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Chan M.K.H.,Tuen Mun Hospital | Werner R.,University of Hamburg | Ayadi M.,Leon Berard Cancer Center | Blanck O.,University of Lubeck | Blanck O.,CyberKnife Center Northern Germany
Strahlentherapie und Onkologie | Year: 2014

Purpose: To investigate the adequacy of three-dimensional (3D) Monte Carlo (MC) optimization (3DMCO) and the potential of four-dimensional (4D) dose renormalization (4DMCrenorm) and optimization (4DMCO) for CyberKnife (Accuray Inc., Sunnyvale, CA) radiotherapy planning in lung cancer.Materials and methods: For 20 lung tumors, 3DMCO and 4DMCO plans were generated with planning target volume (PTV5 mm)=gross tumor volume (GTV) plus 5 mm, assuming 3 mm for tracking errors (PTV3 mmand 2 mm for residual organ deformations. Three fractions of 60 Gy were prescribed to ≥ 95 % of the PTV5 mmEach 3DMCO plan was recalculated by 4D MC dose calculation (4DMCrecalto assess the dosimetric impact of organ deformations. The 4DMCrecalplans were renormalized (4DMCrenormto 95 % dose coverage of the PTV5 mm for comparisons with the 4DMCO plans. A 3DMCO plan was considered adequate if the 4DMCrecalplan showed ≥ 95 % of the PTV3 mmreceiving 60 Gy and doses to other organs at risk (OARs) were below the limits.Results: In seven lesions, 3DMCO was inadequate, providing < 95 % dose coverage to the PTV3 mmComparison of 4DMCrecaland 3DMCO plans showed that organ deformations resulted in lower OAR doses. Renormalizing the 4DMCrecalplans could produce OAR doses higher than the tolerances in some 4DMCrenormplans. Dose conformity of the 4DMCrenormplans was inferior to that of the 3DMCO and 4DMCO plans. The 4DMCO plans did not always achieve OAR dose reductions compared to 3DMCO and 4DMCrenormplans.Conclusion: This study indicates that 3DMCO with 2 mm margins for organ deformations may be inadequate for Cyberknife-based lung stereotactic body radiotherapy (SBRT). Renormalizing the 4DMCrecalplans could produce degraded dose conformity and increased OAR doses; 4DMCO can resolve this problem. © 2014, Springer-Verlag Berlin Heidelberg. Source

Rades D.,University of Lubeck | Hornung D.,University of Hamburg | Blanck O.,University of Lubeck | Blanck O.,CyberKnife Center Northern Germany | And 7 more authors.
Strahlentherapie und Onkologie | Year: 2014

Background and purpose. Three doses were compared for local control of irradiated metastases, freedom from new brain metastases, and survival in patients receiving stereotactic radiosurgery (SRS) alone for one to three newly diagnosed brain metastases. Patients and methods. In all, 134 patients were assigned to three groups according to the SRS dose given to the margins of the lesions: 13-16 Gy (n=33), 18 Gy (n=18), and 20 Gy (n=83). Additional potential prognostic factors were evaluated: age (≤60 vs. >60 years), gender, Karnofsky Performance Scale score (70-80 vs. 90-100), tumor type (non-small-cell lung cancer vs. melanoma vs. others), number of brain metastases (1 vs. 2-3), lesion size (<15 vs. ≥15 mm), extracranial metastases (no vs. yes), RPA class (1 vs. 2), and interval of cancer diagnosis to SRS (≤24 vs. >24 months). Results. For 13-16 Gy, 18 Gy, and 20 Gy, the 1-year local control rates were 31, 65, and 79%, respectively (p<0.001). The SRS dose maintained significance on multivariate analysis (risk ratio: 2.25; 95% confidence interval: 1.56-3.29; p<0.001). On intergroup comparisons of local control, 20 Gy was superior to 13-16 Gy (p<0.001) but not to 18 Gy (p=0.12); 18 Gy showed a strong trend toward better local control when compared with 13-16 Gy (p=0.059). Freedom from new brain metastases (p=0.57) and survival (p=0.15) were not associated with SRS dose in the univariate analysis. Conclusion. SRS doses of 18 Gy and 20 Gy resulted in better local control than 13-16 Gy. However, 20 Gy and 18 Gy must be compared again in a larger cohort of patients. Freedom from new brain metastases and survival were not associated with SRS dose. © 2014 Springer-Verlag. Source

Huttenlocher S.,University of Lubeck | Sehmisch L.,University of Lubeck | Schild S.E.,Mayo Medical School | Blank O.,CyberKnife Center Northern Germany | And 2 more authors.
Anticancer Research | Year: 2014

Background/Aim: To develop a tool for estimating the risk of developing new cerebral lesions in 69 melanoma patients receiving radiosurgery for 1-3 cerebral metastases. Patients and Methods: Ten factors were investigated: lactate dehydrogenase (LDH), radiosurgery dose, age, gender, performance status, maximum diameter, location and number of cerebral lesions, extra-cranial spread, time between melanoma diagnosis and radiosurgery. Two factors, number of lesions and extra-cranial spread, were included in the tool. Scoring points were achieved by dividing the 6-month rate of freedom from new cerebral lesions by 10. Results: Sum scores were 9, 11, 12 or 14 points. Six-month rates of freedom from new brain metastases were 28%, 63%, 59% and 92% (p=0.002). Three prognostic groups were designed: A (9 points), B (11-12 points) and C (14 points). Freedom from new cerebral lesion rates were 28%, 60% and 92% (p<0.001). Conclusion: Group A and B patients should be considered for additional whole-brain radiotherapy (WBRT). © 2014, International Institute of Anticancer Research. All rights reserved. Source

Rades D.,University of Lubeck | Huttenlocher S.,University of Lubeck | Hornung D.,University of Hamburg | Blanck O.,CyberKnife Center Northern Germany | And 2 more authors.
Radiation Oncology | Year: 2014

Background: An important issue in palliative radiation oncology is the whether whole-brain radiotherapy should be added to radiosurgery when treating a limited number of brain metastases. To optimize personalized treatment of cancer patients with brain metastases, the value of whole-brain radiotherapy should be described separately for each tumor entity. This study investigated the role of whole-brain radiotherapy added to radiosurgery in breast cancer patients. Methods: Fifty-eight patients with 1-3 brain metastases from breast cancer were included in this retrospective study. Of these patients, 30 were treated with radiosurgery alone and 28 with radiosurgery plus whole-brain radiotherapy. Both groups were compared for local control of the irradiated metastases, freedom from new brain metastases and survival. Furthermore, eight additional factors were analyzed including dose of radiosurgery, age at radiotherapy, Eastern Cooperative Oncology Group (ECOG) performance score, number of brain metastases, maximum diameter of all brain metastases, site of brain metastases, extra-cranial metastases and the time from breast cancer diagnosis to radiotherapy. Results: The treatment regimen had no significant impact on local control in the univariate analysis (p=0.59). Age ≤59years showed a trend towards improved local control on univariate (p=0.066) and multivariate analysis (p=0.07). On univariate analysis, radiosurgery plus whole-brain radiotherapy (p=0.040) and ECOG 0-1 (p=0.012) showed positive associations with freedom from new brain metastases. Both treatment regimen (p=0.039) and performance status (p=0.028) maintained significance on multivariate analysis. ECOG 0-1 was positively correlated with survival on univariate analysis (p<0.001); age ≤59years showed a strong trend (p=0.054). On multivariate analysis, performance status (p<0.001) and age (p=0.041) were significant. Conclusions: In breast cancer patients with few brain metastases, radiosurgery plus whole-brain radiotherapy resulted in significantly better freedom from new brain metastases than radiosurgery alone. However, this advantage did not lead to significantly better survival. © Rades et al.; licensee BioMed Central Ltd. Source

Rades D.,University of Lubeck | Huttenlocher S.,University of Lubeck | Rudat V.,Saad Specialist Hospital | Hornung D.,University of Hamburg | And 5 more authors.
Anticancer Research | Year: 2015

Patients and Methods: Patients receiving 20 Gy (n=20) were compared to those receiving 16-18.5 Gy (n=10) for local control, distant brain control and overall survival. Seven other variables were also evaluated.Aim: To determine the optimal dose of radiosurgery-alone for patients with 1-3 cerebral metastases from breast cancer.Results: Radiosurgery dose achieved significance on univariate (p=0.002; log-rank and Wilcoxon test) and multivariate analysis (p=0.004) of local control. Twelve-month local control rates were 94% after 20 Gy and 48% after 16-18.5 Gy. On univariate analysis of distant brain control, radiosurgery dose was not a significant factor, with 12-month rates of 73% and 60%, respectively. Regarding overall survival, radiosurgery dose was of borderline significance (p=0.059; Wilcoxon test). Twelve-month overall survival rates were 75% and 40%, respectively. On Cox regression analysis, radiosurgery dose exhibited a trend for improving survival (p=0.10).Conclusion: Radiosurgery with 20 Gy resulted in significantly better local control and led to a trend towards improved overall survival compared to treatment with 16-18.5 Gy. Source

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