L-[1-C-11]-tyrosine PET to evaluate response to hyperthermic isolated limb perfusion for locally advanced soft-tissue sarcoma and skin cancer

PET with L-[1-C-11]-tyrosine (TYR) was investigated in patients undergoing hyperthermic isolated limb perfusion (HILP) with recombinant tumor necrosis factor alpha (rTNF-alpha) and melphalan for locally advanced soft-tissue sarcoma and skin cancer of the lower limb. Methods: Seventeen patients (5 women, 12 men; age range 24-75 y; mean age 52 y) were studied. TYR PET studies were performed before HILP and 2 and 8 wk afterwards. The protein synthesis rates (PSRs) in nanomoles per milliliter per minute were calculated. After final PET studies, tumors were resected and pathologically examined. Patients with pathologically complete responses (pCR) showed no viable tumors after treatment. Those with pathologically partial responses (pPR) showed various amounts of viable tumors in the resected tumor specimens, Results: Six patients (35%) showed a pcR and 11 patients (65%) showed a pPR. All tumors were depicted as hot spots on PET studies before HILP. The PSR in the pCR group at 2 and 8 wk after perfusion had decreased significantly (P 0.91 for having viable tumor after HILP was 100%, whereas the predictive value of a PSR less than or equal to 0.91 for having nonviable tumor tissue after HILP was 75%, The 2 patients in the pPR groups with a PSR