bone groups was longer than that of the brain group,and the risk of death decreased by up to 60%in the lung and bone groups as compared with that of the brain group.When SBRT was concurrently given with ICIs,the mPFS in the lung and brain groups were significantly longer than that of the bone group(29.6 months vs.16.5 months vs.12.1 months).When SBRT with 8–12 Gy per fraction was combined with ICIs,the mPFS in the lung group was significantly prolonged as compared with that of the bone and brain groups(25.4 months vs.15.2 months vs.12.0 months).Among patients receiving SBRT on lung lesions and brain metastases,the mPFS in the concurrent group was longer than that of the SBRT→ICIs group(29.6 months vs.11.4 months,P=0.0003 and 12.1 months vs.8.9 months,P=0.2559).Among patients receiving SBRT with<8 Gy and 8–12 Gy per fraction,the mPFS in the concurrent group was also longer than that of the SBRT→ICIs group(20.1 months vs.5.3 months,P=0.0033 and 24.0 months vs.13.4 months,P=0.1311).The disease control rates of the lung,bone,and brain groups were 90.7%,83.3%,and 70.1%,respectively.Conclusion The study demonstrated that the addition of SBRT on lung lesions versus bone and brain metastases to ICIs improved the prognosis in advanced NSCLC patients.This improvement was related to the sequence of radiotherapy combined with ICIs and the radiotherapy fractionation regimens.Dose fractionation regimens of 8–12 Gy per fraction and lung lesions as radiotherapy targets might be the appropriate choice for advanced NSCLC patients receiving ICIs combined with SBRT.

Comprehensive Treatment Uncertainty Analysis and PTV Margin Estimation for Fiducial Tracking in Robotic Liver Stereotactic Body Radiation Therapy

Objective This study aims to quantify the uncertainties of CyberKnife Synchrony fiducial tracking for liver stereotactic body radiation therapy(SBRT)cases,and evaluate the required planning target volume(PTV)margins.Methods A total of 11 liver tumor patients with a total of 57 fractions,who underwent SBRT with synchronous fiducial tracking,were enrolled for the present study.The correlation/prediction model error,geometric error,and beam targeting error were quantified to determine the patient-level and fraction-level individual composite treatment uncertainties.The composite uncertainties and multiple margin recipes were compared for scenarios with and without rotation correction during treatment.Results The correlation model error-related uncertainty was 4.3±1.8,1.4±0.5 and 1.8±0.7 mm in the superior-inferior(SI),left-right,and anterior-posterior directions,respectively.These were the primary contributors among all uncertainty sources.The geometric error significantly increased for treatments without rotation correction.The fraction-level composite uncertainties had a long tail distribution.Furthermore,the generally used 5-mm isotropic margin covered all uncertainties in the left-right and anterior-posterior directions,and only 75%of uncertainties in the SI direction.In order to cover 90%of uncertainties in the SI direction,an 8-mm margin would be needed.For scenarios without rotation correction,additional safety margins should be added,especially in the superior-inferior and anterior-posterior directions.Conclusion The present study revealed that the correlation model error contributes to most of the uncertainties in the results.Most patients/fractions can be covered by a 5-mm margin.Patients with large treatment uncertainties might need a patient-specific margin.

Therapeutic Effects of Stereotactic Radiotherapy on 389 Cases of Brain Glioma

Objective： To investigate the treatment effectiveness and side effects of stereotactic radiotherapy for brain glioma. Methods： From Jun. 1995 to Dec. 1998, 389 cases of brain gliomas were treated by stereotactic radiotherapy, among which 151 cases were treated by stereotactic radiosurgery （SRS） and the other 238 cases, by fractionated stereotactic radiotherapy （FSRT）. In the SRS group, the marginal tumor dose was 20 to 30 Gy （median, 2.6 Gy）. One to 6 isocenters （median, 2.48） and 5 to 21 irradiation arcs （median, 8.45） were applied. In the FSRT group, the per-fraction marginal tumor dose was 8 to 12 Gy with 1 to 6 isocenters （median, 2.53）, 6 to 20 irradiation arcs （median, 8.25） and 2-5 fractions delivered everyday or every other day. Results： Three months after treatment, the complete and partial response rates were 13.9% and 45.7% in SRS group respectively. The stable disease rate was 17.2%. The total effective rate was 76.8%. In FSRT group, the complete and partial remission rates were 19.7% and 47.9% respectively. The stable disease rate was 20.6%. The total effective rate was 88.2%. The total effective rate of FSRT group was higher than that in SRS group （X^2=9.874, P=0.020）. The 1-year, 3-year and 5-year survival rate of all patients was 54.3%, 29.3%, 16.5% respectively. The 1-year, 3-year and 5-year survival rate in SRS group and FSRT group was 52.3% vs 26.5%, 11.9% vs 55.5%, and 31.1 vs 19.3% respectively. There was no significant difference between the two groups （X^2=2.16, P=0.1417）. The brain edema caused by the main radiation was more severe in the SRS group than in FSRT group （X^2=4.916, P=0.027）. Conclusion： It is effective for brain glioma to be treated by stereotactic radiotherapy. Compared with SRS, the FSRT has the advantage of good effect and less side response.

Concise review of stereotactic irradiation for pediatric glial neoplasms:Current concepts and future directions

Brain tumors,which are among the most common solid tumors in childhood,remain a leading cause of cancer-related mortality in pediatric population.Gliomas,which may be broadly categorized as low grade glioma and high grade glioma,account for the majority of brain tumors in children.Expectant management,surgery,radiation therapy(RT),chemotherapy,targeted therapy or combinations of these modalities may be used for management of pediatric gliomas.Several patient,tumor and treatment-related characteristics including age,lesion size,grade,location,phenotypic and genotypic features,symptomatology,predicted outcomes and toxicity profile of available therapeutic options should be considered in decision making for optimal treatment.Management of pediatric gliomas poses a formidable challenge to the physicians due to concerns about treatment induced toxicity.Adverse effects of therapy may include neurological deficits,hemiparesis,dysphagia,ataxia,spasticity,endocrine sequelae,neurocognitive and communication impairment,deterioration in quality of life,adverse socioeconomic consequences,and secondary cancers.Nevertheless,improved understanding of molecular pathology and technological advancements may pave the way for progress in management of pediatric glial neoplasms.Multidisciplinary management with close collaboration of disciplines including pediatric oncology,surgery,and radiation oncology is warranted to achieve optimal therapeutic outcomes.In the context of RT,stereotactic irradiation is a viable treatment modality for several central nervous system disorders and brain tumors.Considering the importance of minimizing adverse effects of irradiation,radiosurgery has attracted great attention for clinical applications in both adults and children.Radiosurgical applications offer great potential for improving the toxicity profile of radiation delivery by focused and precise targeting of well-defined tumors under stereotactic immobilization and image guidance.Herein,we provide a concise review of stereotactic irradiation for pediatric glial neoplasms in light of the literature.

Stereotactic radiotherapy for intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma(iCCA)is an aggressive malignancy with an increasing incidence worldwide and poor prognosis,despite several advances and continuous efforts to develop effective treatments.Complete surgical resection is the mainstay of treatment and offers a potentially curative option,but is only possible in less than a third of patients,owing to advanced disease.Chemotherapy is a well-established treatment in the adjuvant and palliative setting,however,confers limited benefit.Conventional radiotherapy is challenging due to local toxicity.With recent advances in stereotactic ablative radiotherapy(SABR),it is now possible to focus ablative beams of radiotherapy precisely aimed at tumours to minimise damage to surrounding viscera.This review details the history,technical background and application of SABR to iCCA,with directions for future research suggested.

Use of stereotactic radiosurgery in the treatment of gynecologic malignancies:A review

Recent retrospective studies have reported the use ofstereotactic radiosurgery(SRS) in the treatment of gy-necologic cancers. SRS uses real-time imaging and highdose radiation beams attached to precise robotic armsto target malignant lesions while sparing normal tissue.The purpose of this review is to examine the indicationsfor SRS in gynecologic oncology, review the currentliterature regarding the use of SRS in gynecologic can-cers, and identify future directions for research in thisarea. Literature on stereotactic radiosurgery was re-viewed using the PubMed search engine. Articles writ-ten in English from 1993-2013 were reviewed, and 20 case series and clinical trials were included. The safetyand efficacy SRS has been demonstrated in all gyne-cologic disease sites including cervical, endometrial,vulvar, vaginal, and ovarian cancers. Indications for itsuse include non-central pelvic recurrences in previouslyirradiated patients, complex or non-resectable diseaserecurrence, and solitary brain metastases. Toxicitiesare usually mild, though grade 3-4 toxicities have been reported. SRS is a promising second line treatment modality for patients with primary or recurrent disease who cannot undergo standard surgical or radiation therapy. Further research is required to determine optimal dosing and fractionation schedules, delineate appropriate patient populations, and assess longterm morbidity and survival.

Observation of the therapeutic efficacy of stereotactic radiotherapy in 44 cases of retroperitoneal metastatic tumor

Objective: To investigate the therapeutic effects of stereotactic radiotherapy for retroperitoneal metastatic tumor. Methods: From August 1997 to October 2004, 44 patients with retroperitoneal metastatic tumors were treated with stereotactic radiotherapy. The planning target volume was encompassed by 90%–95% isodose line. Fractional dose was from 6 Gy to 8 Gy, and they were treated 2–3 times per-week and 4–8 times in all. The total radiation doses of PTV were from 32 Gy to 48 Gy. Re- sults: After the radiotherapy, the pain was obviously relieved in 81.8% patients. Three months after completion of radiotherapy passed and then, abdominal CT was performed to evaluate the results. The whole effective rate was 81.8% [CR 27.7% (12/44) and PR 54.5% (24/44)], and six months after radiotherapy, CR was 27.7% (12/44) and PR was 59.1% (26/44). The middle survival time was 12 months. Conclusion: It is suggested that stereotactic radiotherapy for retroperitoneal metastatic tumor is a safe and effective method.

Radiation pneumonitis after stereotactic radiation therapy for lung cancer

Stereotactic body radiation therapy(SBRT)has a locacontrol rate of 95%at 2 years for non-small cell lungcancer(NSCLC)and should improve the prognosis oinoperable patients,elderly patients,and patients withsignificant comorbidities who have early-stage NSCLCThe safety of SBRT is being confirmed in internationalmulti-institutional PhaseⅡtrials for peripheral lungcancer in both inoperable and operable patients,bureports so far have found that SBRT is a safe and effective treatment for early-stage NSCLC and early metastatic lung cancer.Radiation pneumonitis(RP)is oneof the most common toxicities of SBRT.Although mospost-treatment RP is Grade 1 or 2 and either asymptomatic or manageable,a few cases are severe,symptomatic,and there is a risk for mortality.The reportedrates of symptomatic RP after SBRT range from 9%to28%.Being able to predict the risk of RP after SBRT isextremely useful in treatment planning.A dose-effecrelationship has been demonstrated,but suggesteddose-volume factors like mean lung dose,lung V20and/or lung V2.5 differed among the reports.We foundthat patients who present with an interstitial pneumo-nitis shadow on computed tomography scan and high levels of serum Krebs von den Lungen-6 and surfactant protein D have a high rate of severe radiation pneumo-nitis after SBRT.At our institution,lung cancer patients with these risk factors have not received SBRT since 2006,and our rate of severe RP after SBRT has de-creased significantly since then.

Stereotactic body radiation therapy for non-small cell lung cancer:A review

Stereotactic body radiation therapy(SBRT) is the treatment of choice for medically inoperable patients with early stage non-small cell lung cancer(NSCLC). A literature search primarily based on PubMed electronic databases was completed in July 2018. Inclusion and exclusion criteria were determined prior to the search, and only prospective clinical trials were included. Nineteen trials from 2005 to 2018 met the inclusion criteria, reporting the outcomes of 1434 patients with central and peripheral early stage NSCLC. Patient eligibility,prescription dose and delivery, and follow up duration varied widely. Threeyears overall survival ranged from 43% to 95% with loco-regional control of up to 98% at 3 years. Up to 33% of patients failed distantly after SBRT at 3 years. SBRT was generally well tolerated with 10%-30% grade 3-4 toxicities and a few treatment-related deaths. No differences in outcomes were observed between conventionally fractionated radiation therapy and SBRT, central and peripheral lung tumors, or inoperable and operable patients. SBRT remains a reasonable treatment option for medically inoperable and select operable patients with early stage NSCLC. SBRT has shown excellent local and regional control with toxicity rates equivalent to surgery. Decreasing fractionation schedules have been consistently shown to be both safe and effective. Distant failure is common, and chemotherapy may be considered for select patients. However, the survival benefit of additional interventions, such as chemotherapy, for early stage NSCLC treated with SBRT remains unclear.

Role of stereotactic body radiation therapy for hepatocellular carcinoma

The integration of new technologies has raised an interest in liver tumor radiotherapy,with literature evolving to support its efficacy.These advances,particularly stereotactic body radiation therapy(SBRT),have been critical in improving local control or potential cure in liver lesions not amenable to first-line surgical resection or radiofrequency ablation.Active investigation of SBRT,particularly for hepatocellular carcinoma(HCC),has recently started,yielding promising local control rates.In addition,data suggest a possibility that SBRT can be an alternative option for HCC unfit for other local therapies.However,information on optimal treatment indications,doses,and methods remains limited.In HCC,significant differences in patient characteristics and treatment availability exist by country.In addition,the prognosis of HCC is greatly influenced by underlying liver dysfunction and treatment itself in addition to tumor stage.Since they are closely linked to treatment approach,it is important to understand these differences in interpreting outcomes from various reports.Further studies are required to validate and maximize the efficacy of SBRT by a large,multi-institutional setting.

Role of stereotactic body radiotherapy for oligometastasis from colorectal cancer

Systemic chemotherapy has enabled prolongation of survival in patients with stage IV colorectal cancer. This has subsequently increased the relative significance of local therapy for patients with oligometastases because they can be cured by removal of oligometastatic lesions. One of the most frequently reported tumor histologies for oligometastases is colorectal cancer. Resection is the standard therapy in most settings of oligometastases. Recently, studies have shown that stereotactic body radiotherapy (SBRT) may become a treatment option that provides high local control with minimal morbidity. Two-year local control rates following SBRT for hepatic and pulmonary oligometastases are almost over 80% and are even higher for patients treated with high-dose regimens. The indications of SBRT for other metastatic sites or conditions include isolated lymph nodes, spinal and adrenal metastasis, and post-surgical pelvic recurrence. Many retrospective studies have indicated that SBRT for various lesions results in good outcomes with low morbidity, both in the curative and palliative setting. However, few reports with a high level of evidence have indicated the efficacy of SBRT compared to standard therapy. Hereafter, the optimal indication of SBRT needs to be prospectively investigated to obtain convincing evidence.

Stereotactic conformal radiotherapy of hepatic metastases:clinical analysis of 8 cases

ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓａｌｗａｙｓａｒｏｕｔｉｎｅｔｏｒｅｓｅｃｔｌｅｓｉｏｎｓｏｆｔｈｅｂｏｄｙｂｙｓｕｒｇｅｒｙ．Ｓｃｉｅｎｔｉｓｔｓｈａｖｅｔｒｉｅｄｔｏｏｂｔａｉｎｔｈｅｓａｍｅｒｅｓｕｌｔｓｗｉｔｈｏｕｔｓｕｒｇｅｒｙ，ｂｕｔｆａ...

Initial experience with stereotactic body radiotherapy for intrahepatic hepatocellular carcinoma recurrence after liver transplantation

BACKGROUND Graft hepatocellular carcinoma(HCC)recurrence after liver transplant is more frequently encountered.Graft hepatectomy is technically challenging and is associated with high morbidity.Stereotactic body radiation therapy(SBRT)has been shown to be safe and effective for the treatment of primary HCC.However,its role in HCC recurrence in a liver graft remains unclear.AIM To evaluate the safety and efficacy of SBRT for the treatment of graft HCC recurrence after liver transplantation.METHODS A retrospective study was conducted.From 2012 to 2018,6 patients with intrahepatic HCC recurrence after liver transplant were treated with SBRT at Queen Mary Hospital,the University of Hong Kong.The primary outcome was time to overall disease progression and secondary outcomes were time to local progression and best local response,as assessed with the Modified response Evaluation Criteria for Solid Tumours criteria.Patients were monitored for treatment related toxicities and graft dysfunction.RESULTS A total of 9 treatment courses were given for 13 tumours.The median tumour size was 2.3 cm(range 0.7-3.6 cm).Two(22%)patients had inferior vena cava tumour thrombus.The best local treatment response was:5(55%)complete response,1(11%)partial response and 3(33%)stable disease.After a median follow up duration of 15.5 mo,no local progression or mortality was yet observed.The median time to overall disease progression was 6.5 mo.There were 6 regional progression in the liver graft(67%)and 2 distant progression in the lung(22%).There was no grade 3 or above toxicity and there was no graft dysfunction after SBRT.CONCLUSION SBRT appears to be safe in this context.Regional progression is the mode of failure.

Stereotactic body radiotherapy for isolated paraaortic lymph node recurrence from colorectal cancer

AIM： To evaluate the efficacy and complications of stereotactic body radiotherapy in localized paraaortic lymph node recurrence from colorectal cancer. METHODS： From 2003 to 2009, 7 patients with paraaortic lymph node recurrence （1-3 lesions） from colorectal cancer were treated with stereotactic body radiotherapy. Total gross tumor volumes ranged from 4 to 40 mL. The doses were escalated from 36 Gy/patient to 51 Gy/patient and were delivered in 3 fractions. RESULTS： One and 3 year overall survival rates were 100% and 71.4%, respectively, and median survival was 37 mo. Grade IV intestinal obstruction was reported in 1 of 7 patients. This patient received 48 Gy in 3 fractions with a maximum point dose to the intestine of 53 Gy and V45Gy = 3.6 mL. However, 6 patients received an intestinal maximum point dose of 〈 51 Gy and V45Gy of 〈 1 mL, and did not develop any severe complications. CONCLUSION： This pilot study suggests selected paraaortic lymph node recurrence （1-3 closed lesions） that failed to respond to chemotherapy can be potentially salvaged by stereotactic body radiotherapy.

Stereotactic body radiation therapy in patients with hepatocellular carcinoma: A mini-review

Stereotactic body radiation therapy(SBRT) is an emerging treatment for hepatocellular carcinoma. This technique results in excellent local control rates with favorable toxicity profile despite being predominantly used in heavily pretreated patients or those unsuitable for other local therapies. SBRT may be used as a sole treatment or in combination with other local therapies as well as a bridging strategy for patient awaiting liver transplants. This brief review describes current practice of SBRT with respect to radiation technique, patient selection and treatment concepts. It summarizes available evidence from retroand prospective studies evaluating SBRT alone, SBRT in combination with other treatments and SBRT compared to other local treatment approaches.

Hepatocellular carcinoma with child Pugh-A Cirrhosis treated with stereotactic body radiotherapy

AIM To evaluate the control, survival, and hepatic function for Child Pugh(CP)-A patients after Stereotactic body radiotherapy(SBRT) in hepatocellular carcinoma(HCC).METHODS From 2009 to 2016, 40 patients with Barcelona Liver Clinic(BCLC) stages 0-B HCC and CP-A cirrhosis completed liver SBRT. The mean prescription dose was 45 Gy(40 to 50 Gy in 4-5 fractions). Local relapse, defined as recurrence within the planning target volume was assessed with intravenous multiphase contrast computed tomography or magnetic resonance imaging every 4-6 mo after completion of SBRT. Progression of cirrhosis was evaluated by CP and Model for End Stage Liver Disease scores every 3-4 mo. Toxicities were graded per the Common Terminology Criteria for Adverse Events(v4.03). Median follow-up was 24 mo.RESULTS Forty-nine HCC lesions among 40 patients were analyzed in this IRB approved retrospective study. Median tumor diameter was 3.5 cm(1.5-8.9 cm). Six patients with tumors ≥ 5 cm completed planned selected transarterial chemoembolization(TACE) in combination with SBRT. Eight patients underwent orthotropic live transplant(OLT) with SBRT as a bridging treatment(median time to transplant was 12 mo, range 5 to 23 mo). The Pathologic complete response(PCR) rate in this group was 62.5%. The 2-year in-field local control was 98%(1 failure). Intrahepatic control was 82% and 62% at 1 and 2 years, respectively. Overall survival(OS) was 92% and 60% at 1 and 2 years, with a median survival of 41 mo per Kaplan Meier analysis. At 1 and 2 years, 71% and 61% of patients retained CPA status. Of the patients with intrahepatic failures, 58% developed progressive cirrhosis, compared to 27% with controlled disease(P = 0.06). Survival specific to hepatic failure was 92%, 81%, and 69% at 12, 18, and 24 mo. There was no grade 3 or higher toxicity. On univariate analysis, gross tumor volume(GTV) < 23 cc was associated with freedom from CP progression(P = 0.05), hepatic failure-specific survival(P = 0.02), and trended with OS(P = 0.10).CONCLUSION SBRT is safe and effective in HCC with early cirrhosis and may extend waiting time for transplant in patients who may not otherwise be immediate candidates.