ABSTRACT:A 72-year-old man with advanced locally invasive basal cell carcinoma of the forehead failed several pretreatments including surgery and radiation. MRI was not feasible because of the presence of facial implants. CT scan did not provide clear evidence of vital/avital tumor sites as a result of slow progression and previous radiation treatments. Due to limited treatment options, the patient underwent evaluation with 68 Ga-OncoFAP PET/CT for potential stereotactic body radiation therapy. We present a rare case of advanced and metastasized basal cell carcinoma with vigorous FAP (fibroblast activation protein) expression.

AbstractIntroductionTwo optimization algorithms VOLO™ and sequential optimization algorithm (SEQU) are compared in the Precision® treatment planning system from Accuray® for stereotactic radiosurgery and stereotactic body radiotherapy (SBRT) treatment plans. The aim is to compare the two algorithms to assess if VOLO™ is better of SEQU in certain treatment site.Materials and MethodsSixty clinical treatment cases were compared. Entities include Acoustic neuroma (AN), lung metastases, and liver metastases. In each entity, 10 SEQU and 10 VOLO™ treatment plans were optimized. The Ray‐Tracing calculation algorithm was used for all treatment plans and the treatments were planned exclusively with fixed cones (5–50 mm). The number of nodes, beams, total MU, and treatment time were compared. Conformity index (CI), new conformity index (nCI), homogeneity index (HI), gradient index (GI), and target coverage were examined for agreement. Dmin, Dmean, Dmax, D100%, D98%, and D2% dose in the target volume as well as exposure to organs at risk was checked. To determine peripheral doses, the isodose volumes from V10% to V98% were evaluated.ResultsAN treatment plans showed significant differences for the number of nodes, beams, total MU, treatment time, D98%, D100% for the target volume, and the doses for all organs at risk. VOLO™ achieved better results on average. Total MU, treatment time, coverage, and D98% are significantly better for VOLO™ for lung metastases. For liver metastases, a significant reduction in number of nodes, total MU, and treatment time was observed for VOLO™ plans. The mean target coverage increased slightly with VOLO™, while the mean CI deteriorated slightly. The averages of Dmin, Dmean, D98%, D100%, and V80% resulted in a significant increase for VOLO™.ConclusionThe results of the present study indicate that VOLO™ should be used in place of SEQU as a standard for AN cases moving forward. Despite the lack of significance in the lung and liver cases, VOLO™ optimization is recommended because OAR sparing was similar, but coverage, Dmin, and Dmean were increased, and thus better tumor control can be expected.

AbstractIntroductionIn order to understand the interaction processes of photons and electrons of the CyberKnife VSI‐System, a modeling of the LINAC head must take place. Here, a Monte Carlo simulation can help. By comparing the measured data with the simulation data, the agreement can be checked.Materials and methodsFor the Monte Carlo simulations, the toolkit EGSnrc with the user codes BEAMnrc and DOSXZYnrc was used. The CyberKnife VSI‐System has two collimation systems to define the field size of the beam. On the one hand, it has 12 circular collimators and, on the other, an IRIS‐aperture. The average energy, final source width, dose profiles, and output factors in a voxel‐based water phantom were determined and compared to the measured data.ResultsThe average kinetic energy of the electron beam for the CyberKnife VSI LINAC head is 6.9 MeV, with a final source width of 0.25 cm in x‐direction and 0.23 cm in y‐direction. All simulated dose profiles for both collimation systems were able to achieve a global gamma criterion of 1%/1 mm to the measured data. For the output factors, the deviation from simulated to measured data is < 1% from a field size of 12.5 mm for the circular collimators and from a field size of 10 mm for the IRIS‐aperture.ConclusionThe beam characteristics of the CyberKnife VSI LINAC head could be exactly simulated with Monte Carlo simulation. Thus, in the future, this model can be used as a basis for electronic patient‐specific QA or to determine scattering processes of the LINAC head.

The aim of this report was to describe the feasibility, overall survival and quality of life of combining multimodal therapy with a complementary therapy concept called LOTUS Care Cure program.The peritoneal carcinomatosis (PC) working group described their observations on the combination of multimodal therapy with a complementary therapy concept based on 132 patients with different cancer entities with suspected PC.PC was not confirmed by laparoscopy in 32.5% of the patients included in the working group of patients with suspected PC.Patient compliance and the feasibility were high.For Ki67, there is a cut-off at 45% with a slower progression at <45% and a faster progression of the disease at >45%.The higher the Karnofsky index, the more improved the therapy and tolerability, with a cut-off of 80%.Overall, 72.0% of patients died.The median survival time in the overall population was 3.74 years (95% CI, 2.57 to 4.91) with a sharp decline in the first 16 weeks.The quality of life of patients can be improved with the implementation of the complementary LOTUS Care Cure Project.Overall, the therapy of PC requires a multi-professional team of therapists and a multimodal therapy concept.The multimodal concept together with the Lotus Care Cure project shows very good feasibility with high compliance and ultimately leads to better and low-risk patient care.

Purpose Data‐driven gating (DDG) approaches for positron emission tomography (PET) are interesting alternatives to conventional hardware‐based gating methods. In DDG, the measured PET data themselves are utilized to calculate a respiratory signal, that is, subsequently used for gating purposes. The success of gating is then highly dependent on the statistical quality of the PET data. In this study, we investigate how this quality determines signal noise and thus motion resolution in clinical PET scans using a center‐of‐mass‐based (COM) DDG approach, specifically with regard to motion management of target structures in future radiotherapy planning applications. Methods PET list mode datasets acquired in one bed position of 19 different radiotherapy patients undergoing pretreatment [ 18 F]FDG PET/CT or [ 18 F]FDG PET/MRI were included into this retrospective study. All scans were performed over a region with organs (myocardium, kidneys) or tumor lesions of high tracer uptake and under free breathing. Aside from the original list mode data, datasets with progressively decreasing PET statistics were generated. From these, COM DDG signals were derived for subsequent amplitude‐based gating of the original list mode file. The apparent respiratory shift d from end‐expiration to end‐inspiration was determined from the gated images and expressed as a function of signal‐to‐noise ratio SNR of the determined gating signals. This relation was tested against additional 25 [ 18 F]FDG PET/MRI list mode datasets where high‐precision MR navigator‐like respiratory signals were available as reference signal for respiratory gating of PET data, and data from a dedicated thorax phantom scan. Results All original 19 high‐quality list mode datasets demonstrated the same behavior in terms of motion resolution when reducing the amount of list mode events for DDG signal generation. Ratios and directions of respiratory shifts between end‐respiratory gates and the respective nongated image were constant over all statistic levels. Motion resolution d / d max could be modeled as , with d max as the actual respiratory shift. Determining d max from d and SNR in the 25 test datasets and the phantom scan demonstrated no significant differences to the MR navigator‐derived shift values and the predefined shift, respectively. Conclusions The SNR can serve as a general metric to assess the success of COM‐based DDG, even in different scanners and patients. The derived formula for motion resolution can be used to estimate the actual motion extent reasonably well in cases of limited PET raw data statistics. This may be of interest for individualized radiotherapy treatment planning procedures of target structures subjected to respiratory motion.

The aim was to evaluate stereotactic body radiation therapy (SBRT) treatment planning variability for early stage nonsmall cell lung cancer (NSCLC) with respect to the published guidelines of the Stereotactic Radiotherapy Working Group of the German Society for Radiation Oncology (DEGRO).

Purpose: Many technological and methodical advances have made stereotactic body radiotherapy (SBRT) more accurate and more efficient during the last years. This study aims to investigate whether experience in SBRT and technological innovations also translated into improved local control (LC) and overall survival (OS).Methods and Materials: A database of 700 patients treated with SBRT for lung metastases in 20 German centers between 1997 and 2014 was used for analysis. It was the aim of this study to investigate the impact of fluorodeoxyglucose positron-emission tomography (FDG-PET) staging, biopsy confirmation, image guidance, immobilization, and dose calculation algorithm, as well as the influence of SBRT experience, on LC and OS.Results: Median follow-up time was 14.3 months (range, 0-131.9 months), with 2-year LC and OS of 81.2% (95% confidence interval [CI] 75.8%-85.7%) and 54.4% (95% CI 50.2%-59.0%), respectively. In multivariate analysis, all treatment technologies except FDG-PET staging did not significantly influence outcome. Patients who received pre-SBRT FDG-PET staging showed superior 1- and 2-year OS of 82.7% (95% CI 77.4%-88.6%) and 64.8% (95% CI 57.5%-73.3%), compared with patients without FDG-PET staging resulting in 1-and 2-year OS rates of 72.8% (95% CI 67.4%-78.8%) and 52.6% (95% CI 46.0%-60.4%), respectively (P=.012). Experience with SBRT was identified as the main prognostic factor for LC: institutions with higher SBRT experience (patients treated with SBRT within the last 2 years of the inclusion period) showed superior LC compared with less-experienced centers (P <= .001). Experience with SBRT within the last 2 years was independent from known prognostic factors for LC.Conclusion: Investigated technological and methodical advancements other than FDG-PET staging before SBRT did not significantly improve outcome in SBRT for pulmonary metastases. In contrast, LC was superior with increasing SBRT experience of the individual center. (C) 2016 Elsevier Inc. All rights reserved.

Many technological and methodical advances have made stereotactic body radiotherapy (SBRT) more accurate and more efficient during the last years. This study aims to investigate whether technological innovations and experience in SBRT also translated into improved local control (LC) and overall survival (OS). The working group "Stereotactic Radiotherapy" of the German Society for Radiation Oncology established a database of 700 patients treated with SBRT for lung metastases in 20 German centers between 1997 and 2014. It was the aim of this study to analyze the impact of FDG-PET staging (fluoro-deoxy-glucose positron emission tomography), biopsy confirmation, image guidance, immobilization and dose calculation algorithm as well as the influence of SBRT treatment experience on LC and OS. Median follow-up time was 14.3 months (range 0-131.9 months) with 2-year LC and OS of 81.2% and 54.4%, respectively. In multivariate analysis, all treatment technologies except FDG-PET staging did not significantly influence outcome. Patients who received pre-SBRT FDG-PET staging showed superior 1- and 2-year OS of 82.7% and 64.8% compared to patients without FDG-PET staging resulting in 1- and 2-year OS rates of 72.8% and 52.6%, respectively (p=0.012). SBRT treatment experience was identified as the main prognostic factor for local control: institutions with higher SBRT experience (patients treated with SBRT within the last 24 months) showed superior LC compared to less experienced centers (p≤0.001). SBRT treatment experience within the last 24 months was independent from known prognostic factors for LC. Technological and methodical advancements except FDG-PET staging prior to SBRT did not significantly improve outcome in SBRT for pulmonary metastases. On the contrary, LC was superior with increasing SBRT treatment experience of the individual center.

This study investigates differences between treatment plans generated by Ray Tracing (RT) and Monte Carlo (MC) calculation algorithms in homogeneous and heterogeneous body regions. Particularly, we focus on the head and on the thorax, respectively, for robotic stereotactic radiotherapy and radiosurgery with Cyberknife. Radiation plans for tumors located in the head and in the thorax region have been calculated and compared to each other in 47 cases and several tumor types.

Objectives: The current literature on stereotactic body radiotherapy (SBRT) for oligometastatic disease is characterized by small patient cohorts with heterogeneous primary tumors, metastases location and dose regimes. Hence, this study established a multi-institutional database of 700 patients treated with SBRT for pulmonary metastases to identify prognostic factors influencing survival and local control.Materials and methods: All German radiotherapy departments were contacted and invited to participate in this analysis. A total number of 700 patients with medically inoperable lung metastases treated with SBRT in 20 centers between 1997 and 2014 were included in a database. Primary and metastatic tumor characteristics, treatment characteristics and follow-up data including survival, local control, distant metastases, and toxicity were evaluated. Lung metastases were treated with median PTV-encompassing single doses of 12.5 Gy (range 3.0-33.0 Gy) in a median number of 3 fractions (range 1-13).Results: After a median follow-up time of 14.3 months, 2-year local control (LC) and overall survival (OS) were 81.2% and 54.4%, respectively. In multivariate analysis, OS was most significantly influenced by pretreatment performance status, maximum metastasis diameter, primary tumor histology, time interval between primary tumor diagnosis and SBRT treatment and number of metastases. For LC, independent prognostic factors were pretreatment performance status, biological effective dose (BED) at PTV isocenter (BEDISO) and single fraction (PTV-encompassing) dose in multivariate analysis. Radiation-induced pneumonitis grade 2 or higher was observed in 6.5% of patients. The only factor significantly influencing toxicity was BEDISO (p = 0.006).Conclusion: SBRT for medically inoperable patients with pulmonary metastases achieved excellent local control and promising overall survival. Important prognostic factors were identified for selecting patients who might benefit most from this therapy approach. (C) 2016 Elsevier Ireland Ltd. All rights reserved.

Recent studies have demonstrated an increase in the necessity of adaptive planning over the course of lung cancer radiation therapy (RT) treatment. In this study, we evaluated intrathoracic changes detected by cone-beam CT (CBCT) in lung cancer patients during RT.

We present a case of radiotherapy for a 66-year-old patient with squamous cell carcinoma on the left main bronchus undergoing implantation of pacemaker, implantable cardioverter defibrillator (ICD) as well as cardiopulmonary support (CPS) device. The radiation area was determined according to 4D List Mode positron emission tomography-computed tomography (PET-CT) data. Planning Target Volume (PTV) included a part of the active ICD. For the optimal tumor coverage and sparing of both the implantable cardiac devices and organs at risk, we combined the conformal radiotherapy with stereotactic body radiotherapy (SBRT) using helical tomotherapy. The prescription dose of 25.2Gy was applied by conventional radiotherapy. SBRT was performed hypofractionated with a prescription dose of 35Gy in 5 fractions. A dynamic electrocardiogram was performed during every radiation fraction. The implanted aggregates were checked three times a week. Despite partial localization of the active ICD in the radiation field, the tumor was treated without inappropriate shock delivery during radiation treatment and over twelve months afterwards. The reduced tumor size as well as tumor metabolic activity were observed by PET-CT three months after radiation treatment. The patient exhibited no signs of pneumonitis on the last radiological follow-up examination six months after radiotherapy. The reduced dyspnea and cough over the first four months after treatment were observed.In conclusion, tumor shrinkage and temporary clinical improvement of the patient as well as no technical complications of implanted cardiac devices were achieved by the radiation treatment.

PURPOSE:Most radiobiological models for prediction of tumor control probability (TCP) do not account for the fact that many events could remain unobserved because of censoring. We therefore evaluated a set of TCP models that take into account this censoring. METHODS AND MATERIALS:We applied 2 fundamental Bayesian cure rate models to a sample of 770 pulmonary metastasis treated with stereotactic body radiation therapy at German, Austrian, and Swiss institutions: (1) the model developed by Chen, Ibrahim and Sinha (the CIS99 model); and (2) a mixture model similar to the classic model of Berkson and Gage (the BG model). In the CIS99 model the number of clonogens surviving the radiation treatment follows a Poisson distribution, whereas in the BG model only 1 dominant recurrence-competent tissue mass may remain. The dose delivered to the isocenter, tumor size and location, sex, age, and pretreatment chemotherapy were used as covariates for regression. RESULTS:Mean follow-up time was 15.5 months (range: 0.1-125). Tumor recurrence occurred in 11.6% of the metastases. Delivered dose, female sex, peripheral tumor location and having received no chemotherapy before RT were associated with higher TCP in all models. Parameter estimates of the CIS99 were consistent with the classical Cox proportional hazards model. The dose required to achieve 90% tumor control after 15.5 months was 146 (range: 114-188) Gy10 in the CIS99 and 133 (range: 101-164) Gy10 in the BG model; however, the BG model predicted lower tumor control at long (≳20 months) follow-up times and gave a suboptimal fit to the data compared to the CIS99 model. CONCLUSIONS:Biologically motivated cure rate models allow adding the time component into TCP modeling without being restricted to the follow-up period which is the case for the Cox model. In practice, application of such models to the clinical setting could allow for adaption of treatment doses depending on whether local control should be achieved in the short or longer term.

PURPOSE:This report of the Working Group on Stereotactic Radiotherapy of the German Society of Radiation Oncology (DEGRO) aims to provide a practical guideline for safe and effective stereotactic body radiotherapy (SBRT) of liver tumors.METHODS:The literature on the clinical evidence of SBRT for both primary liver tumors and liver metastases was reviewed and analyzed focusing on both physical requirements and special biological characteristics.RESULTS:Recommendations were developed for patient selection, imaging, planning, treatment delivery, motion management, dose reporting, and follow-up. Radiation dose constraints to critical organs at risk are provided.CONCLUSION:SBRT is a well-established treatment option for primary and secondary liver tumors associated with low morbidity.

The German Society of Radiation Oncology (DEGRO) initiated a multicenter trial to develop and evaluate adequate modules to assert core procedures in radiotherapy. The aim of this prospective evaluation was to methodical assess the required resources for radiotherapy in pediatric and adolescent patients.

Background: Several prognostic factors for local tumor control probability (TCP) after stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) have been described, but no attempts have been undertaken to explore whether a nonlinear combination of potential factors might synergistically improve the prediction of local control.Methods and Materials: We investigated a support vector machine (SVM) for predicting TCP in a cohort of 399 patients treated at 13 German and Austrian institutions. Among 7 potential input features for the SVM we selected those most important on the basis of forward feature selection, thereby evaluating classifier performance by using 10-fold cross-validation and computing the area under the ROC curve (AUC). The final SVM classifier was built by repeating the feature selection 10 times with different splitting of the data for cross-validation and finally choosing only those features that were selected at least 5 out of 10 times. It was compared with a multivariate logistic model that was built by forward feature selection.Results: Local failure occurred in 12% of patients. Biologically effective dose (BED) at the isocenter (BEDISO) was the strongest predictor of TCP in the logistic model and also the most frequently selected input feature for the SVM. A bivariate logistic function of BEDISO and the pulmonary function indicator forced expiratory volume in 1 second (FEV1) yielded the best description of the data but resulted in a significantly smaller AUC than the final SVM classifier with the input features BEDISO, age, baseline Karnofsky index, and FEV1 (0.696 +/- 0.040 vs 0.789 +/- 0.001, P < .03). The final SVM resulted in sensitivity and specificity of 67.0% +/- 0.5% and 78.7% +/- 0.3%, respectively.Conclusions: These results confirm that machine learning techniques like SVMs can be successfully applied to predict treatment outcome after SBRT. Improvements over traditional TCP modeling are expected through a nonlinear combination of multiple features, eventually helping in the task of personalized treatment planning. (C) 2014 Elsevier Inc.