Helical TomoTherapy
In October 2004, City of Hope became the first facility in the Western U.S. to offer radiation therapy treatment using the TomoTherapy HI-ART System®. The system combines the advances in Intensity Modulated Radiation Therapy (IMRT), 3D medical imaging, and computer control that have been instrumental in improving cancer treatment.
Current treatment requires two separate apparatus—one images the target, the other delivers the radiation. With helical TomoTherapy, the computed tomography (CT) scanner is married to the radiation source, all in one system, thereby increasing the precision of the treatment. As the patient lies on a treatment couch, the device rotates continuously around him or her. Its radiation beam turns on and off rapidly, splitting into hundreds of tiny beamlets that deliver precise amounts of energy to the tumor.
Helical tomotherapy improves the treatment of tumors adjacent to sensitive organs such as the lungs, where it is difficult to target tumors without affecting the healthy tissue around them. It is also useful in treating prostate cancer, where limiting radiation to the adjacent rectum and bladder is critical.
Importantly for patients who will be treated with a bone marrow transplantation, physicians will evaluate the potential of helical tomotherapy to specifically irradiate just the bone marrow, while sparing normal tissues.
TomoTherapy Fact-Sheets: download (.pdf);
Image Guided Radiation Therapy
The latest radiation therapy techniques, such as intensity modulated radiation therapy (IMRT), are based on sparing the maximum healthy tissue from inadvertent irradiation. In order for this to be accomplished, treatment margins around the tumor are minimized, thus precision and accuracy of targeting are critical to success.
However, due to the uncontrolled movement of internal organs or structures and the uncertainties remaining in repeating and maintaining the set-up of the patient, delivering the planned treatment accurately to the target is a significant challenge. This could result in a geographical miss of the target organ, or over-treatment of critical structures.
Image Guided Radiation Therapy (IGRT) provides radiation oncologists with the tools to see the tumor better, track its movement and stay on target. TomoTherapy, as the next generation of IMRT treatment, which incorporates advance sparing of normal structures, with image based targeting, has virtually replaced standard IMRT at City of Hope.
Three Dimensional Conformal Therapy
3-D conformal therapy is based on the three dimensional treatment planning from reconstructed CT or MRI data. This data provides the treatment planning system with the necessary information regarding the tumor volume, as well as normal structures. The major advantage of conformal radiation therapy is the ability to precisely shape high dose regions of radiation to the tumor or target volume, while at the same time sparing the normal tissue.
Total Body Irradiation
City of Hope was a pioneer in the development of bone marrow transplantation (BMT) and was one of the first medical centers in the nation to perform this procedure. City of Hope physicians continue to be on the cutting edge of this revolutionary technique used to treat leukemia, lymphoma, Hodgkin's disease and other types of cancers that have not responded to traditional therapies. An important part of bone marrow transplantation is Total Body Irradiation Therapy, a procedure that is used to irradiate the entire body of the patient. This form of radiation - done in conjunction with high dose chemotherapy - purges the patient's bone marrow, which subsequently is replaced with new donated bone marrow that no longer contains cancer cells. The donated marrow may be from a matched donor (allogeneic) or marrow from the patient (autologous).
Total Marrow Irradiation
In June, 2005, City of Hope performed the first total marrow irradiation procedure in the world using TomoTherapy technology. Since then, the total marrow irradiation program has been expanded and has become available in a number of clinical trials.
For years, radiation oncologists have treated blood and bone marrow cancers with total body irradiation, and solid tumors with broad radiation beams. During this process, it is difficult to keep radiation from damaging organs in surrounding areas. TomoTherapy technology, with its tiny radiation beamlets, targets tumors more precisely. City of Hope can now deliver radiation to the entire marrow compartment where the cancer cells reside, in a precisely focused manner. This total marrow irradiation potentially improves treatment while reducing recovery time and side effects.
Stereotactic Radiosurgery and Stereotactic Radiotherapy
Stereotactic Radiosurgery and Stereotactic Radiotherapy are forms of highly focused external beam radiation therapy used to treat small tumors such as those in the head and brain. These treatment procedures demand the participation of a multi-disciplinary oncology treatment team, consisting of the radiation oncologist, neurosurgeon, neuro-oncologist, medical physicist and radiation therapist.
Some of the clinical indications for this therapy include:
- Brain metastases
- Gliomas
- Acoustic neuromas
- Meningiomas
- Pituitary adenomas
- Pediatric brain tumors
- Low grade astrocytomas
Stereotactic Radiosurgery is a procedure that gives a focused single dose of radiation to a small target area with pin-point accuracy. Stereotactic Radiotherapy refers to similarly precise therapy given with smaller doses over a period of time. Patient treatments are generally completed in less than an hour. Patient comfort and stabilization is achieved with the use of either a frameless or rigid frame immobilization technique, which provide millimeter accuracy.
