Radiosensitizer

A radiosensitizer is a drug that makes tumor cells more sensitive to radiation therapy.

One of the major limitations of radiotherapy is that the cells of solid tumors become deficient in oxygen. Solid tumors can outgrow their blood supply, causing a low-oxygen state known as hypoxia. Oxygen is a potent radiosensitizer, increasing the effectiveness of a given dose of radiation by forming DNA-damaging free radicals. Tumor cells in a hypoxic environment may be as much as 2 to 3 times more resistant to radiation damage than those in a normal oxygen environment.[1] Much research has been devoted to overcoming this problem including the use of high pressure oxygen tanks, blood substitutes that carry increased oxygen, hypoxic cell radiosensitizers such as misonidazole and metronidazole, and hypoxic cytotoxins, such as tirapazamine. A newer approach involves the use of an oxygen diffusion-enhancing compound to re-oxygenate hypoxic tumor tissue.[2] One such compound, trans sodium crocetinate, is currently being tested in a multi-center clinical trial in 59 patients newly diagnosed with glioblastoma multiforme.[3]

References

  1. ↑ Harrison LB, Chadha M, Hill RJ, Hu K, Shasha D (2002). "Impact of tumor hypoxia and anemia on radiation therapy outcomes". Oncologist 7 (6): 492–508. doi:10.1634/theoncologist.7-6-492. PMID 12490737.
  2. ↑ Sheehan JP, Shaffrey ME, Gupta B, Larner J, Rich JN, Park D (2010). "Improving the radiosensitivity of radioresistant and hypoxic glioblastoma". Future Oncology 6 (10): 1591–1601. doi:10.2217/fon.10.123. PMID 21062158.
  3. ↑ "Safety and Efficacy Study of Trans Sodium Crocetinate (TSC) With Concomitant Radiation Therapy and Temozolomide in Newly Diagnosed Glioblastoma (GBM)". ClinicalTrials.gov. November 2011. Retrieved 18 September 2012.

 This article incorporates public domain material from the U.S. National Cancer Institute document "Dictionary of Cancer Terms".

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