A CT-assisted method of dosimetry in brachytherapy of lung cancer. Rotterdam Oncological Thoracic Study Group.
Radiother Oncol
; 55(1): 75-80, 2000 Apr.
Article
in En
| MEDLINE
| ID: mdl-10788691
ABSTRACT
BACKGROUND:
The toxicity of endobronchial brachytherapy (EB), in particular fatal haemoptysis and bronchial wall necrosis, has been correlated with the total dose, fraction size, volume encompassed by the 100% isodose, and a proximal tumor location. We describe a CT-based planning method which, by improving target volume definition and volumetric dose information, can improve the therapeutic ratio of EB. MATERIALS ANDMETHODS:
Sixteen CT-assisted EB procedures were performed in patients who were treated with palliative high-dose rate EB. The CT data were used to analyze applicator position in relation to anatomy. An example of a three-dimensional optimized treatment plan was generated and analyzed using different types of dose-volume histograms.RESULTS:
The procedure was well tolerated by patients and no post-procedure complications were observed. The bronchial applicator was eccentrically positioned at the level of the carina/mainstem bronchus in 12 (of 14) CT scans. A planning CT prior to EB was not found to be useful as the final target volume and/or the final applicator position were not reliably predicted before the therapeutic bronchoscopy. CT-scans performed with the applicator in situ allowed the bronchial segments in the target volume to be identified and enabled dose prescription to the bronchial mucosa.CONCLUSIONS:
CT-assisted EB is feasible and underlines the need for using centered applicators for proximally located tumors. By enabling accurate mucosal dose prescription, CT-assisted EB may reduce the toxicity of fractionated EB in the curative setting. However, faster on-line EB treatment planning is needed for the routine clinical application of this technique.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Radiotherapy Dosage
/
Radiotherapy Planning, Computer-Assisted
/
Brachytherapy
/
Tomography, X-Ray Computed
/
Lung Neoplasms
Type of study:
Etiology_studies
/
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
Radiother Oncol
Year:
2000
Document type:
Article
Affiliation country:
Netherlands