What is Nuclear Medicine

The word Medicine is a very familiar word to all of us, but what do you mean by the terminology Nuclear Medicine? Is it something related to the nucleus of an atom and medicine, if so what is the interconnection between these two. By reading this article, you can sense out what Nuclear Medicine is.

Nuclear Medicine – Definition

Nuclear Medicine is a combined field of the radioactivity and the medicine where radioactivity is used to diagnose and treat the patients. The diagnosis part is done by using the radioactive substances to produce images of the body in a non-invasive way. The treatment part is mainly used to cure the diseases at the molecular level, such as cancers which are considered as deadly diseases. In these methods, the radionuclides and the pharmaceutical compounds are collaborated to produce radiopharmaceuticals. These radiopharmaceuticals are the substances which are injected or inserted into the human body to achieve the above medical purposes.

History of Nuclear Medicine

The beginning of the nuclear medicine cannot be clearly identified and in general we consider that the discovery of the X-ray by Henri Becquerel as the first step in nuclear medicine. Even though the x-ray was found in late 1890’s the real usage began after four decades from that. In 1934 artificial radioactivity was discovered by two Curies, Fredric Curie and Irene Curie. This is considered as the most significant milestone in Nuclear Medicine. In 1935 John .H. Lawrence, father of the Nuclear Medicine took his first step in Nuclear Therapy by treating a leukemia patient with phosphorus-32.The production of first radiopharmaceutical (I-131) and its first usage to treat thyroid cancer was successfully tested in 1946 at Oak Ridge National Laboratory. This was a turning point in all Nuclear Medicine history and after that, the world made a huge leap in Nuclear Medicine. The field spread drastically in 1950’s and 1960’s and scientists and clinicians identified those radioisotopes (first the I(odine)-131) not only as therapeutically important elements but also as medical image producing elements. In 1962 David Khul brought in the method of emission reconstruction tomography which was later known as SPECT and PET and also used in radiology scanning method, we already known as CT.

Nuclear Medicine Technology in Diagnosis

We already knew that there are two basic categories in nuclear Medicine as treatment and diagnosis. Let’s see how these categories are technologically set together. First, we will consider the diagnostic technology.

Small amount (1/1000000 of an ounce) of a radio-pharmaceutical is inserted into the patient’s body through injection, swallowing or inhalation. Then, it is distributed in the patient’s whole body and concentrated in the disease area or the abnormality. The radioactive element of the radiopharmaceutical emits gamma rays. These rays can be detected by a special gamma camera placed near the patient’s body. Then, the clinician takes photos according to the need. This differs from X-rays as in X-rays radioactive elements are used outside the body to create an image, but in PET(Positron emission tomography) or SPECT (single-photon emission computerized tomography) machines use the rays produced in the body, therefore, they give clearer and sensitive images. This is why Nuclear Medicine is utilized as a live imaging method where clinicians can observe not only the structure but also how the organs are functioning. These images are used by clinicians to determine various pathological doings such as heat pump rate, brain cell functionality, kidney functionality, bone density and bone fractures, etc.

Nuclear Medicine Technology in Treatment

Radionuclide Therapy (RNT) is the method of treating patients using Nuclear Medicine. Here also the same technology is used which is described above, but using a different property of radioisotopes (or radiopharmaceuticals). In a cancerous area, damaged cells are dividing uncontrollably at a higher rate than normal rate as their DNA structure is damaged . Radiation can be used to destroy those damaged cells and stop their growth. Radiation can be used both internally and externally for the treatment. The external method is mainly used to treat tumors where a beam of gamma rays from a radioactive cobalt-60 source is focused on the cancerous area to kill the damaged cells. The internal method (Brachytherapy) is a complex treatment method where a small radiation source, usually a gamma or beta emitter is placed in the targeted area. Then, the radiopharmaceutical is sent through a tube to that area and released. The therapies for breast cancers and thyroid cancers are done by this method, and this is more cost effective and also makes a lesser overall radiation in the body.

The usage of radioisotopes in this medical method is mainly because of their ability to eliminate and their shorter half –life than other elements.(These two properties relate to each other.) The lesser dosage used in radiotherapy and the scanning process is to avoid the damage by the radioactive elements. When using a lesser dosage its ability of killing the cells also is reduced, but if the activity level is controlled by using a lesser dosage in small targeted area both goals can be scored; the higher destroying rate and the lesser damage rate.