Volumetric Radiosurgery for 1 to 10 Brain Metastases: A Multicenter, Single-Arm, Phase 2 Study

Nichol, Alan; Ma, Roy; Hsu, Fred; Gondara, Lovedeep; Carolan, Hannah; Olson, Robert; Schellenberg, Devin; Germain, François; Cheung, Arthur; Peacock, Michael; Bergman, Alanah; Vollans, E.; Vellani, R.; McKenzie, Michael

doi:10.1016/j.ijrobp.2015.10.017

Cited by 43 publications

(35 citation statements)

References 25 publications

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“…Preliminary results presented in this paper in trajectory‐log analysis suggest that the machine delivery inaccuracies will be insignificant when compared to patient setup inaccuracies; however, the accuracy of these trajectory logs have not been independently verified and these results should only be used as a consistency check. Once implemented, these treatments will allow the treatment of larger number of targets (more than 3) in a time efficient manner.…”

Section: Discussionmentioning

confidence: 99%

A simple and robust trajectory‐based stereotactic radiosurgery treatment

2017

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Introduction: We present a Trajectory-based Volumetric Modulated Arc Therapy (TVMAT) technique for Stereotactic Radiosurgery (SRS) that takes advantage of a modern linacs ability to modulate dose rate and move the couch dynamically. In addition, we investigate the quality of the developed TVMAT method and the dosimetric accuracy of the technique. Methods: The main feature of the TVMAT technique is a standard beam trajectory formed by dynamic motion of the treatment couch and the linac gantry. The couch rotates slowly through 180 degrees while the gantry delivers radiation through continuous sweeps of the gantry. The number of partial arcs that constitute the trajectory can be varied between two and eight and as the number of partial arcs increases, the trajectory more finely samples 4p geometry. Along these trajectories, the multi-leaf collimator (MLC) and dose rate are optimized through an inverse planning framework. The TVMAT method was tested on ten cranial SRS patients who were previously treated with the Dynamic Conformal Arc (DCA) technique. The plans were compared with the DCA and a four-arc VMAT technique with regards to dose to the OAR, dose falloff, V12Gy, and V4Gy. Validation measurements were performed using ion-chamber and Gafchromic film. In addition, the trajectory-log files were analyzed and compared with the treatment plan beam data. Results: The TVMAT treatment plans were successfully delivered with a treatment time between 3-8 min which mostly depended on total cumulated dose. Ion chamber measurements had an average measured error of 1.1 AE 0.6% and a maximum value of 2.2% of the delivered dose. The 2%, 2 mm gamma pass rates for the film measurements were 96% or greater. In a preliminary comparison of ten patients who underwent SRS treatments with the DCA technique, the TVMAT and VMAT techniques were able to produce plans with comparable dose falloff and OAR doses, while achieving better dose conformality, V4Gy and V12Gy when compared to the original DCA plans. The improvement of the TVMAT plans were as follows (mean % improvement AE standard err): Conformity (10 AE 2%), V4 (20 AE 20%), V12 (27 AE 10%), volume weighted mean dose to organs at risk (13 AE 13%), homogeneity index (2 AE 2%) and falloff (4 AE 2%). Conclusion: We have developed and validated a trajectory-based dose delivery method which has dose distribution improvements while having a treatment time of 3-8 min. In addition, it has the potential for a simpler planning experience while maintaining an accurate delivery on the Varian Truebeam Linac.

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Section: Discussionmentioning

confidence: 99%

A simple and robust trajectory‐based stereotactic radiosurgery treatment

2017

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“…Stereotactic radiosurgery (SRS) for patients with multiple brain metastases is becoming more common . Linear accelerator‐based treatment using a single isocenter to treat multiple targets improves the efficiency of the delivery and has been the subject of numerous recent publications .…”

Section: Introductionmentioning

confidence: 99%

The spatial accuracy of two frameless, linear accelerator‐based systems for single‐isocenter, multitarget cranial radiosurgery

Ezzell

2017

J Applied Clin Med Phys

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Single‐isocenter, multitarget cranial stereotactic radiosurgery (SRS) is more efficient than using an isocenter for each target, but spatial positioning uncertainties can be magnified at locations away from the isocenter. This study reports on the spatial accuracy of two frameless, linac‐based SRS systems for multitarget, single‐isocenter SRS as a function of distance from the isocenter. One system uses the ExacTrac platform for image guidance and the other localizes with cone beam computed tomography (CBCT). For each platform, a phantom with 12 target BBs distributed up to 13.8 cm from the isocenter was aligned starting from five different initial offsets and then imaged with the treatment beam at seven different gantry and couch angles. The distribution of the resulting positioning errors demonstrated the value of adding a 1‐mm PTV margin for targets up to about 7–8 cm from the isocenter. For distances 10 cm or more, the CBCT‐based alignment remained within 1.1 mm while the ExacTrac‐based alignment differed by up to 2.2 mm.

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“…Nichol et al treated patients who had between 1 and 10 metastases with a similar treatment [volumetric modulated arc therapy (VMRT) SIB], delivering 20 Gy to the whole brain and 47.5 Gy to the metastases in 5 daily fractions. The authors observed a median survival duration of 10.1 months (15). We applied WBRT plus a conventional boost and found a median survival duration of 13.3 months in solitary metastases and 7.4 months in single metastases.…”

Section: Survivalmentioning

confidence: 89%

Whole brain radiotherapy plus conventional boost in non-small cell lung cancer patients with brain metastasis: a retrospective analysis of overall survival

Kandaz

Güler²,

Yazar³

et al. 2018

Turkish Neurosurgery

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(20). Probably due to improvements in overall survival, the incidence of brain metastasis is on the rise. Primary cancers such as breast cancer, lung cancer, melanoma and renal cell carcinoma are most likely to metastasise to the brain. Lung cancer is a significant source of brain metastasis. Approximately 34%-64% of patients with non-small cell lung █ INTRODUCTION B rain metastases are the most common type of intracranial tumours (8 times more common than primary brain tumours) and are significantly relevant in patients with cancer. Brain metastases are a widespread complication of systemic cancers and occur in one out of three cancer patients AIM: To evaluate the clinical characteristics and treatment outcomes of non-small cell lung cancer (NSCLC) patients with brain metastasis, who were treated by whole brain radiotherapy with a conventional boost at a single institution. MATERIAL and METHODS: A total of 296 patients diagnosed with NSCLC with brain metastasis and referred to our clinic for radiotherapy between 2000 and 2017 were included in this retrospective study. RESULTS: The median age was 60.8 ± 12.1 years, with a range of 21-85 years. The estimated median survival time for all patients was 7.81 ± 0.66 months (95% CI: 6.52-9.11). The one-year survival, two-year survival and three-year survival rates were 18.8%, 5.8% and 2.9%, respectively. The median survival of patients with solitary brain metastasis who received 45 Gy radiotherapy was 14.70 ± 2.80 months (95% CI: 9.20-20.20). These patients had 6 and 12 months survival rates of 65.4% and 42.6%, respectively. The median survival time of patients with solitary brain metastasis who received > 45 Gy radiotherapywas 13.86 ± 2.56 months (95% CI: 8.08-18.02). These patients had 6 and 12 months survival rates of 66.2% and 27.2%, respectively. There was no significant difference between the two groups (p=0.321). The median survival duration of patients under 65 years was 9.65 ± 1.02 months. The median survival time of patients aged 65 years and overwas 5.15 ± 0.51 months. There was a statistically significant difference in the median survival rates between the groups (p<0.001). CONCLUSION: Patients with solitary metastasis or single metastases tolerated whole brain radiotherapy with a conventional boost. Although the overall survival rates were numerically better in the high dose RT group, the difference was not statistically significant. Prospective studies with a larger sample size are needed to consolidate our results.

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Volumetric Radiosurgery for 1 to 10 Brain Metastases: A Multicenter, Single-Arm, Phase 2 Study

Abstract: For non-deep brain metastases, 47.5 Gy in 5 fractions was tolerable. Volumetric radiosurgery was effective for long-term control of treated brain metastases.

Cited by 43 publications

References 25 publications

A simple and robust trajectory‐based stereotactic radiosurgery treatment

A simple and robust trajectory‐based stereotactic radiosurgery treatment

The spatial accuracy of two frameless, linear accelerator‐based systems for single‐isocenter, multitarget cranial radiosurgery

Whole brain radiotherapy plus conventional boost in non-small cell lung cancer patients with brain metastasis: a retrospective analysis of overall survival

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