Orthovoltage X-rays

Orthovoltage X-rays
A 200 kV orthovoltage X-ray tube used for radiation therapy, 1938. Orthovoltage X-ray machines are similar to diagnostic (radiography) X-ray machines, except that higher voltages are used and the X-ray tube is longer, to prevent the high voltages from arcing across the tube. ICD10 =
ICD-992.22
OPS-301 code8-521

Orthovoltage X-rays are produced by X-ray tubes operating at voltages in the 100–500 kV range, and therefore the X-rays have a peak energy in the 100–500 keV range.[1] Orthovoltage X-rays are sometimes termed "deep" X-rays (DXR).[2] They cover the upper limit of energies used for diagnostic radiography, and are used in external beam radiotherapy to treat cancer and tumors. They penetrate tissue to a useful depth of about 4–6 cm.[3] This makes them useful for treating skin, superficial tissues, and ribs, but not for deeper structures such as lungs or pelvic organs.[4] The relatively low energy of orthovoltage X-rays causes them to interact with matter via different physical mechanisms compared to higher energy megavoltage X-rays or radionuclide γ-rays, increasing their relative biological effectiveness. [5]

  1. ^ Podgorsak, E. B. (2005). "Treatment Machines for External Beam Radiotherapy". Radiation oncology physics: a handbook for teachers and students. Vienna: International Atomic Energy Agency. p. 125. ISBN 978-92-0-107304-4.
  2. ^ Cerry, Pam; Duxbury, Angela (1998). Practical Radiotherapy: Physics and Equipment. London: Greenwich Medical Media. p. 107. ISBN 9781900151061.
  3. ^ Hill, Robin; Healy, Brendan; Holloway, Lois; Kuncic, Zdenka; Thwaites, David; Baldock, Clive (21 March 2014). "Advances in kilovoltage x-ray beam dosimetry". Physics in Medicine and Biology. 59 (6): R183–R231. Bibcode:2014PMB....59R.183H. doi:10.1088/0031-9155/59/6/R183. PMID 24584183.
  4. ^ Hansen, Eric; Roach III, Mack (2007). Handbook of Evidence-based Radiation Oncology. New York: Springer. p. 5. ISBN 9780387306476.
  5. ^ Bell, Brett I.; Vercellino, Justin; Brodin, N. Patrik; Velten, Christian; Nanduri, Lalitha S.Y.; Nagesh, Prashanth K.B.; Tanaka, Kathryn E.; Fang, Yanan; Wang, Yanhua; Macedo, Rodney; English, Jeb; Schumacher, Michelle M.; Duddempudi, Phaneendra K.; Asp, Patrik; Koba, Wade; Shajahan, Shahin; Liu, Laibin; Tomé, Wolfgang A.; Yang, Weng-Lang; Kolesnick, Richard; Guha, Chandan (3 August 2022). "Orthovoltage X-Rays Exhibit Increased Efficacy Compared with γ-Rays in Preclinical Irradiation". Cancer Research. 82 (15): 2678–2691. doi:10.1158/0008-5472.CAN-22-0656. PMC 9354647. PMID 35919990.