Evaluation of a diode detector array for measurement of dynamic wedge dose distributions

1993 ◽  
Vol 20 (2) ◽  
pp. 381-382 ◽  
Author(s):  
Dennis D. Leavitt ◽  
Lars Larsson
Keyword(s):  
Detector Array ◽  
Dose Distributions ◽  
Dynamic Wedge ◽  
Diode Detector

A study of enhanced dynamic wedge dosimetry using a 2D ion chamber array detector

2015 ◽  
Vol 14 (4) ◽  
pp. 394-402
Author(s):  
S. A. Syam Kumar ◽  
P. Aparna ◽  
P. T. Anjana ◽  
C. P. Aswathi ◽  
G. P. Sitha
Keyword(s):  
Array Detector ◽  
Good Tool ◽  
Dose Distributions ◽  
Ion Chamber ◽  
Dynamic Wedge ◽  
Shoulder Region ◽  
Different Depths ◽  
Solid Water ◽  
Scanned Images ◽  
2D Array

AbstractThe purpose of this work was to study the dosimetric properties of the enhanced dynamic wedge using a Seven29 ion chamber array. The PTW Seven29 ion chamber array and solid water phantoms were used for the study. Primarily, the solid water phantoms with the two-dimensional (2D) array were scanned using a computed tomography scanner at different depths. Using these scanned images, planning was performed for different wedge angles at 6 and 15 MV. A dose of 100 CGy was delivered in each case. For each delivery, the required monitoring units (MUs) were calculated. Using the same setup with a Varian Clinac iX, the calculated MU was delivered for different wedge angles. Subsequently, the different wedged dose distributions that had been obtained were analysed using Verisoft software. A shoulder-like region was observed in the profile; this region reduced as depth increased. The percentage deviation between the planned and measured doses at the shoulder region fell within the range of 0·9–4·3%. The standard deviation between planned and measured doses at shoulder region in the profile fell within 0·08±0·02 at different depths. The standard deviations between planned and measured wedge factors for different depths (2·5, 5, 10 and 15 cm) were 0·0021, 0·0007, 0·0050 and 0·0001 for 6 MV and 0·0024, 0·0191, 0·0013 and 0·0005 for 15 MV, respectively. On the basis of the studies that we performed, it can be concluded that the 2D ion chamber array is a good tool for enhanced dynamic wedge dosimetry.

scholarly journals Evaluation and comparison of dose distributions for nasopharyngeal carcinoma patients treated by Jaws-Only IMRT technique and by 3D-CRT technique at Dong Nai General Hospital

2017 ◽  
Vol 1 (T4) ◽  
pp. 79-87
Author(s):  
Tai Thanh Duong ◽  
Son Dong Nguyen ◽  
Loan Thi Hong Truong ◽  
Trang Thi Hong Nguyen
Keyword(s):  
Radiation Therapy ◽  
Nasopharyngeal Carcinoma ◽  
General Hospital ◽  
Radiation Treatment ◽  
Planning System ◽  
Detector Array ◽  
Treatment Planning System ◽  
Dose Distributions ◽  
Array Measurements ◽  
3D Crt

The goal of radiation therapy is twofold: maximize the possibility of destroy malignant cells while minimizing the damage to healthy tissue. The introduction of intensity modulated radiation therapy (IMRT) technique has brought improvements in this goal. Multi-leaf collimator (MLC) is a useful tool for IMRT. However, the use of MLC is not necessarily mandatory. The Panther Treatment Planning System version 4.6, Prowess Inc., enables the implementation of this technique for accelerator without MLC (the socalled Jaws-Only IMRT technique). This study aims to evaluate the results of application of Jaws-only IMRT technique for nasopharyngeal carcinoma patients at Dong Nai general hospital. Twenty five patients were randomly selected for this study. For each patient, two plans were generated: 3D-CRT (Three-Dimensional Radiation Treatment) and JO-IMRT. The dose distributions, dose-volume histograms (DVH), conformity indexes (COIN), homogeneity indexes (HI) were used to compare between these two plans and find out the best plan. Pretreatment verifications were performed for all patients' plans using ion chamber (Farmer Type Chamber FC65-P, IBA), detector array (MapCHECK2, Sun Nuclear Corporation and Octavius 4D 1500, PTW). The average deviation between measurement and calculation for point dose was 2.3±1.1 %, within limit dose constraint. For detector array measurements, the gamma index with 3 % dose difference and 3 mm was higher than 95 %. The results showed that the JO-IMRT technique had generated better dose distribution in the target volume and reduced dose to healthy tissues compared to 3D-CRT.

Measuring dose distributions for enhanced dynamic wedges using a multichamber detector array

1997 ◽  
Vol 24 (9) ◽  
pp. 1515-1519 ◽  
Author(s):  
H. Helen Liu ◽  
Eugene P. Lief ◽  
Edwin C. McCullough
Keyword(s):  
Detector Array ◽  
Dose Distributions

SU-FF-T-195: Effect of Respiratory Gating On the Dose Distributions of Dynamic Wedge and IMRT Treatment Fields

2007 ◽  
Vol 34 (6Part10) ◽  
pp. 2446-2446
Author(s):  
P Lindsay ◽  
T Briere ◽  
P Balter ◽  
R Sadagopan ◽  
G Starkschall ◽  
...  
Keyword(s):  
Respiratory Gating ◽  
Dose Distributions ◽  
Dynamic Wedge

Machine QA for VMAT: a Rotational Synchronicity Test with the Delta4 Diode Detector Array

2011 ◽  
Vol 23 (3) ◽  
pp. S21
Author(s):  
W. Beasley ◽  
C. Boylan ◽  
A. Pooler ◽  
R. Mackay
Keyword(s):  
Detector Array ◽  
Diode Detector
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