Role of pentoxifylline and vitamin E in attenuation of radiation-induced fibrosis.
OBJECTIVE
To evaluate the use of pentoxifylline and vitamin E as monotherapy and in combination for the treatment of radiation-induced fibrosis (RIF).


METHODS
Literature retrieval was performed through MEDLINE (1966-March 2004) using the terms vitamin E, alpha-tocopherol, pentoxifylline, radiation-induced fibrosis, and radiation injury.


RESULTS
Few treatments exist for managing RIF of soft tissues. Due to its antioxidant properties, vitamin E may reduce the oxidative damage induced by radiation. The precise mechanism of action for pentoxifylline in management of RIF remains unclear. Uncontrolled studies evaluating vitamin E or pentoxifylline as monotherapy in RIF have shown modest improvement in clinical regression of fibrosis. However, controlled data are needed to verify these benefits. Studies involving pentoxifylline plus vitamin E demonstrated regression in RIF. The combination was more effective than placebo and may be superior to monotherapy with either agent. Adverse effects were rarely reported in the studies and consisted mainly of gastrointestinal and nervous system effects.


CONCLUSIONS
Overall, pentoxifylline is well tolerated and is one of the few commercially available drugs with clinical data for management of RIF. Despite a lack of large, well-designed clinical trials, pentoxifylline plus vitamin E should be considered as an option in patients with symptomatic RIF.
Chiao
Teresa B
TB
Veterans Affairs (VA) Medical Center, San Francisco, CA 94121-1545, USA. teresa.chiao@med.va.gov
Lee
Audrey J
AJ
D000975:Antioxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004359:Drug Therapy, Combination; D005355:Fibrosis; D006801:Humans; D010431:Pentoxifylline / Q000008:administration & dosage / Q000627:therapeutic use*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D011832:Radiation Injuries / Q000188:drug therapy* / Q000517:prevention & control; D014810:Vitamin E / Q000008:administration & dosage / Q000627:therapeutic use*
D000975:Antioxidants; D010975:Platelet Aggregation Inhibitors; D014810:Vitamin E; D010431:Pentoxifylline