Skip to main content Accessibility help
×
Home
  • Print publication year: 2018
  • Online publication date: February 2018

28 - Radiation Oncology

from Section 5 - Gynecologic Oncology

Summary

Introduction

All living things come in contact with radiation; most radiation exposure does not cause harmful complications. Certain types of radiation, specifically ionizing radiation, provide useful interventions in cancer treatment. This type of radiation provokes cellular injury from which normal tissue recovers more effectively than malignant tissue.

Radiation may be provided from isotopes such as radium, iridium, and cesium. Machines such as the linear accelerator or the betatron also create therapeutic forms of radiation which are important in cancer management. Terms used in the discussion of radiation are defined in Box 28.1. This chapter will describe treatment mechanisms and complications of radiation therapy in gynecologic malignancies. Cervical and endometrial cancers are the most commonly treated gynecologic cancers, but radiation also has a role in the management of leiomyosarcoma and vulvar cancers. There is no role for radiation therapy in the management of ovarian cancers due to the effects of radiation on the bowel.

Box 28.1 Terms Used in Discussion of Radiation

X-rays – a form of electromagnetic radiation. X-rays are emitted by electrons.

Gamma rays – these radiations originate from the decay of an atomic nucleus. The wavelengths of gamma rays are typically longer than the wavelengths of x-rays, but some types of gamma rays used in radiation therapy are also referred to as x-rays.

Photon – the elementary particle of ionizing radiation. Gamma rays and x-rays are both considered photons.

Ionization – this process occurs when an atom or proton gains or loses an electron; it thus forms an ion and becomes either negatively or positively charged.

Ionizing radiation – a form of radiation that is harmful to living tissue because it disrupts molecular bonds through the process of ionization.

Scope of the Problem

The most common gynecologic cancers treated by radiation therapy are cervical cancer and endometrial cancer. In early stages, surgery alone may be selected while in other stages the patient may be treated with a combination of surgery and radiation therapy, or with both chemotherapy and radiation. In the most advanced cases, radiation therapy may be used alone. The effects on normal surrounding tissues usually limit the dose of radiation. The sigmoid, the recto sigmoid, and the rectum are the most susceptible pelvic organs to radiation injury. The small bowel also limits radiation dose.

1. Basic principles in gynecologic radiation therapy. In: DiSaia, PJ, Creasman, WT eds. Clinical Gynecologic Oncology, 8th ed. Philadephis: Mosby, 2012.
2. Martin, DD. Review of radiation therapy in the pregnant cancer patient. Clin Obstet Gynecol 2011 Dec;54(4):591–601.
3. Laughlin, J. Development of the technology of radiation therapy. Radiographics 1989;9(6):1245–6.
4. Vicens, RA, Rodriguez, J, Sheplan, L, Mayo, C III, Mayo, L, Jensen, C. Brachytherapy in pelvic malignancies: a review for radiologists. Abdom Imaging 2015 Oct;40(7):2645–59.
5. Cancer facts and figures. 2014 Supplemental Data. Estimated 2014 New Cancer Cases by Site, Sex, & Age. American Cancer Society. www.cancer.org/research/cancerfactsstatistics/index Accessed August 26, 2016.
6. Tang, J, Tang, Y, Yang, J, Huang, S. Chemoradiation and adjuvant chemotherapy in advanced cervical adenocarcinoma. Gynecol Oncol 2012 May;125(2):297–302.
7. Lanciano, RM, Martz, K, Coia, LR, Hanks, GE. Tumor and treatment factors improving outcome in stage III-B cervix cancer. Int J Radiat Oncol Biol Phys 1991;20:95–100.
8. ACOG.Practice Bulletin No. 35: Diagnosis and treatment of cervical carcinomas. Inter J Gyn & Obst 2002 May;78:79–91.
9. Chao, A, Lin, CT, Lai, CH. Updates in systemic treatment for metastatic cervical cancer. Curr Treat Options Onc 2014;15:1–13.
10. Trifiletti, DM, Swisher-McClure, S, Showalter, TN, Hegarty, SE, Grover, S. Postoperative chemoradiation therapy in high-risk cervical cancer: re-evaluating the findings of gynecologic oncology group study 109 in a large, population-based cohort. In J Radiation Oncol Biol Phys 2015 93(5):1032–44.
11. ACOG. Practice Bulletin No.149: Endometrial Cancer. American College of Obstetricians and Gynecologists. Obstet Gyn 2015 Apr;125(4):1006–26.
12. Carmen, MG del, Eisner, B, Willet, CG, Fuller, AF. Intraoperative radiation therapy in the management of gynecologic and genitourinary malignancies. Surg Oncol Clin N Am 2003 Oct;12(4):1031–42.
13. Giuntoli, RL,Metzinger, DS, DiMarco, CS, Cha, SS, Sloan, JA, Keeney, GL, Gostout, BS. Retrospective review of 208 patients with leiomyosarcoma of the uterus: prognostic indicators, surgical management, and adjuvant therapy. Gyn Onc 2003 Jun;89(3):460–9.
14. Foley, OW, Rauh-Hain, JA, Clemmer, J, Clark, RM, Hall, T, Diver, EJ et al. Trends in the treatment of uterine leiomyosarcoma in the medicare population. Int J Gynecol Cancer 2015 Mar 25(3):453–58.
15. Sharma, DN. Radiation in vulvar cancer. Curr Opin Obstet Gynecol 2012 Feb;24(1):24–30.
16. Lonn, S, Gilbert, ES, Ron, E, Smith, SA, Stovall, M, Curtis, RE. Comparison of second cancer risks from brachytherapy and external beam therapy after uterine corpus cancer. Cancer Epidemiol Biomar Prev 2010 Feb;19(2): 464–74.
17. Stanic, S, Mayadev, JS. Tolerance of the small bowel to therapeutic irradiation: a focus on late toxicity in patients receiving para-aortic nodal irradiation for gynecologic malignancies. Int J Gynecol Cancer 2013 May;23(4):592–7.
18. Huffman, LB, Hartenbach, EM, Carter, J, Rash, JK, Kushner, DM. Maintaining sexual health throughout gynecologic cancer survivorship: a comprehensive review and clinical guide. Gynecol Oncol 2016 Feb;140(2):359–68.
19. Foley, OW, Rauh-Hain, JA, Carmen, MG del. The role of intraoperative radiation therapy in the management of recurrent and locally advanced gynecologic cancers. Int J Gynecol Cancer 2013 Jan;23(1):9–15.
20. Foley, OW, Rauh-Hain, JA, Clark, RM, Goodman, A, Growdon, WB, Boruta, DM et al. Intraoperative radiation therapy in the management of gynecologic malignancies. Am J Clin Oncol 2016 Aug;39(4):329–34.
21. Bennett, MH, Feldmeier, J, Smee, R, Milross, C. Hyperbaric oxygenation for tumour sensitisation to radiotherapy. Cochrane Database Syst Rev 2012 Apr; 18(4):CD005007.
22. Franchena, M, Zee, J van der. Use of combined radiation and hyperthermia for gynecological cancer. Curr Opin Obstet Gynecol 2010 Feb;22(1):9–14.
23. Kunos, CA, Spelic, M. Role of stereotactic radiosurgery in gynecologic cancer. Curr Opin Oncol 2013 Sep;25(5):532–8.