Dosimetric comparison of irradiated small bowel volume with intensity modulated radiotherapy and volumetric modulated arc therapy in adjuvant pelvic radiation therapy for endometrial carcinoma

Authors

  • Maria Philip Department of Radiation Oncology, Amala Institute of Medical Sciences, Thrissur, Kerala, India
  • Febin Antony Department of Radiation Oncology, Amala Institute of Medical Sciences, Thrissur, Kerala, India https://orcid.org/0000-0002-8019-4866
  • Jomon Rapahel Chalissery Department of Radiation Oncology, Amala Institute of Medical Sciences, Thrissur, Kerala, India
  • Minu Boban Department of Radiation Oncology, Amala Institute of Medical Sciences, Thrissur, Kerala, India

DOI:

https://doi.org/10.18203/2349-3933.ijam20232210

Keywords:

IMRT, VMAT, Small bowel, Endometrial carcinoma

Abstract

Newer treatment techniques help in reducing dose to small bowel (SB) which is an organ at risk (OAR) for pelvic radiotherapy (RT). However, instead of SB, bowel bag is contoured routinely and constraints are given. In this retrospective case series, we compared the dose received by SB while using intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques in patients receiving adjuvant pelvic RT for endometrial carcinoma. 10 patients with stage II EC who received VMAT were included in this single institution study. SB was contoured retrospectively in the planning computed tomography scan of these patients. An IMRT plan was also generated with a similar planning target volume coverage and organ at risk (OAR) constraints of the previously approved VMAT plan. Volume receiving 10 Gy, 20 Gy, 30 Gy, 40 Gy and 45 Gy of SB was analysed and a dosimetric comparison was made among the two plans. Anaylysis of variance (ANOVA) and unpaired t tests were used for dosimetric comparison. Mean SB volume receiving 10 Gy (V10 Gy) was 85.3% and 83.7% with IMRT and VMAT respectively. Mean SB volume receiving 45 Gy (V45 Gy) was 4.1% and 5% with IMRT and VMAT respectively. No statistically significant difference was noted in the low dose or high dose irradiated volume of SB using both techniques; however, the volume of SB getting irradiated in the absence of optimisation was found to be high in both the groups which can translate in to acute and late bowel toxicity. Further prospective studies have to be conducted to know the clinical significance of this dose-volume relationship to SB.

References

Harkenrider MM, Abu-Rustum N, Albuquerque K, et al. Radiation Therapy for Endometrial Cancer: An American Society for Radiation Oncology Clinical Practice Guideline. Pract Radiat Oncol. 2023;13(1):41-65.

Sourati A, Ameri A, Malekzadeh M. Acute Side Effects of Radiation Therapy. 1st Edition. Springer Nature eBook. 2017.

Portelance L, Winter K, Jhingran A, Miller BE, Salehpour MR, D'Souza DP, et al. Post-operative pelvic intensity modulated radiation therapy (IMRT) with chemotherapy for patients with cervical carcinoma/RTOG 0418 phase II study. Int J Rad Oncol Biol Physics. 2009;75(3):S640-1.

Yeung AR, Pugh SL, Klopp AH, Gil KM, Wenzel L, Westin SN, et al. Improvement in Patient-Reported Outcomes With Intensity-Modulated Radiotherapy (RT) Compared With Standard RT: A Report From the NRG Oncology RTOG 1203 Study. J Clin Oncol. 2020;38(15):1685-92.

Jia MX, Zhang X, Yin C, Feng G, Li N, Gao S, Liu DW. Peripheral dose measurements in cervical cancer radiotherapy: a comparison of volumetric modulated arc therapy and step-and-shoot IMRT techniques. Radiat Oncol. 2014;9:61.

Mundt AJ, Lujan AE, Rotmensch J, Waggoner SE, Yamada SD, Fleming G, et al. Intensity-modulated whole pelvic radiotherapy in women with gynecologic malignancies. Int J Radiat Oncol Biol Phys. 2002;52(5):1330-7.

Ray A, Sarkar B. Small bowel toxicity in pelvic radiotherapy for postoperative gynecological cancer: comparison between conformal radiotherapy and intensity modulated radiotherapy. Asia Pac J Clin Oncol. 2013;9(3):280-4.

Klopp AH, Yeung AR, Deshmukh S, Gil KM, Wenzel L, Westin SN, et al. Patient-Reported Toxicity During Pelvic Intensity-Modulated Radiation Therapy: NRG Oncology-RTOG 1203. J Clin Oncol. 2018;36(24):2538-44.

Antony F, Mathew VK, Jomon RC, Paul GG, Sivakumar S. Dosimetric comparison of organs at risk with three-dimensional conformal radiation, intensity-modulated radiation and volumetric-modulated arc therapy in cervical cancer: a case series. Int J Adv Med. 2021;8:586-90.

Bentzen SM, Constine LS, Deasy JO, Eisbruch A, Jackson A, Marks LB, et al. Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC): an introduction to the scientific issues. Int J Radiat Oncol Biol Phys. 2010;76(3):S3-9.

Cozzi L, Dinshaw KA, Shrivastava SK, Mahantshetty U, Engineer R, Deshpande DD, et al. A treatment planning study comparing volumetric arc modulation with RapidArc and fixed field IMRT for cervix uteri radiotherapy. Radiother Oncol. 2008;89(2):180-91.

Antony F, Chalissery JR, Varghese KM, Gopu GP, Boban M. Relationship of irradiated bone marrow volume and neutropenia in patients undergoing concurrent chemoradiation therapy for cervical cancer. J Cancer Res Ther. 2022;18(6):1498-503.

Tan Mbbs Mrcp Frcr Md LT, Tanderup PhD K, Kirisits PhD C, et al. Image-guided Adaptive Radiotherapy in Cervical Cancer. Semin Radiat Oncol. 2019;29(3):284-98.

Yoon SM, Luterstein E, Chu FI, Cao M, Lamb J, Agazaryan N, et al. Clinical outcomes of stereotactic magnetic resonance image-guided adaptive radiotherapy for primary and metastatic tumors in the abdomen and pelvis. Cancer Med. 2021;10(17):5897-906.

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Published

2023-07-26

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Section

Case Series