External Radiation Therapy
Radiation doses are based on the type, stage, and location of the tumor as well as on the patient’s size, condition and overall treatment goals. Radiation doses are given in increments, usually three to five times a week, until the total dose is reached. The goals of radiation therapy include cure, in which the cancer is completely destroyed and not expected to recur; control, in which the cancer doesn’t progress or regress but is expected to progress at some later time; or palliation, in which radiation is given to relieve symptoms caused by the cancer (such as bone pain, bleeding, and headache).
External beam radiation therapy is delivered by machines that aim a concentrated beam of high-energy particles (photons and gamma rays) at the target site. There are two types of radiotherapy machines; units containing cobalt or cesium as radioactive sources for gamma rays, and linear accelerators that use electricity to produce X-rays.
Linear accelerators produce high energy with great penetrating ability. Some (known as orthovoltage machines) produce less powerful electron beams that may be used for superficial tumors.
Radiation therapy may be augmented by chemotherapy, brachytherapy (radiation implant therapy), or surgery, as needed.
- Equipment for Radiotherapy Procedure
Radiation therapy machine need for film badge or pocket dosimeter.
- Implementation of Radiotherapy Procedure
1. Explain the treatment to the patient and his family.
Review the treatment goals, and discuss the range of potential adverse effects as well as interventions to minimize them. Also discuss possible long-term complications and treatment issues. Educate the patient and his family about local cancer services.
2. Make sure the radiation oncology department has obtained informed consent.
3. Review the patient’s clinical record for recent laboratory and imaging results, and alert the radiation oncology staff to any abnormalities or other pertinent results (such as myelosuppression, paraneoplastic syndromes, oncologic emergencies, and tumor progression).
4. Transport the patient to the radiation oncology department.
5. The patient begins by undergoing simulation (treatment planning), in which the target area is mapped out on his body using a machine similar to the radiation therapy machine. Then the target area is tattooed or marked in ink on his body to ensure accurate treatments.
6. The physician and radiation oncologist determine the duration and frequency of treatments, depending on the patient’s body size, size of portal, extent and location of cancer, and treatment goals.
7. The patient is positioned on the treatment table beneath the machine. Treatments last from a few seconds to a few minutes. Reassure the patient that he won’t feel anything and won’t be radioactive. After treatment is complete, the patient may return home or to his room.
- Special considerations
1. Explain to the patient that the full benefit of radiation treatments may not occur until several weeks or months after treatments begin. Instruct him to report long-term adverse effects.
2. Emphasize the importance of keeping follow-up appointments with the physician.
3. Refer the patient to a support group, such as a local chapter of the American Cancer Society.
- Home care after Radiotherapy done
Instruct the patient and his family about proper skin care and management of possible adverse effects.
- Complications of Radiotherapy
Adverse effects arise gradually and diminish gradually after treatments. They may be acute, subacute (accumulating as treatment progresses), chronic (following treatment), or long-term (arising months to years after treatment). Adverse effects are localized to the area of treatment, and their severity depends on the total radiation dose, underlying organ sensitivity, and the patient’s overall condition.
Common acute and subacute adverse effects can include altered skin integrity, altered GI and genitourinary function, altered fertility and sexual function, altered bone marrow production, fatigue, and alopecia.
Chronic and long-term complications or adverse effects may include radiation pneumonitis, neuropathy, skin and muscle atrophy, telangiectasia, fistulas, altered endocrine function, and secondary cancers.
Other complications of treatment include headache, alopecia, xerostomia, dysphagia, stomatitis, altered skin integrity (wet or dry desquamation), nausea, vomiting, heartburn, diarrhea, cystitis, and fatigue.
- Documentation of Radiotherapy Procedure
Record radiation precautions taken during treatment; interventions used and their effectiveness; grading of adverse effects; teaching given to the patient and his family and their responses to it; the patient’s tolerance of isolation procedures and the family’s compliance with procedures; discharge plans and teaching; and referrals to local cancer services, if any.