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Editorial The Clinical Use of Magnetic Resonance Spectroscopy Ever since it first became apparent that NMR signals could be obtained from living tissues there has been great interest in the application of the method to medicine. A large number of 1.5 T MRI instruments has been installed in hospitals around the world, and most could easily be adapted to MRS. How close are we to seeing a routine clinical use for this investigation? This issue is devoted to the proceedings of the 17th L. H. Gray Conference, which addressed this question in relation to cancer, a disease that urgently needs improved treatment and, to a lesser degree, improved diagnosis. The structure of the conference moved from the use of MRS in model cancers to a consideration of its clinical use, and the last session was an open discussion on the planning of clinical trials. The papers and reviews in this issue set out some of the opportunities and problems. MRS techniques can be used in the laboratory to monitor cancer cell chemistry for diagnosis, for tumour grading and the assessment of hypoxia, and possibly to aid the scheduling of radiotherapy; they can also be used to monitor the effects of most if not all non-surgical treatments. It is also possible to measure tumour blood flow and perfusion and the uptake and metabolism of anticancer drugs or specially designed probe molecules. In view of all these active areas of research it is not surprising that MRS has taken an important role in the scientific study of cancer and its treatment, as it has in several other diseases. But can any of this be translated into routine clinical investigations? At present, there are still significant technical problems with clinical MRS, Sensitivity for localized "P is marginal at 1.5 T, so there is a tendency to maximize the volume of interest at the risk of including some normal tissues. Also, quantitation of MRS spectra is still not routine. 'H MRS, which has better sensitivity, is only usable at present (with a,few exceptions) for studies on brain tumours. Nevertheless, the published data suggest that useful information can be acquired. In the 10 years since the first spectra of a human tumour were obtained many hundreds have been published. Dr Negendank's review (p.??, this issue), the most detailed assessment of the MRS spectra of human tumours yet published, is optimistic about the use of the method in monitoring human cancer. In particular, 31P spectra of treated tumours show a remarkably uniform MRS response: the phosphomonoester peak, which usually increases in spectra from an unresponsive tumour, falls rapidly in most tumours that respond. This result holds out the possibility of a completely new departure in the cancer clinic - a method for predicting whether a tumour will lespond to the treatment regime within a short $ ,~in~t~ati~~;~thqapy. qtimetqf $: ' Ca'nc'e 'tr&atiiefit.'At*@&Sntis qorely in need of a general improvement of this ,.+ind,,.-Ovex.the last JQ p a r s or :so the routine practice of chemotherapy and radiotherapy has 6e&d?efiiled to the point where standard 'cocktails' of anticancer .drugs or -radiotheraWlr.egim,have been devised for .all cancers. Unfortunately, most cancers fail to respond to any individual drug (response rates of 3(1-40% are typical) and there is no way to tell whether a treatment has succeeded until the cancer begins to shrink - or grow. MRS could provide a way to 'fine-tune' treatment in each individual patient.
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iv
One of the major problems at the moment in this field is that each centre can only accrue patients at a slow rate, limited by instrument time, local patient referral patterns and treatment practices. To find out whether we have a practical method we need to organize multi-centre collaborative trials. These will need careful planning to minimize problems with different instrument types, different MRS methods and different treatment protocols, among other things, but the advantage of successful trials of this kind would be a much quicker (and possibly more generally accepted) answer to the question: ‘Js there a clinical use for MRS?’ The final session of the Gray Conference addressed some of these points, and there was general agreement that multi-centre trials are needed. A similar conclusion was reached at a Workshop held in Washington in December 1991, and alluded to in Dr Shtern’s paper (~325,this issue). It is to be hoped that these initiatives will provoke a serious effort to bring this perennially promising technique into routine clinical use. J. R. Griffiths Editor-in-Chief
Editorial The Clinical Use of Magnetic Resonance Spectroscopy Ever since it first became apparent that NMR signals could be obtained from living tissues there has been great interest in the application of the method to medicine. A large number of 1.5 T MRI instruments has been installed in hospitals around the world, and most could easily be adapted to MRS. How close are we to seeing a routine clinical use for this investigation? This issue is devoted to the proceedings of the 17th L. H. Gray Conference, which addressed this question in relation to cancer, a disease that urgently needs improved treatment and, to a lesser degree, improved diagnosis. The structure of the conference moved from the use of MRS in model cancers to a consideration of its clinical use, and the last session was an open discussion on the planning of clinical trials. The papers and reviews in this issue set out some of the opportunities and problems. MRS techniques can be used in the laboratory to monitor cancer cell chemistry for diagnosis, for tumour grading and the assessment of hypoxia, and possibly to aid the scheduling of radiotherapy; they can also be used to monitor the effects of most if not all non-surgical treatments. It is also possible to measure tumour blood flow and perfusion and the uptake and metabolism of anticancer drugs or specially designed probe molecules. In view of all these active areas of research it is not surprising that MRS has taken an important role in the scientific study of cancer and its treatment, as it has in several other diseases. But can any of this be translated into routine clinical investigations? At present, there are still significant technical problems with clinical MRS, Sensitivity for localized "P is marginal at 1.5 T, so there is a tendency to maximize the volume of interest at the risk of including some normal tissues. Also, quantitation of MRS spectra is still not routine. 'H MRS, which has better sensitivity, is only usable at present (with a,few exceptions) for studies on brain tumours. Nevertheless, the published data suggest that useful information can be acquired. In the 10 years since the first spectra of a human tumour were obtained many hundreds have been published. Dr Negendank's review (p.??, this issue), the most detailed assessment of the MRS spectra of human tumours yet published, is optimistic about the use of the method in monitoring human cancer. In particular, 31P spectra of treated tumours show a remarkably uniform MRS response: the phosphomonoester peak, which usually increases in spectra from an unresponsive tumour, falls rapidly in most tumours that respond. This result holds out the possibility of a completely new departure in the cancer clinic - a method for predicting whether a tumour will lespond to the treatment regime within a short $ ,~in~t~ati~~;~thqapy. qtimetqf $: ' Ca'nc'e 'tr&atiiefit.'At*@&Sntis qorely in need of a general improvement of this ,.+ind,,.-Ovex.the last JQ p a r s or :so the routine practice of chemotherapy and radiotherapy has 6e&d?efiiled to the point where standard 'cocktails' of anticancer .drugs or -radiotheraWlr.egim,have been devised for .all cancers. Unfortunately, most cancers fail to respond to any individual drug (response rates of 3(1-40% are typical) and there is no way to tell whether a treatment has succeeded until the cancer begins to shrink - or grow. MRS could provide a way to 'fine-tune' treatment in each individual patient.
F
iv
One of the major problems at the moment in this field is that each centre can only accrue patients at a slow rate, limited by instrument time, local patient referral patterns and treatment practices. To find out whether we have a practical method we need to organize multi-centre collaborative trials. These will need careful planning to minimize problems with different instrument types, different MRS methods and different treatment protocols, among other things, but the advantage of successful trials of this kind would be a much quicker (and possibly more generally accepted) answer to the question: ‘Js there a clinical use for MRS?’ The final session of the Gray Conference addressed some of these points, and there was general agreement that multi-centre trials are needed. A similar conclusion was reached at a Workshop held in Washington in December 1991, and alluded to in Dr Shtern’s paper (~325,this issue). It is to be hoped that these initiatives will provoke a serious effort to bring this perennially promising technique into routine clinical use. J. R. Griffiths Editor-in-Chief
