Radiation OncologyTypes of Radiation Therapy
TYPES OF RADIATION THERAPY
There are two types of radiation therapy, external and internal. External therapy beams radiation from the outside of the body into the area of the body that needs treatment. Internal radiation therapy (called Brachytherapy) delivers radiation from inside the body through “seeds,” needles, or a radiation source placed directly on the affected area. Certain types of radiation are best suited to specific areas of the body. The type of radiation selected by the radiation oncologist depends upon the location of the tumor.
EXTERNAL BEAM THERAPY
INTENSITY MODULATED RADIATION THERAPY (IMRT)
IMAGE GUIDED RADIATION THERAPY (IGRT)
BRACHYTHERAPY
CONTURA MULTI-LUMEN BRACHYTHERAPY
STEREOTACTIC RADIOSURGERY (SRS)
RAPIDARC RADIOTHERAPY
CONTURA MULTI-LUMEN BRACHYRTHERAPY
St. Vincent Hospital offers Contura Multi-Lumen Balloon Brachytherapy, a partial-breast radiation treatment that allows breast cancer patients requiring radiation therapy after a lumpectomy to be treated in five days, rather than six to seven weeks for whole-breast irradiation.
“Brachytherapy is from the Greek word meaning ‘close’ or ‘internal,’ referring to a way of delivering treatment from inside rather than outside. By targeting treatment from inside the breast, radiation treatment is completed n five days, allowing patients to return more quickly to their day-to-day lives.
Radiation therapy is given to most patients who have a lumpectomy for breast cancer, to kill cancer cells or prevent them from reproducing or spreading, reducing the risk of recurrence. Whole breast irradiation uses a radiation source outside the body to treat the cancer site, typically involving daily treatments for six days per week over a six- to seven-week period.
Many breast cancer patients may be appropriate candidates for alternatives to whole breast radiation treatment known as partial breast irradiation or breast brachytherapy, a technique for delivering internally targeted radiation. Breast brachytherapy delivers radiation to the breast tissue surrounding the lumpectomy cavity rather than to the entire breast.
The Contura is a small balloon-based device implanted into the breast to treat the “rind” of tissue surrounding the cavity left by lumpectomy surgery. After being inserted, the balloon is inflated and filled with saline; vacuum is used to help the balloon fit closely within the often irregularly shaped lumpectomy cavity. Then a radiation seed is sent through five separate “lumens” or channels inside the balloon, allowing the radiation dose to be “contoured” to reach the targeted area. The dose is directed by where the seed sits in the balloon, allowing us to concentrate the radiation dose on the tumor area. If the seed were too close to the skin in channel one, oncologists might place the seed in channels three or four for a longer time than in channel one.
Before the introduction of Contura in 2007, balloon brachytherapy was available with only a single channel for delivery of the radiation seed. Some patients who were possible candidates for the therapy were excluded because the location of the lesion relative to their breast size did not allow appropriate placement of the radiation seed to minimize radiation dose to the skin, chest wall or ribs.
Contura Multi-Lumen Balloon Brachytherapy was developed to address this problem by using five separate channels to place the radiation seed. It also employs vacuum suction to help the balloon fit closely within the often irregularly shaped lumpectomy cavity, so the targeted areas receive the prescribed therapeutic dose.
EXTERNAL BEAM THERAPY
This is state-of-the-art therapy that directs the exact dosage of high energy precisely to the cancer site, but keeps radiation to other parts of the body to a minimum. It’s a high-tech treatment that beams the radiation from outside the body. The radiation oncology department can choose from a variety of special machines that produce ionizing radiation (such as photons or high-energy x-rays) that destroy cancer cells. St. Vincent Hospital uses Varian's Trilogy™, as well as our high performance clinic linear accelerator.
Your external beam treatment schedule
Your schedule for treatment will depend entirely on your individual situation. However, patients usually receive external beam therapy five times a week. Sometimes, a patient is treated twice a day. An entire course of treatment may last from one to nine weeks, depending on the type of cancer and the goal of the treatment.
How treatment is performed
We carefully direct the radiation to the tumor and the surrounding area to destroy the tumor and any nearby extensions. We try our best to spare any surrounding tissues. Still, radiation may affect some healthy cells.
The radiation therapist will not be in the room with you when you receive external beam therapy. The therapist will closely monitor you on a television screen during your treatment. We also have an intercom system that allows us to be in constant contact with you. The treatment room may be cooler than desired because our radiation machines require cooler temperatures for best operation. During the treatment, you will be asked to lie very still on the treatment table. The radiation therapist can move the treatment machine so the radiation beam can be precisely targeted to the exact area of the tumor. The machine can rotate 360 degrees around you so the radiation can hit the tumor from different angles. Each treatment is painless and lasts only a few minutes.
Weekly check-ups
You will see the radiation oncologist and the radiation nurse on a weekly basis to keep track of the treatment progress and answer any questions. You may receive blood tests, x-rays, or other tests to determine how well the treatments are working.
INTENSITY MODULATED RADIATION THERAPY (IMRT)
IMRT is a specific way to deliver radiation treatments that allows the doctor to give higher doses of radiation to the cancer while protecting as much normal tissue as possible. Our state-of-the-art machines contain 120 individual leaves that are computer-controlled and can be driven at different speeds across the treatment area so the shape of the radiation dose can be matched to the shape of the tumor. The goal for IMRT is to improve cure rates and reduce side effects. The entire IMRT treatment typically takes 20-30 minutes. The time the radiation beam is actually on during treatment is approximately 30 seconds from each direction.
IMAGE GUIDED RADIATION THERAPY (IGRT)
IGRT, or image-guided radiotherapy, is the most advanced form of radiation therapy currently available. Tumors can move during treatment (usually due to patient respiration) and between treatments (usually due to day-to-day variations in patient setup). IGRT uses advanced imaging techniques to verify patient position and tumor position at the time of treatment. Knowing exactly where the tumor is allows clinicians to reduce the amount of tissue irradiated, targeting only the tumor and sparing the surrounding normal tissue. Irradiating less normal tissue reduces the toxicity of radiotherapy, improving the patient's quality of life, and may make it possible to deliver higher radiation doses to the tumor and thereby increase the likelihood of local tumor control. IGRT can be combined with IMRT or delivered with traditional external beam radiation therapy.
With Trilogy™ radiation treatment system, patients are positioned on a treatment couch, and an x-ray system mounted on a robotic arm is rotated around the body, to gather images that pinpoint a tumor's exact location. These images are then compared with existing images (MRI, CT or other kinds of scans) in order to determine if the tumor as moved since the last treatment. Because tissues and organs can settle around bones differently each time a patient lies down on a treatment table, tumors can end up in different positions from one treatment session to another.
IGRT can be used to treat prostate cancer patients through the use of daily ultrasounds to pinpoint the exact location of a tumor prior to each daily radiation treatment.
BRACHYTHERAPY
Brachytherapy delivers radiation from inside the body through an implant, “seeds” or needles or a radiation source placed directly on the affected area. The source of the radiation can be temporary or permanent. Brachytherapy can be either high dose rate or low dose rate.
The radiation oncologist will decide which type of brachytherapy treatment is required based on location, tumor extent and other factors.
Brachytherapy techniques offer numerous patient benefits, including:
• Shorter treatment times
• More convenient
• Less possibility of discomfort
• Better ability to deliver the radiation to the tumor while sparing normal tissues
Brachytherapy can be used to treat several types of cancer. The most common types of cancer treated with brachytherapy include breast, cervical, vaginal, uterine, prostate and pterygium of the eye.
High Dose Rate (HDR) Brachytherapy
Procedures that were once performed using low dose rate (LDR) brachytherapy have been made better and more convenient by delivering the dose in a much shorter time period using high dose rate therapy (HDR). Sometimes, HDR brachytherapy is done in combination with external beam therapy to help destroy the main mass of tumor cells. The radiation oncologist will decide which type of HDR implant is required based on location, tumor extent, and other factors.
The three types of HDR implants are:
Intracavitary—an applicator is inserted into a body cavity to reach the tumor.
Intralumenal—catheters are inserted into a “tube” such as the bronchus, esophagus, or bile duct.
Interstitial—more complex. The implants are done in the Radiation Oncology surgical suite with the patient under anesthesia or sedation. Interstitial catheters are inserted through the body tissue to encompass the tumor.
HDR techniques offer numerous benefits, including:
-Shorter treatment times
-More convenient
-Less possibility of discomfort
-Better ability to deliver the radiation to the tumor while sparing normal tissues
Specific Cancers that Can Be Treated with HDR
Breast Cancer
There are two ways that breasts can be treated using HDR. Your radiation oncologist will decide which procedure is best for you depending on the individual details of your condition.
• Interstitial Implant: HDR is delivered through interstitial catheters inserted in the breast while the patient is under anesthesia or sedated. The catheters are attached to the after-loading device at the time of treatment with the radiation source. These catheters stay in the breast during the week that treatment is given and are removed after the last treatment. The implant can be done at the time the lumpectomy is healed.
• MammoSite or Contura: HDR is delivered by inserting a balloon in the tumor cavity during surgery at the time the lumpectomy is done, or it can be inserted at a later date. A catheter is connected to the balloon that is attached to the after-loading device at the time of treatment with the radiation source. These treatments can be given right after the surgery is performed.
Gynecologic Cancer
• Brachytherapy is a key treatment option for cancer of the cervix, vagina, and uterus. Depending on the type of treatment your radiation oncologist decides is best for your particular condition, an applicator can be inserted into the uterus and/or vagina while you are anesthetized, sedated, or medicated.
High dose rate (HDR) brachytherapy offers the advantage of outpatient applicator insertions, eliminating the 48-72 hours of bed-rest required with low dose radiation (LDR) techniques. These are intracavitary implants. Patients treated with intracavitary implant receive 3-6 treatments.
Prostate Cancer
There are two forms of brachytherapy used to treat prostate cancer, High Dose Rate (temporary) and Low Dose Rate (permanent seeds). Your radiation oncologist will decide which procedure is best, based on your individual condition.
• HDR Prostate Implantation: is done in the surgical suite at St. Vincent Hospital Regional Cancer Center in Radiation Oncology. However, the implant procedure does not require a surgical incision. The needles penetrate through the prostate; they are seen on an ultrasound screen and can be accurately guided to their final position. While the needles are being inserted, the ultrasound probe is in the rectum. The needles are then connected to an after-loading device at the time of radiation treatment. Usually, there are few side effects from High Dose Rate brachytherapy. However, there may be some inflammation and tenderness at the treatment site. Patients treated with HDR prostate implants receive 2-3 treatments.
• LDR Prostate Seed Implantation: is also done in the surgical suite at St. Vincent Hospital Regional Cancer Center in Radiation Oncology. However, the implant procedure does not require a surgical incision. Instead, seeds—smaller than grains of rice—are contained in thin needles, which are passed into the prostate gland through the skin between the scrotum and rectum. As the needles penetrate the prostate, they are seen on an ultrasound screen and can be accurately guided to their final position. While the needles are being inserted, the ultrasound probe is in the rectum. The tiny seeds, which are radioactive, are permanently implanted directly in the prostate where they give off low-level radiation continuously for approximately one to two years. Most of the radiation is released between two to six months after the implant depending on the type of seed used. Since only a small volume is irradiated by each seed, relatively little radiation reaches the adjacent cancer-free organs such as the rectum and bladder.
Strontium 90 Eye Applicator for Treatment of a Pterygium
After an opthalmogist surgically removes the pterygium from the eye, the patient comes to the Radiation Oncology Department to have the surgical area treated to prevent re-growth of the pterygium. This involves numbing the eye with a solution and putting a radioactive source over the area for less than a minute. The patient wears a patch over the treated eye for about an hour after treatment until the numbness has worn off.
STEREOTACTIC RADIOSURGERY (SRS)
Stereotactic radiosurgery is a very sophisticated type of radiation therapy treatment in which high doses of radiation are delivered using a very precise beam in five or less visits. In spite of the term, radiosurgery, no incision is made and treatment is generally given as an outpatient visit.
Using Trilogy™, our clinicians can offer stereotactic radiosurgery when appropriate. It is generally used for smaller lesions and metastases. Historically, this approach was used primarily in neurosurgery, for treating brain lesions and abnormalities. However, the Trilogy system is optimized to deliver stereotactic radiosurgery to tumors in the body, as well. The precision of the system is what makes this feasible; it can deliver a very high dose with sub-millimeter accuracy. That power and precision is what Varian's Trilogy system delivers for us.
Patient Benefits
• Small lesions can be treated with radiotherapy, reducing the need for more invasive treatments such as surgery or chemotherapy.
• The use of powerful beams means reduced treatment times, far shorter than Cyberknife™. Shorter treatments mean less time lying on a table, and more comfort for the patient.
• The most accurate beam means the most accurate treatment.
• The most advanced patient positioning tools mean the most accurate treatment and a reduction in side effects.
• The ability to deliver treatments that shrink-wrap the radiation dose to the tumor means a reduction in the side effects of the treatment.
RAPIDARC RADIOTHERAPY
RapicArc radiotherapy treatment is now offered to cancer patients who need radiation oncology at the St. Vincent Hospital site of the Regional Cancer Collaborative in Green Bay. This breakthrough technology speeds up the delivery of radiation therapy and delivers it more precisely as doctors target tumors from every angle with this image-guided IMRT (intensity-modulated radiation therapy) that makes a 360-degree revolution around the patient while delivering the prescribed dose of radiation that spares healthy surrounding tissue while targeting the unique anatomy of the tumor.
During the treatment, the radiation beam is shaped and reshaped using a multi-leaf collimator, a device with 120 computer-controlled mechanical fingers that create apertures of different shapes and sizes. During the RapidArc treatment, specialized software algorithms vary three parameters simultaneously: the speed of the rotation around the patient; the shape of the aperture, and the dose delivery rate.
The speed of RapidArc makes treatments easier on the patient, lasting less than two minutes long instead of 20 minutes or more, so they are more comfortable and don’t have to hold still so long. That shortened time translates to more precise treatment.
Because RapidArc technology targets tumors so precisely, it is particularly useful in cancers of the prostate, head and neck and can spare healthy tissues nearby including the spinal cord, brain stem, eyes, optic nerve and chiasm, parotid glands and brain.
RapidArc treatments are delivered using the Trilogy medical linear accelerator from Varian Medical Systems which St. Vincent has used for patients since 2008.
The new technology “is a breakthrough marrying advanced imaging so we can see the cancer precisely with a high technology treatment delivery system so we can give higher doses of radiation directly to the cancer,” said Radiation Oncologist Dr. Linda Gemer, Medical Director of St. Vincent’s Radiation Oncology Department. “All of this technology is designed for better cancer control and more comfort for the patient.”
There are two types of radiation therapy, external and internal. External therapy beams radiation from the outside of the body into the area of the body that needs treatment. Internal radiation therapy (called Brachytherapy) delivers radiation from inside the body through “seeds,” needles, or a radiation source placed directly on the affected area. Certain types of radiation are best suited to specific areas of the body. The type of radiation selected by the radiation oncologist depends upon the location of the tumor.
EXTERNAL BEAM THERAPY
INTENSITY MODULATED RADIATION THERAPY (IMRT)
IMAGE GUIDED RADIATION THERAPY (IGRT)
BRACHYTHERAPY
CONTURA MULTI-LUMEN BRACHYTHERAPY
STEREOTACTIC RADIOSURGERY (SRS)
RAPIDARC RADIOTHERAPY
CONTURA MULTI-LUMEN BRACHYRTHERAPY
St. Vincent Hospital offers Contura Multi-Lumen Balloon Brachytherapy, a partial-breast radiation treatment that allows breast cancer patients requiring radiation therapy after a lumpectomy to be treated in five days, rather than six to seven weeks for whole-breast irradiation.
“Brachytherapy is from the Greek word meaning ‘close’ or ‘internal,’ referring to a way of delivering treatment from inside rather than outside. By targeting treatment from inside the breast, radiation treatment is completed n five days, allowing patients to return more quickly to their day-to-day lives.
Radiation therapy is given to most patients who have a lumpectomy for breast cancer, to kill cancer cells or prevent them from reproducing or spreading, reducing the risk of recurrence. Whole breast irradiation uses a radiation source outside the body to treat the cancer site, typically involving daily treatments for six days per week over a six- to seven-week period.
Many breast cancer patients may be appropriate candidates for alternatives to whole breast radiation treatment known as partial breast irradiation or breast brachytherapy, a technique for delivering internally targeted radiation. Breast brachytherapy delivers radiation to the breast tissue surrounding the lumpectomy cavity rather than to the entire breast.
The Contura is a small balloon-based device implanted into the breast to treat the “rind” of tissue surrounding the cavity left by lumpectomy surgery. After being inserted, the balloon is inflated and filled with saline; vacuum is used to help the balloon fit closely within the often irregularly shaped lumpectomy cavity. Then a radiation seed is sent through five separate “lumens” or channels inside the balloon, allowing the radiation dose to be “contoured” to reach the targeted area. The dose is directed by where the seed sits in the balloon, allowing us to concentrate the radiation dose on the tumor area. If the seed were too close to the skin in channel one, oncologists might place the seed in channels three or four for a longer time than in channel one.
Before the introduction of Contura in 2007, balloon brachytherapy was available with only a single channel for delivery of the radiation seed. Some patients who were possible candidates for the therapy were excluded because the location of the lesion relative to their breast size did not allow appropriate placement of the radiation seed to minimize radiation dose to the skin, chest wall or ribs.
Contura Multi-Lumen Balloon Brachytherapy was developed to address this problem by using five separate channels to place the radiation seed. It also employs vacuum suction to help the balloon fit closely within the often irregularly shaped lumpectomy cavity, so the targeted areas receive the prescribed therapeutic dose.
EXTERNAL BEAM THERAPY
This is state-of-the-art therapy that directs the exact dosage of high energy precisely to the cancer site, but keeps radiation to other parts of the body to a minimum. It’s a high-tech treatment that beams the radiation from outside the body. The radiation oncology department can choose from a variety of special machines that produce ionizing radiation (such as photons or high-energy x-rays) that destroy cancer cells. St. Vincent Hospital uses Varian's Trilogy™, as well as our high performance clinic linear accelerator.
Your external beam treatment schedule
Your schedule for treatment will depend entirely on your individual situation. However, patients usually receive external beam therapy five times a week. Sometimes, a patient is treated twice a day. An entire course of treatment may last from one to nine weeks, depending on the type of cancer and the goal of the treatment.
How treatment is performed
We carefully direct the radiation to the tumor and the surrounding area to destroy the tumor and any nearby extensions. We try our best to spare any surrounding tissues. Still, radiation may affect some healthy cells.
The radiation therapist will not be in the room with you when you receive external beam therapy. The therapist will closely monitor you on a television screen during your treatment. We also have an intercom system that allows us to be in constant contact with you. The treatment room may be cooler than desired because our radiation machines require cooler temperatures for best operation. During the treatment, you will be asked to lie very still on the treatment table. The radiation therapist can move the treatment machine so the radiation beam can be precisely targeted to the exact area of the tumor. The machine can rotate 360 degrees around you so the radiation can hit the tumor from different angles. Each treatment is painless and lasts only a few minutes.
Weekly check-ups
You will see the radiation oncologist and the radiation nurse on a weekly basis to keep track of the treatment progress and answer any questions. You may receive blood tests, x-rays, or other tests to determine how well the treatments are working.
INTENSITY MODULATED RADIATION THERAPY (IMRT)
IMRT is a specific way to deliver radiation treatments that allows the doctor to give higher doses of radiation to the cancer while protecting as much normal tissue as possible. Our state-of-the-art machines contain 120 individual leaves that are computer-controlled and can be driven at different speeds across the treatment area so the shape of the radiation dose can be matched to the shape of the tumor. The goal for IMRT is to improve cure rates and reduce side effects. The entire IMRT treatment typically takes 20-30 minutes. The time the radiation beam is actually on during treatment is approximately 30 seconds from each direction.
IMAGE GUIDED RADIATION THERAPY (IGRT)
IGRT, or image-guided radiotherapy, is the most advanced form of radiation therapy currently available. Tumors can move during treatment (usually due to patient respiration) and between treatments (usually due to day-to-day variations in patient setup). IGRT uses advanced imaging techniques to verify patient position and tumor position at the time of treatment. Knowing exactly where the tumor is allows clinicians to reduce the amount of tissue irradiated, targeting only the tumor and sparing the surrounding normal tissue. Irradiating less normal tissue reduces the toxicity of radiotherapy, improving the patient's quality of life, and may make it possible to deliver higher radiation doses to the tumor and thereby increase the likelihood of local tumor control. IGRT can be combined with IMRT or delivered with traditional external beam radiation therapy.
With Trilogy™ radiation treatment system, patients are positioned on a treatment couch, and an x-ray system mounted on a robotic arm is rotated around the body, to gather images that pinpoint a tumor's exact location. These images are then compared with existing images (MRI, CT or other kinds of scans) in order to determine if the tumor as moved since the last treatment. Because tissues and organs can settle around bones differently each time a patient lies down on a treatment table, tumors can end up in different positions from one treatment session to another.
IGRT can be used to treat prostate cancer patients through the use of daily ultrasounds to pinpoint the exact location of a tumor prior to each daily radiation treatment.
BRACHYTHERAPY
Brachytherapy delivers radiation from inside the body through an implant, “seeds” or needles or a radiation source placed directly on the affected area. The source of the radiation can be temporary or permanent. Brachytherapy can be either high dose rate or low dose rate.
The radiation oncologist will decide which type of brachytherapy treatment is required based on location, tumor extent and other factors.
Brachytherapy techniques offer numerous patient benefits, including:
• Shorter treatment times
• More convenient
• Less possibility of discomfort
• Better ability to deliver the radiation to the tumor while sparing normal tissues
Brachytherapy can be used to treat several types of cancer. The most common types of cancer treated with brachytherapy include breast, cervical, vaginal, uterine, prostate and pterygium of the eye.
High Dose Rate (HDR) Brachytherapy
Procedures that were once performed using low dose rate (LDR) brachytherapy have been made better and more convenient by delivering the dose in a much shorter time period using high dose rate therapy (HDR). Sometimes, HDR brachytherapy is done in combination with external beam therapy to help destroy the main mass of tumor cells. The radiation oncologist will decide which type of HDR implant is required based on location, tumor extent, and other factors.
The three types of HDR implants are:
Intracavitary—an applicator is inserted into a body cavity to reach the tumor.
Intralumenal—catheters are inserted into a “tube” such as the bronchus, esophagus, or bile duct.
Interstitial—more complex. The implants are done in the Radiation Oncology surgical suite with the patient under anesthesia or sedation. Interstitial catheters are inserted through the body tissue to encompass the tumor.
HDR techniques offer numerous benefits, including:
-Shorter treatment times
-More convenient
-Less possibility of discomfort
-Better ability to deliver the radiation to the tumor while sparing normal tissues
Specific Cancers that Can Be Treated with HDR
Breast Cancer
There are two ways that breasts can be treated using HDR. Your radiation oncologist will decide which procedure is best for you depending on the individual details of your condition.
• Interstitial Implant: HDR is delivered through interstitial catheters inserted in the breast while the patient is under anesthesia or sedated. The catheters are attached to the after-loading device at the time of treatment with the radiation source. These catheters stay in the breast during the week that treatment is given and are removed after the last treatment. The implant can be done at the time the lumpectomy is healed.
• MammoSite or Contura: HDR is delivered by inserting a balloon in the tumor cavity during surgery at the time the lumpectomy is done, or it can be inserted at a later date. A catheter is connected to the balloon that is attached to the after-loading device at the time of treatment with the radiation source. These treatments can be given right after the surgery is performed.
Gynecologic Cancer
• Brachytherapy is a key treatment option for cancer of the cervix, vagina, and uterus. Depending on the type of treatment your radiation oncologist decides is best for your particular condition, an applicator can be inserted into the uterus and/or vagina while you are anesthetized, sedated, or medicated.
High dose rate (HDR) brachytherapy offers the advantage of outpatient applicator insertions, eliminating the 48-72 hours of bed-rest required with low dose radiation (LDR) techniques. These are intracavitary implants. Patients treated with intracavitary implant receive 3-6 treatments.
Prostate Cancer
There are two forms of brachytherapy used to treat prostate cancer, High Dose Rate (temporary) and Low Dose Rate (permanent seeds). Your radiation oncologist will decide which procedure is best, based on your individual condition.
• HDR Prostate Implantation: is done in the surgical suite at St. Vincent Hospital Regional Cancer Center in Radiation Oncology. However, the implant procedure does not require a surgical incision. The needles penetrate through the prostate; they are seen on an ultrasound screen and can be accurately guided to their final position. While the needles are being inserted, the ultrasound probe is in the rectum. The needles are then connected to an after-loading device at the time of radiation treatment. Usually, there are few side effects from High Dose Rate brachytherapy. However, there may be some inflammation and tenderness at the treatment site. Patients treated with HDR prostate implants receive 2-3 treatments.
• LDR Prostate Seed Implantation: is also done in the surgical suite at St. Vincent Hospital Regional Cancer Center in Radiation Oncology. However, the implant procedure does not require a surgical incision. Instead, seeds—smaller than grains of rice—are contained in thin needles, which are passed into the prostate gland through the skin between the scrotum and rectum. As the needles penetrate the prostate, they are seen on an ultrasound screen and can be accurately guided to their final position. While the needles are being inserted, the ultrasound probe is in the rectum. The tiny seeds, which are radioactive, are permanently implanted directly in the prostate where they give off low-level radiation continuously for approximately one to two years. Most of the radiation is released between two to six months after the implant depending on the type of seed used. Since only a small volume is irradiated by each seed, relatively little radiation reaches the adjacent cancer-free organs such as the rectum and bladder.
Strontium 90 Eye Applicator for Treatment of a Pterygium
After an opthalmogist surgically removes the pterygium from the eye, the patient comes to the Radiation Oncology Department to have the surgical area treated to prevent re-growth of the pterygium. This involves numbing the eye with a solution and putting a radioactive source over the area for less than a minute. The patient wears a patch over the treated eye for about an hour after treatment until the numbness has worn off.
STEREOTACTIC RADIOSURGERY (SRS)
Stereotactic radiosurgery is a very sophisticated type of radiation therapy treatment in which high doses of radiation are delivered using a very precise beam in five or less visits. In spite of the term, radiosurgery, no incision is made and treatment is generally given as an outpatient visit.
Using Trilogy™, our clinicians can offer stereotactic radiosurgery when appropriate. It is generally used for smaller lesions and metastases. Historically, this approach was used primarily in neurosurgery, for treating brain lesions and abnormalities. However, the Trilogy system is optimized to deliver stereotactic radiosurgery to tumors in the body, as well. The precision of the system is what makes this feasible; it can deliver a very high dose with sub-millimeter accuracy. That power and precision is what Varian's Trilogy system delivers for us.
Patient Benefits
• Small lesions can be treated with radiotherapy, reducing the need for more invasive treatments such as surgery or chemotherapy.
• The use of powerful beams means reduced treatment times, far shorter than Cyberknife™. Shorter treatments mean less time lying on a table, and more comfort for the patient.
• The most accurate beam means the most accurate treatment.
• The most advanced patient positioning tools mean the most accurate treatment and a reduction in side effects.
• The ability to deliver treatments that shrink-wrap the radiation dose to the tumor means a reduction in the side effects of the treatment.
RAPIDARC RADIOTHERAPY
RapicArc radiotherapy treatment is now offered to cancer patients who need radiation oncology at the St. Vincent Hospital site of the Regional Cancer Collaborative in Green Bay. This breakthrough technology speeds up the delivery of radiation therapy and delivers it more precisely as doctors target tumors from every angle with this image-guided IMRT (intensity-modulated radiation therapy) that makes a 360-degree revolution around the patient while delivering the prescribed dose of radiation that spares healthy surrounding tissue while targeting the unique anatomy of the tumor.
During the treatment, the radiation beam is shaped and reshaped using a multi-leaf collimator, a device with 120 computer-controlled mechanical fingers that create apertures of different shapes and sizes. During the RapidArc treatment, specialized software algorithms vary three parameters simultaneously: the speed of the rotation around the patient; the shape of the aperture, and the dose delivery rate.
The speed of RapidArc makes treatments easier on the patient, lasting less than two minutes long instead of 20 minutes or more, so they are more comfortable and don’t have to hold still so long. That shortened time translates to more precise treatment.
Because RapidArc technology targets tumors so precisely, it is particularly useful in cancers of the prostate, head and neck and can spare healthy tissues nearby including the spinal cord, brain stem, eyes, optic nerve and chiasm, parotid glands and brain.
RapidArc treatments are delivered using the Trilogy medical linear accelerator from Varian Medical Systems which St. Vincent has used for patients since 2008.
The new technology “is a breakthrough marrying advanced imaging so we can see the cancer precisely with a high technology treatment delivery system so we can give higher doses of radiation directly to the cancer,” said Radiation Oncologist Dr. Linda Gemer, Medical Director of St. Vincent’s Radiation Oncology Department. “All of this technology is designed for better cancer control and more comfort for the patient.”
