Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
ORIGINAL ARTICLE
Year : 2008  |  Volume : 4  |  Issue : 4  |  Page : 156-163

Modeling correlation indices between bladder and Foley's catheter balloon dose with CT-based planning using limited CT slices in intracavitary brachytherapy for carcinoma of cervix


Department of Radiotherapy, Postgraduate Institute of Medical Education and Research, Chandigarh-160 012, India

Correspondence Address:
Arun S Oinam
Department of Radiotherapy, PGIMER, Chandigarh-160 012
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0973-1482.44285

Rights and Permissions

Purpose: To derive and validate an index to correlate the bladder dose with the catheter balloon dose using limited computed tomography (CT) slices. Materials and Methods: Applicator geometry reconstructed from orthogonal radiographs were back-projected on CT images of the same patients for anatomy-based dosimetric evaluation. The correlation indices derived using power function of the catheter balloon dose and the bladder volume dose were validated in 31 patients with cervical cancer. Results: There was significant correlation between International Commission on Radiation Units (ICRU)-38 balloon reference dose (Dr) and the dose received by 25% bladder volume (D 25 ) (P < 0.0001). Significant correlation was also found between the reference dose of mid-balloon point (D rm ) and the dose to D 25 (P < 0.0001). Average percentage difference [100 x (observed index - expected index) / expected index] of observed value of I' 25 (index for the dose to D25 bladder with respect to mid-balloon reference point) from that of expected value was 0.52%, when the index was modeled with reference dose alone. Similarly the average percentage difference for I'10cc (index for the dose to 10 cc volume of bladder with respect to mid balloon point) was 0.84%. When this index was modeled with absolute bladder volume and reference dose, standard deviation of the percentage difference between observed and expected index for D rm reduced by approximately 2% when compared to D r . Conclusion: For clinical applications, correlation index modeled with reference dose and volume predicts dose to absolute volume of bladder. Correlation index modeled with reference dose gives a good estimate of dose to relative bladder volume. From our study, we found D rm to be a better indicator of bladder dose than D r .


[FULL TEXT] [PDF]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed3379    
    Printed152    
    Emailed0    
    PDF Downloaded318    
    Comments [Add]    

Recommend this journal