International Journal of Radiation Oncology * Biology * Physics
Volume 76, Issue 2 , Pages 485-489, 1 February 2010

Effects of Bladder Distension on Organs at Risk in 3D Image-Based Planning of Intracavitary Brachytherapy for Cervical Cancer

Presented at the 50th Annual Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO), Boston, MA, September 21–25, 2008.

  • Robert Y. Kim, M.D.

      Affiliations

    • Department of Radiation Oncology, University of Alabama Medical Center, Birmingham, AL
    • Corresponding Author InformationReprint requests to: Robert Y. Kim, M.D., Department of Radiation Oncology, University of Alabama at Birmingham, 1824 6th Avenue South, Birmingham, AL 35249-6832. Tel: (205) 975-0222; Fax: (205) 975-0784
  • ,
  • Sui Shen, Ph.D.

      Affiliations

    • Department of Radiation Oncology, University of Alabama Medical Center, Birmingham, AL
  • ,
  • Hui-Yi Lin, Ph.D.

      Affiliations

    • Department of Medical Statistics Section of the Comprehensive Cancer Center, University of Alabama Medical Center, Birmingham, AL
  • ,
  • Sharon A. Spencer, M.D.

      Affiliations

    • Department of Radiation Oncology, University of Alabama Medical Center, Birmingham, AL
  • ,
  • Jennifer De Los Santos, M.D.

      Affiliations

    • Department of Radiation Oncology, University of Alabama Medical Center, Birmingham, AL

Received 7 October 2008; received in revised form 29 January 2009; accepted 30 January 2009. published online 20 May 2009.

Purpose

To investigate the effects of bladder distension on organs at risk (OARs) in the image-based planning of intracavitary brachytherapy for cervical cancer.

Methods and Materials

Thirteen patients with cancer of the cervix were treated with high-dose radiation brachytherapy (800 cGy/fraction for 3 fractions). For the three-dimensional (3D) analysis, pelvic CT scans were obtained from patients with indwelling catheters in place (defined as empty bladder) and from patients who received 180-cc injections of sterile water in their bladders (defined as full bladder). To compare the International Commission on Radiation Units and Measurements (ICRU) point doses with 3D-volume doses, the volume dose was defined by using two different criteria, D2cc (the minimum dose value in a 2.0-cm3 volume receiving the highest dose) and D50% (the dose received by 50% of the volume of the OAR) for OARs.

Results

The bladder D2cc was located more cranially in the bladder base and was distributed in multiple spots in 46% of patients. The rectal D2cc was located in the area of the ICRU point as a single “hot spot.” For patients with a full bladder, the mean bladder D2cc increased from 634 to 799 cGy (28.8%, p = 0.002). However, the bowel D2cc decreased from 475 to 261 cGy (45.0%, p < 0.001). There were no substantial differences in rectal and sigmoid D2cc values. However, the mean D50% values of both the bladder and the bowel decreased from 108 to 80 cGy (23.7%, p < 0.001) and from 282 to 221 cGy (19.7%, p = 0.004) with a full bladder, respectively.

Conclusions

An increase in bladder volume resulted in a significant reduction in bowel D2cc values at the expense of an increase in bladder D2cc values. Treatment with a distended bladder is preferable to protect the bowel.

Cervical cancer, Intracavitary brachytherapy, 3D Treatment planning, Bladder distension, High-dose rate

To access this article, please choose from the options below

Login to an existing account or Register a new account.

  • Purchase this article for 30.00 USD (You must login/register to purchase this article)

    Online access for 24 hours. The PDF version can be downloaded as your permanent record.

  • Subscribe to this title

    Get unlimited online access to this article and all other articles in this title 24/7 for one year.

  • Claim access now

    For current subscribers with Society Membership or Account Number.

  • Visit SciVerse ScienceDirect to see if you have access via your institution.
 

 Conflict of interest: none.

PII: S0360-3016(09)00189-8

doi:10.1016/j.ijrobp.2009.02.002

International Journal of Radiation Oncology * Biology * Physics
Volume 76, Issue 2 , Pages 485-489, 1 February 2010