RuPAC2021 - List of Authors (Chernyaev, A.P.)

Paper	Title	Page
MOPSA45	Experimental Simulation of Volume Repainting Technique at Proton Synchrotron in Context of Spot Scanning Proton Therapy	192
	Belikhin, M.A. Belikhin, A.P. Chernyaev MSU, Moscow, Russia A.A. Pryanichnikov, A.E. Shemyakov PhTC LPI RAS, Protein, Moscow region, Russia
	Background: Reduction the influence of respiration-induced intrafractional motion of tissues is one of the main tasks of proton therapy with a scanning beam. Repainting is one of the techniques of motion compensation. It consists in multiple repeated irradiations of the entire volume or individual iso-energy layers with a dose that is a multiple of the prescribed dose. As a result, the dose is averaged, which leads to an increase in the uniformity of the dose field. Purpose: Experimental simulation of volume sequential repainting and dosimetric estimation of its capabilities in the context of spot scanning proton therapy (SSPT) using dynamic phantom. Materials and Methods: Simulation of respiration-like translational motion is performed using the non-anthropomorphic water dynamic phantom. Target of this phantom is compatible with EBT-3 films. Estimation of repainting technique is based on the analysis of average dose, dose uniformity in region of interests located within planning target volume, and dose gradients. Results: Repainting was estimated for motion with amplitudes of 2, 5, 10 mm with different number of iterations up to 10 at the prescribed dose of 6 Gy. This one increased the uniformity of the dose field from 85,9% to 96,0% at an amplitude of 10 mm and 10 iterations. Conclusions: Volume repainting improves the uniformity of dose distribution. However, the irradiation time increases, and the dose gradients deteriorate in proportion to the amplitude of motion.
DOI •	reference for this paper ※ doi:10.18429/JACoW-RuPAC2021-MOPSA45
About •	Received ※ 28 September 2021 — Revised ※ 29 September 2021 — Accepted ※ 09 October 2021 — Issued ※ 16 October 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPSC55	Development of the Low Intensity Extraction Beam Control System at Protom Synchrotron for Proton Radiography Implementation	439
	A.A. Pryanichnikov, Belikhin, M.A. Belikhin, A.E. Shemyakov, P.B. Zhogolev PhTC LPI RAS, Protvino, Russia Belikhin, M.A. Belikhin, A.A. Pryanichnikov, A.E. Shemyakov, P.B. Zhogolev Protom Ltd., Protvino, Russia Belikhin, M.A. Belikhin, A.P. Chernyaev, A.A. Pryanichnikov MSU, Moscow, Russia V. Rykalin ProtonVDA, Naperville, Illinois, USA
	Currently, the calculation of the proton range in patients receiving proton therapy is based on the conversion of Hounsfield CT units of the patient’s tissues into the relative stopping power of protons. Proton radiography is able to reduce these uncertainties by directly measuring proton stopping power. However, proton imaging systems cannot handle the proton beam intensities used in standard proton therapy. This means that for implementation of proton radiography it is necessary to reduce the intensity of the protons significantly. This study demonstrates the current version of the new beam control system for low proton intensity extraction. The system is based on automatic removable unit with special luminescence film and sensitive photoreceptor. Using of the removable module allows us to save initial parameters of the therapy beam. Remote automatic control of this unit will provide switch therapy and imaging modes between synchrotron cycles. The work describes algorithms of low flux beam control, calibration procedures and experimental measurements. Measurements and calibration procedures were performed with certified Protom Faraday Cup, PTW Bragg Peak Chamber and specially designed experimental external detector. The development can be implemented in any proton therapy complexes based on the Protom synchrotron. This allow us to use initial synchrotron beam as a tool for patient verification and to eliminate proton range uncertainties.
DOI •	reference for this paper ※ doi:10.18429/JACoW-RuPAC2021-WEPSC55
About •	Received ※ 17 September 2021 — Accepted ※ 20 September 2021 — Issued ※ 04 October 2021
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Experimental Simulation of Volume Repainting Technique at Proton Synchrotron in Context of Spot Scanning Proton Therapy

192

Belikhin, M.A. Belikhin, A.P. Chernyaev
MSU, Moscow, Russia
A.A. Pryanichnikov, A.E. Shemyakov
PhTC LPI RAS, Protein, Moscow region, Russia

Background: Reduction the influence of respiration-induced intrafractional motion of tissues is one of the main tasks of proton therapy with a scanning beam. Repainting is one of the techniques of motion compensation. It consists in multiple repeated irradiations of the entire volume or individual iso-energy layers with a dose that is a multiple of the prescribed dose. As a result, the dose is averaged, which leads to an increase in the uniformity of the dose field. Purpose: Experimental simulation of volume sequential repainting and dosimetric estimation of its capabilities in the context of spot scanning proton therapy (SSPT) using dynamic phantom. Materials and Methods: Simulation of respiration-like translational motion is performed using the non-anthropomorphic water dynamic phantom. Target of this phantom is compatible with EBT-3 films. Estimation of repainting technique is based on the analysis of average dose, dose uniformity in region of interests located within planning target volume, and dose gradients. Results: Repainting was estimated for motion with amplitudes of 2, 5, 10 mm with different number of iterations up to 10 at the prescribed dose of 6 Gy. This one increased the uniformity of the dose field from 85,9% to 96,0% at an amplitude of 10 mm and 10 iterations. Conclusions: Volume repainting improves the uniformity of dose distribution. However, the irradiation time increases, and the dose gradients deteriorate in proportion to the amplitude of motion.

DOI •

reference for this paper ※ doi:10.18429/JACoW-RuPAC2021-MOPSA45

About •

Received ※ 28 September 2021 — Revised ※ 29 September 2021 — Accepted ※ 09 October 2021 — Issued ※ 16 October 2021

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPSC55

Development of the Low Intensity Extraction Beam Control System at Protom Synchrotron for Proton Radiography Implementation

439

A.A. Pryanichnikov, Belikhin, M.A. Belikhin, A.E. Shemyakov, P.B. Zhogolev
PhTC LPI RAS, Protvino, Russia
Belikhin, M.A. Belikhin, A.A. Pryanichnikov, A.E. Shemyakov, P.B. Zhogolev
Protom Ltd., Protvino, Russia
Belikhin, M.A. Belikhin, A.P. Chernyaev, A.A. Pryanichnikov
MSU, Moscow, Russia
V. Rykalin
ProtonVDA, Naperville, Illinois, USA

Currently, the calculation of the proton range in patients receiving proton therapy is based on the conversion of Hounsfield CT units of the patient’s tissues into the relative stopping power of protons. Proton radiography is able to reduce these uncertainties by directly measuring proton stopping power. However, proton imaging systems cannot handle the proton beam intensities used in standard proton therapy. This means that for implementation of proton radiography it is necessary to reduce the intensity of the protons significantly. This study demonstrates the current version of the new beam control system for low proton intensity extraction. The system is based on automatic removable unit with special luminescence film and sensitive photoreceptor. Using of the removable module allows us to save initial parameters of the therapy beam. Remote automatic control of this unit will provide switch therapy and imaging modes between synchrotron cycles. The work describes algorithms of low flux beam control, calibration procedures and experimental measurements. Measurements and calibration procedures were performed with certified Protom Faraday Cup, PTW Bragg Peak Chamber and specially designed experimental external detector. The development can be implemented in any proton therapy complexes based on the Protom synchrotron. This allow us to use initial synchrotron beam as a tool for patient verification and to eliminate proton range uncertainties.

DOI •

reference for this paper ※ doi:10.18429/JACoW-RuPAC2021-WEPSC55

About •

Received ※ 17 September 2021 — Accepted ※ 20 September 2021 — Issued ※ 04 October 2021

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)