Pentoxifylline in the treatment of radiation-induced fibrosis.
OBJECTIVE
Fibrotic sequelae remain the most important dose-limiting toxicity of radiation therapy to soft tissue. Functionally, this is reflected in loss of range of motion and muscle strength and the development of limb edema and pain. Tumor necrosis factor alpha and fibroblast growth factor 2 (FGF2), which are abnormally elevated in irradiated tissues, may mediate radiation fibrovascular injury.


METHODS
In an open label drug trial, we studied the effects of pentoxifylline (400 mg orally tid for 8 weeks) on 30 patients who displayed late, radiation-induced fibrosis at 1 to 29 years posttreatment (40 to 84 Gy). The primary outcome measurement was change in physical impairments thought to be secondary to radiation, including active and passive range of motion (AROM and PROM), muscle strength, limb edema, and pain. Plasma levels of cytokines (tumor necrosis factor alpha and FGF2) also were measured. Twenty-seven patients completed baseline and 8-week assessments, and 24 patients completed baseline, 8-week, and 16-week assessments.


RESULTS
After 8 weeks of pentoxifylline intervention, 20 of 23 patients with impaired AROM and 19 of 22 with impaired PROM improved; 11 of 19 patients with muscle weakness showed improved motor strength; five of seven patients with edema had decreased limb girth; and nine of 20 patients had decreased pain. Pretreatment FGF2 levels dropped from an average of 44.9 pg/mL to 24.0 pg/mL after 8 weeks of treatment.


CONCLUSIONS
Patients receiving pentoxifylline demonstrated improved AROM, PROM, and muscle strength and decreased limb edema and pain. Reversal of these delayed radiation effects was associated with a decrease in circulating FGF2.
Okunieff
Paul
P
University of Rochester School of Medicine, 601 Elmwood Ave, Box 647, Rochester, NY 14642, USA. Paul_Okunieff@urmc.rochester.edu
Augustine
Elizabeth
E
Hicks
Jeanne E
JE
Cornelison
Terri L
TL
Altemus
Rosemary M
RM
Naydich
Boris G
BG
Ding
Ivan
I
Huser
Amy K
AK
Abraham
Edward H
EH
Smith
Judith J
JJ
Coleman
Norman
N
Gerber
Lynn H
LH
D000293:Adolescent; D000328:Adult; D000368:Aged; D016207:Cytokines / Q000097:blood / Q000187:drug effects; D005355:Fibrosis; D006801:Humans; D008875:Middle Aged; D010431:Pentoxifylline / Q000494:pharmacology / Q000627:therapeutic use*; D011832:Radiation Injuries / Q000188:drug therapy* / Q000209:etiology; D011837:Radiation-Protective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D011878:Radiotherapy / Q000009:adverse effects*; D016059:Range of Motion, Articular / Q000187:drug effects; D017695:Soft Tissue Injuries / Q000188:drug therapy* / Q000209:etiology; D016896:Treatment Outcome
D016207:Cytokines; D011837:Radiation-Protective Agents; D010431:Pentoxifylline