Nuclear Medicine as a Medical Specialty - Essay Example

Nuclear Medicine Introduction Nuclear medicine refers to a medical specialty that offers a safe and painless approach to diagnosing and treating diseases. It provides an opportunity to undertake procedures to determine medical information that would have otherwise not be available, require surgery or call for more costly and invasive diagnostic tests. Usually, the procedure would identify abnormalities early in the disease progression allowing for early treatment. The practice has been in existence for over 60 years with America alone having undertaken over 333 million procedures to date according to the Society of Nuclear Medicine, SNM (7). Furthermore, of the 5,000 nuclear medicine centres currently in the US, over 18 million procedures are performed yearly. Therefore, if properly administered, nuclear medicine scans could provide critical information that would be diagnostically and therapeutically beneficial to human health. Nuclear medicine refers to a pharmaceutical that is affixed to some radioactive material referred to as a radioisotope or tracer. This combination is referred to as radiopharmaceutical (SNM 2). Radiopharmaceuticals occur in numerous variations for the study of different body parts. The choice of which radioisotope to use would be dependent on the condition that needs diagnosis or treatment. A radiopharmaceutical would be introduced into the body of a patient through inhalation, swallowing or injection. Usually, just a small amount would be given. The pharmaceutical component of the radiopharmaceutical would be designed such that it goes to a specific site of the body that has been affected by disease or abnormality. On the other hand, the radioactive component would emit radiation referred to as gamma rays which would be detected by a specialised kind of camera known as gamma camera (Shulthess 16). When undertaking the imaging procedure, the patient would be expected to lie down on a bed. It is then that the gamma camera would be placed nearer to the body and pictures taken for the next couple of minutes, usually between 20 and 45 (Oyen et al. 1785). This camera gives images that inform on what occurs in the body of the patient thus diagnosis of diseases. Gamma cameras come in varied sizes and types, the determinant of what camera to use being the kind of picture required (Shulthess 17). They neither hurt nor make any frightening noise. Unlike other imaging devices like ultrasound and CT scans, gamma cameras do not transmit radiation to patients. Scans in Nuclear Medicine A Single Photon Emission Computed Tomography, SPECT is a type of scan in nuclear medicine whose imaging instruments produce 3-dimensional images of how the radioactive tracer molecules are distributed in the patient body into which they have been introduced. According to the US National Institute of Biomedical imaging and Bioengineering, NIBIB, the images would be generated from a computer that captures the numerous projections of the body captured at diverse angles. The gamma camera detectors on SPECT imagers detect the gamma rays emitted from the tracers in the body of the patient (Biersack and Freeman 23). These cameras mounted on a rotating support have detectors moving in a tight circular motion around the immobile patient. Positron Emission Tomography, PET scan makes use of radiopharmaceuticals to develop 3-dimensional images. Whereas SPECT scans would measure gamma rays, radiotracer decay in PET scans yield minute particles referred to us positrons (Prakash 90). A positron is a particle that has almost the same mass as that of an electron though it is oppositely charged. Positrons react with electrons occurring in the body with their combination causing annihilation of the two particles (Shulthess 18). Consequently, some energy would be produced in the form of two photons that would discharge off in opposite directions. It is the measure of these photons on PET scanner detectors that gives information for the creation of images of the internal organs of the body (Biersack and Freeman 15).This way, PET scans could be used to detect any biochemical changes in body tissues or organs which would be useful for the identification of the onset of a disease even before anatomical changes associated with the disease could be identified by other imaging processes. There are other minor types of scans in nuclear medicine. Thyroid scans evaluate the functioning and structure of thyroid glands using radioactive iodine tracer. An evenly gray image indicates that the thyroid is correctly positioned, sized and shaped. With nodules known to absorb iodine, lighter or darker scans signify tumour on the thyroid. Furthermore, the proportion of absorbed iodine as read from the computer identifies the extent of the tumour (Prakash 19). A nuclear heart scan gives information on the health of the heart. The scan checks the flow of blood to the heart muscle with signs of some muscles not getting blood being an indication of coronary heart disease which could lead to angina, heart attack or other related complications. This scan is referred to as myocardial perfusion scanning. Other nuclear heart scans include the myocardial viability testing and ventricular function scanning used to look out for damages on the heart muscle and how well the heart pumps blood to the body respectively. A bone scan would be carried out to determine whether cancers have affected the bones while kidney or renal scan tests the functioning of the kidneys, mostly looking out for scarring on the kidneys (Biersack and Freeman 15). However, SPECT and PET are the most common types of scans in nuclear medicine. How Nuclear Medicine Works Nuclear medicine applies to two domains of activity, diagnostic and therapeutic. In diagnostic nuclear medicine, radiopharmaceuticals that deliver low radiation doses would be introduced to the target organs, though some non-target organs could also be exposed. This could range between a few to hundred of mGy, usually 10mSv to 20mSv (Biersack and Freeman 46; Oyen et al. 1786). According to the World Nuclear Association, WNA, these doses facilitate the imaging of organs to assist physicians in the location and identification of tumours, anomalies in size or other functional and physiological organ problems. Should the radioisotope be partially or excessively taken up in the organ, the organ malfunction would be ascertained. Additionally, should unusual pattern or isotope movement rate be observed after a series of images for a period of time, then, organ malfunction would also be probable. Numerous kinds of diseases could be diagnosed using nuclear medicine. According to SNM, nuclear medicine could identify abnormal lesions occurring deep in the body without the need for any exploratory surgery (5). In the same way, it could be used for the determination of the functionality of certain body organs. This has been used to determine whether the heart pumps blood adequately, the brain receives adequate blood supply and brain cells function properly. In addition, nuclear medicine could help determine whether kidneys function normally and whether the stomach empties normally. It could determine the blood volume of a patient, vitamin absorption, lung functionality and bone density. Even before x-ray could reveal, nuclear medicine locates minute bone fractures. WNA further observes the application of nuclear medicine in identifying epilepsy, Alzheimer’s disease and Parkinson’s disease. It could find cancers, establish whether infected bones would heal and determine response to treatment. It has also been used after a heart attack to assess the extent to which the heart could have been damaged. In the same way, it tells how well the just transplanted organs function. For therapeutic nuclear medicine, high radiation doses would be delivered to tumours, though normal tissues could also be exposed. WNA observes that rapidly dividing cells are prone to damage from irradiation, the reason why cancerous growths could be controlled or eliminated using nuclear medicine. In some cases, external irradiation with gamma rays could be conducted, referred to as gamma knife radiosurgery, on the precise location of a tumour. Alternatively, internal radionuclide therapy could be employed through the administration of a minute radiation source in the target area. Because radiopharmaceuticals do not perfectly target tumours only, Biersack and Freeman advocate for determining the side effects of irradiation on organs at risk such as bone marrow (47). The aim of therapeutic nuclear medicine is to reduce tumour size, kill malignant tissues and reduce pain. According to SNM, radioactive iodine has been used to treat thousands of patients suffering from hyperthyroidism (6). It has also been used to treat numerous cancers (lymphomas) and bone pain resulting from cancer. In nuclear medicine, the treatment given to children differs from that given to adults. This follows the argument given by Shulthess that the two sets of individuals differ in their normal physiology, psychology and pathophysiology thus the need for consideration of special issues when planning to undertake a scan (575). When working with children, child-oriented staff should be involved, with patience, imagination, truthfulness and flexibility being critical. Whereas parents could also be worried as the children patients, it would be important that they offer the much needed security and comfort. Thus, communication and understanding would provide ways to realise the full potential of the imaging process. In addition to children, pregnant and breastfeeding women also need specialised assessment by a nuclear medicine specialist before administration of nuclear medicine. Benefits of Nuclear Medicine The value of a diagnostic procedure relative to another could be difficult to accurately assess. However, nuclear medicine has been beneficial in diagnosing numerous harmful diseases. In some medical institutions, the approach has been used to effectively treat different kinds of cancers and conditions (Oyen et al, 1787). The radiation from radiopharmaceuticals could scan even the most sensitive body parts to evaluate whether a serious disease could be developing. It is a safe procedure that provides information that could be unavailable if other imaging procedures such as CT scans and MRI were used thus informing of a disease early enough for appropriate course of action. Furthermore, it provides a less traumatic experience than the normal exploratory surgical procedures. Nuclear medicine allows for full body scan, a fact that could be considered important when lesions occur in varied body parts such as would be the case with cancer dissemination where lesions are suspect but no indication exists. In spite of these benefits, nuclear medicine has some limitations. With the costly facilities required, WNA argues that the practice calls for immense investments. The mild radiation produced could develop to cancers among patients if appropriate care is not taken into account. This threatens the health of patients, thus not the best alternative to traditional treatment methods. Conclusion Nuclear medicine refers to a radiopharmaceutical, a combination of a radioisotope and medicine. This combination could be used for diagnosis, with mild radioisotope, where PET and SPECT scans and other minor forms of scans would be undertaken to identify anomalies or diseases in human body. It could be used with strong radioisotopes for therapeutic purposes. Even though nuclear medicine presents immense benefits with regards to human health, care should be observed when handling children and expectant and breastfeeding women. All in all, nuclear medicine provides greater benefits in diagnosis of conditions that some common scans could fail to detect thus a significant step in healthcare to preserve human health. Works Cited Biersack, H., and L. M. Freeman. Clinical Nuclear Medicine. Shrewsbury: Springer, 2007. Print. Oyen, W. J. G., et al. ‘Targeted Therapy in Nuclear Medicine – Current Status and Future Prospects.’ Annals of Oncology 18.11 (2007): 1782 – 1792. Print. Prakash, D. Nuclear Medicine: A Guide for Healthcare Professionals and Patients. New York, NY: Springer, 2014. Print. Shulthess, G. K., ed. Molecular Anatomic Imaging: PET-CT and SPECT-CT Integrated Modality Imaging. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2007. Print. Society of Nuclear Medicine US National Institute of Biomedical imaging and Bioengineering. ‘Nuclear Medicine.’ Nih.gov. National Institutes of Health, 2014. Web. 1 Dec. 2014. World Nuclear Association. Radioisotopes in Medicine. London, 27 Nov. 2014. Web. 1 Dec. 2014. Read More