Premium
Sci‐Sat AM (2) Therapy‐07: Feasibility of 3D ultrasound guided brachytherapy for lung cancer using a porcine lung tumour model
Author(s) -
Lewis C,
Bickhram M,
Yu E,
Wei Z,
Hornblower V,
Malthaner R
Publication year - 2006
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2244703
Subject(s) - brachytherapy , ultrasound , dosimetry , medicine , nuclear medicine , radiation therapy , radiation treatment planning , radiology , lung cancer , lung , biomedical engineering , pathology
The standard treatment of localized early stage non‐small cell lung cancer is surgical resection. However, most patients are not candidates for surgery due to poor lung function and comorbidities. Minimally invasive interstitial brachytherapy may be an option for these patients. An in vivo dosimetry test box was constructed to simulate the thoracic cavity and allow 3D ultrasound imaging of the brachytherapy needles. The box stabilizes the ultrasound probe and facilitates insertion of brachytherapy needles parallel to the probe axis. Seeds were implanted, targeted at the centre of a 1.5 cm agar sphere in 6% gelatin and then imaged using the 3D ultrasound and CT scans. The dosimetric impact of seed location was examined using Theraplan Plus. The DVH (dose volume histogram) was calculated assuming an I 125seed activity that would cover the sphere with an arbitrary D90 of 25Gy if the seed was located at the centre of the sphere. DVH D90 values for the actual implanted seed positions will be presented comparing CT to ultrasound. This procedure was repeated in an ex vivo lung tumour model consisting of agar spheres implanted into excised collapsed porcine lungs. Initial 3D ultrasound measurements were done with a probe designed for prostate brachytherapy. However, the measurements will be repeated with a smaller diameter thoracoscopic ultrasound probe that will be used clinically. This pilot work demonstrates the feasibility of using 3D ultrasound to target seed insertion and calculate dosimetry in a brachytherapy lung tumour model.