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Purpose: Automated treatment planning is a new frontier in radiotherapy. The Auto-Planning module of the Pinnacle 3 treatment planning system (TPS) was evaluated for liver stereotactic body radiation therapy treatments., Methods: Ten cases were included in the study. Six plans were generated for each case by four medical physics experts. The first two planned with Pinnacle TPS, both with manual module (MP) and Auto-Planning one (AP). The other two physicists generated two plans with Monaco TPS (VM). Treatment plan comparisons were then carried on the various dosimetric parameters of target and organs at risk, monitor units, number of segments, plan complexity metrics and human resource planning time. The user dependency of Auto-Planning was also tested and the plans were evaluated by a trained physician., Results: Statistically significant differences (Anova test) were observed for spinal cord doses, plan average beam irregularity, number of segments, monitor units and human planning time. The Fisher-Hayter test applied to these parameters showed significant statistical differences between AP e MP for spinal cord doses and human planning time; between MP and VM for monitor units, number of segments and plan irregularity; for all those between AP and VM. The two plans created by different planners with AP were similar to each other., Conclusions: The plans created with Auto-Planning were comparable to the manually generated plans. The time saved in planning enables the planner to commit more resources to more complex cases. The independence of the planner enables to standardize plan quality., (Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Objective: To compare patterns of acute and late radiological lung injury following either 3D conformal or image-guided volumetric modulated arc therapy stereotactic radiotherapy for Stage I non-small-cell lung cancer., Methods: We included 148 patients from a prospective mono-institutional stereotactic body radiation therapy (SBRT) series (time interval 2004-2014), treated with prescription BED 10 Gy (at 80%) in the range 100-120 Gy. The first 95 patients (2004-2010) were planned with 3D-CRT, with a stereotactic body frame. The second cohort (2010-2014) included 53 patients, planned with volumetric IMRT on a smaller planning target volume generated from a patient's specific internal target volume, with a frameless approach through cone-beam CT guidance. Acute and late radiological modifications were scored based on modified Kimura's and Koenig's classifications, respectively., Results: Median follow-up time was 20.5 months. The incidence of acute radiological changes was superimposable between the groups: increased density was observed in 68.4 and 64.2% of patients for 3D-CRT and VMAT, respectively, and patchy ground glass opacity in 23.7 and 24.5%, respectively; diffuse ground glass opacity was 2.6 vs 9.4%, respectively, and patchy consolidation 2.6 vs 1.9%, respectively. Late changes occurred in approximately 60% of patients: modified conventional pattern was the most frequent modification (25 vs 32.6%, respectively); other patterns were less common (mass-like 19.6 vs 17.4%, and scar-like 13 vs 10.9%, respectively)., Conclusion: Results of the present study indicate that the pattern of radiological lung changes following SBRT for peripheral early stage non-small-cell lung cancer is not influenced by the different techniques used for planning and delivery. Advances in knowledge: This comparative observational study shows that smaller margins, image guidance and most importantly dose distribution do not change the pattern of radiological injury after lung SBRT; the same scoring system can be used, and expected incidence is similar.

Purpose: A large-scale multi-institutional planning comparison on lung cancer SABR is presented with the aim of investigating possible criticism in carrying out retrospective multicentre data analysis from a dosimetric perspective., Methods: Five CT series were sent to the participants. The dose prescription to PTV was 54Gy in 3 fractions of 18Gy. The plans were compared in terms of PTV-gEUD2 (generalized Equivalent Uniform Dose equivalent to 2Gy), mean dose to PTV, Homogeneity Index (PTV-HI), Conformity Index (PTV-CI) and Gradient Index (PTV-GI). We calculated the maximum dose for each OAR (organ at risk) considered as well as the MLD2 (mean lung dose equivalent to 2Gy). The data were stratified according to expertise and technology., Results: Twenty-six centers equipped with Linacs, 3DCRT (4% - 1 center), static IMRT (8% - 2 centers), VMAT (76% - 20 centers), CyberKnife (4% - 1 center), and Tomotherapy (8% - 2 centers) collaborated. Significant PTV-gEUD2 differences were observed (range: 105-161Gy); mean-PTV dose, PTV-HI, PTV-CI, and PTV-GI were, respectively, 56.8±3.4Gy, 14.2±10.1%, 0.70±0.15, and 4.9±1.9. Significant correlations for PTV-gEUD2 versus PTV-HI, and MLD2 versus PTV-GI, were observed., Conclusions: The differences in terms of PTV-gEUD2 may suggest the inclusion of PTV-gEUD2 calculation for retrospective data inter-comparison., (Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Stereotactic Ablative Radiotherapy (SABR) has been previously investigated as an alternative to thoracic surgery in patients with a limited number of pulmonary nodules from different primary tumors. We here report the clinical outcomes of a series of consecutive patients homogeneously selected and treated with single dose SABR in our Institution. Eligibility criteria were: 1-5 lung metastases, maximum tumor diameter <50 mm, absent or controlled extra-thoracic disease, adequate pulmonary function, no prior radiotherapy, performance status ECOG 0-1. All patients were treated with a single dose of 26 Gy prescribed to the 80% isodose, by 3D-CRT or by IGRT-VMAT. Follow-up consisted of clinical evaluation and periodic CT scans. Primary endpoints were Local Control (LC), toxicity and Progression-Free Survival (PFS). Secondary endpoints were Cancer-Specific Survival (CSS) and Overall Survival (OS). Out of 102 patients treated with SABR between october 2003 and october 2011, we selected 67 patients for a total of 90 lesions. Main primary tumor sites were lung and colon-rectum (37.3% and 43.3% of lesions, respectively). Median follow up time was 24 months. Treated metastasis progression at SABR site was observed in 10 lesions (11.1%), and actuarial LC rates at 1 and 2 years were respectively 93.4% and 88.1%. Systemic failure occurred in 37 patients (55.2%) at a median interval of 8 months after SABR. PFS rates were 72% and 55.4% at 1 and 2 year. Seven patients had grade 1 (10.4%) and 8 grade 2-3 late radiological toxicity (11.9%), while 6 experienced late chest wall toxicity (2 rib fractures, 4 chronic chest pain, 8.9%). CSS rates at 1 and 2 years were 90% and 76%, while OS rates were 85.1% and 70.5%, respectively. Median survival time was 40 months. On multivariate analysis, a disease-free interval longer than 24 months was close to significance for a benefit in CSS (p = 0.07; HR 0.34 [95% CI 0.1-1.12]). The study includes a cohort of patients treated with single fraction 26 Gy SABR followed for a prolonged time interval. Single fraction SABR appears to be an effective treatment option, with little observed acute toxicity and limited late toxicity (<15%); its advantages also include a high patients' compliance, a short overall treatment time and an easy combination with systemic therapies. These results might provide supportive evidence to the use of single fraction SABR as a valid and acceptable alternative to surgery for pulmonary metastases from different primary tumors.

Purpose: Patient-specific quality assurance in volumetric modulated arc therapy (VMAT) brain stereotactic radiosurgery raises specific issues on dosimetric procedures, mainly represented by the small radiation fields associated with the lack of lateral electronic equilibrium, the need of small detectors and the high dose delivered (up to 30 Gy). GafchromicTM EBT2 and EBT3 films may be considered the dosimeter of choice, and the authors here provide some additional data about uniformity correction for this new generation of radiochromic films., Methods: A new analysis method using blue channel for marker dye correction was proposed for uniformity correction both for EBT2 and EBT3 films. Symmetry, flatness, and field-width of a reference field were analyzed to provide an evaluation in a high-spatial resolution of the film uniformity for EBT3. Absolute doses were compared with thermoluminescent dosimeters (TLD) as baseline. VMAT plans with multiple noncoplanar arcs were generated with a treatment planning system on a selected pool of eleven patients with cranial lesions and then recalculated on a water-equivalent plastic phantom by Monte Carlo algorithm for patient-specific QA. 2D quantitative dose comparison parameters were calculated, for the computed and measured dose distributions, and tested for statistically significant differences., Results: Sensitometric curves showed a different behavior above dose of 5 Gy for EBT2 and EBT3 films; with the use of inhouse marker-dye correction method, the authors obtained values of 2.5% for flatness, 1.5% of symmetry, and a field width of 4.8 cm for a 5×5 cm2 reference field. Compared with TLD and selecting a 5% dose tolerance, the percentage of points with ICRU index below 1 was 100% for EBT2 and 83% for EBT3. Patients analysis revealed statistically significant differences (p<0.05) between EBT2 and EBT3 in the percentage of points with gamma values<1 (p=0.009 and p=0.016); the percent difference as well as the mean difference between calculated and measured isodoses (20% and 80%) were found not to be significant (p=0.074, p=0.185, and p=0.57)., Conclusions: Excellent performances in terms of dose homogeneity were obtained using a new blue channel method for marker-dye correction on both EBT2 and EBT3 GafchromicTM films. In comparison with TLD, the passing rates for the EBT2 film were higher than for EBT3; a good agreement with estimated data by Monte Carlo algorithm was found for both films, with some statistically significant differences again in favor of EBT2. These results suggest that the use of GafchromicTM EBT2 and EBT3 films is appropriate for dose verification measurements in VMAT stereotactic radiosurgery; taking into account the uncertainty associated with Gafchromic film dosimetry, the use of adequate action levels is strongly advised, in particular, for EBT3.

Introduction: Stereotactic body radiation therapy (SBRT) has an emerging role in patients affected with pulmonary metastases. Purpose of this study was to evaluate efficacy and tolerability of SBRT in a cohort of patients treated between 2003 and 2009 at our institution., Methods: A total of 61 patients with oligometastatic lung tumors (single pulmonary nodules in 73.7%) were included in the study. SBRT was performed with a stereotactic body frame and a 3D-conformal technique. Fifty-one patients received 26 Gy in 1 fraction, 22 a dose of 45 Gy in 3 fractions and 3 a dose of 36 Gy in 4 fractions. Primary tumor was lung cancer in 45.7% of patients, colorectal cancer in 21.3% and a variety of other origins in 33%. The primary endpoint was local control, secondary endpoints were survival and toxicity., Results: After a median follow-up interval of 20.4 months, local control rates at 2 and 3 years were 89% and 83.5%, overall survival 66.5% and 52.5%, cancer-specific survival 75.4% and 67%, progression-free survival 32.4% and 22.3%. Tumor volume was significantly associated to survival, with highest rates in patients with single small tumors. Median survival time was 42.8 months, while median progression-free survival time was 11.9 months. Toxicity profiles were good, with just one case of grade III toxicity (pneumonitis)., Conclusion: This study shows that SBRT is an effective and safe local treatment option for patients with lung metastases. Definitive results are strictly correlated to clinical selection of patients., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Materials and Methods: The aim was to retrospectively investigate correlations between potential predictive parameters and the occurrence of radiation-induced lung injury in patients with primary or secondary lung tumours treated with stereotactic body radiation therapy (SBRT). Sixty patients (63 tumours) underwent SBRT, with a dose of 45 Gy in 3 fractions over 5 days or 26 Gy in single fraction. The following parameters were tested for correlation with Radiation Therapy Oncology Group (RTOG) lung toxicity score: planning target volume (PTV), tumour location, primary vs. metastatic tumour, and Mean Lung Dose (in 2 Gy fractions, MLD2). Normal Tissue Complication Probability (NTCP) values were then estimated., Results: The median follow-up time was 30.9 months (range 6.7-56.7). RTOG grade 0-1 toxicity was observed in 54/63 (85.7%) and grade 2-3 in 9/63 (14.3%) cases. Mean values of MLD(2) for RTOG grade 0-1 and 2-3 were respectively 11.2 Gy (95% Confidence Interval (CI) 10.1-12.3 Gy) and 20.3 Gy (95% CI 16.6-23.9 Gy). NTCP mean values for RTOG grade 0-1 and 2-3 were respectively 4% (95% CI 2-5.9%) and 37% (95% CI 11.6-62.3%). Univariate analysis, performed with t-Student test, showed a statistically significant difference between MLD(2) values in the two groups (t=5.93 and p < or = 0.001). Logistic regression analysis showed a good correlation between MLD(2) and toxicity scores 2-3 (p=0.008, odds ratio 1.5). From logistic regression relationship between the observed rates of grade 2-3 and MLD(2), a D(50)=19.8 Gy and a gamma50= 2.2 were obtained. From the sigmoid-shaped dose-response relationship between NTCP and MLD(2), a D(50)=22.4 Gy and gamma(50)= 2.2 were derived., Discussion: MLD(2) is strongly associated to the risk of lung injury. Higher NTCP values are associated with a higher risk, but when comparing the expected to the observed toxicity rate, NTCP seems to underestimate the risk.