Intensity Modulated Radiation Therapy (IMRT)

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By adding this latest technologically advanced treatment modality (IMRT -Intensity Modulated Radiation Therapy),Winter Haven Hospital will the able to better serve the members of our community and will be the only institution in east polk county providing this service.

“The primary goal in radiation treatment of cancer,” explains Inder Bhutiani, M.D., board certified radiation oncologist and Medical Director of the Radiation Oncology Department at Winter Haven Hospital, “is to treat the tumor enough to completely destroy it while minimizing side effects. All the advances made at our hospital over the last decade have been focused on that goal. IMRT is the latest technological advancement and is without a doubt, the most significant.” IMRT (Intensity Modulated Radiation Therapy) is a very sophisticated modality of radiation therapy that allows physicians to deliver cancer killing radiation doses to a specific target (tumor) volume without treating surrounding healthy tissue thereby reducing side effects. “We are extremely excited about this new form of radiation therapy,” states Hee Jae Yoon, M.D., board certified radiation oncologist at Winter Haven Hospital and partner of Dr. Bhutiani. “Our diagnostic and imaging technology has always allowed us to accurately define cancer tissue and critical structures. We take that information and use shielding and treatment beam arrangements to optimize the radiation treatment. IMRT allows us to take that process one step further. Through advanced computer planning processes and using state-of-the-art treatment, we are able to conform the radiation dose specifically to the patient’s tumor. We can literally ‘bend’ the radiation dose around critical structures without compromising the tumor dose.”

One might conclude that all this complexity is more taxing on the patient, but this is not the case explains Dr. Bhutiani. “The advancements we are describing are ‘behind the scenes’ as far as the patient is concerned. The patient work-up and treatment time is not significantly different than our current 3-dimensional treatment delivery time. However, the man-hours required by Dr. Yoon, our staff, and me will increase due to the complexity of the planning process.

To best understand the IMRT process, a step-by-step explanation is necessary. Once the radiation oncologist has determined the area and the extent of the cancer, the patient will be scheduled for a CT simulation. This is no different than a diagnostic CT except the patient is scanned in the position that will be duplicated during the daily treatments. The patient then goes home and does not return until the treatment plan has been computed and verified.

The images from the CT are transferred into the treatment planning computer. The treatment planning computer uses the images of the patient and reconstructs the patient’s anatomy in virtual reality similar to slicing an orange and putting the slices back together. At this point, the radiation oncologist “outlines” the cancer and the critical structures on the computer. This is done with the help of all the diagnostic procedures done during the patient’s work up and staging such as other CT scans, Magnetic Resonance Imaging (MRI), Nuclear Medicine scans, etc. In some cases, these other studies can also be imported into the treatment planning computer and superimposed on the CT images allowing the physician to look at both scans simultaneously. The optimal beam arrangement is then determined by the physician as well as the desired radiation treatment doses. The computer then calculates the settings that the treatment machine will use to tailor the delivery of the radiation dose. Once those settings are determined and upon final approval by the radiation oncologist, the patient will be ready to begin daily radiation treatments.

“The time consuming step is the calculation time the computer needs to optimize the dose to the target without exceeding any doses to critical structures. We have given the computer a difficult problem and in most cases, it will take it some time to come to an acceptable solution,” explains Dr. Yoon. “Additionally, after the plan is approved, each treatment angle (field) must be individually measured and verified prior to starting the actual treatment. These are complex ‘fluences’ of doses and the easy traditional methods of field verification cannot be used,” adds Dr. Bhutiani. “The planning process has changed, but as far as the patient is concerned, the actual treatments will seem no different than before.

Many cancer patients receiving radiation therapy will benefit from the use of IMRT. “IMRT is especially useful in the treatment of breast cancer, prostate cancer, head and neck cancer, brain cancer, and pancreatic cancer just to name a few. By delivering curable doses of radiation and at the same time minimizing the side effects of the treatment, we will be able to provide more effective state of the art treatment for patients,” states Dr. Bhutiani.

By adding this latest technologically advanced treatment modality, our team in Radiation Oncology, including our physicists, dosimetrist, radiation therapy and technologists and secretaries will be able to better serve the members of our community and will be the only institution in east polk county providing this service.

Seated (L to R); Laurie Offerman, RT(R)(T), Radiation Therapist, Sharon Baker, Office Assistant, Standing (L to R); Jenny Bunch, Office Assistant, Sharon Duffy, RT(R)(T), Radiation Therapist, Inder K. Bhutiani, MD, Radiation Oncologist, Hee Jae Yoon, MD, Radiation Oncologist, Tammy J. Clark RT (R)(T), Radiation Therapist, Mary Baluch, Volunteer, Third Row; Danny Bryan, Mold Room Technician, Philip Morrill, BS, C:MD, Medical Dosimetrist, Frank Schlagel, RT(T), Radiation Therapist and William R. Wedding, MS, Medical Physicist.

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