Scanned Proton Beam Performance and Calibration of the Shanghai Advanced Proton Therapy Facility
Publication date: Available online 24 August 2019Source: MethodsXAuthor(s): Hang Shu, Chongxian Yin, Haiyang Zhang, Ming Liu, Manzhou Zhang, Liying Zhao, Kecheng Chu, Xiaolei Dai, Michael F. MoyersAbstractThe Shanghai Advanced Proton Therapy facility (SAPT) is a hospital-based facility that began construction in December of 2014 with commissioning of the first scanned proton beam line starting in October of 2017. Proton beams are extracted from a synchrotron accelerator with energies between 70 and 235 MeV. Beam delivery uses the modulated scanning and energy stacking techniques to produce a maximal scanning area of 40 × 30 cm2 at the iso-center. Prior to clinical use, the beam delivery system was characterized and calibrated following the guidelines of the IEC 62667 medical electronic equipment standard including the spot size in air, spot position, depth dose distributions, and lateral dose profiles, as well as the beam monitor calibrations following the IAEA TRS-398 recommendations with small differences.•The measured dosimetric results showed that the full width at half maximum (FWHM) for the beam spot size in air varied approximately from 6 mm to 13 mm. The dose fall-off (DDF) derived from the measured depth dose in water varied from 4.7 mm at 235 MeV to 0.7 mm at 70 MeV. The homogeneity of the scanned field was better than 2% for various energies as expected.•Furthermore, the beam reproducibi...
CONCLUSION: Combined proton-photon treatments may play a role in developing a new solution for proton therapy without a gantry. Optimal combinations improve on IMRT plans and reduce the risk of side effects while making protons available to more patients. PMID: 31923713 [PubMed - as supplied by publisher]
CONCLUSION: The proposed mp-MRI-guided DIL boost using proton radiation therapy is feasible without violating OAR constraints and demonstrates a potential clinical benefit by improving DIL TCP. This retrospective study suggested the use of IMPT-based DIL SIB may represent a strategy to improve tumor control. ADVANCES IN KNOWLEDGE: This study investigated the planning of mp-MRI-guided DIL boost in prostate proton radiation therapy and estimated its clinical impact with respect to TCP and NTCP. PMID: 31904261 [PubMed - as supplied by publisher]
CONCLUSIONS: The feasibility of using range probing to assess range errors was demonstrated. The theoretical uncertainty margins in the institution-specific setting potentially may be reduced by ∼25%. PMID: 31896099 [PubMed - as supplied by publisher]
Abstract We developed a synchrotron-based real-time-image gated-spot-scanning proton-beam therapy (RGPT) system and utilized it to clinically operate on moving tumors in the liver, pancreas, lung, and prostate. When the spot-scanning technique is linked to gating, the beam delivery time with gating can increase, compared to that without gating. We aim to clarify whether the total treatment process can be performed within approximately 30 min (the general time per session in several proton therapy facilities), even for gated-spot-scanning proton-beam delivery with implanted fiducial markers. Data from 152 pati...
CONCLUSION: We derived NTCP models to predict G2-RIA after PT, providing a comprehensive modelling framework for acute, late and permanent occurrences that, once externally validated, could be exploited for individualized scalp sparing treatment planning strategies in brain tumor patients. PMID: 31805517 [PubMed - as supplied by publisher]
CONCLUSIONS: If the in-air halo for low-energy proton beams is not fully modeled by the TPS, this could potentially lead to under-dosing small, shallow treatment volumes in PBS treatment plans. PMID: 31793202 [PubMed - as supplied by publisher]
ConclusionsVMAT and PBSPT for RNI in patients with high risk BC risks underdosage in the high AX, SCV, and IMN nodal regions unless comprehensive target delineation is performed.
CONCLUSIONS: Beam characterization and machine commissioning results, and the exhaustive end-to-end tests performed to assess the proper functionality of the system, confirm that it is safe and accurate to treat patients. ADVANCES IN KNOWLEDGE: This is the first paper addressing the beam commissioning and the beam validation of a compact, gantry-mounted, pencil beam scanning proton accelerator system with dynamic layer-by-layer multileaf collimation. PMID: 31782941 [PubMed - as supplied by publisher]
Conclusion: With a dosimetric success rate of 78.5–97.9%, this software may facilitate online adaptive IMPT of prostate cancer using a fast, free and open implementation.
CONCLUSIONS: This work demonstrate the clinical acceptability of substituting MR converted RSP images instead of CT for IMPT planning of prostate cancer. This further translates into higher contouring accuracy along with lesser imaging dose. PMID: 31734604 [PubMed - as supplied by publisher]