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Objective@#To investigate the effectiveness and adverse effects of Cyberknife stereotactic body radiotherapy (SBRT) on liver metastases from PCa.@*METHODS@#From June 2009 to September 2016, we treated 20 cases of PCa liver metastases by Cyberknife SBRT, at a total dose of 36 (30－50) Gy, on 1－3 liver metastatic lesions, for 3－5 times, with a prescription isodose line of 70－92%. We assessed the therapeutic effect according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST), calculated the survival and disease-control rates using the Kaplan-Meier method, and analyzed the adverse events based on the National Cancer Institute Common Terminology Criteria for Adverse Events－Version 4.0 (CTCAE 4.0).@*RESULTS@#Of all the cases treated, complete response (CR) was found in 8 (40.0%), partial response (PR) in 9 (45.0%), stable disease (SD) in 2 (10.0%), and progressive disease (PD) in 1 (5.0%), with a local control rate (CR+PR) of 85.0% and a disease-control rate (CR+PR+SD) of 95.0%. Among the 14 patients with elevated PSA, 10 (71.4%) showed a significant decrease after treatment. The median follow-up time was 17 months, the 1- and 2-year survival rates were 85.0% and 15.0%, respectively, and the median survival time of the 20 patients was 16.5 months (95% CI: 12.12－22.88). Cyberknife SBRT was well tolerated in all the patients, with only a few mild adverse events (mainly grades 1 and 2 but no 4 and 5) during the whole course of treatment.@*CONCLUSIONS@#Cyberknife SBRT is safe and effective in the treatment of PCa liver metastases, with a high local control rate, and capable of reducing the PSA level and raising the long-term survival rate of the patients.
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Objective To determine whether the quality insurance verification of Cyberknife Synchrony meet the clinical requirements of 3D tumor motion. Methods CT images were collected with modified Sunchrony phantom, and then a Synchrony E2E treatment plan was developed.A ball-cube with EBT film was loaded on the bed,and then placed in different movement directions to implement phantom verification plan.E2E film analysis software was used for film analysis to obtain the tracking error. Results The treatment accuracy of Synchrony in one-dimensional, two-dimensional and three-dimensional directions were 0.91, 1.03 and 0.90 mm respectively. Conclusion The present quality assurance validation method of Synchrony meets the demand of clinical three-dimensional tumor motion.
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Objective To execute physical performance testing of Mobetron 2000 mobile intraoperative radiotherapy system.Methods Mobetron 2000 mobile intraoperative radiotherapy system had its indexes measured according to TG51 protocol such as percent depth dose (PDD),output dose,beam energy,field flatness and symmetry,X-ray pollution,dose linearity and repeatability.Three-dimensional water phantom was used for verification and acceptance when the measurement was executed,while the calimator end was tangent to the water surface and the nominal ource-skin distance was 50 cm.Results All the indexes of the system met the desired requirements except 12 MeV beam energy.Conclusion The system can be promoted clinically for safe,reliable and efficient treatment.
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<p><b>BACKGROUND AND OBJECTIVE</b>CybeKnife is a newly developed technology in the field of stereotactic radiosurgery/radiotherapy (SRS/SRT). Compared with conventional SRS/SRT, there are many advantages for CyberKnife in terms of treating tumors that move with respiration, being real-time image-guidance, frameless, high accurateness, and so on. Recently, it has been used to treat different types of malignant carcinoma including intracranial and caudomedial tumors. This study was designed to evaluate the short-term efficacy and toxicity of the CyberKnife radiotherapy for locally advanced pancreatic cancer.</p><p><b>METHODS</b>A total of 20 patients with locally advanced (stage II-III) pancreatic cancer treated with CyberKnife were recruited between April 2009 and December 2009. Of 20 patients, 13 were with cancer located at the pancreatic head and 7 were located at the pancreatic body and tail. The planning target volume (PTV) was defined as gross tumor volume (GTV) plus 2-3 mm, and more than 95% PTV should be covered by 75% isodose surface. The median of PTV was 47 cm³ (26-64 cm³). The median total prescription dose was 40 Gy (32-55 Gy) at 3-6 fractions. During treatment delivery, X-Sight Spine Tracking System was used in 5 patients to track movement of the tumor. Other 15 patients were implanted fiducials in the tumors to track movement of the tumor and patient breathing patterns.</p><p><b>RESULTS</b>The median follow-up time was 7 months (3-11 months). All patients had finished the treatment and 19 were alive by the last follow-up. Slight fatigue was the most common complain. Evaluated by CT scan, 6 were complete response, 9 were partial response, 3 were stable disease, and 1 was progression; 1 was dead. There were 6 patients with grade I granulocytopenia, 7 with grade I nausea, and 5 with grade II vomiting.</p><p><b>CONCLUSIONS</b>The CyberKnife radiosurgery for the locally advanced pancreatic cancer shows a high rate of local control and minimal toxicity. Long-term follow-up is necessary to evaluate the survival and late toxicity.</p>