Proton-decoupled 19F spectroscopy of 5-FU catabolites in human liver.

An RF network and a dual-tuned surface coil are described for obtaining proton-decoupled, NOE enhanced 19F spectra from a whole body clinical imager operating at 1.5 Tesia. The network removes 19F frequency noise from the decoupler transmitter, and prevents preamplifier saturation from high-level decoupling signals. Proton decoupling of 19F spectra was optimized using a sample of urine containing 5-fluorouracil (5-FU) and its catabolite fluoro-beta-alanine (FBAL). Proton-decoupled 19F spectroscopy in vivo is demonstrated by obtaining both nonlocalized spectra and spectra localized with three-dimensional chemical shift imaging from the liver of patients undergoing 5-FU chemotherapy.

Metabolic characterization of human soft tissue sarcomas in vivo and in vitro using proton-decoupled phosphorus magnetic resonance spectroscopy.

We applied 1H-decoupling and nuclear Overhauser enhancement to obtain well-resolved 31P magnetic resonance spectra accurately localized to 20 soft tissue sarcomas in vivo, using three-dimensional chemical shift imaging. Fifteen spectra had large phosphomonoester signals (21% of total phosphorus) that contained high amounts of phosphoethanolamine (compared to those of phosphocholine) but no signals from glycerophosphoethanolamine, and glycerophosphocholine was detected in only four cases. Prominent nucleoside triphosphates (52% of phosphorus) and low inorganic phosphate (10% of phosphorus) indicated that a large fraction of these 15 sarcomas contained viable cells, and this impression was confirmed histologically in 13 of the sarcomas. High-resolution in vitro 31P spectra of extracts of surgical specimens of four of the sarcomas studied in vivo and six additional sarcomas confirmed the in vivo assignments of metabolites and revealed considerable inter- and intratumoral variations of metabolite concentrations associated with histological variations in the relative amounts of cells and of matrix materials or spontaneous necrosis. Seven sarcomas, all high grade with pleomorphic or round cells rather than spindle cells, contained an unidentified phosphodiester signal in vivo; its absence in the extract spectra indicates that it may be from an abnormally mobile membrane component. We have documented a means to obtain new information about in vivo metabolism in human sarcomas and to provide a basis on which to examine the uses of 31P magnetic resonance spectroscopy in the clinical management of sarcomas.

Proton magnetic resonance spectroscopy in patients with glial tumors: a multicenter study.

The authors represent a cooperative group of 15 institutions that examined the feasibility of using metabolic features observed in vivo with 1H-magnetic resonance (MR) spectroscopy to characterize brain tumors of the glial type. The institutions provided blinded, centralized MR spectroscopy data processing long with independent central review of MR spectroscopy voxel placement, composition and contamination by brain, histopathological typing using current World Health Organization criteria, and clinical data. Proton 1H-MR spectroscopy was performed using a spin-echo technique to obtain spectra from 8-cc voxels in the tumor and when feasible in the contralateral brain. Eighty-six cases were assessable, 41 of which had contralateral brain spectra. Glial tumors had significantly elevated intensities of choline signals, decreased intensities of creatine signals, and decreased intensities of N-acetylaspartate compared to brain. Choline signal intensities were highest in astrocytomas and anaplastic astrocytomas, and creatine signal intensities were lowest in glioblastomas. However, whether expressed relative to brain or as intratumoral ratios, these metabolic characteristics exhibited large variations within each subtype of glial tumor. The resulting overlaps precluded diagnostic accuracy in the distinction of low-and high-grade tumors. Although the extent of contamination of the 1H-MR spectroscopy voxel by brain had a marked effect on metabolite concentrations and ratios, selection of cases with minimal contamination did not reduce these overlaps. Thus, each type and grade of tumor is a metabolically hetero-geneous group. Lactate occurred infrequently and in all grades. Mobile lipids, on the other hand, occurred in 41% of high-grade tumors with higher mean amounts found in glioblastomas. This result, coupled with the recent demonstration that intratumoral mobile lipids correlate with microscopic tumor cell necrosis, leads to the hypothesis that mobile lipids observed in vivo in 1H-MR spectroscopy may correlate independently with prognosis of individual patients.

Quantitation of 5-fluorouracil catabolism in human liver in vivo by three-dimensional localized 19F magnetic resonance spectroscopy.

The development of clinical applications of 19F magnetic resonance (MR) spectroscopy of 5-fluorouracil (5-FU) has been limited by the inability to localize 19F spectra to specific regions of interest, making it difficult to quantitate drug and metabolite concentrations accurately. To develop methodology for quantitation, we studied the liver of patients receiving rapid bolus i.v. injections of 5-FU. In serial studies, 5-FU disappeared from the liver within 17-26 min, and its catabolite, alpha-fluoro-beta-alanine (FBAL), rose to reach a plateau after 40 min. A high peak level of fluoro-ureido-propionic acid preceded that of FBAL in only one patient, and dihydrofluorouracil was never observed. During the plateau, we obtained MR imaging-directed 19F MR spectra localized using three-dimensional chemical shift imaging. The spin-lattice relaxation time of FBAL in liver, measured using a variable nutation angle method, was 1.6 +/- 0.2 s (mean +/- SD; n = 5). The concentration of FBAL at 60 +/- 10 min after injection was 1.0 +/- 0.2 mm in liver (mean +/- SD; n = 7). This amount represents approximately 20% of the injected dose and 1.4 times the initial hepatic 5-FU concentration. Our approach may permit one to obtain molar concentrations of fluoropyrimidine metabolites simultaneously in hepatic cancers and surrounding liver, and it helps expand pharmacokinetic modeling of fluoropyrimidine catabolism.

Metabolic characterization of human non-Hodgkin's lymphomas in vivo with the use of proton-decoupled phosphorus magnetic resonance spectroscopy.

Development of biological and clinical uses of in vivo 31P magnetic resonance spectroscopy has been hampered by poor anatomic localization of spectra and poor resolution of overlapping signals within phosphomonoester and phosphodiester regions of the spectrum. We applied 1H-decoupling and nuclear Overhauser enhancement to improve resolution of 31P magnetic resonance spectra accurately localized to 21 non-Hodgkin's lymphomas (NHL) by using three-dimensional chemical shift imaging. All 21 spectra had large phosphomonoester signals (26% of total phosphorus) that contained high amounts of phosphoethanolamine relative to phosphocholine. There were no signals from glycerophosphoethanolamine or glycerophosphocholine but only a broad signal from membrane phospholipids in the phosphodiester region (20% of phosphorus). Prominent nucleoside triphosphates (47% of phosphorus) and low inorganic phosphate (7% of phosphorus) indicate well-perfused tissue with viable cells. Mean intracellular pH was 7.23. These characteristics were similar in all grades and stages of NHL. By analogy with recently reported studies in cell lines in vitro, we hypothesize that the pattern of phospholipid metabolites observed in NHL in vivo is partly a manifestation of sustained activation of phospholipase C or D. The techniques we implemented permitted us to obtain more information about in vivo metabolism of NHL than has heretofore been available. This information is important for the establishment of appropriate experimental models and provides a basis from which to examine potential clinical uses of 31P magnetic resonance spectroscopy.

Renal cell carcinoma: treatment with recombinant interleukin-2 plus beta-interferon.

Preclinical data have demonstrated synergy between interleukin-2 (IL-2) and beta-interferon (IFN-beta) in stimulating natural-killer (NK) cell activity and in increasing expression of IL-2 receptors. Based on results of a phase I trial, a combination of IL-2 and IFN-beta was administered three times weekly by intravenous (IV) bolus injection with 5 x 10(6) Cetus U/m2 of IL-2 and 6 x 10(6) U/m2 of IFN-beta to 24 patients with advanced renal cell carcinoma (RCC). Of 22 assessable patients there were six (27%) objective responses including one complete remission (CR) and five partial responses (PRs). There were three minor responses (MRs), 11 stable disease (SD), and two progressive disease (PD). Two of the objective responses have continued for almost 2 years. Response sites include lymph nodes, lungs, and bone. Toxicities requiring dose reduction include arthralgia, weight loss, fatigue, decreased performance status, depression, and hypotension. Five of 10 patients who had a prior nephrectomy without local recurrence achieved an objective response as compared with only one of 12 without a prior nephrectomy or with a local recurrence (P = .04). Mean peak lymphokine-activated killer (LAK) cell activity of the objective responders was 88 lytic units (LU) as compared with 4 LU in the nonresponders (P = .01). Mean peak NK cell activity was 288 LU in the objective responders as compared with 100 LU in the nonresponders (P = .10).(ABSTRACT TRUNCATED AT 250 WORDS)

Exacerbation of epidemic Kaposi's sarcoma with a combination of interleukin-2 and beta-interferon: results of a phase 2 study.

Epidemic Kaposi's sarcoma (EKS) is the most common neoplastic manifestation of acquired immune deficiency syndrome (AIDS). The underlying immune deficiency can be partially reversed in vitro with interleukin-2 (IL-2). The type 1 interferons (IFN), alpha and beta, inhibit the growth of the etiologic agent of AIDS, the human immunodeficiency virus, have antitumor activity against Kaposi's sarcoma, and are synergistic with IL-2 in stimulating natural killer cell activity. Four patients with EKS were treated three times weekly with simultaneous intravenous injections of recombinant IL-2 (5 X 10(6) Cetus units/m2) and recombinant IFN-beta (6 X 10(6) units/m2). All patients had generalized disease, were without systemic symptoms, had no prior opportunistic infection, and had stable disease at the initiation of therapy. No patient had an objective response. Three patients exhibited rapid disease progression within 2-4 weeks of starting treatment, necessitating discontinuation of therapy and early closure of the study. This adverse result may have resulted from the significant levels of gamma-interferon (IFN-gamma) that can be generated with this dose and schedule of IL-2. Investigators using IL-2 should monitor IFN-gamma levels and avoid intermediate to high-dose bolus IL-2 therapy in patients with EKS.

A phase I study of recombinant interleukin 2 plus recombinant beta-interferon.

Interleukin 2 (IL-2) therapies have antitumor activities against several neoplasms. In vitro these activities are enhanced by beta-interferon (IFN-beta). Therefore, we initiated a Phase I trial with a combination of IL-2 and IFN-beta three times weekly. The IFN-beta was administered i.v. Initially, the IL-2 was administered s.c. However, neutralizing antibody to the IL-2 developed in five patients, and the route of administration of the IL-2 was changed to i.v. Forty-seven patients were entered on the study. The maximum tolerated doses for the combination given i.v. were 5 x 10(6) units/m2 of IL-2 and 10 x 10(6) units/m2 of IFN-beta. Dose-limiting toxicities were profound fatigue/decreased performance status, anorexia/weight loss, depression, and arthralgias. Hypotension, exfoliative skin rash, thrombocytopenia, diarrhea, temperature greater than 40.6 degrees C, and peripheral edema were rarely dose limiting. Thirty-two patients were evaluable for response. After 4 weeks of treatment, 21 patients had stable disease, three patients had a minor response, and one patient had a partial response. Significant lymphokine-activated killer cell (LAK) activity was seen in seven patients (22%) and required 5 x 10(6) units/m2 of IL-2. Those who had progressive disease had significantly less LAK activity than those with either stable disease or a response. This therapy also induced more than 60 units/ml of endogenous gamma-interferon 4 h after the i.v. IL-2 administration. This study demonstrates that (a) intermittent i.v. bolus IL-2 therapy can generate LAK activity, (b) LAK activity may be associated with an antitumor response, (c) significant levels of gamma-interferon are induced by this therapy, and (d) IL-2 and IFN-beta given three times weekly i.v. is both tolerable and biologically active. The recommended Phase II dose is 5 x 10(6) units/m2 of IL-2 plus 6 x 10(6) units/m2 of IFN-beta.