The paper "Radiation Therapy" is a wonderful example of medical research. The essay aims to address a two-fold objective to wit: (1) to discuss the brief history of radiation therapy and the diseases it treats; and (2) to identify the energy levels used in therapeutic x-ray machines and some of the recent advances in radiation therapy. Radiation Therapy Radiation therapy aims to deliver a precisely measured dose of radiation to a defined tumor volume with as little damage as possible to the surrounding tissue (Yarbro, Wujcik & Gobel, 2011, 250).
It involves the use of ionizing radiation to eradicate the tumor, promote high-quality life, and prolong survival at an affordable cost in treating benign and malignant diseases. The development and use of radiation therapy have evolved over the past centuries. The foundation of radiation therapy started when a German physicist named Wilhelm Conrad Roentgen discovered the x-ray in 1895. At the same time, Antoine Henri Becquerel discovered the radioactivity in Uranium while Marie and Pierre Curie discovered polonium and radium. Then on, radiobiologic experiments done during the early 1900s were in line with the radiation therapy, among of which include the law of Bergonié and Tribondeau which states that radiosensitivity is highest in tissues with the highest mitotic index and lowest in well-differentiated tissues (Yarbro, Wujcik & Gobel, 2011, 251).
Meanwhile, experiments conducted during the 1920-1940s led to fractionation, treatment of deep tumors with x-ray, and brachytherapy with radium. Cobalt therapy became the standard for treatment in the 1950s, first-linear accelerators were developed, and combined-modality treatment was pursued in clinical trials. The combination of both technological and scientific advances has led to the emergence of 3D conformal radiation therapy treatment planning.
Over the centuries, many refinements have been done to address toxicities and complications derived from radiotherapy, meet patient care needs, and maximize treatment dose while preserving quality life and survival. Radiotherapy treats various forms of both benign and malignant cancer but this therapy can also be used to treat lupus erythematous, rodent ulcer, epithelioma, and tuberculosis during the early times after the discovery of x-ray and radium (Goroll & Mulley, 2009, 701). The energy levels used in modern-day therapeutic x-ray machines depend upon the size, shape, and location of the tumor.
Therapeutic x-rays aim to eradicate and destroy cancerous tissues and tumors, with wavelengths ranging up to 100 A (amperes) and energy levels that vary according to radiosensitivity. In addition, the development of x-ray machines for therapeutic use has been concerned with the production of higher energy beams and ordered the highest photon energy levels with conventional x-ray tubes to be 0.1 MeV to extend up to 40 MeV (Hollins, 2001, 140). With various forms of cancer and treatment modalities, the energy levels used in each therapeutic x-ray machine will be differentiated according to cancer type and prospective treatment. The emergence of computers and the technological era have led to advances in imaging technologies in radiotherapy.
From two-dimensional x-ray images and hand calculations, the delivery of radiotherapy evolved to three-dimensional x-ray based images with increasingly c. omplex computer algorithms (Bucci, Bevan & Roach, 2005, 117). Other recent advances include the four-dimensional (4D) conformal radiotherapy and the megavoltage cone-beam CT (MVCT) which will allow the reconstruction of the actual daily-delivered dose based on the patient’ s anatomy in real-time or the adaptive radiotherapy.
A more sophisticated form of radiotherapy called intensity-modulated radiotherapy (IMRT) has become the standard therapy at many academic and private institutions.
Bucci, M.K., Bevan, A. & Roach, M. (2005). Advances in radiation therapy: conventional to 3D, to IMRT, to 4D, and beyond. A Cancer Journal for Clinicians, 55(2): pp. 117-134.
Goroll, A.H. & Mulley, A.G. (2009). Principles of Radiation Therapy. Primary Care Medicine: Office Evaluation and Management of the Adult Patient (6th ed.) (p. 699-703). Philadelphia: Lippincott Williams & Wilkins.
Hollins, M. (2001). X-rays. Medical Physics (2nd ed.) (p. 125-143). Cheltenham: Nelson Thornes Ltd.
Yarbro, C.H., Wujcik, D. & Gobel, B.H. (2011). Principles of Radiation Therapy. Cancer Nursing: Principles and Practice (7th ed.) (p. 249-268). Massachusetts: Jones and Bartlett Publishers, LLC.