A new sigmoidal function describing the small field dose profile data from a linear accelerator

1995 ◽  
Vol 22 (5) ◽  
pp. 543-547 ◽  
Author(s):  
Chan F. Lam
Keyword(s):  
Linear Accelerator ◽  
Small Field ◽  
Sigmoidal Function ◽  
Profile Data ◽  
Dose Profile

scholarly journals SMALL FIELD DOSIMETRY OF CONVERGENT BEAMS RADIOTHERAPY BY LINEAR ACCELERATOR

1994 ◽  
Vol 50 (4) ◽  
pp. 489-496
Author(s):  
YASUHIRO KAWAHARADA ◽  
ICHIROU KOYAMA ◽  
MASAMI YAMADA
Keyword(s):  
Linear Accelerator ◽  
Small Field ◽  
Small Field Dosimetry

Small field size dose-profile measurements using gel dosimeters, gafchromic films and micro-thermoluminescent dosimeters

2009 ◽  
Vol 44 (3) ◽  
pp. 249-256 ◽  
Author(s):  
C.J. Wong ◽  
T. Ackerly ◽  
C. He ◽  
W. Patterson ◽  
C.E. Powell ◽  
...  
Keyword(s):  
Field Size ◽  
Small Field ◽  
Thermoluminescent Dosimeters ◽  
Dose Profile ◽  
Gafchromic Films

scholarly journals Grid Monte Carlo Simulation of a Medical Linear Accelerator

2018 ◽  
Vol 3 (12) ◽  
pp. 40-43 ◽  
Author(s):  
Didi Samir ◽  
Mustapha Zerfaoui ◽  
Abdelilah Moussa ◽  
Yassine Benkhouya ◽  
Mehdi El Ouartiti
Keyword(s):  
Monte Carlo ◽  
Linear Accelerator ◽  
Field Size ◽  
Dose Profile ◽  
Depth Dose ◽  
Grid Simulation ◽  
Medical Linear Accelerator ◽  
Measured Dose ◽  
Better Than ◽  
Good Agreement

A full grid simulation of the head of an Elekta Synergy Platform medical linear accelerator is performed using the Geant4 Monte Carlo platform. The simulation includes all components of the accelerator head and a homogeneous water phantom. Results in terms of depth doses and lateral dose profiles are presented for 6 MV photon beam with the 10x10 cm2 reference field size at 100 cm distance from the source. Overall, a good agreement with the measured dose data is achieved with a precision better than 0.93% and 2.63% for the depth dose profile and lateral dose profiles respectively.

Feasibility of lateral dose profile measurements in a small field using TLDs

2015 ◽  
Vol 60 (3) ◽  
pp. N47-N57
Author(s):  
Bailin Zhang ◽  
Jinhan Zhu ◽  
Yinghui Li ◽  
Shaowen Chen ◽  
Lixin Chen ◽  
...  
Keyword(s):  
Small Field ◽  
Dose Profile

Total scatter factor for small fields in radiotherapy: a dosimetric comparison

2017 ◽  
Vol 17 (3) ◽  
pp. 292-296
Author(s):  
Qurat-ul-ain Shamsi ◽  
Saeed Ahmad Buzdar ◽  
Saima Altaf ◽  
Atia Atiq ◽  
Maria Atiq ◽  
...  
Keyword(s):  
Linear Accelerator ◽  
Intensity Modulated Radiotherapy ◽  
Volume Averaging ◽  
Small Field ◽  
Scatter Factor ◽  
Small Field Dosimetry ◽  
Intensity Modulated ◽  
Target Volumes ◽  
Small Fields ◽  
The Given

AbstractPurposeSmall field dosimetry is complicated and accuracy in the measurement of total scatter factor (TSF) is crucial for dosimetric calculations, in making optimum intensity-modulated radiotherapy plans for treating small target volumes. In this study, we intended to determine the TSF measuring properties of CC01 and CC04 detectors for field sizes ranging from sub-centimetre to the centimetre fields.Material and methodsCC01 and CC04 chamber detectors were used to measure TSF for 6 and 18 MV photon beam delivered from the linear accelerator, through small fields in a water phantom. Small fields were created by collimator jaws and multi-leaf collimators separately, with field sizes ranging from 0·6 to 10 cm2 and 0·5 to 20 cm2, respectively.ResultsCC01 measured TSF at all the given field sizes created by jaws and multi-leaf collimators for both 6 and 18 MV beams whereas CC04 could not measure TSF for field sizes <1 cm2 due to volume averaging and perturbation effects.ConclusionCC01 was shown to be effective for measurement of TSF in sub-centimetre field sizes. CC01 can be employed to measure other dosimetric quantities in small fields using different energy beams.

scholarly journals Assessing small-field output factors using a 2D monolithic diode array on a beam-matched Elekta linear accelerator

2020 ◽  
Vol 1662 ◽  
pp. 012024
Author(s):  
L Muñoz ◽  
M Petasecca ◽  
P Metcalfe ◽  
J Bucci ◽  
M Jackson ◽  
...  
Keyword(s):  
Linear Accelerator ◽  
Diode Array ◽  
Small Field ◽  
Output Factors

scholarly journals An Empirical Model for Describing the Small Field Penumbra in Radiation Therapy

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Shi-Qiang Tang ◽  
Yee-Min Jen ◽  
Jia-Ming Wu
Keyword(s):  
Empirical Model ◽  
Geometric Analysis ◽  
Least Square ◽  
Model Parameters ◽  
Square Root ◽  
Small Field ◽  
Estimation Model ◽  
Mathematical Methods ◽  
Dose Profile ◽  
Penumbra Region

Purpose. We developed a mathematic empirical model for describing the small field penumbra in order to analyze the potential dose perturbation caused by overlapping field to avoid the dose calculation errors in linear accelerator-based radiosurgery. Materials and methods. A ball phantom was fabricated for measuring penumbra at 4 different gantry angles in the coplanar plane. A least square root estimation (LSRE) Model was created to fit the measured penumbra dose profile and to predict the penumbra dose profile at any gantry angles. The Sum of Squared Errors (SSE) was used for finding the parameters n and t for the best fitting of the LSRE model. Geometric and mathematical methods were used to derive the model parameters. Results. The results showed that the larger the gantry angle of the field, the more the expansion of the penumbra dose profile. The least square root estimation model for describing small field penumbra is as follows: PenumbraDš=T⋅1/2⋅1−š/n+š2+t where PenumbraDš denotes the dose profile D(š) at the penumbra region, T is the penumbra height (usually in scalar 100), n is the parameter for curvature, š = x − Wd/2 (x and š are the values in cm on x-axis), and t is the radiation transmission of the collimator. Geometric analysis establishes the correlation between the penetration depth of the exposure and its effect on the penumbra region in ball phantom. The penumbra caused by an exposure at any arbitrary angles can be geometrically derived by using a one-variable quadratic equation. Conclusion. The dose distribution in penumbra region of small field can be created by the LSRE model and the potential overdosage or underdosage owing to overlapping field perturbation can be estimated.

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