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SU-D-213AB-05: Commissioning a CT Compatible LDR T&O Applicator Using Analytical Calculation with ID and 3D Dosimetry.

Publication ,  Journal Article
Adamson, J; Newton, J; Steffey, B; Cai, J; Adamovics, J; Oldham, M; Chino, J; Craciunescu, O
Published in: Med Phys
June 2012

PURPOSE: To determine the characteristics of a new commercially available CT-compatible LDR Tandem and Ovoid (T&O) applicator using 3D dosimetry. METHODS: We characterized source attenuation through the asymmetric gold shielding in the buckets by measuring dose with diode and 3D dosimetry and compared to an analytical line integral calculation. For 3D dosimetry, a cylindrical PRESAGE dosimeter (9.5cm diameter, 9.2cm height) with a central 6mm channel bored for source placement was scanned with the Duke Large field of view Optical CT-Scanner (DLOS) before and after delivering a nominal 7.7Gy at a distance of 1 cm using a Cs-137 source loaded in the bucket. The optical CT scan time lasted approximately 15 minutes during which 720 projections were acquired at 0.5° increments, anda 3D dose distribution was reconstructed with a 0.5mm3 isotropic voxel size. The 3D dose distribution was applied to a CT-based T&O implant to determine effect of ovoid shielding on the dose delivered to ICRU 38 Point A as well as D2cc of the bladder, rectum, bowel, and sigmoid. RESULTS: Dose transmission through the gold shielding at a radial distance of 1-3cm from midplane of the source was 86.6%, 86.1, and 87.0% for analytical calculation, diode, and 3D dosimetry, respectively. For the gold shielding of the bucket, dose transmission calculated using the 3D dosimetrymeasurement was found to be lowest at oblique angles from the bucket witha minimum of ∼51%. For the patient case, attenuation from the buckets leadto a decrease in average Point A dose of ∼4% and decrease in D2cc to bladder, rectum, sigmoid, and bowel of 2%, 15%, 2%, and 7%, respectively. CONCLUSIONS: The measured 3D dose distribution provided unique insight to the dosimetry and shielding characteristics of the investigated applicator, the technique for which can be applied to commissioning of other brachytherapy applicators. John Adamovics is the owner of Heuris Pharma LLC. Partially supported by NIH Grant R01 CA100835-01.

Duke Scholars

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2012

Volume

39

Issue

6Part3

Start / End Page

3612

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Adamson, J., Newton, J., Steffey, B., Cai, J., Adamovics, J., Oldham, M., … Craciunescu, O. (2012). SU-D-213AB-05: Commissioning a CT Compatible LDR T&O Applicator Using Analytical Calculation with ID and 3D Dosimetry. Med Phys, 39(6Part3), 3612. https://doi.org/10.1118/1.4734665
Adamson, J., J. Newton, B. Steffey, J. Cai, J. Adamovics, M. Oldham, J. Chino, and O. Craciunescu. “SU-D-213AB-05: Commissioning a CT Compatible LDR T&O Applicator Using Analytical Calculation with ID and 3D Dosimetry.Med Phys 39, no. 6Part3 (June 2012): 3612. https://doi.org/10.1118/1.4734665.
Adamson J, Newton J, Steffey B, Cai J, Adamovics J, Oldham M, et al. SU-D-213AB-05: Commissioning a CT Compatible LDR T&O Applicator Using Analytical Calculation with ID and 3D Dosimetry. Med Phys. 2012 Jun;39(6Part3):3612.
Adamson, J., et al. “SU-D-213AB-05: Commissioning a CT Compatible LDR T&O Applicator Using Analytical Calculation with ID and 3D Dosimetry.Med Phys, vol. 39, no. 6Part3, June 2012, p. 3612. Pubmed, doi:10.1118/1.4734665.
Adamson J, Newton J, Steffey B, Cai J, Adamovics J, Oldham M, Chino J, Craciunescu O. SU-D-213AB-05: Commissioning a CT Compatible LDR T&O Applicator Using Analytical Calculation with ID and 3D Dosimetry. Med Phys. 2012 Jun;39(6Part3):3612.

Published In

Med Phys

DOI

EISSN

2473-4209

Publication Date

June 2012

Volume

39

Issue

6Part3

Start / End Page

3612

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • 5105 Medical and biological physics
  • 4003 Biomedical engineering
  • 1112 Oncology and Carcinogenesis
  • 0903 Biomedical Engineering
  • 0299 Other Physical Sciences