Radiat Oncol J.  2014 Jun;32(2):57-62. 10.3857/roj.2014.32.2.57.

The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University

• Tharavichtikul E
• Meungwong
• Chitapanarux T
• Chakrabandhu S
• Klunklin P
• Onchan W
• Wanwilairat S
• Traisathit P
• Galalae R
• Chitapanarux I

• KMID: 1842041
• DOI: http://doi.org/10.3857/roj.2014.32.2.57

Abstract

PURPOSE
To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University.
MATERIALS AND METHODS
Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities.
RESULTS
Thirty-nine patients were evaluated for late rectal toxicity. The mean cumulative dose in term of EQD2 to rectum was 64.2 Gy. Grade 1 toxicities were the most common findings. According to endoscopic exam, the most common toxicities were congested mucosa (36 patients) and telangiectasia (32 patients). In evaluation between rectal dose in EQD2 and toxicities, no association of cumulative rectal dose to rectal toxicity, except the association of cumulative rectal dose in EQD2 >65 Gy to late effects of normal tissue (LENT-SOMA) scale > or = grade 2 (p = 0.022; odds ratio, 5.312; 95% confidence interval, 1.269-22.244).
CONCLUSION
The cumulative rectal dose in EQD2 >65 Gy have association with > or = grade 2 LENT-SOMA scale.

Keyword

Cervical cancer; Radiotherapy; Cumulative dose; Rectum; Toxicity; Association

MeSH Terms

Brachytherapy
Estrogens, Conjugated (USP)
Humans
Mucous Membrane
Odds Ratio
Radiotherapy
Rectum
Retrospective Studies
Telangiectasis
Uterine Cervical Neoplasms*
Estrogens, Conjugated (USP)