ABSTRACT
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 cause muscle edema and necrosis in previously normal tissue, reflected as increased signal on T2-weighted scans. In order to evaluate the prevalence of these effects, we reviewed all patients receiving IAC and MRI at our institution. METHODS: Our study population consisted of 24 patients 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 muscle group involved by the tumor or peritumoral edema on the initial scan was excluded from the study. Catheter position during IAC was recorded as central or peripheral. Scans were scored positive if muscle groups in regions remote from the tumor site demonstrated increased T2 signal following IAC. RESULTS: Six out of these 24 patients (25%) were found to have positive results. A significant association was found between 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. Knowledge of this post-chemotherapy MR finding should help prevent confusion during the interpretation of follow-up MR examinations.
Subject(s)
Antineoplastic Agents/administration & dosage , Infusions, Intra-Arterial/adverse effects , Magnetic Resonance Imaging , Muscle, Skeletal/injuries , Muscle, Skeletal/pathology , Adult , Aged , Bone Neoplasms/drug therapy , Catheterization/adverse effects , Edema/etiology , Female , Humans , Male , Middle Aged , Muscle Neoplasms/drug therapy , NecrosisABSTRACT
A 29-yr-old man with several years of back pain was referred for a bone scan. High-resolution regional spot images of the skeleton were obtained following intravenous injection of 20 mCi 99mTc-methylene diphosphonate. Posterior and lateral images of the skull showed focal increased uptake in several regions of the skull. Upon questioning, the patient stated that he had received acupuncture treatment for his back pain several times in the same regions as the increased uptake. The needle placement was confirmed by the patient's acupuncturist. Acupuncture can cause enhanced bone metabolism demonstrated by increased activity on bone scans.
