scholarly journals Small spot size versus large spot size: Effect on plan quality for lung cancer in pencil beam scanning proton therapy

2022 ◽  
Author(s):  
Suresh Rana ◽  
Anatoly B. Rosenfeld
Keyword(s):  
Lung Cancer ◽  
Size Effect ◽  
Proton Therapy ◽  
Spot Size ◽  
Pencil Beam ◽  
Plan Quality ◽  
Beam Scanning ◽  
Large Spot ◽  
Pencil Beam Scanning ◽  
Small Spot

scholarly journals Impact of Spot Size and Beam-Shaping Devices on the Treatment Plan Quality for Pencil Beam Scanning Proton Therapy

2016 ◽  
Vol 95 (1) ◽  
pp. 190-198 ◽  
Author(s):  
Maryam Moteabbed ◽  
Torunn I. Yock ◽  
Nicolas Depauw ◽  
Thomas M. Madden ◽  
Hanne M. Kooy ◽  
...  
Keyword(s):  
Proton Therapy ◽  
Treatment Plan ◽  
Spot Size ◽  
Beam Shaping ◽  
Pencil Beam ◽  
Plan Quality ◽  
Beam Scanning ◽  
Pencil Beam Scanning

scholarly journals Clinical Outcomes of Pencil Beam Scanning Proton Therapy in Locally Advanced Non-Small Cell Lung Cancer: Propensity Score Analysis

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3497
Author(s):  
Nalee Kim ◽  
Jae Myoung Noh ◽  
Woojin Lee ◽  
Byoungsuk Park ◽  
Hongryull Pyo
Keyword(s):  
Lung Cancer ◽  
Propensity Score ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Proton Therapy ◽  
Small Cell ◽  
Pencil Beam ◽  
Small Cell Lung ◽  
Beam Scanning ◽  
Pencil Beam Scanning

This study compared the efficacy and safety of pencil beam scanning proton therapy (PBSPT) versus intensity-modulated (photon) radiotherapy (IMRT) in patients with stage III non-small cell lung cancer (NSCLC). We retrospectively reviewed 219 patients with stage III NSCLC who received definitive concurrent chemoradiotherapy between November 2016 and December 2018. Twenty-five patients (11.4%) underwent PBSPT (23 with single-field optimization) and 194 patients (88.6%) underwent IMRT. Rates of locoregional control (LRC), overall survival, and acute/late toxicities were compared between the groups using propensity score-adjusted analyses. Patients treated with PBSPT were older (median: 67 vs. 62 years) and had worse pulmonary function at baseline (both FEV1 and DLCO) compared to those treated with IMRT. With comparable target coverage, PBSPT exhibited superior sparing of the lung, heart, and spinal cord to radiation exposure compared to IMRT. At a median follow-up of 21.7 (interquartile range: 16.8–26.8) months, the 2-year LRC rates were 72.1% and 84.1% in the IMRT and PBSPT groups, respectively (p = 0.287). The rates of grade ≥ 3 esophagitis were 8.2% and 20.0% after IMRT and PBSPT (p = 0.073), respectively, while corresponding rates of grade ≥ 2 radiation pneumonitis were 28.9% and 16.0%, respectively (p = 0.263). PBSPT appears to be an effective and safe treatment technique even for patients with poor lung function, and it does not jeopardize LRC.

scholarly journals Innovations and the Use of Collimators in the Delivery of Pencil Beam Scanning Proton Therapy

2021 ◽  
Vol 8 (1) ◽  
pp. 73-83
Author(s):  
Daniel E. Hyer ◽  
Laura C. Bennett ◽  
Theodore J. Geoghegan ◽  
Martin Bues ◽  
Blake R. Smith
Keyword(s):  
Proton Therapy ◽  
Spot Size ◽  
Low Energy ◽  
Healthy Tissue ◽  
Pencil Beam ◽  
New Paradigm ◽  
Beam Scanning ◽  
Multileaf Collimators ◽  
Pencil Beam Scanning ◽  
Tissue Sparing

Abstract Purpose The development of collimating technologies has become a recent focus in pencil beam scanning (PBS) proton therapy to improve the target conformity and healthy tissue sparing through field-specific or energy-layer–specific collimation. Given the growing popularity of collimators for low-energy treatments, the purpose of this work was to summarize the recent literature that has focused on the efficacy of collimators for PBS and highlight the development of clinical and preclinical collimators. Materials and Methods The collimators presented in this work were organized into 3 categories: per-field apertures, multileaf collimators (MLCs), and sliding-bar collimators. For each case, the system design and planning methodologies are summarized and intercompared from their existing literature. Energy-specific collimation is still a new paradigm in PBS and the 2 specific collimators tailored toward PBS are presented including the dynamic collimation system (DCS) and the Mevion Adaptive Aperture. Results Collimation during PBS can improve the target conformity and associated healthy tissue and critical structure avoidance. Between energy-specific collimators and static apertures, static apertures have the poorest dose conformity owing to collimating only the largest projection of a target in the beam's eye view but still provide an improvement over uncollimated treatments. While an external collimator increases secondary neutron production, the benefit of collimating the primary beam appears to outweigh the risk. The greatest benefit has been observed for low- energy treatment sites. Conclusion The consensus from current literature supports the use of external collimators in PBS under certain conditions, namely low-energy treatments or where the nominal spot size is large. While many recent studies paint a supportive picture, it is also important to understand the limitations of collimation in PBS that are specific to each collimator type. The emergence and paradigm of energy-specific collimation holds many promises for PBS proton therapy.

SU-D-BRE-03: Dosimetric Impact of In-Air Spot Size Variations for Commissioning a Room-Matched Beam Model for Pencil Beam Scanning Proton Therapy

2014 ◽  
Vol 41 (6Part3) ◽  
pp. 112-112
Author(s):  
Y Zhang ◽  
A Giebeler ◽  
A Mascia ◽  
F Piskulich ◽  
L Perles ◽  
...  
Keyword(s):  
Proton Therapy ◽  
Spot Size ◽  
Beam Model ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Pencil Beam Scanning
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