Editing Brain tumor (section)

===Radiation therapy===
The goal of radiation therapy is to kill tumor cells while leaving normal brain tissue unharmed. In standard [[external beam radiation therapy]], multiple treatments of standard-dose "fractions" of radiation are applied to the brain. This process is repeated for a total of 10 to 30 treatments, depending on the type of tumor. This additional treatment provides some patients with improved outcomes and longer survival rates.{{citation needed|date=December 2020}}

[[Radiosurgery]] is a treatment method that uses computerized calculations to focus radiation at the site of the tumor while minimizing the radiation dose to the surrounding brain. Radiosurgery may be an adjunct to other treatments, or it may represent the primary treatment technique for some tumors. Forms used include [[stereotactic]] radiosurgery, such as [[Gamma knife]], [[Cyberknife (device)|Cyberknife]] or [[Novalis radiosurgery|Novalis Tx]] [[radiosurgery]].<ref>{{cite web |url=http://www.sdcyberknife.com/comparison.htm |title=Radiosurgery treatment comparisons – Cyberknife, Gamma knife, Novalis Tx |access-date=22 July 2014 |url-status=dead |archive-url=https://web.archive.org/web/20070520230154/http://www.sdcyberknife.com/comparison.htm |archive-date=20 May 2007  }}</ref>{{medrs|date=July 2014}}

[[Radiation therapy|Radiotherapy]] is the most common treatment for secondary brain tumors. The amount of radiotherapy depends on the size of the area of the brain affected by cancer. Conventional external beam "whole-brain radiotherapy treatment" (WBRT) or "whole-brain irradiation" may be suggested if there is a risk that other secondary tumors will develop in the future.<ref>{{cite web |publisher=Cancer Research UK |url=http://www.cancerhelp.org.uk/help/default.asp?page=5301 |title=Treating secondary brain tumours with WBRT |access-date=5 June 2012 |url-status=live |archive-url=https://web.archive.org/web/20071025211917/http://www.cancerhelp.org.uk/help/default.asp?page=5301 |archive-date=25 October 2007  }}</ref> Stereotactic radiotherapy is usually recommended in cases involving fewer than three small secondary brain tumors. Radiotherapy may be used following, or in some cases in place of, resection of the tumor. Forms of radiotherapy used for brain cancer include [[external beam radiation therapy]], the most common, and [[brachytherapy]] and [[proton therapy]], the last especially used for children.

People who receive stereotactic radiosurgery (SRS) and whole-brain radiation therapy (WBRT) for the treatment of metastatic brain tumors have more than twice the risk of developing learning and memory problems than those treated with SRS alone.<ref>{{cite web |publisher=MD Anderson Cancer Center |url=http://www.mdanderson.org/diseases/braincancer/display.cfm?id=8f11775f-75bb-4d7b-b3ac46878a1d56d0&method=displayfull&pn=00c8a30f-c468-11d4-80fb00508b603a14 |title=Whole Brain Radiation increases risk of learning and memory problems in cancer patients with brain metastases |access-date=5 June 2012 |url-status=dead |archive-url=https://web.archive.org/web/20081005220401/http://www.mdanderson.org/diseases/braincancer/display.cfm?id=8f11775f-75bb-4d7b-b3ac46878a1d56d0&method=displayfull&pn=00c8a30f-c468-11d4-80fb00508b603a14 |archive-date=5 October 2008  }}</ref><ref>{{cite web |publisher=International RadioSurgery Association |url=http://www.irsa.org/metastatic_tumors.html |title=Metastatic brain tumors |access-date=5 June 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120616155755/http://www.irsa.org/metastatic_tumors.html |archive-date=16 June 2012 }}</ref> Results of a 2021 systematic review found that when using SRS as the initial treatment, survival or death related to brain metastasis was not greater than alone versus SRS with WBRT.<ref>{{cite book | vauthors = Garsa A, Jang JK, Baxi S, Chen C, Akinniranye O, Hall O, Larkin J, Motala A, Newberry S, Hempel S | title = Radiation Therapy for Brain Metasases | date = 2021-06-09 | pmid = 34152714 | doi = 10.23970/ahrqepccer242 | s2cid = 236256085 }}</ref>

Postoperative conventional daily radiotherapy improves survival for adults with good functional well-being and high grade glioma compared to no postoperative radiotherapy. Hypofractionated radiation therapy has similar efficacy for survival as compared to conventional radiotherapy, particularly for individuals aged 60 and older with [[glioblastoma]].<ref>{{cite journal | vauthors = Khan L, Soliman H, Sahgal A, Perry J, Xu W, Tsao MN | title = External beam radiation dose escalation for high grade glioma | journal = The Cochrane Database of Systematic Reviews | volume = 5 | issue = 8 | pages = CD011475 | date = May 2020 | pmid = 32437039 | pmc = 7389526 | doi = 10.1002/14651858.CD011475.pub3 }}</ref>