scholarly journals Skin Dosimetry with EBT3 Radiochromic Film in Radiotherapy of Parotid Cancer

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Mohammad Taghi Bahreyni Toossi
Keyword(s):  
Radiochromic Film ◽  
Parotid Cancer

Geometrical accuracy of the Novalis stereotactic radiosurgery system for trigeminal neuralgia

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 351-355 ◽  
Author(s):  
Javad Rahimian ◽  
Joseph C. Chen ◽  
Ajay A. Rao ◽  
Michael R. Girvigian ◽  
Michael J. Miller ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Trigeminal Neuralgia ◽  
Image Fusion ◽  
Stereotactic Radiosurgery ◽  
Ct Images ◽  
Radiochromic Film ◽  
Quality Assurance Program ◽  
Content Type ◽  
Geometrical Accuracy ◽  
Fine Print

Object. Stringent geometrical accuracy and precision are required in the stereotactic radiosurgical treatment of patients. Accurate targeting is especially important when treating a patient in a single fraction of a very high radiation dose (90 Gy) to a small target such as that used in the treatment of trigeminal neuralgia (3 to 4—mm diameter). The purpose of this study was to determine the inaccuracies in each step of the procedure including imaging, fusion, treatment planning, and finally the treatment. The authors implemented a detailed quality-assurance program. Methods. Overall geometrical accuracy of the Novalis stereotactic system was evaluated using a Radionics Geometric Phantom Chamber. The phantom has several magnetic resonance (MR) and computerized tomography (CT) imaging—friendly objects of various shapes and sizes. Axial 1-mm-thick MR and CT images of the phantom were acquired using a T1-weighted three-dimensional spoiled gradient recalled pulse sequence and the CT scanning protocols used clinically in patients. The absolute errors due to MR image distortion, CT scan resolution, and the image fusion inaccuracies were measured knowing the exact physical dimensions of the objects in the phantom. The isocentric accuracy of the Novalis gantry and the patient support system was measured using the Winston—Lutz test. Because inaccuracies are cumulative, to calculate the system's overall spatial accuracy, the root mean square (RMS) of all the errors was calculated. To validate the accuracy of the technique, a 1.5-mm-diameter spherical marker taped on top of a radiochromic film was fixed parallel to the x–z plane of the stereotactic coordinate system inside the phantom. The marker was defined as a target on the CT images, and seven noncoplanar circular arcs were used to treat the target on the film. The calculated system RMS value was then correlated with the position of the target and the highest density on the radiochromic film. The mean spatial errors due to image fusion and MR imaging were 0.41 ± 0.3 and 0.22 ± 0.1 mm, respectively. Gantry and couch isocentricities were 0.3 ± 0.1 and 0.6 ± 0.15 mm, respectively. The system overall RMS values were 0.9 and 0.6 mm with and without the couch errors included, respectively (isocenter variations due to couch rotation are microadjusted between couch positions). The positional verification of the marker was within 0.7 ± 0.1 mm of the highest optical density on the radiochromic film, correlating well with the system's overall RMS value. The overall mean system deviation was 0.32 ± 0.42 mm. Conclusions. The highest spatial errors were caused by image fusion and gantry rotation. A comprehensive quality-assurance program was developed for the authors' stereotactic radiosurgery program that includes medical imaging, linear accelerator mechanical isocentricity, and treatment delivery. For a successful treatment of trigeminal neuralgia with a 4-mm cone, the overall RMS value of equal to or less than 1 mm must be guaranteed.

Predicting optical densitometer response as a function of light source characteristics for radiochromic film dosimetry

1997 ◽  
Vol 24 (12) ◽  
pp. 1935-1942 ◽  
Author(s):  
L. E. Reinstein ◽  
G. R. Gluckman ◽  
H. I. Amols
Keyword(s):  
Light Source ◽  
Radiochromic Film ◽  
Film Dosimetry ◽  
Source Characteristics

High-resolution dosimetry using radiochromic film and a document scanner

1996 ◽  
Vol 41 (11) ◽  
pp. 2357-2365 ◽  
Author(s):  
M A Stevens ◽  
J R Turner ◽  
R P Hugtenburg ◽  
P H Butler
Keyword(s):  
High Resolution ◽  
Radiochromic Film

scholarly journals Strategy of Neck Dissection in Parotid Cancer.

2002 ◽  
Vol 105 (2) ◽  
pp. 178-187 ◽  
Author(s):  
Takeshi Beppu ◽  
Shin-etsu Kamata ◽  
Kazuyoshi Kawabata ◽  
Tomohiko Nigauri ◽  
Katsufumi Hoki ◽  
...  
Keyword(s):  
Neck Dissection ◽  
Parotid Cancer

Optical characterization of a radiochromic film by total reflectance and transmittance measurements

2004 ◽  
Vol 31 (7) ◽  
pp. 2147-2154 ◽  
Author(s):  
Franco Fusi ◽  
Luca Mercatelli ◽  
Giacomo Marconi ◽  
Giacomo Cuttone ◽  
Giovanni Romano
Keyword(s):  
Optical Characterization ◽  
Radiochromic Film ◽  
Total Reflectance

A new method of readout in radiochromic film dosimetry

1998 ◽  
Vol 43 (8) ◽  
pp. 2251-2263 ◽  
Author(s):  
Peer Oliver Kellermann ◽  
Adolf Ertl ◽  
Erich Gornik
Keyword(s):  
New Method ◽  
Radiochromic Film ◽  
Film Dosimetry

The determination of dose characteristics of ruthenium ophthalmic applicators using radiochromic film

1997 ◽  
Vol 24 (12) ◽  
pp. 2034-2037 ◽  
Author(s):  
G. Taccini ◽  
F. Cavagnetto ◽  
G. Coscia ◽  
S. Garelli ◽  
A. Pilot
Keyword(s):  
Radiochromic Film
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