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Letter from the editors
Seminars in Nuclear Medicine V O L . XIV, N O . 1
J A N U A R Y 1984
L e t t e r f r o m the E d i t o r s PACKER has done a yeoman D R.pieceSAMof work in assembling an issue of the Seminars devoted to the application of nuclear medicine techniques in ophthalmology. The general application and acceptance of these techniques has been somewhat slow due to the great technical difficulties in applying them. However, as shown in this issue, there are a number of areas in which the nuclear medicine physician may play a role in aiding the ophthalmologist. A simple technique that has achieved the most widespread use in ophthalmology is that of radionuclide dacryocystography. The evaluation of the lacrimal ducts is a natural application of radionuclide techniques at their simplest. The nuclear medicine physician evaluates both the patency and physiologic function of the duets following the transit of radiotracers from the conjunctiva to the lacrimal sac and finally through the duct. The technique allows us to obtain not only good and easily interpreted imaging data, but also useful time activity relationships. Another extremely simple and highly original application of nuclear medicine techniques is that described by Freeman et al in which they have shown a differential uptake of 99mTcpertechnetate in the eye of diabetic patients. Reasoning that in the diabetic there is an increased permeability of the vasculature and therefore a radiotracer should escape more readily, they have utilized radionuclide ocular imaging to determine if a change in uptake of radiopertechnetate can be detected. This paper uniquely demonstrates differences in both images and time activity relationships that occur in the diabetic patient compared with the normal individual. In the area of ocular oncology, a number of Seminars in Nuclear Medicine, Vol. XIV, N o. 1 (January), 1 9 8 4
perplexing and difficult problems arise. The series of articles in this issue devoted to the application of radionuclides in patients with malignancies involving the eye, presents a sufficient number of ideas to hold great hope for future applications both in diagnosis and therapy. In spite of remarkable improvements in instrumentation, the old radiophosphorus uptake test remains the most reliable test in evaluating tumors of the eye. Recent studies with gallium suggest the possibility of this agent having a role in this area. In addition, a large number of compounds are described that have a potential for eye tumor localization and may, with further refinement, prove practical. This most desirable goal would hopefully be to replace the betaemitting radiophosphorus with a useful gammaemitting radionuclide that could make the evaluation of eye tumors in the routine clinical laboratory a practical endeavor. A natural follow-up to the development of radiopharmaceuticals that localize eye tumors should be the evolution of radiotracers that can be used for treatment. Conceivably, by simply increasing the dose used for diagnostic studies of eye tumors, enough could be delivered locally for therapy. Currently radionuclide techniques do hold a role in therapy, but unfortunately they require concomitant surgery. The placement of the gamma-emitting radioactive plaques behind tumors has been pioneered by Dr. Packer and the results appear to be quite encouraging. Unfortunately, follow-ups are not yet long enough to determine whether or not the extremely high rate of metastatic disease associated with intraocular melanoma can be reversed by early and energetic radionuelide therapy. In nuclear ophthalmology there also is a role 1
2
for the more modern and highly sophisticated techniques associated with nuclear medicine. The cyclotron plays a role here in the application of high energy particle therapy as an alternative to the implantment of radioactive plaques for treatment of intraocular tumors. It should be pointed out that particle therapy also is not totally noninvasive since it is necessary to put markers surgically behind the tumor in carrying out this procedure. A more sophisticated application of the cyclotron is the development of positron-emitting radiopharmaceuticals that can be used to measure eye metabolism and provide information both in terms of diagnosis of eye malignancies and in follow-up of tumors after treatment to determine whether or not the residual tumor mass is alive and functioning or simply represents the residual scar. The inability of the ophthalmologist to differentiate between dead tumor surrounded by scar tissue and active
FREEMAN AND BLAUFOX
potentially growing tumor tissue, is a serious problem in follow-up and one which the nuclear medicine techniques can potentially overcome. This issue of the Seminars dealing with nuclear ophthalmology once again serves to show that there is virtually no area of the body, nor problem in medicine that cannot potentially be approached with nuclear medicine techniques and with sulficient ingenuity and attention, solved. We have had an overwhelming response to our inclusion of Gamuts in each issue. This is in no small part due to the continuing efforts of our Gamuts editor, Dr. Bob Stadalnik. In order to clear some of our backlog we are including an unusually large number of Gamuts in this issue for your enjoyment. Leonard M. Freeman, M.D. M. Donald Blaufox, M.D., Ph.D.
J A N U A R Y 1984
L e t t e r f r o m the E d i t o r s PACKER has done a yeoman D R.pieceSAMof work in assembling an issue of the Seminars devoted to the application of nuclear medicine techniques in ophthalmology. The general application and acceptance of these techniques has been somewhat slow due to the great technical difficulties in applying them. However, as shown in this issue, there are a number of areas in which the nuclear medicine physician may play a role in aiding the ophthalmologist. A simple technique that has achieved the most widespread use in ophthalmology is that of radionuclide dacryocystography. The evaluation of the lacrimal ducts is a natural application of radionuclide techniques at their simplest. The nuclear medicine physician evaluates both the patency and physiologic function of the duets following the transit of radiotracers from the conjunctiva to the lacrimal sac and finally through the duct. The technique allows us to obtain not only good and easily interpreted imaging data, but also useful time activity relationships. Another extremely simple and highly original application of nuclear medicine techniques is that described by Freeman et al in which they have shown a differential uptake of 99mTcpertechnetate in the eye of diabetic patients. Reasoning that in the diabetic there is an increased permeability of the vasculature and therefore a radiotracer should escape more readily, they have utilized radionuclide ocular imaging to determine if a change in uptake of radiopertechnetate can be detected. This paper uniquely demonstrates differences in both images and time activity relationships that occur in the diabetic patient compared with the normal individual. In the area of ocular oncology, a number of Seminars in Nuclear Medicine, Vol. XIV, N o. 1 (January), 1 9 8 4
perplexing and difficult problems arise. The series of articles in this issue devoted to the application of radionuclides in patients with malignancies involving the eye, presents a sufficient number of ideas to hold great hope for future applications both in diagnosis and therapy. In spite of remarkable improvements in instrumentation, the old radiophosphorus uptake test remains the most reliable test in evaluating tumors of the eye. Recent studies with gallium suggest the possibility of this agent having a role in this area. In addition, a large number of compounds are described that have a potential for eye tumor localization and may, with further refinement, prove practical. This most desirable goal would hopefully be to replace the betaemitting radiophosphorus with a useful gammaemitting radionuclide that could make the evaluation of eye tumors in the routine clinical laboratory a practical endeavor. A natural follow-up to the development of radiopharmaceuticals that localize eye tumors should be the evolution of radiotracers that can be used for treatment. Conceivably, by simply increasing the dose used for diagnostic studies of eye tumors, enough could be delivered locally for therapy. Currently radionuclide techniques do hold a role in therapy, but unfortunately they require concomitant surgery. The placement of the gamma-emitting radioactive plaques behind tumors has been pioneered by Dr. Packer and the results appear to be quite encouraging. Unfortunately, follow-ups are not yet long enough to determine whether or not the extremely high rate of metastatic disease associated with intraocular melanoma can be reversed by early and energetic radionuelide therapy. In nuclear ophthalmology there also is a role 1
2
for the more modern and highly sophisticated techniques associated with nuclear medicine. The cyclotron plays a role here in the application of high energy particle therapy as an alternative to the implantment of radioactive plaques for treatment of intraocular tumors. It should be pointed out that particle therapy also is not totally noninvasive since it is necessary to put markers surgically behind the tumor in carrying out this procedure. A more sophisticated application of the cyclotron is the development of positron-emitting radiopharmaceuticals that can be used to measure eye metabolism and provide information both in terms of diagnosis of eye malignancies and in follow-up of tumors after treatment to determine whether or not the residual tumor mass is alive and functioning or simply represents the residual scar. The inability of the ophthalmologist to differentiate between dead tumor surrounded by scar tissue and active
FREEMAN AND BLAUFOX
potentially growing tumor tissue, is a serious problem in follow-up and one which the nuclear medicine techniques can potentially overcome. This issue of the Seminars dealing with nuclear ophthalmology once again serves to show that there is virtually no area of the body, nor problem in medicine that cannot potentially be approached with nuclear medicine techniques and with sulficient ingenuity and attention, solved. We have had an overwhelming response to our inclusion of Gamuts in each issue. This is in no small part due to the continuing efforts of our Gamuts editor, Dr. Bob Stadalnik. In order to clear some of our backlog we are including an unusually large number of Gamuts in this issue for your enjoyment. Leonard M. Freeman, M.D. M. Donald Blaufox, M.D., Ph.D.