Fred Radio Radiation Therapy For Head And Neck Cancer

Radiation Therapy for Head and Neck Cancers Teresa T. Sy Ortin, MD September 27, 2007 Introduction to Radiation Oncology - Radiation has been an effective tool for treating cancer for more than 100 years. - Radiation oncologists to use radiation to eradicate cancer. - About two-thirds of all cancer patients will receive radiation therapy as part of their treatment. What Is Radiation Therapy? - Radiation therapy works by damaging the DNA within cancer cells and destroying their ability to reproduce. - When the damaged cancer cells are destroyed by radiation, the body naturally eliminates them. - Normal cells can be affected by radiation, but they are able to repair themselves. - Sometimes radiation therapy is the only treatment a patient needs. - Other times, it is combined with other treatments, like surgery and chemotherapy. Brief History of Radiation therapy - The first patient was treated with radiation in1896, two months after the discovery of the X-ray - Back then, both doctors & non-physicians treated cancer patients with radiation - Rapid technology advances began in the early 150s with cobalt units followed by linear accelerators a few years later - Recent technology advances have made radiation more effective and precise

- The doctor who oversees the radiation therapy treatments. Medical Radiation Physicist - Ensures that complex treatment plans are properly tailored for each patient. Dosimetrist - Works with the radiation oncologist and medical physicist to calculate the proper dose of radiation given to the tumor. Radiation Therapist - Administers the daily radiation under the doctor’s prescription and supervision. Radiation Oncology Nurse - Cares for the patient and family by providing education, emotional support and tips for managing side effects. Types of Radiation Therapy - Radiation therapy can be delivered two ways – externally and internally. - External beam radiation therapy delivers radiation using a linear accelerator. - Internal radiation therapy, called brachytherapy or seed implants, involves placing radioactive sources inside the patient. - The type of treatment used will depend on the location, size and type of cancer. HDR Brachytherapy applicator (high dose radiation) - Putting tubes in nasopharynx - Radioactive material

Cobalt 60 - Uses radioactive material Linear accelerator - radiation source: high energy x-ray machine - Very high in energy & very penetrating Cobalt 60 vs. Linear Accelerator - In terms of quality of radiation, which is more effective? SAME - In terms of energy (energy determines penetration) - Cobalt 60 – fixed at 1.24 millivolts - Linear accelerator – since electrically generated, you can specify → low and high energy - e.g. Patient, obese with AP diameter of more than 30 → Prefer to use linear accelerator How Is Radiation Therapy Used? Radiation therapy is used two different ways. - To cure cancer: - Destroy tumors that have not spread to other body parts. - Reduce the risk that cancer will return after surgery or chemotherapy. - To reduce symptoms: - Shrink tumors affecting quality of life, like a lung tumor that is causing shortness of breath. - Alleviate pain by reducing the size of a tumor. Meet the Radiation Oncology Team Radiation Oncologist

- Emphasize: brachytherapy is a very localized treatment - Most often than not, used in combination with external beam radiation because you cannot cover surrounding areas - Effective only where you put the applicator - Most of the time, when we do radiation treatment, we want to be very radical, radiate a bigger area - In an attempt to deliver more radiation to the tumor Mold Brachytherapy - PALATE - e.g. Patient’s with cancer of palate - Make a dental mode - And put tubes in the region where we think should receive radiation - Conduit for radioactive material to go in - After treatment, just remove dental mode

Interstitial Brachytherapy 1

- FLOOR OF MOUTH - e.g. We want o radiate tongue → insert needles submentally into the floor of the mouth into the tongue - High dose rad system – after treatment patient can go home - In earlier centuries, do interstitial treatment → needle have to stay for 3-4 days - Also have for TONGUE Intraoral treatment - These machines have accessories that look like cones - For cooperative patients Fractionation schemes Hyperfractionation - EORTC - 10-15% improvement in local control - Most radiation treatment are done once a day - But it has been shown you get better results if you do it 2x a day Accelerated fractionation schedules Shortened overall treatment time Instead of 6 weeks  3-4 weeks Result are good but toxicity  not acceptable RTOG 90-03 compared the three regimens - Recent analysis of 1073 patients enrolled showed concomittant boost and hyperfractionation regimens yielded significantly higher local regional control, however, did not improve LRC rate over the standard fractionation. Accelerated repopulation - Treatment with any cytotoxic agent, including radiation, can trigger surviving cells ( clonogens) in a tumor to divide faster than before. This is known as accelerated repopulation. - This starts in head neck cancer in the human about 4 weeks after the initiation of fractionated radiotherapy. About 0.6 Gy per day is needed to compensate for this repopulation. - This phenomenon mandates that treatment should be completed as soon as practical once it has started; it may be better to delay the start than to introduce interruptions during treatment. Planning Radiation Therapy - Simulation - Each treatment is mapped out in detail using treatment planning software. - Radiation therapy must be aimed at the same target every time. Doctors use several devices to do this: - Skin markings or tattoos. - Immobilization devices – casts, molds, headrests. External Radiation Therapy - Specialized types of external beam radiation therapy - Three-dimensional conformal radiation therapy (3D-CRT) - Uses CT or MRI scans to create a 3-D picture of the tumor. - Beams are precisely directed to avoid radiating normal tissue. - Intensity modulated radiation therapy (IMRT) - A specialized form of 3D-CRT. - Radiation is broken into many “beamlets” and the intensity of each can be adjusted individually.

H&N 9 beam vs. 5 beam IMRT - Protection of the salivary gland - During preparation, when all images are obtained - Radiation oncology sit on computer to contour to target tumor, contour sensitive organs that have to be protected during treatment - In head and neck area, the salivary gland is very important - Years ago, prior to advent of this treatment, it is given that patient will have dry mouth after treatment - Nowadays with this 3D conformal techniques, especially IMRT, we can spare salivary glands - Document benefit of this type of radiation for head and neck area

- UCSF-San Francisco - Al Sarraf regimen with IMRT for nasopharynx - Of 35 patients treated - Local control was 100% with a median follow-up of 21.8 months. - Xerostomia was grade 0 in 50%, and another 50% grade I. No patients had grade II xerostomia. - As the machine rotates, doctor determines how many beam - 2 beam - Can be front and back - Can distribute beam into 5 separate beams - If it is 3D confirmal, as the beam rotates, you can shape it the way you like it - By way of CT or MRI External radiation therapy Proton beam therapy - Uses protons rather than x-rays to treat certain types of cancer - Allows doctors to better focus the dose on the tumor with the potential to reduce the dose to nearby healthy tissue Neutron beam therapy - A specialized form of radiation therapy that can be used to treat certain tumors that are very difficult to kill using conventional radiation therapy - -radio intensive Sterotactic radiotherapy - Sometimes called stereotactic radiosurgery, this technique allows the radiation oncologist to precisely focus beams of radiation to destroy certain tumors, sometimes in only one treatment Notes:  No knife – misnomer, this treatment is used in place of surgery  Ex. Small tumors in brain  Instead of requiring surgeons to open up there are certain qualification criteria ex. <5cm  Not near critical areas like optic nerve or optic chiasm  Gamma knife or x knife radiosurgery 2

Internal Radiation Therapy - Places radioactive material into tumor or surrounding tissue. - Also called brachytherapy – brachy Greek for “short distance.” - Radiation sources placed close to the tumor so large doses can hit the cancer cells. - Allows minimal radiation exposure to normal tissue. - Radioactive sources used are thin wires, ribbons, capsules or seeds. - These can be either permanently or temporarily placed in the body. Dental clearance prior to radiation therapy - Patients undergoing radiation will be having problem with oral infection → Dental carries - Long after treatment, cannot have dental extraction - Tissue grow too slowly after radiation - They may have infection → lead to osteoradionecrosis Nutritional support, assessment and guidance Patient cannot eat, saliva is so thick, dry mouth, mucositis Head and Neck RT Primary therapy - e.g. Patient with glottic cancer - Early cancer of vocal cord - Instead of treatment radically, like removing entire larynx → Can have radiation as primary treatment - 90% cure rate Adjuvant therapy - primary tx already done - e.g. Tongue malignancy Preoperative treatment - decreasing tumor size (radiation before surgery) Concurrent w/ chemotherapy - very popular - Not a sloppy treatment - Proven that despite good treatment, you still get a little benefit when you give a little chemotherapy together - drug: CISPLATIN - Used for doing this chemoradiation regimen - Better benefit, however ↑ side effects - Patients needs more attention Palliation - Bleeding, tumors obstructing the airway Use of RT Primary therapy - nasopharyngeal carcinoma - early glottic carcinoma - early stage head and neck tumors Adjuvant - T3, T4 lesions - Positive margins - RT to neck if positive nodes on histopathology esp. if with extracapsular extension Chemoradiation - Locally advanced NPCA stage 3 and 4 - Al-Sarraf, JCO, 1998 - Organ Preservation in Oropharyngeal Malignacies - VALSG - Calais - Fonasteire

- Adjuvant for postop. with high risk features on histopath. - Meta- analysis of Chemotherapy on Head and Neck Cancer Collaborative Group. - 63 randomized trials- 10741 patients. - In larynx, mainly done for organ preservation - Results - Small statistically significant benefit with the addition of chemotherapy to localregional therapy, which consists of a 4% improvement in survival at 2 and 5 years. - Due to favorable effect of concurrent and - Alternating benefit of radiation and chemotherapy resulting in an 8% overall improvement in survival. Pre-op Radiotherapy - Rarely used. - Only for situations where the cancer is marginally resectable or has a very rapid growth rate. - Patients with small radiocurable tumors and large adenopathy may be treated with definitive radiation to the primary tumor and preoperative radiation to the neck with a planned neck dissection to follow radiation. - RADIOTHERAPY FOLLOWED BY CHEMOTHERAPY - Occasionally yields complete or partial response of the tumor in 20% and 60% of patients. - In spite of these dramatic responses, overall control rates in randomized trials have only been a few percentage points better than those achievable with RT alone. - For occasional patients referred after chemotherapy, we radiation the entire original volume with adequate margins to equivalent doses as primary radiotherapy alone. A small dose reduction is sometimes made when acute reactions are excessive. Side Effects of Radiation Therapy - Side effects, like skin tenderness, are generally limited to the area receiving radiation. - Unlike chemotherapy, radiation usually doesn’t cause hair loss or nausea. - Most side effects begin during the second or third week of treatment. - Side effects may last for several weeks after the final treatment. HEAD AND NECK RT Side effects and complications - Mucositis - loss of taste - pharyngitis - weight loss secondary to malnutrition - xerostomia Management of complications - nutritional support - use of sialagogues, artificial saliva - salt irrigation - radioprotectors (amifostine) - skin care Is Radiation Therapy Safe? - Many advances have been made in the field to ensure it remains safe and effective. - Multiple healthcare professionals develop and review the treatment plan to ensure that the target area is receiving the dose of radiation needed.

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- The treatment plan and equipment are constantly checked to ensure proper treatment is being given.

Transcribed by: Fred Monteverde Notes from: Mitzel Mata Fred Monteverde Mitzel Mata Emy Onishi Cecile Ong Regina Luz Section C 2009!

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