On the total system error of a robotic radiosurgery system: phantom measurements, clinical evaluation and long-term analysis

Pantelis, E.; Moutsatsos, A.; Antypas, Christos; Zoros, E.; Pantelakos, P.; Lekas, Leonidas; Romanelli, Pantaleo; Zourari, K.; Hourdakis, C. J.

doi:10.1088/1361-6560/aad516

Cited by 20 publications

(18 citation statements)

References 41 publications

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“…Unlike other SRS techniques, the CK does not require general or local anesthesia still ensuring a comparable level of accuracy (12). Particularly, the CK was found to have clinically relevant accuracy of 0.7 +/-0.3 mm, minimizing normal brain radiation exposure and allowing for high doses of radiation to targeted areas (12,16). Given its recent development, few case series have been reported on CK for rMGs of the brain, and indications are still debated.…”

Section: Introductionmentioning

confidence: 99%

CyberKnife for Recurrent Malignant Gliomas: A Systematic Review and Meta-Analysis

et al. 2021

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Background and ObjectivePossible treatment strategies for recurrent malignant gliomas include surgery, chemotherapy, radiotherapy, and combined treatments. Among different reirradiation modalities, the CyberKnife System has shown promising results. We conducted a systematic review of the literature and a meta-analysis to establish the efficacy and safety of CyberKnife treatment for recurrent malignant gliomas.MethodsWe searched PubMed, MEDLINE, and EMBASE from 2000 to 2021 for studies evaluating the safety and efficacy of CyberKnife treatment for recurrent WHO grade III and grade IV gliomas of the brain. Two independent reviewers selected studies and abstracted data. Missing information was requested from the authors via email correspondence. The primary outcomes were median Overall Survival, median Time To Progression, and median Progression-Free Survival. We performed subgroup analyses regarding WHO grade and chemotherapy. Besides, we analyzed the relationship between median Time To Recurrence and median Overall Survival from CyberKnife treatment. The secondary outcomes were complications, local response, and recurrence. Data were analyzed using random-effects meta-analysis.ResultsThirteen studies reporting on 398 patients were included. Median Overall Survival from initial diagnosis and CyberKnife treatment was 22.6 months and 8.6 months. Median Time To Progression and median Progression-Free Survival from CyberKnife treatment were 6.7 months and 7.1 months. Median Overall Survival from CyberKnife treatment was 8.4 months for WHO grade IV gliomas, compared to 11 months for WHO grade III gliomas. Median Overall Survival from CyberKnife treatment was 4.4 months for patients who underwent CyberKnife treatment alone, compared to 9.5 months for patients who underwent CyberKnife treatment plus chemotherapy. We did not observe a correlation between median Time To Recurrence and median Overall Survival from CyberKnife. Rates of acute neurological and acute non-neurological side effects were 3.6% and 13%. Rates of corticosteroid dependency and radiation necrosis were 18.8% and 4.3%.ConclusionsReirradiation of recurrent malignant gliomas with the CyberKnife System provides encouraging survival rates. There is a better survival trend for WHO grade III gliomas and for patients who undergo combined treatment with CyberKnife plus chemotherapy. Rates of complications are low. Larger prospective studies are warranted to provide more accurate results.

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Section: Introductionmentioning

confidence: 99%

CyberKnife for Recurrent Malignant Gliomas: A Systematic Review and Meta-Analysis

et al. 2021

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“…Center‐to‐center offsets were measured independently for each target by comparing the difference in the 3D center‐of‐mass of each target between the gels (polymerized area) and plans (high‐dose area). The center‐of‐mass was calculated by averaging the distributions of the centers‐of‐mass derived by various ranges of dose thresholds, taking into account the dose gradient of each target 17,23 . Table 5 shows the largest geometric offset (0.8 mm) caused by 1.5 mm HDMM head rotation without plan adaptation in scenario 1.…”

Section: Resultsmentioning

confidence: 99%

Validation of PTV margin for Gamma Knife Icon frameless treatment using a PseudoPatient® Prime anthropomorphic phantom

Han

Diagaradjane

Luo

et al. 2020

J Applied Clin Med Phys

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The Gamma Knife Icon allows the treatment of brain tumors mask‐based single‐fraction or fractionated treatment schemes. In clinic, uniform axial expansion of 1 mm around the gross tumor volume (GTV) and a 1.5 mm expansion in the superior and inferior directions are used to generate the planning target volume (PTV). The purpose of the study was to validate this margin scheme with two clinical scenarios: (a) the patient’s head remaining right below the high‐definition motion management (HDMM) threshold, and (b) frequent treatment interruptions followed by plan adaptation induced by large pitch head motion. A remote‐controlled head assembly was used to control the motion of a PseudoPatient® Prime head phantom; for dosimetric evaluations, an ionization chamber, EBT3 films, and polymer gels were used. These measurements were compared with those from the Gamma Knife plan. For the absolute dose measurements using an ionization chamber, the percentage differences for both targets were less than 3.0% for all scenarios, which was within the expected tolerance. For the film measurements, the two‐dimensional (2D) gamma index with a 2%/2 mm criterion showed the passing rates of ≥87% in all scenarios except the scenario 1. The results of Gel measurements showed that GTV (D100) was covered by the prescription dose and PTV (D95) was well above the planned dose by up to 5.6% and the largest geometric PTV offset was 0.8 mm for all scenarios. In conclusion, the current margin scheme with HDMM setting is adequate for a typical patient’s intrafractional motion.

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“…To calculate the single-fraction margins for these two techniques, technique-specific systematic and random errors, expressed as 1 standard deviation of a Gaussian distribution, were taken from literature. For VMAT-APBI, these are beam isocenter accuracy, couch accuracy, and intrafraction motion (Table 1) [25][26][27][28][29]. For CyberKnife-APBI, this is the CyberKnife total system error, which combines imaging and beam adjustment errors.…”

Section: Comprehensive Ctv To Ptv Margin Calculationmentioning

confidence: 99%

“…Cyberknife fiducial tracking [28,29] 0.23 -* Applicable for the situation of a free breathing planning CT scan with a scanning time much shorter than the breathing cycle time. ing at least 95% CTV coverage in 90% of patients [20].…”

Section: Total System Errormentioning

confidence: 99%

Fiducial marker motion relative to the tumor bed has a significant impact on PTV margins in partial breast irradiation

Hoekstra

Habraken

Swaak-Kragten

et al. 2021

Radiotherapy and Oncology

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Introduction: With the introduction of accelerated partial breast irradiation (APBI) and the trend of reducing the number of fractions, the geometric accuracy of treatment delivery becomes critical. APBI patient setup is often based on fiducials, as the seroma is frequently not visible on pretreatment imaging. We assessed the motion of fiducials relative to the tumor bed between planning CT and treatment, and calculated margins to compensate for this motion. Methods: A cohort of seventy patients treated with APBI on a Cyberknife was included. Planning and inroom pretreatment CT scans were registered on the tumor bed. Residual motion of the centers of mass of surgical clips and interstitial gold markers was calculated. We calculated the margins required per desired percentage of patients with 100% CTV coverage, and the systematic and random errors for fiducial motion. Results: For a single fraction treatment, a margin of 1.8 mm would ensure 100% CTV coverage in 90% of patients when using surgical clips for patient set-up. When using interstitial markers, the margin should be 2.2 mm. The systematic and random errors were 0.46 mm for surgical clip motion and 0.60 mm for interstitial marker motion. No clinical factors were found predictive for fiducial motion. Conclusions: Fiducial motion relative to the tumor bed between planning CT and APBI treatment is nonnegligible and should be included in the PTV margin calculation to prevent geographical miss. Systematic and random errors of fiducial motion were combined with other geometric uncertainties to calculate comprehensive PTV margins for different treatment techniques.

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On the total system error of a robotic radiosurgery system: phantom measurements, clinical evaluation and long-term analysis

Cited by 20 publications

References 41 publications

CyberKnife for Recurrent Malignant Gliomas: A Systematic Review and Meta-Analysis

CyberKnife for Recurrent Malignant Gliomas: A Systematic Review and Meta-Analysis

Validation of PTV margin for Gamma Knife Icon frameless treatment using a PseudoPatient® Prime anthropomorphic phantom

Fiducial marker motion relative to the tumor bed has a significant impact on PTV margins in partial breast irradiation

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