Cancer Treatment - Taking Pride in the Advances in Radiation Therapy

Unfortunately, people are misinformed. Also, most people’s perceptions of radiation therapy are colored by unfortunate anecdotes, which people have not put into their proper perspective. After all, one hears about bad outcomes when people travel in motor vehicles.  Yet, people do not fear the potential dangers of driving or being a passenger they way dread the thought of radiation therapy.  Furthermore, society does not make the distinction between cleanly prescribed medical radiation and nuclear accidents like Chernobyl. 

Moreover, the earliest radiotherapy machines did not have energy high enough to penetrate to the area of interest, also known as the target, such as the prostate gland.  Instead, the radiation unintentionally deposited a substantial dose on the skin, resulting in burns.  Also, these machines were stationary, and could not rotate around the area that needed to be treated.

Today, such equipment has been supplanted by sophisticated, computer driven, high energy linear accelerators, which can treat a target from multiple angles, thus spreading out the radiation dose instead of concentrating it on only one area.  This is one measure that protects normal tissue.

In the early days, there were no treatment planning computers to perform dosimetry, the precise measurement of the radiation dose in the target and the normal tissues through which the radiation beam passed.

Also, there were no data to show that by prescribing radiation therapy in a protracted manner over several weeks, the normal tissues recovered from the insult of radiation, while tumor cells died and were naturally eliminated by the body.

Today, radiation oncologists know how much radiation therapy each organ can tolerate before it incurs injury. Hence, radiation therapy can be safely prescribed to treat the target properly, yet spare the healthy, surrounding organs.

When the radiation oncologist cannot avoid treating the skin, such as when the chest wall is irradiated after a mastectomy to prevent a recurrence on the chest wall, a prophylactic treatment break is given to prevent or reduce the severity of a burn.  Also, such a problem is temporary, and with proper care, patients get through it.

Through the evolution of radiation therapy, radiation oncologists have learned that shaping the treatment field to conform to the shape of the target limits the amount of normal tissue exposed to radiation.  This means that the treatment field, which is normally a square or a rectangle, can be shaped with lead blocking devices to match the shape of or target.  Modern techniques use CAT scans and 3-D treatment planning computers for this purpose.

More sophisticated imaging tools, such as high resolution CAT scans, MRI scans, and PET scans, further enable radiation oncologists to confine radiation therapy to the target. For example, CAT scan and conformal blocking techniques for breast cancer allows the treatment team to spare virtually all the heart when the left breast or chest wall is treated.