Treatment planning and delivery practice of lung SBRT: Results of the 2022 ESTRO physics survey.

Background And Purpose: The use of Stereotactic Body Radiation Therapy (SBRT) in lung cancer is increasing. However, there is no consensus on the most appropriate treatment planning and delivery practice for lung SBRT. To gauge the range of practice, quantify its variability and identify where consensus might be achieved, ESTRO surveyed the medical physics community.

Patient specific quality assurance in SBRT: a systematic review of measurement-based methods.

This topical review focuses on Patient-Specific Quality Assurance (PSQA) approaches to stereotactic body radiation therapy (SBRT). SBRT requires stricter accuracy than standard radiation therapy due to the high dose per fraction and the limited number of fractions. The review considered various PSQA methods reported in 36 articles between 01/2010 and 07/2022 for SBRT treatment.

Helical tomotherapy and two types of volumetric modulated arc therapy: dosimetric and clinical comparison for several cancer sites.

Radiotherapy accelerators have undergone continuous technological developments. We investigated the differences between Radixact™ and VMAT treatment plans. Sixty patients were included in this study.

Concurrent Chemoradiation in Anal Cancer Patients Delivered with Bone Marrow-Sparing IMRT: Final Results of a Prospective Phase II Trial.

We investigated the role of the selective avoidance of haematopoietically active pelvic bone marrow (BM), with a targeted intensity-modulated radiotherapy (IMRT) approach, to reduce acute hematologic toxicity (HT) in anal cancer patients undergoing concurrent chemo-radiation. We designed a one-armed two-stage Simon's design study to test the hypothesis that BM-sparing IMRT would improve by 20% the rate of G0-G2 (vs. G3-G4) HT, from 42% of RTOG 0529 historical data to 62% (α = 0.

Adoption of Expansion Margins to Reduce the Dose Received by the Coronary Arteries and the Risk of Cardiovascular Events in Lymphoma Patients.

Purpose: Mediastinal radiation therapy (RT) in patients with lymphoma implies involuntary coronary artery (CA) exposure, resulting in an increased risk of coronary artery disease (CAD). Accurate delineation of CAs may spare them from higher RT doses. However, heart motion affects the estimation of the dose received by CAs.

Dosimetric Multicenter Planning Comparison Studies for Stereotactic Body Radiation Therapy: Methodology and Future Perspectives.

In this review a summary of the published literature pertaining to the stereotactic body radiation therapy multiplanning comparison, data sharing strategies, and implementation of benchmark planning cases to improve the skills and knowledge of the participating centers was investigated. A total of 30 full-text articles were included. The studies were subdivided in 3 categories: multiplanning studies on dosimetric variability, planning harmonization before clinical trials, and technical and methodologic studies.

Small field correction factors determination for several active detectors using a Monte Carlo method in the Elekta Axesse linac equipped with circular cones.

A Monte Carlo (MC) method was used to determine small field output correction factors for several active detectors (Exradin A16, Exradin A26, PTW microLion, PTW microDiamond, Exradin W1 and IBA RAZOR) for an Elekta Axesse linac equipped with circular cones. MC model of the linac was built with the GamBet software, using the Penelope code system. The dose-to-water simulation for each cone, ranging from 5 to 30 mm of diameter size, was used to calculate field factors and the results were validated together with Gafchromic EBT3 film.

Clinical evaluation of a transmission detector system and comparison with a homogeneous 3D phantom dosimeter.

Purpose: To evaluate the performances of the Dolphin system for pre-treatment verification (IBA Dosimetry, Schwarzenbruck, Germany) based on transmission measurements, employing a clinical perspective.

Methods And Materials: Fifty treatment plans were verified by Dolphin and Delta detectors (Scandidos, Uppsala, Sweden) during the same session and subsequently by the Delta itself. The attenuation factor of the transmission detector (required for on-line dosimetry) was evaluated by comparing Delta measurements with and without Dolphin.

SBRT planning for spinal metastasis: indications from a large multicentric study.

Background: The dosimetric variability in spine stereotactic body radiation therapy (SBRT) planning was investigated in a large number of centres to identify crowd knowledge-based solutions.

Methods: Two spinal cases were planned by 48 planners (38 centres). The required prescription dose (PD) was 3 × 10 Gy and the planning target volume (PTV) coverage request was: V > 90% (minimum request: V > 80%).

A multi-center output factor intercomparison to uncover systematic inaccuracies in small field dosimetry.

Large uncertainties in output factor (OF) small fields dosimetry motivated multicentric studies. The focus of the study was the determination of the OFs, for different linacs and radiosurgery units, using new-generation detectors. Intercomparison studies between radiotherapy centers improved quality dosimetry practices.

Evaluation of a commercial automatic treatment planning system for liver stereotactic body radiation therapy treatments.

Purpose: Automated treatment planning is a new frontier in radiotherapy. The Auto-Planning module of the Pinnacle treatment planning system (TPS) was evaluated for liver stereotactic body radiation therapy treatments.

Methods: Ten cases were included in the study.

Volumetric modulated arc therapy (VMAT) to deliver nodal irradiation in breast cancer patients.

To evaluate feasibility, safety, toxicity profile and dosimetric results of volumetric modulated arc therapy (VMAT) to deliver regional nodal irradiation (RNI) after either mastectomy or breast conservation (BCS) in high-risk breast cancer patients. Between January 2015 and January 2017, a total of 45 patients were treated with VMAT to deliver RNI together with whole breast or post-mastectomy radiotherapy. The fractionation schedule comprised 50 Gy in 25 fractions given to supraclavicular and axillary apex nodes and to whole breast (after BCS) or chest wall (after mastectomy).

Incorporating FDG-PET-defined pelvic active bone marrow in the automatic treatment planning process of anal cancer patients undergoing chemo-radiation.

Background: To investigate whether the incorporation of FDG-PET into the automatic treatment planning process may be able to decrease the dose to active bone marrow (BM) for locally advanced anal cancer patients undergoing concurrent chemo-radiation (CHT-RT).

Methods: Ten patients with locally advanced anal cancer were selected. Bone marrow within the pelvis was outlined as the whole outer contour of pelvic bones or employing FDG-PET to identify active BM within osseous structures.

Frontiers in planning optimization for lung SBRT.

Emerging data are showing the safety and the efficacy of Stereotactic Body Radiation therapy (SBRT) in lung cancer management. In this context, the very high doses delivered to the Planning Target Volume, make the planning phase essential for achieving high dose levels conformed to the shape of the target in order to have a good prognosis for tumor control and to avoid an overdose in relevant healthy adjacent tissue. In this non-systematic review we analyzed the technological and the physics aspects of SBRT planning for lung cancer.

Small field output factors evaluation with a microDiamond detector over 30 Italian centers.

Purpose: The aim of the study was a multicenter evaluation of MLC&jaws-defined small field output factors (OF) for different linear accelerator manufacturers and for different beam energies using the latest synthetic single crystal diamond detector commercially available. The feasibility of providing an experimental OF data set, useful for on-site measurements validation, was also evaluated.

Methods: This work was performed in the framework of the Italian Association of Medical Physics (AIFM) SBRT working group.

Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT.

Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined.

Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using pcxmc software (pcxmc 2.

Lung stereotactic ablative body radiotherapy: A large scale multi-institutional planning comparison for interpreting results of multi-institutional studies.

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.

Multicentre treatment planning inter-comparison in a national context: The liver stereotactic ablative radiotherapy case.

Purpose: To compare five liver metastasis stereotactic ablative radiotherapy (SABR) plans optimised in fourteen centres with 3D-Conformal-RT, IMRT, VMAT, CyberKnife and Tomotherapy and identify possible dosimetric differences.

Methods: Dose prescription was 75 Gy in 3 fractions, normalised at 67%-95% isodose.

Results: Excluding few cases, all institutions achieved the planning objectives.

Optimized volumetric modulated arc therapy versus 3D-CRT for early stage mediastinal Hodgkin lymphoma without axillary involvement: a comparison of second cancers and heart disease risk.

Purpose: The purpose of this study was to evaluate the risks of second cancers and cardiovascular diseases associated with an optimized volumetric modulated arc therapy (VMAT) planning solution in a selected cohort of stage I/II Hodgkin lymphoma (HL) patients treated with either involved-node or involved-site radiation therapy in comparison with 3-dimensional conformal radiation therapy (3D-CRT).

Methods And Materials: Thirty-eight patients (13 males and 25 females) were included. Disease extent was mediastinum alone (n=8, 21.

Role of the technical aspects of hypofractionated radiation therapy treatment of prostate cancer: a review.

The increasing use of moderate (<35 fractions) and extreme (<5 fractions) hypofractionated radiation therapy in prostate cancer is yielding favorable results, both in terms of maintained biochemical response and toxicity. Several hypofractionation (HF) schemes for the treatment of prostate cancer are available, although there is considerable variability in the techniques used to manage intra-/interfraction motion and deliver radiation doses. We performed a review of the published studies on HF regimens as a topic of interest for the Stereotactic Ablative Radiotherapy working group, which is part of the Italian Association of Medical Physics.

Comparison of Gafchromic EBT2 and EBT3 for patient-specific quality assurance: cranial stereotactic radiosurgery using volumetric modulated arc therapy with multiple noncoplanar arcs.

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.

125I brachytherapy for localized prostate cancer: a single institution experience.

Aims And Background: To evaluate the clinical outcome of a cohort of localized prostate cancer patients treated with 125I permanent brachytherapy at the University of Turin.

Methods And Study Design: A retrospective analysis was carried out on 167 consecutive patients with early stage prostate adenocarcinoma who underwent 125I brachytherapy between January 2003 and December 2010. A minimum follow-up of ≥ 12 months was mandatory for inclusion.

Stereotactic body radiation therapy for early stage non-small cell lung cancer: results of a prospective trial.

Patients affected with early stage (IA-IB) non-small cell lung cancer (NSCLC), deemed medically inoperable, are usually treated by conventional 3D-CRT, with poor results in terms of local tumour control and survival. Hypofractionated stereotactic body radiation therapy (SBRT) appears to be a valid alternative option, with high rates of local control and promising survival rates according to recent reported series. We herein report the final results of a prospective phase II trial of SBRT in 62 stage I NSCLC patients, homogeneously treated with three fractions of 15Gy each, given every other day during a 1 week time, up to a total dose of 45Gy; dose was prescribed to the 80%-isodose encompassing planning target volume.

Absolute and relative dose measurements with Gafchromic EBT film for high energy electron beams with different doses per pulse.

The authors have evaluated the accuracy, in absolute and relative dose measurements, of the Gafchromic EBT film in pulsed high-energy electron beams. Typically, the electron beams used in radiotherapy have a dose-per-pulse value of less than 0.1 mGy/pulse.

Dosimetric predictors of radiation-induced lung injury in stereotactic body radiation therapy.

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.