Role of Body Mass Index in Intensity Modulated Radiation Therapy for Head and Neck Cancer
Main Article Content
Keywords
: body mass index; number of monitor units; head and neck cancer; intensity modulated radiation therapy; homogeneity index; conformity index.
Abstract
Background: Radiation treatment of head and neck cancer is a difficult process because of the complex anatomy and close proximity of various organs at risk (OARs). This study aimed to assess the impact of body mass index (BMI) on the quality of the 11-field intensity modulated radiation therapy plan for head and neck cancer patients. Methods and materials: The CT scans of thirteen head and neck cancer patients were selected at the Zhianawa Cancer Center (ZCC). The Monaco treatment planning system (TPS) V5.51.10 with the Monte Carlo (XVMC) algorithm V1.6 was utilized to generate an 11F-IMRT plan and was carried out on an ELEKTAMLCi2 linear accelerator. The effect of body mass index was assessed by planning target volume (PTV) coverage, homogeneity index (HI), conformity index (CI), OARs dose, the monitor units (MUs), and delivery time. Results: the target volume was better covered as well as the dose was slightly homogeneous for overweight patients, whereas the conformity of dose distribution significantly improved in normal weight patients (P-value < 0.05). The majority of organs were better spared in the overweight group. For BMI 25 kg/m2, the dose was significantly reduced by 23.6 % and 65.2 % for the brainstem and contralateral optic nerve, respectively (P-value < 0.05). Conclusion: Increasing body mass index enhanced the overall plan quality except of conformity of dose distribution in target
volume among entire techniques.
References
2. Derks, M., van Lonkhuijzen, L. R., Bakker, R. M., Stiggelbout, A. M., de Kroon, C. D., Westerveld, H., ... & Ter Kuile, M. M. (2017). Long-term morbidity and quality of life in cervical cancer survivors: a multicenter comparison between surgery and radiotherapy as primary treatment. International Journal of Gynecologic Cancer, 27(2).
3. Dunne, S., Mooney, O., Coffey, L., Sharp, L., Desmond, D., Timon, C., ... & Gallagher, P. (2017). Psychological variables associated with quality of life following primary treatment for head and neck cancer: a systematic review of the literature from 2004 to 2015. Psycho‐oncology, 26(2), 149-160.
4. Alterio, D., Marvaso, G., Ferrari, A., Volpe, S., Orecchia, R., & Jereczek-Fossa, B. A. (2019, June). Modern radiotherapy for head and neck cancer. In Seminars in oncology (Vol. 46, No. 3, pp. 233-245). WB Saunders.
5. Afrin, K. T., & Ahmad, S. (2020). 3D conformal, IMRT and VMAT for the treatment of head and neck cancer: a brief literature review. Journal of Radiotherapy in Practice, 1-4
6. Van der Veen, J., & Nuyts, S. (2017). Can intensity-modulated-radiotherapy reduce toxicity in head and neck squamous cell carcinoma?. Cancers, 9(10), 135.
7. Yavas, G., Yavas, C., Kerimoglu, O. S., & Celik, C. (2014). The impact of body mass index on radiotherapy technique in patients with early-stage endometrial cancer: a single-center dosimetric study. International Journal of Gynecologic Cancer, 24(9).
8. Boyle, J. M., Craciunescu, O., Steffey, B., Cai, J., & Chino, J. (2014). Body mass index, dose to organs at risk during vaginal brachytherapy, and the role of three-dimensional CT-based treatment planning. Brachytherapy, 13(4), 332-336.
9. Ishimaru, F., Tanooka, M., Inoue, H., Odawara, S., Takada, Y., Niwa, Y., ... & Hirota, S. (2014). Body mass index can affect gastrointestinal and genitourinary toxicity in patients with prostate cancer treated with external beam radiation therapy. Oncology Letters, 7(1), 209-214.
10. Weir, C. B., & Jan, A. (2019). BMI classification percentile and cut off points.
11. Cao, T., Dai, Z., Ding, Z., Li, W., & Quan, H. (2019). Analysis of different evaluation indexes for prostate stereotactic body radiation therapy plans: conformity index, homogeneity index and gradient index. Precision Radiation Oncology, 3(3), 72-79.
12. Yan, L., Xu, Y., Chen, X., Xie, X., Liang, B., & Dai, J. (2019). A new homogeneity index definition for evaluation of radiotherapy plans. Journal of applied clinical medical physics, 20(11), 50-56.
13. Sakthivel, V., Mani, G. K., Mani, S., & Boopathy, R. (2017). Radiation-induced second cancer risk from external beam photon radiotherapy for head and neck cancer: impact on in-field and out-of-field organs. Asian Pacific journal of cancer prevention: APJCP, 18(7), 1897.