What to Expect During Radiotherapy

• Simulation
  
• Preparation
  
• Scheduling
  
• Arrival
  
• The setting
  
• How radiation therapy is administered
  
• Dosages
  
• Departure
  

By now you have consulted with several types of oncologists and have decided that radiation therapy is a good choice for treating your NHL. Perhaps it will be used alone if you have a single tumor or perhaps one of several sites will be irradiated to alleviate unpleasant symptoms such as pressure or pain. Radiation may be used in conjunction with other therapies such as chemotherapy or surgery.

We are justifiably afraid of radiation. We know that sunlight can burn us, that x-ray technicians leave the room and wear lead aprons when they treat us. We know we should be wary of too many diagnostic x-rays, and that large amounts of radiation caused tremendous damage at Hiroshima, Nagasaki, and Chernobyl. In spite of fears about radiation, many NHL patients are pleasantly surprised to find that radiation therapy is a smooth, quick, silent, painless treatment.

In this article we will acquaint you with a typical radiotherapy experience. Most radiotherapy used for NHL is external radiotherapy and is administered in the outpatient setting, so we will walk you through an outpatient treatment, beginning with your preparation, including treatment simulation, scheduling, arriving at the treatment office, encountering certain medical personnel and other patients, advancing through the treatment itself, and finishing with what you can expect afterward.

Although there are different kinds of radiation, including x-rays and electron, proton, or neutron beams, for the sake of readability in this article we will not distinguish among them. We will use only the term radiation.

The information this article provides is not a substitute for your doctor's knowledge. Always ask your doctor when an aspect of your treatment is unclear, and report immediately to your doctor any adverse reactions that arise during or after treatment.

If you would like greater detail on radiation therapy, The Chemotherapy and Radiation Therapy Survival Guide, by Judith McKay, Nancee Hirano, Myles Lampenfeld, Making the Radiation Therapy Decision, by David Brenner and Eric Hall, and Coping with Radiation Therapy: A Ray of Hope, by Daniel Cukier and Virginia McCullough are books that focus on radiation therapy from the patient's perspective.

The following sections will walk you through preparation and treatment simulation, scheduling, receiving therapy, departure, and the days that follow treatment.

Simulation

Your first one or two treatment visits to the radiation oncology treatment offices will be spent determining precise details of how best to treat you: positioning you on the treatment bed, marking your skin with small dots of temporary or permanent ink, and creating shields for sensitive organs. All of these preparations are called simulation, and may take several hours spread over one or more visits.

Several medical specialists are involved in this stage of your treatment. These include your radiation oncologist, the radiation therapy technician who will administer the treatment, a dosimetrist who calculates the correct dose, and the radiation physicist who calibrates the machine. Some of these staff members may work behind the scenes.

For these initial visits, which are lengthy, make yourself as comfortable as possible by wearing clothing that doesn't bind, that goes on and off easily, and has no metal zippers. Bring a cassette player if you like, and use the restroom before the simulation starts.

If parts of your head or neck are being irradiated, a mask or helmet may be made to protect the areas that are cancer-free and to help you remain still during treatment.

None of these preparations are painful, although some NHL survivors report feeling a little claustrophobic if they have a mask or helmet made, or uncomfortably stiff if they have to hold still for a long time. The substance used to make masks and helmets takes a few minutes to harden and must harden on your head in order to provide an exact fit. While you are able to breathe normally with them in place, during this time you must hold quite still.

Special shields or blocks may be made to shape the radiation beam to match exactly your tumor's shape. Beams of invisible radiation generated by the machinery are usually emitted shaped like rectangles, from two to fifteen inches in any dimension. If these beams were trained against your tumor, nearby healthy tissue within the two- to fifteen-inch rectangle would be irradiated, too, suffering damage. To avoid this effect, shields or blocks with cutaways in the silhouette of your tumor are created using your x-ray films as guides.

The masks and shields made for you are used only by you. You may see the same kinds of devices belonging to other patients hanging nearby or in other treatment areas.

The machinery used during simulation looks and moves just as the genuine radiation equipment does, but instead it generates only a plain light beam to verify positioning, ink markings, and the fit of masks and shields.

After all shields, blocks, masks, or helmets are made and your skin is marked, the entire simulation will be repeated with all pieces in place--exactly like a dress rehearsal.

As your treatment progresses and your tumor shrinks, new blocks may be made to match the new shape of your tumor, and these simulations may be repeated.

Preparation

Radiation therapy often makes many patients increasingly tired as it progresses. For this reason, once treatment starts, it would be wise to have a friend or loved one along, not only for emotional support, but to handle issues such as saving written instructions for diet and aftercare, understanding and remembering verbal instructions, communicating insurance information and handling the co-pay, if any, and assisting with the drive home.

If the area near your stomach is being irradiated, it's best to eat very lightly beforehand and to arrive with an empty stomach. This will reduce the chance of nausea.

Ask the medical staff about using cosmetics, antiperspirants, aftershaves, and lotions before treatment. They may interfere with treatment, or they may cause your skin to become hypersensitive if they are exposed to radiation.

Ask as well about clothing with metal zippers, removable dentures, pacemakers, surgical staples, and contact lenses.

Scheduling

Years of research have shown that a large amount of radiation can be delivered to a tumor safely if it's spread out over several weeks. This is called fractionating the dose, or simply, fractionation. It spares healthy tissue from unnecessary damage and gives it time to recover.

Dosage fractionation means that you will have to visit the treatment center several times a week, or perhaps every day, for two to six weeks, depending on your treatment plan. It also means that each dose of radiation lasts only two to four minutes. If your tumor is irradiated from several different angles, each angle may take two to four minutes after the machine is repositioned. After the lengthy time spent in simulation, you may feel that ten to thirty minutes of treatment time is an anticlimax.

Don't be surprised if the schedule on which your radiotherapy is administered differs from the schedules you hear others discussing, because your radiation schedule always is tailored to your particular circumstances, based on the size, number, and location of tumors, your overall health, your body size, and the subtype of NHL you have.

Depending on what treatment is being used, the timing of your radiation therapy may be influenced by the quantity of white blood cells remaining in your blood after your last treatment. Thus, for certain regimens that expose a lot of bone marrow or the spleen to radiation, your blood may be tested when you arrive, using a standard measurement known as a complete blood count (CBC). If your white blood counts are too low, treatment may be delayed a few days or a week.

For each treatment, you might want to call the treatment center before leaving home or work. Radiation therapy machines sustain heavy use, and must be taken offline periodically for recalibration or repair. You can save your valuable time by calling first to see whether appointments are running on time.

After a few treatments, you may begin to feel that all of your time is spent traveling to the office or chatting in the waiting room, because treatment itself is so brief.

Arrival

If you are receiving radiation to the head, stomach, or abdomen, make a point of discussing nausea and diarrhea medications with your doctor before treatment starts. Although the new antinausea drugs (anti-emetics) are excellent, ask for suppositories in case oral medications won't stay in your stomach. If you do develop nausea, subsequent treatments may be preceded by an injection of one of the new antinausea drugs, such as Zofran.

Ask your doctor if you should avoid possibly dangerous circumstances such as excessive sunlight or crowds.

Ask about skin care, too. External beam radiation, the most common radiological means of treating NHL, must pass through your skin to reach tumor sites, and irritation may result. Newer, higher voltage equipment used today causes less damage to skin because the damaging rays concentrate in deeper layers, but some skin reaction still is possible.

The setting

The source of radiation will be a machine that either safely contains a radioactive substance, such as Cobalt 60, or generates its own radiation as needed. Like a CT scanner or a gamma camera, the radiation machine is designed to move around you and your bed as you hold still. Many models are almost silent, but some make a sound like a vacuum cleaner, and of course they may click and whir as they reposition.

The room in which treatment is given has thick walls and is lead-clad to prevent the very small amount of radiation that bounces off your shields, known as scatter, from affecting the medical staff, those in the waiting room, and random passersby. For the safety of the staff, the treatment room will contain only you when the machine is engaged. (The small dose of radiation they would sustain if they stayed with you would probably not harm them, but if they stayed with all patients, all day, every day, the dose from scatter would indeed accumulate to dangerous levels.)

The staff can see and hear you at all times, because there are microphones and cameras connecting you and them. If you feel at all bad, just let them know. Music and wall art sometimes are available in the treatment room to lower your boredom and stress levels.

How radiation therapy is administered

There are four ways to administer radiation therapy: external radiotherapy (also called external beam radiotherapy), radioimmunotherapy, internal radiotherapy, and brachytherapy. The latter two, internal radiotherapy and brachytherapy, are seldom used for NHL, so we will define them briefly and move on.

Internal radiotherapy is radiation therapy aimed directly and only at your exposed tumor while your body is open during surgery. Brachytherapy is the implantation of a source of radiation directly into or very near the tumor.

External radiotherapy

External radiotherapy, also called external beam radiation, currently is the most common means of treating NHL tumors, and is administered as described in the earlier section, "The setting," using the blocks, shields, masks, or helmets made expressly for you, along with sandbags to hold your arms and legs still, and blankets to keep you warm.

You should feel no pain, no heat, no sensation at all during treatment, although some survivors say that they feel a sensation of energizing--not quite a tingling--in the area of the tumor during treatment. It may indeed be that some of us can sense a highly active biological entity such as a tumor reacting to the disruption of its DNA.

Some find the absence of sensation eerie, but most people are grateful that the treatment is comfortable and brief.

Radioimmunotherapy

Radioimmunotherapy is a new treatment, still in advanced clinical trials, but quite promising. It combines the principle of radiation therapy with one of the newest treatments available, tumor targeting with monoclonal antibodies.

Radioimmunotherapy involves linking one molecule of a radioactive substance, a radioisotope such as iodine-131 or yttrium-90, to a monoclonal antibody. The benefit of radioimmunotherapy over existing radiation treatments is that less healthy tissue is exposed to radiation because the antibody attaches to cancerous tissue only. Some healthy tissue is affected because the radioactive substance decays as the antibody travels to the tumor, but it is thought that this effect is less than that sustained during external beam therapy. Radioimmunotherapy is administered into a vein like chemotherapy.

The correct dose of radioimmunotherapy must first be determined. To calculate this dose, a small "tracer" amount of the substance will be injected first, and visualized using a CT scan or other imaging device. Based on what is seen, the doctors in charge will determine the total dose you should receive.

You will be kept in a lead-shielded hospital room throughout this treatment, and your body wastes will be disposed of in accordance with rules for handling hazardous waste. Face-to-face family visits will be very limited or denied entirely. The nurses who care for you may wear protective clothing.

If the radioisotope iodine-131 is to be used, your thyroid gland will be shielded first, unless it has been infiltrated with NHL. The radioactive isotope, I-131, will destroy the thyroid gland if it is absorbed.

To shield the thyroid, large doses of nonradioactive iodine, iodine-123, are given to you first. This substance is taken up by the thyroid in excess compared to other body tissues. After the maximum amount has been absorbed, the thyroid cannot absorb more iodine for several days. This protects the thyroid gland from absorbing subsequent doses of I-131.

This method of treatment is not likely to be used for those who have had previous allergic reactions to iodine in shrimp, other foods, or in other medications.

Dosages

For external beam radiation, a typical dosage for NHL is 180 to 200 centiGreys (cGy) five times a week. If a higher dosage is required, more sessions are added, but the dose per exposure is not raised. This moderate dose per exposure has been determined to be the best amount for killing NHL cells while allowing healthy cells to recover.

Different subtypes of NHL require different doses of radiation. The varying doses depend primarily on the different sites involved, whether they are nodal or extranodal, and the bulkiness of the tumors. Diffuse disease, for instance, requires more radiation in order to combat growth. Other types of NHL are unaffected by all but the most extreme doses of radiotherapy, which makes this treatment useless against them owing to severe or fatal damage to other tissue.

Departure

After each of your first few treatment sessions, make sure you have received written instructions regarding any necessary dietary or behavioral changes, information about possible side effects, prescriptions, and phone numbers for emergencies, before leaving the doctor's office. Often, side effects of radiation therapy do not emerge until you've had two or more weeks of treatment. If you have prepared for these possibilities by asking questions during the treatment visits when you feel well, side effects may be easier to deal with.

You are not likely to feel unwell after your treatments, but if you do, do not leave without telling the medical staff of your problem.