Radiation therapy can effectively eradicate cancerous cells while sparing nearby healthy tissue. Your specific course of radiation therapy treatment depends upon its type and location of tumor.
Most patients receive external beam radiation five days a week for several weeks. You will lie down on a table, sometimes wearing a mask or mold to ensure you stay in the correct position during treatment.
External beam radiation
Radiation therapy is an effective option for many different cancers, such as ovarian, lung, prostate and brain tumors. This form of treatment involves using a machine to deliver high-energy beams of radiation directly onto tumors which kill cancer cells while sparing normal tissue; this type is called external beam radiation therapy (EBRT). Most patients receive their treatments as outpatients; most typically they come five days a week for two to nine weeks before stopping treatments altogether.
Before beginning radiation treatment, your physician will perform a physical exam and review your medical history. Imaging tests such as CT and MRI scans will also help your physician plan out your EBRT treatments using simulation, which creates computer plans to analyze both normal tissue and your tumor to create 3-D conformal radiation plans with high doses to the tumor while still protecting healthy areas.
Your next stop will be the radiation treatment room, which may be large and noisy. Here, you will lie down on a table while being aligned by your radiation oncologist using positioning aids (like masks or body molds created during simulation) created during the simulation phase. As it rotates around you body, its machine may make small noises while rotating slowly while you notice colored lights which align with dots on your skin or the mask or body mold created during simulation – these harmless lights show where to aim the beams for treatment.
Hypofractionation allows therapists to administer radiation in small doses over multiple weeks, which helps avoid overwhelming the patient’s body at once with high-dose radiation therapy. Hypofractionation reduces side effects while providing more flexible scheduling of sessions.
Once EBRT treatment is completed, your oncologist will set up follow-up appointments. Bloodwork and other tests will need to be conducted in order to verify that cancer has been successfully eradicated.
Linear accelerator (LINAC)
Linacs are one of the primary machines used for external beam radiation therapy. Linacs use electrons accelerated on linear paths to produce high-energy X-rays and electron beams that are precisely targeted to tumors while sparing nearby healthy tissue.
Linacs can also provide various forms of radiotherapy, such as Intensity-Modulated Radiation Therapy (IMRT) and Stereotactic Body Radiotherapy (SBRT). Radio waves from an array of RF cavities at the beginning of a linac accelerate electrons in bunches that are then tailored to match the shape and size of your tumor before being routed through computerized software to generate an individual treatment plan that matches both diagnosis and goals for treatment; once approved by both medical oncologist (radiation oncologist) and radiation physicist before being transmitted onto a linac for delivery.
As part of your treatment, you lie on a treatment table while your radiation oncologist uses marks on your skin or x-ray imaging devices to precisely align your body to the LINAC machine. Molds or other supports may be necessary for you to remain in position during therapy. Your radiation therapist then operates the LINAC from another room nearby while monitoring you through their x-ray imaging device.
Your radiation oncologist may employ image-guided radiation therapy (IGRT) during your treatment, which involves repeated CT, MRI or PET scans to track changes to tumor size and location during therapy and enable more precise targeting of your tumor by adjusting positioning or dose accordingly.
Your radiation oncologist may recommend either external beam radiotherapy (EBRT) or stereotactic body radiation therapy (SBRT), depending on your diagnosis, to destroy cancer cells and increase survival and reduce tumor recurrence risk. EBRT applies radiation directly to a tumor outside your body; often used as a stand-in therapy; in certain instances such as brain tumors and certain breast cancers it may also be given along with surgery and chemotherapy treatments for optimal care; additionally it can be used shrink a tumor prior to surgery as well as palliative care services.
Accelerated fractionation
Conventional radiation therapy schedules usually last seven weeks. But some physicians now employ other techniques to shorten treatment duration, including smaller doses delivered more frequently or multiple sessions per day or twice daily; this method is known as accelerated fractionation. Accelerated fractionation can also be combined with other forms of therapy like brachytherapy and stereotactic body radiotherapy or image-guided radiotherapy to shorten treatment length.
Hyperfractionation and accelerated radiotherapy have both been demonstrated to produce more effective locoregional control in head and neck cancer. Unfortunately, both strategies may be hindered by acute normal tissue reactions; as well as their limited clinical implementation due to advanced radiation techniques such as IMRT; leading to hybrid regimens being created as workarounds.
Accelerated fractionation provides an opportunity for more rapid tumor cell death with minimal normal tissue reactions, and decreasing dose per fraction reduces cumulative normal tissue damage; this last point is especially relevant as many adverse side effects of radiotherapy result from its accumulation over time.
Researchers recently conducted a comparative analysis between patients with non-metastatic, stage IV SCCHN who could not tolerate concurrent radiochemotherapy and those treated with conventionally fractionated radiation therapy. Results were encouraging: two year PFS-rates for accelerated radiation with concomitant boost were 63% while conventional fractionation achieved 41%; although accelerated radiation with concomitant boost showed greater results overall due to its higher rate of grade >= 2 toxicities occurring more often in both groups.
Traditional understanding of late toxicities suggests they are sensitive to changes in dose accumulation rate. This approach may hold true with acute reactions that result directly from cell depletion; in contrast, late reactions are more sensitive to factors like total dose duration and interfraction interval length.
Hyperfractionation
Hyperfractionation’s goal is to deliver higher doses over a shorter time, thus decreasing normal tissue toxicity risk and improving outcomes. It can be used when conventional radiation therapy has failed or cannot be safely delivered; additionally, chemotherapy treatments often augment this technique and prolong patient lives further than ever before. Speak with your physician today about whether hyperfractionation could benefit your condition.
Hyperfractionation has proven superior locoregional control in head and neck cancer treatment compared to standard fractionated radiotherapy, yet acute toxicities like mucositis have limited its use and made treatment difficult to tolerate due to frequent treatments. A new approach combining hyperfractionation with intensity modulated radiation therapy (IMRT) has been demonstrated to increase patient tolerance while simultaneously decreasing toxicity – this method is currently being examined through large phase III trials.
Hyperfractionation with IMRT was shown to be feasible in three patients, using twice daily sessions of 1.2 Gy per day over five days and according to ICRU report 83 and RTOG 9410 guidelines; weekly kV on-board imaging was carried out during therapy for dosimetric corrections, which led to improved therapeutic effectiveness and significantly decreased dose to organs at risk while increasing therapeutic benefit. This research confirmed that using hyper-fractionation combined with IMRT can significantly decrease organs at risk while simultaneously increasing therapeutic benefit while increasing therapeutic benefit while decreasing dose to organs at risk while increasing therapeutic benefit significantly while decreasing organ dose while simultaneously increasing therapeutic benefit significantly while simultaneously decreasing organ dose while increasing therapeutic benefit significantly while increasing therapeutic benefit simultaneously. This research demonstrated how hyper-fractionation combined with IMRT can significantly decrease organ dose to organs while simultaneously increasing therapeutic benefit while increasing therapeutic benefit simultaneously. This research demonstrated how using both techniques combined together can significantly decrease organ dose to organs while increasing therapeutic benefit while simultaneously increasing therapeutic benefit by increasing therapeutic benefit while simultaneously decreasing organ dose to organs at risk while simultaneously increasing therapeutic benefit by increasing therapeutic benefit while simultaneously decreasing therapeutic benefit while simultaneously increasing therapeutic benefit while simultaneously decreasing organ dose to organs at risk while simultaneously increasing therapeutic benefit while significantly decreasing dose to organs at risk while simultaneously decreasing organ dose to increase therapeutic benefit without increasing therapeutic benefit by an additional factor of 5.8.7 as measured data showed this demonstrated this approach can reduce dose exposure while increasing therapeutic benefit by over 50% over conventional radiation therapy could significantly reduced dose to organs while increasing therapeutic benefit while significantly decreasing organ dose exposure while decreasing organ exposure while decreasing organ dose by increasing therapeutic benefit while significantly reduced organ exposure while increasing therapeutic benefit while decreasing organ dose to organs at risk while improving therapeutic benefit by increased therapeutic increase therapeutic benefit by significant.
Studies have demonstrated improved locoregional control with accelerated hyperfractionation for head and neck cancers, yet this treatment is yet to become widely adopted due to safety concerns resulting from tumor stem cell hypothesis and short potential doubling time of head and neck cancers. Regardless, this technique must be evaluated via properly designed randomised clinical trials before its implementation into mainstream cancer care protocols.
