In Vivo 31P NMR Spectroscopy of Human Musculoskeletal Tumors as a Measure of Response to Chemotherapy

Clinical Magnetic Resonance Spectroscopy

“…In a larger study with post‐chemotherapy follow‐up examinations in 15 patients, and assessment of necrosis upon surgery in eight cases, it was found that the reduction in PDE level (and in the ratios of PDE/Pi, PDE/NTP and PDE/PCr) measured shortly before surgery was associated with a high level of necrosis (162). Correlations of pre‐treatment spectra or early spectral changes with necrosis at resection or changes in tumour volume were neither reported in this study, nor in the ones cited next (157–159, 162, 165, 166). In a preliminary report on 25 cases treated by chemotherapy or TNF mediated hyperthermic isolated limb perfusion, it was noted that early PCr/Pi increases were coupled with >50% necrosis as estimated from MRI and that PME/PCr and PME/NTP increases were more frequent in tumours showing subsequent progression (166).…”

Phosphorus MR spectroscopy in the treatment of human extremity sarcomas

“…20 In two more studies, changes in the ratios of PME were associated with the amounts of necrosis at re-section. 18,21 In the former study, correlations of PME changes with the percentage of tumor regression were far from significant (p = 0.17), and a combined response index scored in between (p = 0.07). 20 Since the pioneering work of Maris et al 71 showing decreasing PME levels with tumor regression, the findings in numerous clinical studies have suggested that a decrease in PME is the only change that occurs in any consistent fashion in responding cancers.…”

“…26 Table 2 makes it clear that PME loss remains the most common outcome in treated extremity tumors, and that according to about half the studies cited they may be preceded by PME increases. 4,5,9,18,21 Changes in tumor pH, NTP, PCr and P i are also observed, though they are less prominent than in experimental tumors (Table 3). Despite the above reports on extremity sarcomas, presenting cases in which an initial change in PME level reversed over time, recent studies with large numbers of cases have indicated that effective treatment causes comparatively drastic decreases in PME concentration that show little if any reversal.…”

“…Note that there appears to be no evidence for the existence of correlation between MRS-measured tumor pH and the proportion of necrosis in the tumor. 70 In the Results section it has already been pointed out that PCr, to be precise PCr/NTP and PCrP i , 21 is a problematic and unrealiable indicator to use, because it represents contamination with signals from the surrounding muscle tissue more than anything else. In view of increased sensitivity of small extremity tumors compared with large ones, 21 the reported correlations with pH and PCr are somewhat obvious.…”

Investigation of the Cerebral Energy Status in Patients with Glutaric Aciduria Type I by31P Magnetic Resonance Spectroscopy

“…Main constituents are phosphoethanolamine and other key precursors of membrane phospholipids in the case of PME as well as glycerophosphocholine and glycerophosphoethanolamine for PDE. Due to the relatively short repetition time, partial saturation may affect the signal intensities, which was corrected by considering appropriate saturation factors for each peak [17]. For this purpose, previously published [5] spin-lattice relaxation times (1.1 s for a-ATP, 1.0 s for b-ATP, 0.9 s for g-ATP, 2.4 s for PCr, 1.1 s for P i , 1.2 s for PME, and 1.3 s for PDE) were utilized.…”