Prospective randomised phase II trial evaluating adjuvant pelvic radiotherapy using either IMRT or 3-Dimensional planning for endometrial cancer

Abstract

Objective

To compare the incidence of grade ≥2 gastrointestinal (GI) or genitourinary (GU) toxicity for patients undergoing 3DRT versus IMRT in the postoperative setting for endometrial cancer.

Methods

Eligible patients were post-operatively randomly assigned to one of two parallel groups in a 1:1 ratio, to have their RT delivered using either a 3DRT technique or using IMRT. The prescription dose was 45 Gy in 25 fractions over 5 weeks followed by vaginal vault brachytherapy. Toxicity was graded according to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version (v) 3.0. Fisher’s exact tests were used to test for associations between toxicity and arm. Differences in dosimetric parameters for patients with or without toxicity were tested using Mann–Whitney U-tests.

Results

84 patients with a median age of 62 were evaluable for primary outcome. The median follow-up was 52 months. 14 (35%) participants from the 3DRT arm and 15 (34%) from the IMRT arm experienced acute grade ≥2 GI toxicity with older patients having a statistically higher risk of grade ≥2 acute GI toxicity. 20 (50%) participants from the 3DRT arm and 25 (57%) from the IMRT arm experienced acute grade ≥2 GI or GU toxicity (p = .662). 12 (30%) patients from the 3DRT arm and 17 (39%) from the IMRT arm experienced acute grade ≥2 GU toxicity (p = .493).

Conclusion

Although IMRT can reduce dose to normal tissue, in this study no benefit in acute GI or GU toxicity outcome was seen.

Keywords:

• Intensity-modulated radiation therapy
• endometrial cancer
• toxicity
• pelvic radiation

Acknowledgements

Cancer Trials Ireland (formerly All Ireland Cooperative Oncology Research Group) CTRIAL-IE (ICORG) 09-06 trial (NCT01164150)

Author contributions

1. Guarantor of integrity of the entire study: C. Gilham

2. Study concepts and design: C Gilham, O McArdle, N. Lavan, O. Salib, M. Dunne

3. Literature research: K. Nugent D. Browne, M Dunne

4. Clinical studies: C. Gilham, O. McArdle, O. Salib, N. Lavan, D. Sharma, S. Bradshaw

5. Experimental studies/data analysis: M. Dunne, A. M Shannon, L. OSullivan

6. Statistical analyses: M. Dunne

7. Manuscript preparation: All authors contributed.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Research data are stored in an institutional repository and will be shared upon request to the corresponding author.

Additional information

Funding

This study was funded by Health Research Board under ICORG/2009 (covering July 2009-June 2012), ICORG/2012 (covering July 2012-Dec 2015) and Grant 2016 HRB/CTI. The funding source were not involved in study design or conduct; in the collection, management, analysis and interpretation of data; preparation, review or approval of the manuscript; or in the decision to submit the manuscript for publication.