CyberKnife Center Northern Germany

Güstrow, Germany

CyberKnife Center Northern Germany

Güstrow, Germany

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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 Lübeck | 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.


Huttenlocher S.,University of Lübeck | Sehmisch L.,University of Lübeck | 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.


Rades D.,University of Lübeck | Huttenlocher S.,University of Lübeck | Dahlke M.,University of Hamburg | Hornung D.,CyberKnife Center Northern Germany | And 5 more authors.
Anticancer Research | Year: 2014

Aim: Two dose groups of patients treated with stereotactic radiosurgery (SRS) alone for 1-3 brain metastases from non-small cell lung cancer (NSCLC) were compared for outcomes. Patients and Methods: Based on the SRS dose administered to the margins of the brain lesions, 46 patients were assigned to groups treated with 15-18 Gy (n=13) or with 20 Gy (n=33). Seven additional factors were investigated: age (<58 vs. >59 years), gender, Karnofsky performance score (KPS 70-80 vs. 90-100), number of brain metastases (1 vs. 2-3), histology (adenocarcinoma vs. other) extracerebral metastases and interval from NSCLC diagnosis to SRS (<6 vs. >6 months). Results: Local control rates for 15-18-Gy and 20-Gy groups were 75% and 92% at one year (p=0.043). SRS dose was significant on multivariate analysis (p=0.030). SRS dose was not associated with freedom from new brain metastases (p=0.24) or survival (p=0.37). Conclusion: SRS with 20 Gy resulted in better control of the irradiated metastases than 15-18 Gy did.


Blanck O.,University of Lübeck | Blanck O.,CyberKnife Center Northern Germany | Bode F.,University of Lübeck | Gebhard M.,University of Lübeck | And 8 more authors.
International Journal of Radiation Oncology Biology Physics | Year: 2014

Purpose To perform a proof-of-principle dose-escalation study to radiosurgically induce scarring in cardiac muscle tissue to block veno-atrial electrical connections at the pulmonary vein antrum, similar to catheter ablation. Methods and Materials Nine mini-pigs underwent pretreatment magnetic resonance imaging (MRI) evaluation of heart function and electrophysiology assessment by catheter measurements in the right superior pulmonary vein (RSPV). Immediately after examination, radiosurgery with randomized single-fraction doses of 0 and 17.5-35 Gy in 2.5-Gy steps were delivered to the RSPV antrum (target volume 5-8 cm3). MRI and electrophysiology were repeated 6 months after therapy, followed by histopathologic examination. Results Transmural scarring of cardiac muscle tissue was noted with doses ≥32.5 Gy. However, complete circumferential scarring of the RSPV was not achieved. Logistic regressions showed that extent and intensity of fibrosis significantly increased with dose. The 50% effective dose for intense fibrosis was 31.3 Gy (odds ratio 2.47/Gy, P<.01). Heart function was not affected, as verified by MRI and electrocardiogram evaluation. Adjacent critical structures were not damaged, as verified by pathology, demonstrating the short-term safety of small-volume cardiac radiosurgery with doses up to 35 Gy. Conclusions Radiosurgery with doses >32.5 Gy in the healthy pig heart can induce circumscribed scars at the RSPV antrum noninvasively, mimicking the effect of catheter ablation. In our study we established a significant dose-response relationship for cardiac radiosurgery. The long-term effects and toxicity of such high radiation doses need further investigation in the pursuit of cardiac radiosurgery for noninvasive treatment of atrial fibrillation. © 2014 Elsevier Inc. All rights reserved.


Rades D.,University of Lübeck | Huttenlocher S.,University of Lübeck | 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.


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

Background: Addition of whole-brain irradiation (WBI) to radiosurgery for treatment of few cerebral metastases is controversial. This study aimed to create an instrument that estimates the probability of developing new cerebral metastases after radiosurgery to facilitate the decision regarding additional WBI.Methods: Nine characteristics were investigated for associations with the development of new cerebral metastases including radiosurgery dose (dose equivalent to <20 Gy vs. 20 Gy vs. >20 Gy for tumor cell kill, prescribed to the 73-90% isodose level), age (≤60 vs. ≥61 years), gender, Eastern Cooperative Oncology Group performance score (0-1 vs. 2), primary tumor type (breast cancer vs. non-small lung cancer vs. malignant melanoma vs. others), number/size of cerebral metastases (1 lesion <15 mm vs. 1 lesion ≥15 mm vs. 2 or 3 lesions), location of the cerebral metastases (supratentorial alone vs. infratentorial ± supratentorial), extra-cerebra metastases (no vs. yes) and time between first diagnosis of the primary tumor and radiosurgery (≤15 vs. >15 months).Results: Number of cerebral metastases (p = 0.002), primary tumor type (p = 0.10) and extra-cerebral metastases (p = 0.06) showed significant associations with development of new cerebral metastases or a trend, and were integrated into the predictive instrument. Scoring points were calculated from 6-months freedom from new cerebral metastases rates. Three groups were formed, group I (16-17 points, N = 47), group II (18-20 points, N = 120) and group III (21-22 points, N = 47). Six-month rates of freedom from new cerebral metastases were 36%, 65% and 80%, respectively (p < 0.001). Corresponding rates at 12 months were 27%, 44% and 71%, respectively.Conclusion: This new instrument enables the physician to estimate the probability of developing new cerebral metastases after radiosurgery alone. Patients of groups I and II appear good candidates for additional WBI in addition to radiosurgery, whereas patients of group III may not require WBI in addition to radiosurgery. © 2014 Huttenlocher et al.; licensee BioMed Central Ltd.


Rades D.,University of Lübeck | Huttenlocher S.,University of Lübeck | Hornung D.,University of Hamburg | Blanck O.,CyberKnife Center Northern Germany | Schild S.E.,Mayo Medical School
BMC Cancer | Year: 2014

Background: It is unclear whether patients with few cerebral metastases benefit from whole-brain irradiation added to radiosurgery. Since primary tumors disseminating to the brain show different behavior, this question should be answered separately for each tumor type. This study compared both treatments in patients with 1-3 cerebral metastases from lung cancer. Methods: Ninety-eight patients receiving radiosurgery alone were retrospectively compared to 50 patients receiving radiosurgery plus whole-brain irradiation for local control, distant cerebral control and overall survival. Ten other characteristics were additionally considered including radiosurgery dose, age, gender, Eastern Cooperative Oncology Group (ECOG) performance score, histology, number of cerebral metastases, maximum diameter of all cerebral metastases, site of cerebral metastases, extra-cerebral metastases, and interval from lung cancer diagnosis to irradiation. Results: The treatment approach had no significant impact on local control (p=0.61). On multivariate analysis of local control, ECOG performance score was significant (risk ratio [RR]: 2.10; p<0.001). The multivariate analysis of distant brain control revealed significant positive associations with radiosurgery plus whole-brain irradiation (RR: 4.67; p<0.001) and one cerebral metastasis (RR: 2.62; p<0.001). Treatment approach was not significantly associated with overall survival (p=0.32). On multivariate analysis, significant associations with overall survival were found for maximum diameter of all cerebral metastases (RR: 1.81; p=0.008), extra-cerebral metastases (RR: 2.98; p<0.001), and interval from lung cancer diagnosis to irradiation (RR: 1.19; p<0.001). Conclusion: Addition of whole-brain irradiation to radiosurgery significantly improved distant brain control in patients with few cerebral metastases from lung cancer. This improvement did not translate into better overall survival. © 2014 Rades et al.


PubMed | CyberKnife Center Northern Germany, Bach Mai Hospital, Mayo Medical School, University of Lübeck and University of Hamburg
Type: Journal Article | Journal: Anticancer research | Year: 2015

To generate a tool that estimates the probability of developing new cerebral metastases after stereotactic radiosurgery (SRS) in breast cancer patients.SRS dose plus seven characteristics (age, performance score, number of cerebral metastases, maximum diameter of all metastases, location of metastases, extra-cerebral spread and time from breast cancer diagnosis until SRS) were analyzed regarding their ability to predict the probability of new cerebral metastases development following SRS. For those characteristics deemed significant, points of 0 (higher risk of new lesions) or 1 (lower risk) were given. Scores were generated by adding the points of significant characteristics.Performance score (p=0.013) and maximum diameter of all metastases (p=0.022) were associated with development of subsequent brain metastases. Two groups were created, 0-1 and 2 points. Freedom from new cerebral metastases rates were 27% and 92%, respectively, at 15 months (p=0.003).This tool helps select breast cancer with few cerebral metastases receiving SRS who may benefit from additional whole-brain irradiation.


PubMed | Cyberknife Center Northern Germany, Mayo Medical School, University of Lübeck and University of Hamburg
Type: Journal Article | Journal: Anticancer research | Year: 2016

To generate a survival score for patients with breast cancer treated with stereotactic radiosurgery (SRS) alone for brain metastases.Seven factors were evaluated in 34 patients, namely age, performance score, number of brain metastases, maximum diameter of all brain metastases, location of brain metastases, extracerebral metastases and time between breast cancer diagnosis and SRS. The score was created from factors having a significant impact on survival. Points of 0 (worse survival) or 1 (better survival) were assigned. Factor scores were added to total prognostic scores for each patient.A significant impact on survival was found for performance score (p<0.001), maximum diameter of cerebral lesions (p=0.002), and extracerebral metastases (p=0.026). Three groups were designated by score: 0-1, 2 and 3 points. One-year survival rates were 48%, 71% and 100%, respectively (p<0.001).This score contributes to appropriate selection of personalized treatment in patients with breast cancer with few cerebral metastases.


PubMed | CyberKnife Center Northern Germany, Bach Mai Hospital, Mayo Medical School, University of Lübeck and University of Hamburg
Type: Comparative Study | Journal: Anticancer research | Year: 2014

Two dose groups of patients treated with stereotactic radiosurgery (SRS) alone for 1-3 brain metastases from non-small cell lung cancer (NSCLC) were compared for outcomes.Based on the SRS dose administered to the margins of the brain lesions, 46 patients were assigned to groups treated with 15-18 Gy (n=13) or with 20 Gy (n=33). Seven additional factors were investigated: age ( 58 vs. 59 years), gender, Karnofsky performance score (KPS 70-80 vs. 90-100), number of brain metastases (1 vs. 2-3), histology (adenocarcinoma vs. other) extracerebral metastases and interval from NSCLC diagnosis to SRS ( 6 vs. >6 months).Local control rates for 15-18-Gy and 20-Gy groups were 75% and 92% at one year (p=0.043). SRS dose was significant on multivariate analysis (p=0.030). SRS dose was not associated with freedom from new brain metastases (p=0.24) or survival (p=0.37).SRS with 20 Gy resulted in better control of the irradiated metastases than 15-18 Gy did.

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