PREVALENCE OF MUSCLE INJURY FOLLOWING INTRAARTERIAL CHEMOTHERAPY

Objective. Intra-arterial chemotherapy (IAC) is frequently used as an adjuvant treatment for musculoskeletal tumors. Past studies have noted that IAC not only induces favorable effects in tumor, but may also ca use muscle edema and necrosis in previously normal tissue, reflected a s increased signal on T2 weighted scans. In order to evaluate the prev alence of these effects, eve reviewed all patients receiving IAC and M RI at our institution. Methods. Our study population consisted of 24 p atients who underwent IAC. All subjects were studied with MRI both pre -and post-IAC. None of the subjects in this study underwent surgery or radiation therapy until after the post-IAC MRI examination. Any muscl e group involved by the tumor or peritumoral edema on the initial scan was excluded from the study. Catheter position during IAC was recorde d as central or peripheral. Scans were scored positive if muscle group s in regions remote from the tumor site demonstrated increased T2 sign al following IAC. Results. Six out of these 24 patients (25%) were fou nd to have positive results. A significant association was found betwe en peripheral catheter position and a positive scan post-IAC (Fisher's exact test, P=0.024). Conclusion. Because of our exclusion criteria, we are convinced that the finding of increased T2 signal in 25% of our patients was caused by IAC and represents muscle edema or necrosis. K nowledge of this post-chemotherapy MR finding should help prevent conf usion during the interpretation of follow-up MR examinations.