Planning issues on linac-based stereotactic radiotherapy

This work aims to summarize and evaluate the current planning progress based on the linear accelerator in stereotactic radiotherapy(SRT).The specific techniques include 3-dimensional conformal radiotherapy,dynamic conformal arc therapy,intensity-modulated radiotherapy,and volumetric-modulated arc therapy(VMAT).They are all designed to deliver higher doses to the target volume while reducing damage to normal tissues;among them,VMAT shows better prospects for application.This paper reviews and summarizes several issues on the planning of SRT to provide a reference for clinical application.

Stereotactic radiotherapy for the treatment of nasopharyngeal carcinoma: a Meta-analysis of 1371 cases in China

Objective The aim of this study was to clarify the outcomes of stereotactic radiotherapy for the treatment of local residual and(or) local recurrent nasopharyngeal carcinoma and to promote scientific clinical treatment and research on it in China and other countries by creating a large data resource.Methods This Meta-analysis conducted a literature search using the China National Knowledge Infrastructure database for all clinical research articles on stereotactic radiotherapy for the treatment of local residual and(or) local recurrent nasopharyngeal carcinoma in China.Data on patient cohort numbers and other research factors were recorded for every relevant clinical research article.Calculated and analyzed these fact sheets to pave the way for the objective of this project.Results A total of 40 clinical research articles including 1,371 patients in China from 1998 to 2012 were identified.The average cohort size was 34 patients(range 9-98 patients).The average total radiation dose range was 16-33.6 Gy.The average study or treatment duration was 3.51 years.The calculated average follow-up time was 31.59 months.Conclusion The study provided the largest resource for further research and Meta-analyses to determine the clinical pathway of stereotactic radiotherapy for the treatment of local residual and(or) local recurrent nasopharyngeal carcinoma.The results indicated that variability in the total radiation dose,treatment or research time,and follow-up duration may have contributed to the complications and side effects of stereotactic radiotherapy for local residual and(or) local recurrent nasopharyngeal carcinoma in China.The calculated average total radiation dose,follow-up time,and treatment and research durations may be referenced for future treatment and research.This study also proposed worldwide cooperation for the metaanalysis of research articles on stereotactic radiotherapy for treating local residual and(or) local recurrent nasopharyngeal carcinoma.

Preliminary Study of Stereotactic Radiotherapy for Lung Cancer

From March 1997 to November 1999, 45 patients with lung cancer were treated by a stereotactic radiotherapy, with 15 cases treated by a stereotactic radiotherapy alone, and 30 cases by the external radiotherapy plus stereotactic radiotherapy. The clinical target volume was 1. 89-187. 26 cm3 with the median being 18. 17 cm3. The doses of plan target volume (PTV) edge was 16-30 Gy/2-3 times and the doses of center was 120% to 150% of PTV edge doses. The overall re- sponse rate was 84.4%(38/45), with 11 complete response (CR) and 27 partial response (PR). This study confirmed that the stereotactic radiotherapy is a safe and effective therapy for lung cancer. For those early-stage patients who can tolerate neither operation nor even conventional radiotherapy for various reasons, it can both achieve therapeutic purpose and improve quality of life.

Effects of Different Doses of Stereotactic Radiotherapy on Recurrence,Metastasis and Survival of Patients with Lung Cancer

Objective:To investigate the effect of different doses of stereotactic radiotherapy(SBRT)on the recurrence,metastasis and survival of lung cancer patients.Methods:The clinical data of 13 patients with lung cancer who were treated in our hospital from May 2016 to June 2020 and were followed up for one year were retrospectively analyzed.The patients treated with low-dose SBRT were divided into the observation group(7 cases)and the patients treated with high-dose SBRT were divided into the control group(6 cases).The clinical efficacy,recurrence,metastasis,survival status and incidence of adverse reactions were compared between the two groups.Results:There were no significant differences in the clinical total effective rate,1-year recurrence rate,metastasis rate and survival rate between the two groups(P>0.05);The incidence of adverse reactions in the observation group was lower than that in the control group,the difference was statistically significant(P<0.05).Conclusion:High dose or low dose SBRT can achieve good curative effect and prognosis in patients with lung cancer,but low dose SBRT has less adverse reactions and higher safety.

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.

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.

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.

Fractionated stereotactic radiotherapy with vagina carotica protection technique for local residual nasopharyngeal carcinoma after primary radiotherapy

Background Local failure of nasopharyngeal carcinoma （NPC） after radiotherapy （RT） remains one of the major treatment failures. This study aimed to evaluate the clinical efficacy and complications of fractionated stereotactic radiotherapy （FSRT） with vagina carotica protection technique for local residual of NPC patients after the primary RT. Methods From August 2006 to August 2010, FSRT with vagina carotica protection technique was applied to 36 patients in our department, the patients aged between 13 and 76 years with a median of 41.3 years, 25 of them were male and 11 were female. According to 2002 Union for International Cancer Control （UICC） Staging System, the stages before primary radiotherapy were： Ila 2, lib 5, III 18, IVa 7, IVb 4. In the first course of radiotherapy, 9 patients received conventional RT, 27 patients received intensity modulated radiotherapy （IMRT） and 20 out of the 36 patients received concurrent chemoradiotherapy. The total dose in the first course of RT was 69.96-76.90 Gy （median, 72.58 Gy）. The intervals between the primary RT and FSRT ranged from 12 to 147 days （median, 39.8 days）. Target volumes ranged from 1.46 to 32.98 cm3 （median, 14.94 cm3）. The total FSRT doses were 10.0-24.0 Gy （median, 16.5 Gy） with 2.0-5.0 Gy per fraction. The most common regimen was 15 Gy in 5 fractions of 3 Gy, the irradiation dose to vagina carotica was less than 2 Gy per fraction. Results The median follow-up time was 34 months （range, 12-59 months）. The 3-year local control rate was 100%; the 3-year overall survival rate was 94.4%; the 3-year disease-free survival rate was 77.8%. In this study, we had one case of cranial nerve injury, two cases of temporal lobe necrosis, and no nasopharyngeal massive hemorrhage was observed. Conclusion FSRT with vagina carotica protection technique is an effective and safe RT regimen for local residual of NPC with reduction of radiation-related neurovascular lesions.

Assessment of Spinal Tumor Treatment Using Implanted 3D-Printed Vertebral Bodies with Robotic Stereotactic Radiotherapy

To investigate the feasibility and early efficacy of 3D-printed vertebral body implantation combined with robotic radiosurgery in the treatment of spinal tumors.This study included 14 patients with spinal tumors from December 2017 to June 2018.Before surgery,all patients were subjected to CT scan and 3D data of the corresponding vertebral segments were collected.Titanium alloy formed 3D-printed vertebral body implantation and robotic stereotactic radiotherapy were performed because of the risk of postoperative residual,high risk of recovery,or recurrence after surgery.The main outcomes included the remission of symptoms,vertebral body stability,robotic stereotactic surgical precision,and local tumor control.All patients received complete and successful combination therapy,and all healed primarily without complications.The error of the coverage accuracy for robotic radiosurgery was less than 0.5 mm,and the error of the rotation angle was less than 0.5
.The therapeutic toxicity was limited(mainly in grades 1–2),and adverse events were uncommon.The evaluation of vertebral body stability and histocompatibility for all patients met the postoperative clinical requirements.For patients with post spinal injury,the pain symptoms were reduced or disappeared(93%),and nerve function was improved or even recovered after treatment(100%).During our follow-up period,most tumors were locally well controlled(93%).3D-printed vertebral body implantation combined with robotic radiosurgery may offer a new treatment of spinal tumors.Chinese clinical trial registry:ChiCTR-ONN-17013946.

Comparison of linac-based fractionated stereotactic radiotherapy and tomotherapy treatment plans for intra-cranial tumors

This study compares and analyzes stereotactic radiotherapy using tomotherapy and linac-based fractionated stereotactic radiotherapy in the treatment of intra-cranial tumors,according to some cases.In this study,linac-based fractionated stereotactic radiotherapy and tomotherapy treatment were administered to five patients diagnosed with intra-cranial cancer in which the dose of 18–20 Gy was applied on 3–5 separate occasions.The tumor dosing was decided by evaluating the inhomogeneous index （II） and conformity index （CI）.Also,the radiation-sensitive tissue was evaluated using low dose factors V1,V2,V3,V4,V5,and V10,as well as the non-irradiation ratio volume （NIV）.The values of the II for each prescription dose in the linacbased non-coplanar radiotherapy plan and tomotherapy treatment plan were （0.125±0.113） and （0.090±0.180）,respectively,and the values of the CI were （0.899±0.149） and （0.917±0.114）,respectively.The low dose areas,V1,V2,V3,V4,V5,and V10,in radiation-sensitive tissues in the linac-based non-coplanar radiotherapy plan fell into the ranges 0.3%–95.6%,0.1%–87.6%,0.1%–78.8%,38.8%–69.9%,26.6%–65.2%,and 4.2%–39.7%,respectively,and the tomotherapy treatment plan had ranges of 13.6%–100%,3.5%–100%,0.4%–94.9%,0.2%– 82.2%,0.1%–78.5%,and 0.3%–46.3%,respectively.Regarding the NIV for each organ,it is possible to obtain similar values except for the irradiation area of the brain stem.The percentages of NIV10%,NIV20%,and NIV30%for the brain stem in each patient were 15%–99.8%,33.4%–100%,and 39.8%–100%,respectively,in the fractionated stereotactic treatment plan and 44.2%–96.5%,77.7%–99.8%,and 87.8%–100%,respectively,in the tomotherapy treatment plan.In order to achieve higher-quality treatment of intra-cranial tumors,treatment plans should be tailored according to the isodose target volume,inhomogeneous index,conformity index,position of the tumor upon fractionated stereotactic radiosurgery,and radiation dosage for radiation-sensitive tissues.

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.

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.

Challenges and opportunities of using stereotactic body radiotherapy with anti-angiogenesis agents in tumor therapy

Microvessels promote proliferation of tumor cells by delivering oxygen and nutrients, but rapid growth of tumors results in unmet demands for oxygen and nutrients, thereby creating a hypoxia microenvironment. Under hypoxic conditions, vascular endothelial cells（ECs） initiate the formation of immature and abnormal microvasculature. This results in leakage and tortuosity that facilitates tumor cell invasion, metastasis and resistance to cytotoxic treatment.Radiotherapy（RT） is a vital tumor treatment modality. Currently, more than 60% of patients with malignant tumors receive RT at certain points during their treatment. Hypoxia induced by abnormal microvessels can hamper the cytotoxic effect of ionizing radiation, particularly, stereotactic body radiotherapy（SBRT）. Anti-angiogenesis（AA） agents are known to reduce and renormalize microvessels in tumors, and hence alleviate hypoxia. The combination of AA agents with SBRT may have a synergistic role in inhibiting the growth of tumors. On the contrary, large doses of irradiation may affect tumor microvessels itself. In this review, we aim to clarify the relationship between SBRT and microvessel formation in tumors. In addition, we provide a retrospective analysis of the combination therapy involving SBRT and AA agents in preclinical and clinical practice to define its role in antitumor treatment.

The effects of stereotactic body radiotherapy on peripheral natural killer and CD3~+CD56~+ NKT-like cells in patients with hepatocellular carcinoma

Background: Both natural killer(NK) and CD3+CD56+ natural killer T(NKT)-like cells play critical roles in the antitumor response. This study aimed to explore the effects of stereotactic body radiotherapy(SBRT) on peripheral NK and NKT-like cells in patients with hepatocellular carcinoma(HCC), and to identify possible surface markers on these cells that correlate with the prognosis. Methods: Twenty-five HCC patients were prospectively enrolled in our study, and 10 healthy individuals were served as healthy controls. Flow cytometry was used to determine the counts and the percentages of peripheral NK and NKT-like cells, cells with certain receptors, and cells with intracellular interferon-γand TNF-α secretion at different time points, including time points of prior to SBRT, at post-SBRT, and 3-month and 6-month after treatment. The Kaplan-Meier method with the log-rank test was applied for survival analysis. Results: The peripheral NKT-like cells was increased at post-SBRT. Meanwhile, elevated levels of inhibitory receptors and reduced levels of activating receptors of NK cells were also observed in NK cells at post-SBRT, but the levels was not significantly different at 3-month and 6-month as compared with the baseline levels. Lower percentage of NKp30+ NK cells before SBRT and higher percentage of CD158b + NK cells after SBRT were associated with poor progression-free survival. In addition, higher percentage of CD3+CD56+ NKT-like cells was associated with a higher overall survival rate in HCC patients. Conclusions: SBRT has an apparent effect on both peripheral NK and CD3+ CD56+ NKT-like cells. Lower percentage of NKp30 + NK cells before SBRT and higher percentage of CD158b + NK cells after SBRT are correlated with poor patients' PFS. Higher percentage of CD3+ CD56+ NKT-like cells is associated with higher OS in HCC patients.

Hepatocellular carcinoma effective stereotactic body radiotherapy using Gold Anchor and the Synchrony system:Two case reports and review of literature

BACKGROUND Radiotherapy for hepatocellular carcinoma(HCC)is considered to have limited efficacy because of treatment intensity considering that the irradiated area includes the liver,which is highly radiosensitive.In this report,we present two cases in which tumor control by surgical resection,radiofrequency ablation,transcatheter arterial chemoembolization(TACE),and lenvatinib administration was difficult,but stereotactic body radiotherapy(SBRT)using the Synchrony system by Radixact?and Gold Anchor?(GA)was effective.CASE SUMMARY A 60-year-old man had a single 10-cm HCC in the right lobe.Viable lesions remained after TACE,and levels of alpha-fetoprotein and protein induced by vitamin K antagonists II(PIVKA-II)decreased and quickly re-elevated.We performed SBRT with GA.Three weeks after implantation,localized radiotherapy(SBRT;40 Gy/5 fractions)was performed using the Synchrony system by Radixact?.Four weeks later,the viable lesion had disappeared,and the PIVKA-II levels decreased.A 77-year-old man had a single 12-cm HCC in the right lobe.The patient experienced recurrence after hepatectomy.Further recurrence occurred after TACE,and we performed SBRT with GA.Because of the proximity of the HCC to the gastrointestinal tract,localized radiotherapy(SBRT;39 Gy/13 fractions)to the HCC was performed 3 wk after implantation using the Synchrony system by Radixact?.Four weeks later,the viable lesion had disappeared on computed tomography,and the PIVKA-Ⅱlevels decreased.CONCLUSION SBRT using the Synchrony system and GA can deliver a large dose accurately and safely,and could have a high therapeutic effect.

Delivered Dose Verification for Lung Cancer Stereotactic Body Radiotherapy Using Cone-Beam CT

Purpose: Verified the delivered dose distribution of lung cancer Stereotactic Body Radiotherapy (SBRT) using the cone-beam CT images. Methods: Twenty lung cancer patients who underwent SBRT with 100 CBCT images were enrolled in this study. Delivered dose distributions were recalculated on CBCT images with the deformed and non-deformed methods, respectively. The planned and delivered dose distributions were compared using the dose-volume histograms. Results: The delivered target coverage (V100) per patient inside target volume deviated on average were 0.83% ± 0.86% and 1.38% ± 1.40% for Pct vs. Pcbct and Pct vs. Pdcbct, respectively. The Conformity Index (CI) and Gradient Index (GI) showed a good agreement among the plans. For the critical organs, only minor differences were observed between the planned dose and the delivered dose. Conclusions: CBCT images were a useful tool for setup and dose delivery verification for lung cancer patients who underwent SBRT.

Observation on the Clinical Effect of Stereotactic Body Radiotherapy in Patients with Oligometastatic Tumors

Objective:To observe the efficacy and safety of stereotactic body radiotherapy(SBRT)in the treatment of extracranial oligometastases.Method:A retrospective analysis of 70 patients with extracranial oligometastasis of malignant tumors who underwent SBRT in our hospital(Shaanxi Provincial People’s Hospital)from January 2019 to December 2021 with≤5 metastases,≤3 metastatic organs,and metastases with diameters of≤5 cm.According to the clinical data of patients,the dose-fractionation mode of SBRT is mainly determined according to the pathology of the primary tumor,the location of the metastatic tumor,and the important structures around the tumor.The local control,survival and adverse reactions were observed.Results:A total of 219 oligometastatic lesions in 70 patients were treated with SBRT.The median follow-up time was 24 months(12-40 months).The local control rate(LCR)of all target lesions assessed 3 months after radiotherapy was 94.1%;the 1-,2-,and 3-year LCRs were 88.6%,74.6%,and 64.9%,respectively.The median progression-free survival(PFS)was 11.8 months(95%CI,8.9-14.7 months),and the 1-and 2-year PFS rates were 48.6%and 32.6%,respectively;the median overall survival(OS)was 31.9 month(95%CI 26.0-37.8 months),the 1-year OS rate was 84.3%.The local control time,PFS,and OS of patients with metastases≤3 cm were significantly better than those with metastases>3 cm,and the differences were statistically significant(P<0.05).Acute adverse reactions after SBRT treatment in oligometastatic patients were mainly bone marrow suppression and gastrointestinal reactions,with incidence rates of 48.98%and 30.61%,respectively;chronic adverse reactions were mainly pain(bone,muscle),radiation enteritis,and radiation pneumonitis,with incidence rates of 38.57%,30.00%,and 24.29%,respectively.The treatment-related adverse reactions were mainly grade 1,which were all improved after symptomatic treatment,except for one patient with bone metastases from lung cancer who had grade 4 myelosuppression.No grade 4 or 5 adverse events occurred in the other patients.Conclusion:The application of SBRT in the treatment of extracranial oligometastases is safe,effective,and has high tolerability.

Precision radiotherapy for brain tumors A 10-year bibliometric analysis

OBJECTIVE： Precision radiotherapy plays an important role in the management of brain tumors. This study aimed to identify global research trends in precision radiotherapy for brain tumors using a bibliometric analysis of the Web of Science. DATA RETRIEVAL： We performed a bibliometric analysis of data retrievals for precision radiotherapy for brain tumors containing the key words cerebral tumor, brain tumor, intensity-modulated radiotherapy, stereotactic body radiation therapy, stereotactic ablative radiotherapy, imaging-guided radiotherapy, dose-guided radiotherapy, stereotactic brachytherapy, and stereotactic radiotherapy using the Web of Science. SELECTION CRITERIA： Inclusion criteria： （a） peer-reviewed articles on precision radiotherapy for brain tumors which were published and indexed in the Web of Science; （b） type of articles： original research articles and reviews; （c） year of publication： 2002-2011. Exclusion criteria： （a） articles that required manual searching or telephone access; （b） Corrected papers or book chapters. MAIN OUTCOME MEASURES： （1） Annual publication output; （2） distribution according to country; （3） distribution according to institution; （4） top cited publications; （5） distribution according to journals; and （6） comparison of study results on precision radiotherapy for brain tumors. RESULTS： The stereotactic radiotherapy, intensity-modulated radiotherapy, and imaging-guided radiotherapy are three major methods of precision radiotherapy for brain tumors. There were 260 research articles addressing precision radiotherapy for brain tumors found within the Web of Science. The USA published the most papers on precision radiotherapy for brain tumors, followed by Germany and France. European Synchrotron Radiation Facility, German Cancer Research Center and Heidelberg University were the most prolific research institutes for publications on precision radiotherapy for brain tumors. Among the top 13 research institutes publishing in this field, seven are in the USA, three are in Germany, two are in France, and there is one institute in India. Research interests including urology and nephrology, clinical neurology, as well as rehabilitation are involved in precision radiotherapy for brain tumors studies. CONCLUSION： Precision radiotherapy for brain tumors remains a highly active area of research and development.

Unraveling the efficacy network: A network meta-analysis of adjuvant external beam radiation therapy methods after hepatectomy

BACKGROUND Primary liver cancer is a malignant tumor with a high recurrence rate that significantly affects patient prognosis.Postoperative adjuvant external radiation therapy(RT)has been shown to effectively prevent recurrence after liver cancer resection.However,there are multiple RT techniques available,and the differ-ential effects of these techniques in preventing postoperative liver cancer re-currence require further investigation.AIM To assess the advantages and disadvantages of various adjuvant external RT methods after liver resection based on overall survival(OS)and disease-free survival(DFS)and to determine the optimal strategy.METHODS This study involved network meta-analyses and followed the PRISMA guidelines.The data of qualified studies published before July 10,2023,were collected from PubMed,Embase,the Web of Science,and the Cochrane Library.We included relevant studies on postoperative external beam RT after liver resection that had OS and DFS as the primary endpoints.The magnitudes of the effects were determined using risk ratios with 95%confidential intervals.The results were analyzed using R software and STATA software.RESULTS A total of 12 studies,including 1265 patients with hepatocellular carcinoma(HCC)after liver resection,were included in this study.There was no significant heterogeneity in the direct paired comparisons,and there were no significant differences in the inclusion or exclusion criteria,intervention measures,or outcome indicators,meeting the assumptions of heterogeneity and transitivity.OS analysis revealed that patients who underwent stereotactic body radiotherapy(SBRT)after resection had longer OS than those who underwent intensity modulated radiotherapy(IMRT)or 3-dimensional conformal RT(3D-CRT).DFS analysis revealed that patients who underwent 3D-CRT after resection had the longest DFS.Patients who underwent IMRT after resection had longer OS than those who underwent 3D-CRT and longer DFS than those who underwent SBRT.CONCLUSION HCC patients who undergo liver cancer resection must consider distinct advantages and disadvantages when choosing between SBRT and 3D-CRT.IMRT,a RT technique that is associated with longer OS than 3D-CRT and longer DFS than SBRT,may be a preferred option.

Role of modern radiotherapy in managing patients with hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is the most common type of primary liver cancer.Several treatment options are available for managing HCC patients,classified roughly as local,local-regional,and systemic therapies.The high postmonotherapy recurrence rate of HCC urges the need for the use of combined modalities to increase tumor control and patient survival.Different international guidelines offer treatment recommendations based on different points of view and classification systems.Radiotherapy(RT)is a well-known local-regional treatment modality for managing many types of cancers,including HCC.However,only some of these treatment guidelines include RT,and the role of combined modalities is rarely mentioned.Hence,the present study reviewed clinical evidence for the use of different combined modalities in managing HCC,focusing on modern RT's role.Modern RT has an increased utility in managing HCC patients,mainly due to two driving forces.First,technological advancement(e.g.,stereotactic body radiotherapy and advanced proton-beam therapy)enables precise delivery of radiation to increase tumor control and reduce side effects in the surrounding normal tissue.Second,the boom in developing target therapies and checkpoint-blockade immunotherapy prolongs overall survival in HCC patients,re-emphasizing the importance of local tumor control.Remarkably,RT combines with systemic therapies to generate the systemic therapy augmented by radiotherapy effect,a benefit now being actively investigated.