CT & PET Simulation

Patients undergoing radiation treatments are required to undergo a process called simulation to accurately identify the area that needs to be treated. During simulation an x-ray study is done to locate the area that needs treatment and then lasers are used to allow marks to be placed on the body. When treatment occurs later, lasers are used to assure the patient is in exactly the right position for treatment. Many times, special devices are made to help hold the patient in the correct position. Sometimes special molds are made that fit closely around key parts of the body. For head and neck cancer or when the brain needs to be treated, customized mesh masks are made to accomplish the same thing. Collectively these are known as immobilization devices, something to prevent movement while the treatment is being given.

At the Cancer Center at Lake City either a CT scanner or a PET/CT scanner is used to take the x-ray study for simulation. The CT scan is then used to develop the treatment plan that will be delivered by either the Varian Linear Accelerator or the TomoTherapy® machine. For patients where there are still cancer cells in the body, the simulation is often performed on the PET/CT scanner. In these cases, the PET/CT provides more information about which parts of the tumor mass have active tumor cells and helps the radiation oncologist create a more precise plan.

Prostate Brachytherapy (Seed Implants)

Prostate Seed implantation is based upon the use of radioactive seeds, each smaller than a grain of rice. The seeds are made of titanium and contain a small amount of either radioactive palladium or iodine. Prostate implantation is a minor procedure performed in the hospital. The entire procedure takes less than an hour. The radioactivity then kills the cancer cells but, because the radiation from each individual seed does not travel very far, there is minimal damage to the tissues that surround the prostate gland. There are cases where the use of seeds is combined with the more traditional external beam radiation therapy to provide the maximum possible effect. Due to the excellent long term results and minimal side effects, this is now becoming the choice of treatment for most men diagnosed with prostate cancer.

At the Cancer Center at Lake City patients can take advantage of the vast experience of our physicians experience in this approach. Real-time treatment planning, available through the Cancer Center at Lake City, allows more accurate placement of the seeds than planning techniques available from other seed implant programs.

To obtain a free brochure about this procedure and other treatment options for prostate cancer, please call our office in Lake City at (386) 758-7822.

Intensity Modulated Radiation Therapy (IMRT)

IMRT is the most advanced system for the delivery of external radiation. This technique allows for the maximum amount of radiation to be delivered to a tumor while minimizing radiation side-effects to the normal surrounding tissue. The Cancer Center at Lake City utilizes the newest IMRT technology.


MammoSite is a method of partial breast irradiation that is designed for selective patients that have been diagnosed with breast cancer. It allows radiation to be delivered directly to the lumpectomy site. The lumpectomy site (the area surrounding where the tumor was removed) is where the cancer typically recurs.

MammoSite is a small catheter that is placed in the lumpectomy cavity. This catheter is then attached to an afterloader that inserts a small radioactive source into the lumpectomy cavity. This procedure allows a patient to receive a complete course of radiation in 5 days which in the past could take 6 weeks.

If you have any questions or would like to receive information about this procedure and our network of cancer centers, please call (386) 758-7822.

High Dose Rate (HDR)

Brachytherapy, which means "short therapy", is a method of placing a radiation source directly into the cancerous tumor. It can be placed through needles, tubes or catheters, or by "applicators" into body cavities by an "afterloader". A computer tells the afterloader at what depth the source is to be inserted as well as how long it is to stay in place. By moving the source to many different precise locations within the treatment device and having the ability to control the time it remains in place, the result is a perfectly delivered dose of radiation to the tumor. Because the radiation does not have to be "beamed in" through normal organs, huge doses of radiation can be safely given in one setting.