A review of the literature has shown that in human breast tumours, large signals from phosphomonoesters (PME) and phosphodiesters (PDE) are evident. In serial measurements in 19 patients with breast cancer, a decrease in PME was significantly associated with a stable or responding disease (p = 0.017), and an increase in PME was associated with disease progression. Extract studies have shown PME to comprise of phosphoethanolamine (PEth) and phosphocholine (PCho), with the PEth to PCho ratio ranging from 1.3 to 12. The PCho content of high grade tumours was found to be higher than low grade tumours. In some animal models, changes in PCho have been shown to correlate with indices of cellular proliferation, and spheroid studies have shown a decrease in PCho content in spheroids with smaller growth fractions. A serial study of 25 patients with advanced primary breast tumours undergoing hormone, chemotherapy or radiotherapy treatments, showed that in this heterogenous group there were significant changes in metabolites that were seen during the first 3 weeks (range 2–4 weeks) of treatment, that correlated with volume change over this period, employed here as a measure of response. Changes in PME (p = 0.003), total phosphate (TP) (p = 0.008) and total nucleoside tri‐phosphate (TNTP) (p = 0.02) over 3 (±1) weeks were significantly associated with response, as were the levels of PME (p < 0.001), PDE (p = 0.01), TP (p = 0.001) and TNTP (p = 0.007) at week 3 (±1). PME at week 3 (±1) was also significantly associated with the best volume response to treatment (p = 0.03). A reproducibility analysis of results from the observation of normal breast metabolism in four volunteers showed a mean coefficient of variation of 25%, after correcting for changes resulting from the menstrual cycle. Reproducibility studies in four patients with breast cancer showed a mean coefficient of variation of 33%, with the reproducibility being better in patients measured on different days (difference in TP was −6%) compared with those measured on the same day (difference in TP was −29%). © 1998 John Wiley & Sons, Ltd.

BANG-gel dosimetry offers the potential for measuring the dose delivered by a radiotherapy treatment technique, in three dimensions, with high spatial resolution and good accuracy. The ability to measure comprehensively a 3D dose distribution is a major advantage of the gel dosimeter over conventional planar and point-based dosimeter devices, particularly when applied to the verification of complex dose distributions characteristic of intensity-modulated radiotherapy (IMRT). In this paper an in-house manufactured BANG-gel dosimeter was applied to study the dose distributions of two irradiation experiments for which the distributions were known: (i) a dosimetrically simple parallel-opposed irradiation, and (ii) a more complex nine-field 'static tomotherapy' intensity-modulated irradiation delivered with the Nomos MIMiC. The uniform distribution in (i) allowed a study of the magnetic resonance (MR) imaging parameters to achieve an optimal trade-off between noise and image resolution (optimum image resolution for the Siemens 1.5T Vision system was determined to be approximately 0.8 mm2 with a slice thickness of 2 mm). The spatial uniformity of gel sensitivity to radiation was found to depend strongly on the presence of oxygen, which must be eliminated for the gel dosimeter to be of use. The gel dosimeter was found to agree well with predicted dose distributions and accurately measured the steep penumbral fall-off of dose, even after many days, proving its potential for the verification of IMRT distributions. In the nine-field IMRT delivery (ii) the predicted dose was computed by both an in-house 'component-delivery' dose algorithm and the Peacock planning-system dose algorithm. Good agreement was found between the two algorithms despite the latter's omission of the change in penumbral characteristics with aperture-size during delivery, lack of inhomogeneity correction and approximate modelling of leaf leakage. These effects were found to be small for the problem studied. The predicted distribution agreed well with the gel-measured distribution at medium and high doses (50-90% isodose lines) although differences of up to 10% were observed at lower doses (30% isodose line). The gel dosimeter was found to have the potential to verify IMRT distributions but required considerable care to achieve accurate results. Attention was required to achieve uniformity of gel sensitivity (to prevent oxygen contamination), and in the calibration process.

Summary An in vivo 31P NMR spectrum was obtained from each of four human breast tumours. The phosphomonoester and phosphodiester region of each spectrum consisted of a broad peak. Chemical extracts from samples of each of the tumours obtained at resection were examined on a high field strength NMR system. The phosphomonoester region in the spectrum from each extract resolved into three peaks consisting of phosphocholine, phosphoethanolamine and a nucleoside monophosphate. The phosphodiester region resolved into two components, glycerophosphorylcholine and glycerophosphorylethanolamine. Comparing the in vivo and in vitro data from each tumour showed that the contribution of phosphodiester was much lower in the in vitro spectra. We believe this to be a consequence of phospholipid, which would not appear in the aqueous extract, contributing to the phosphodiester peak in vivo.The presence of high concentrations of phosphomonoesters (PMEs) in human breast tumours has been demonstrated by several in vitro (Degani et al., 1986;Barzilai et al., 1988;Merchant et al., 1988) and in vivo (Sijens et al., 1988; Glaholm et al., 1989) studies using 31P NMR spectroscopy. Sijens et al. (1988) reported that the positive response of two breast carcinomas to radiotherapy was accompanied by a decrease in the PME content of the tumours. Further, quantitated changes in PME levels have been observed in a patient undergoing endocrine treatment and subsequently chemotherapy for locally advanced breast carcinoma using a whole body 3lP NMR system Glaholm et al. (1989). These findings suggest that the PMEs may be sensitive indicators of tumour cell response to treatment.In vitro studies of chemical extracts from samples of human breast tumours (Merchant et al., 1988) and human cell culture systems (Daly et al., 1987) have suggested that in breast tumours the PMEs consist principally of phosphoethanolamine (PE) with minor contributions from phosphocholine (PC) and several nucleoside monophosphates.In order to assess the extent to which in vitro NMR data are representative of tissue in vivo, and to assist in the interpretation of therapy-induced changes in in vivo spectra, we are comparing high resolution NMR spectra from extracts of human breast tumours with in vivo spectra from the same tumours prior to operation. The present study shows preliminary results from four patients which in three cases are compared with an assessment of necrotic fraction.In vivo measurements were performed using a 1. (Graham et al., 1987). D20 (final concentration 10%) and methylene diphosphonic acid (2.5 gmoles) were added to the aqueous phase of the extract and the pH was adjusted to 7.4. NMR analysis of the aqueous extracts was carried out on a Bruker Spectrospin AC250 spectrometer operating at 101 MHz (for 31P). All measurements were performed under proton-decoupled conditions in a 10 mm probe. At least 2,000 acquisitions were obtained from each sample. The parameters used for each acquisition were: sweep width 7937 Hz; acquisition time 0.5 ms; acquisition ...

Summary Apoptosis was induced by treating L1210 leukaemia cells with mechlorethamine, and SW620 colorectal cells with doxorubicin. The onset and progression of apoptosis were monitored by assessing caspase activation, mitochondrial transmembrane potential, phosphatidylserine externalization, DNA fragmentation and cell morphology. In parallel, 31 P magnetic resonance (MR) spectra of cell extracts were recorded. In L1210 cells, caspase activation was detected at 4 h. By 3 h, the MR spectra showed a steady decrease in NTP and NAD, and a significant build-up of fructose 1,6-bisphosphate (F-1,6-P) dihydroxyacetonephosphate and glycerol-3-phosphate, indicating modulation of glycolysis. Treatment with iodoacetate also induced a build-up of F-1,6-P, while preincubation with two poly(ADP-ribose) polymerase inhibitors, 3-aminobenzamide and nicotinamide, prevented the drop in NAD and the build-up of glycolytic intermediates. This suggested that our results were due to inhibition of glyceraldehyde-3-phosphate dehydrogenase, possibly as a consequence of NAD depletion following poly(ADP-ribose) polymerase activation. Doxorubicin treatment of the adherent SW620 cells caused cells committed to apoptosis to detach. F-1,6-P was observed in detached cells, but not in treated cells that remained attached. This indicated that our observations were not cell line-or treatment-specific, but were correlated with the appearance of apoptotic cells following drug treatment. The 31 P MR spectrum of tumours responding to chemotherapy could be modulated by similar effects.