Effect of shaping accessories (protective blocks and boluses) on dose distribution in the radiation field during remote radiation therapy

1992 ◽  
Vol 26 (6) ◽  
pp. 306-306
Author(s):  
I. A. Karpova ◽  
G. G. Pichugina ◽  
N. A. Lyutova
Keyword(s):  
Radiation Therapy ◽  
Radiation Field ◽  
Dose Distribution ◽  
Remote Radiation

PO-1606: Measurement of dose distribution of cardiosynchronous brain motion in microbeam radiation therapy

2020 ◽  
Vol 152 ◽  
pp. S874
Author(s):  
M. Petasecca ◽  
M. Duncan ◽  
M. Donzelli ◽  
P. Pellicioli ◽  
E. Brauer-Krisch ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Dose Distribution ◽  
Microbeam Radiation Therapy ◽  
Brain Motion

Dose distribution from x-ray microbeam arrays applied to radiation therapy: An EGS4 Monte Carlo study

2005 ◽  
Vol 32 (8) ◽  
pp. 2455-2463 ◽  
Author(s):  
M. De Felici ◽  
R. Felici ◽  
M. Sanchez del Rio ◽  
C. Ferrero ◽  
T. Bacarian ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Radiation Therapy ◽  
Dose Distribution ◽  
Monte Carlo Study ◽  
X Ray

Analysis of the Physical and Radiobiological Equivalence of the Calculated and Measured Dose Distributions for Prostate Stereotactic Radiotherapy

2021 ◽  
Vol 66 (3) ◽  
pp. 68-75
Author(s):  
E. Sukhikh ◽  
L. Sukhikh ◽  
A. Vertinsky ◽  
P. Izhevsky ◽  
I. Sheino ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Dose Distribution ◽  
Three Dimensional ◽  
Anterior Wall ◽  
Dose Distributions ◽  
Stereotactic Radiation ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Gamma Index ◽  
Measured Dose

Purpose: Carrying out the analysis of the physical and radiobiological equivalence of dose distributions obtained during the planning of hypofractionated stereotactic radiation therapy of the prostate cancer and verification using a three-dimensional cylindrical dosimeter. Material and Methods: Based on the anatomical data of twelve patients diagnosed with prostate carcinoma, stage T2N0M0 with low risk, plans were developed for stereotactic radiation therapy with volumetric modulates arc therapy (VMAT). The dose per fraction was 7,25 Gy for 5 fractions (total dose 36,25 Gy) with a normal photon energy of 10 MV. The developed plans were verified using a three-dimensional cylindrical ArcCHECK phantom. During the verification process, the three-dimensional dose distribution in the phantom was measured, based on which the values of the three-dimensional gamma index and the dose–volume histogram within each contoured anatomical structures were calculated with 3DVH software. The gamma index value γ (3 %, 2 mm, GN) at a threshold equal to 20 % of the dose maximum of the plan and the percentage of coincidence of points at least 95 % was chosen as a criterion of physical convergence of the calculated and measured dose distribution according to the recommendations of AAPM TG-218. To analyze the radiobiological equivalence of the calculated and measured dose distribution, the local control probability (TCP) and normal tissue complication probability (NTCP) criteria were used based on the calculated and measured dose–volume histograms. Contours of the target (PTV) and the anterior wall of the rectum were used for the analysis. The approach based on the concept of equivalent uniform dose (EUD) by A. Niemierko was used to calculate the values of TCP/NTCP criteria. Results: The results of physical convergence of plans for all patients on the contour of the whole body were higher than 95 % for the criteria γ (3 %, 2 mm, GN). The convergence along the PTV contour is in the range (75.5–95.2)%. The TCP and NTCP values obtained from the measured dose-volume histograms were higher than the planned values for all patients. It was found that the accelerator delivered a slightly higher dose to the PTV and the anterior wall of the rectum than originally planned. Conclusion: The capabilities of modern dosimetric equipment allow us move to the verification of treatment plans based on the analysis of TCP / NTCP radiobiological equivalence, taking into account the individual characteristics of the patient and the capabilities of radiation therapy equipment.

scholarly journals 352. Definitive Radiation Therapy for Stage I, II Breast Cancer : Dose Distribution of Open Field Beam-(Part 3)

1991 ◽  
Vol 47 (8) ◽  
pp. 1383
Author(s):  
Manabu Nakata ◽  
Takashi Okada ◽  
Shinsuke Yano ◽  
Naomi Enoki ◽  
Hiroki Nohara
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Open Field ◽  
Dose Distribution ◽  
Stage I

Khảo sát một số đặc tính bức xạ của buồng ion hóa CC13 và diode bán dẫn razor đối với các chùm photon kích thước nhỏ trên máy gia tốc tuyến tính xạ trị Clinac IX

2020 ◽  
Author(s):  
Tu Vu Ngoc
Keyword(s):  
Radiation Field ◽  
Dose Response ◽  
Dose Distribution ◽  
Ionization Chamber ◽  
Field Size ◽  
Photon Beams ◽  
Silicon Diode ◽  
Depth Dose ◽  
The Difference

Purpose: Compare percent depth dose (PDD) and off-center ratio (OCR) measured by the CC13 ionization chamber and the RAZOR silicon diode in small photon beams. Method and Materials: Some dosimetric characteristics, such as PDD, OCR, penumbra and radiation field size, were considered in this study for 2x2, 3x3, and 4x4 cm2 field sizes. We used the CC13 ionization chamber and the RAZOR silicon diode to measure dose distribution with depth along the axis and off-center of the beam. From the results obtained, the team investigated the differences in radiation parameters measured by the two types of probes above. Results: There are significant differences in the radiation parameters investigated for the CC13 ionization chamber and the RAZOR silicon diode, especially the width of penumbra. For PDD curves, the difference is less than 5% from dmax to 30 cm, however the difference becomes greater in the build-up region, which reaches to 33% at the water phatom surface. The width of penumbra measured by CC13 is always larger than that of RAZOR, the ratio of the penumbra width between two detectors is 1.8 and 1.3 for energies of 6 MV and 15 MV, respectively. Conclusion: The RAZOR silicon diode has better dose response than the CC13 ionization chamber for measuring the PDD and the OCR in small photon beams.

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