Childhood Cancer

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Childhood Cancer

Treatment

At diagnosis, many parents do not know how to find experienced doctors and the best treatments for their child. State-of-the-art care is available from physicians who participate in the Children’s Oncology Group (COG). This study group includes pediatric surgeons and oncologists, radiation oncologists, researchers, and nurses. COG conducts studies to discover better therapies and supportive care for children with cancer. You can learn more about COG and find a list of its member treatment centers at www.childrensoncologygroup.org.

It is also important that your child be seen by a pediatric ophthalmologist who has experience treating retinoblastoma. The pediatric ophthalmologist should work closely with your child’s pediatric oncologist throughout treatment. Together, they will identify the treatment options (e.g., the current standard of care or a clinical trial) based on the stage and classification of the disease within the eye and whether it has spread outside the eye (see Chapter 9, Choosing a Treatment). Depending on the situation, treatment may include surgery, radiation, chemotherapy, and/or local eye treatments, including cryotherapy and laser therapy. The goals of therapy are to cure the disease and to preserve as much vision as possible.

Surgery and local eye treatments

We relied on the opinions of the surgeon, retina specialist, two pathologists, a retinoblastoma specialist from Canada, parents of children with retinoblastoma, and material from medical journals when deciding on treatment for Hailee (14 months old). They all offered pieces of the puzzle, which allowed us to make an informed decision. Hailee had her eye enucleated, and since all the cancer was removed, further treatment wasn’t necessary. She is followed every 6 months with EUA [exam under anesthesia] and MRI, and has done very well. She has coped well with the enucleation, and she looks beautiful.

Several types of procedures are used to treat retinoblastoma: enucleation, cryotherapy, laser thermotherapy, and laser photocoagulation. The ophthalmologist may also deliver chemotherapy locally to the tumor (see section about chemotherapy later in this chapter). The most appropriate treatment is chosen on an individual basis. An important component of treatment is support from psychologists, social workers, and genetic counselors to help families deal with the cancer, its treatment, the possible loss of an eye and vision, and the potential risk of other family members developing retinoblastoma.

Enucleation

Enucleation is the surgical removal of an eye. It may be necessary if:

•  The tumor is very large and there is no hope that the eye will have useful vision.

•  The eye has glaucoma.

•  The tumor has spread extensively within the eye, to the optic nerve or orbit.

•  Other treatment methods have failed to destroy the disease.

•  The retina cannot be examined because of vitreous hemorrhage or cataract.

Enucleation is a relatively simple operation that is done under general anesthesia. In addition to gently removing the eye, the surgeon will also remove a section of the optic nerve. An implant is placed into the socket immediately after the eyeball is removed. The child will be fitted for an artificial eye several weeks after the procedure.

Jayden was 17 months old when his right eye was enucleated. He had a clear conformer [plastic device] placed in the socket so the tissues wouldn’t grow and his prosthetic would fit. I kept him patched so people wouldn’t stare, but they stared anyway. Jayden got his first prosthetic 3 months later, and he looked amazing. The surgeon carefully kept a lot of his nerves so he has great movement and no one can tell his eye isn’t real.

Jayden has allergies, so there’s a lot of buildup on his prosthesis and we have to take it out and clean it every couple of weeks. He has Elli the Elephant from the German Children’s Eye Cancer Foundation. She has a fake eye that pops out. Jayden will talk to her and say, “OK, Elli, we have to wash your special eye.” He sometimes pops his eye in her eye socket, just to be silly. He likes reading a coloring book with me called Joey’s Special Eye about a boy with retinoblastoma who has a prosthetic eye and wears glasses [see Appendix C, Books, Websites, and Support Groups].

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Hailee (14 months) never experienced any difficulties with her prosthetic eye. We spent a great deal of time preparing Hailee when the eye was about to be enucleated. We read her My Fake Eye [see Appendix C, Books, Websites, and Support Groups], which helped a great deal with the prosthesis. She took the book to daycare and the caregiver read it to the other children. It has never been a big deal for her. She is now 4 years old and continues to do well.

After the enucleation, a pressure patch is placed over the eyelid. When the patch is removed, antibiotic drops are put in the socket for about a week. The eyelid is usually swollen and bruised for the next few days.

Noah had his left eye enucleated at age 2 months. We were able to take him home a couple of hours later. The most difficult part for me was handing him over to the nurse who took him into the operating room, and not getting to see him until he had awakened. We were impressed that he recovered quickly from anesthesia, and, when the bandages were removed 3 days later, that there was virtually no bruising.

After enucleation, the prosthesis needs to be replaced periodically to foster orbital growth. Children who have one or both eyes removed before age 3 may have an altered facial appearance when they mature.

Cryotherapy

Cryotherapy, a freezing treatment, is used to treat small primary tumors or new tumors that develop on the anterior (front part) of the retina. It is most successful if used to treat tumors up to 5 mm in diameter and 3 mm in thickness, and it may have to be repeated numerous times to eliminate all the tumor cells. It is often used in combination with chemotherapy and can also be used after radiation therapy.

During cryotherapy, extreme cold is applied by a small probe placed directly on the part of the eyeball closest to the tumor. The surgeon uses ultrasound to guide the probe to ensure that healthy tissue around the tumor remains unharmed. The procedure is done under local or general anesthesia. The eye and eyelid will swell for one or more days, and an ointment or drops can be used to help decrease the swelling.

One advantage of cryotherapy is that it may help prevent the need for enucleation or radiation therapy. However, it cannot successfully treat larger tumors, and it may cause retinal scars, tears, or detachments that damage vision.

Laser thermotherapy

Zachary was 10 months old when he was diagnosed with unilateral retinoblastoma in the left eye. He had several eye exams since birth because I had retinoblastoma when I was a child. He was treated with cryotherapy and radioactive plaques. Zachary did well, so our experience with cryotherapy was pretty positive. Of course, being so young, he didn’t really know what was going on.

Laser thermotherapy (also known as transpupillary thermal therapy or TTT) is a method of delivering heat directly to the surface of the tumor using infrared radiation and a diode laser. It is used to treat tumors smaller than 3 mm in size. Like cryotherapy, it can be combined with chemotherapy or radiation therapy to treat larger tumors. Children are sedated during this procedure. It leaves a relatively small scar, preserving more vision.

Laser photocoagulation

Westley was 7 months old when he was diagnosed with bilateral retinoblastoma. He had 6 months of chemotherapy (etoposide, carboplatin, and vincristine) one time per month, with monthly eye exams done under anesthesia [EUA]to track his progress. We started cryotherapy and laser treatments on individual tumors after 4 months of initial chemotherapy, to shrink the tumors as much as possible with chemotherapy first. For the first 18 months, he had EUAs once a month, then we moved to EUAs every 6 weeks.

He is almost 3, and he has had 29 EUAs. All but two times so far the regular EUA has shown new tumor growth that has been immediately treated with cryotherapy or laser therapy. We learned quickly that this is the norm; it’s what happens with bilateral retinoblastoma. We find the tumors and get rid of them when they’re little so we can save as much vision as possible. We assume he will continue to have sedated exams every 6 weeks until his sixth birthday. If his tumors become stable, it could stretch out.

Laser photocoagulation is another method for treating small tumors. It is used to treat small tumors located at the back of the retina that are not close to the optic nerve or blood vessels.

This technique cauterizes (burns) tissues around the tumor with focused light from an argon laser, delivered while the child is anesthetized. The light is delivered through the pupil and kills the tumor by destroying its blood supply. Laser photocoagulation is often used in combination with radiation, sometimes used in combination with chemotherapy, and occasionally used alone. Many treatment/cancer centers have replaced this procedure with laser thermotherapy.

Radiation therapy

Retinoblastoma is very sensitive to radiation, which is sometimes used to destroy local disease while attempting to maintain vision. The use of radiation has decreased in recent decades because of the risk of damage caused by high doses of radiation to growing tissues in small children. Two methods of radiotherapy are used to treat retinoblastoma: external beam radiotherapy and plaque radiotherapy.

External beam radiotherapy

External beam radiation therapy (also called EBRT) is generally required if the tumor has extended outside of the orbit, but it is sometimes used for retinoblastoma that is still contained within the eye. Due to advances in other therapies and the potential for adverse long-term effects, radiotherapy isn’t generally used to treat retinoblastoma that’s outside the eye. Because young children must be sedated for external beam radio-therapy, and the delivery of the radiation doses must be very precise to minimize damage to other tissues, only professionals who specialize in pediatric radiation therapy should treat your child.

External beam radiotherapy has traditionally been delivered by a linear accelerator targeted at the tumor. The current standard protocol is a total dose of 3,500 to 4,000 centigrays (cGy), given in daily doses over a 4- to 5-week period. Some centers give a lower total dose of external beam radiation to children who have already had their tumors treated with local therapies. The actual radiotherapy treatment takes approximately 2 or 3 minutes, but the preparation takes significantly longer. A number of centers now offer a newer type of radiotherapy (called proton beam), which is associated with fewer long-term side effects and is becoming a more common treatment for retinoblastoma. For more information, see Chapter 17, Radiation Therapy.

The doctor had been optimistic that Noah would have unilateral disease, so we were all quite devastated to learn 5 months later that he had new tumors in his remaining eye. Both were small enough to treat with laser, but unfortunately one was adjacent to the optic nerve so Noah had to have radiotherapy. The treatment was very localized. His white blood cell count dropped some, but not seriously. He experienced a mild radiation burn on the opposite side of the treated eye and some eyebrow hair loss.

Late effects may develop in the months or years after external beam radiation. They may include cataracts, slowed growth of the bones in the orbit, vision loss, reduced tear production, chronic conjunctivitis, damage to retina and optic nerve, and an increased risk of second cancers in the radiation field. Children with the hereditary form of the disease are more likely to develop subsequent cancers outside the radiation field, and the use of radiotherapy increases this risk. Children who have had radiation to the eye need expert follow-up evaluations on a routine basis.

Plaque radiotherapy

Plaque radiotherapy, also called brachytherapy, is a type of radiation therapy that places small pellets (sometimes called seeds) of radioactive material (iodine, cobalt, or ruthenium) near the tumor. The seeds are contained in a carrier that shields healthy tissue from the radiation. The radioactive material and the carrier together are called a plaque.

This type of radiotherapy is used primarily to treat small, single tumors in children with unilateral, early-stage disease that cannot be treated successfully with other local therapies. It is very effective and can be used in combination with chemotherapy. The pediatric oncologist, ophthalmologist, and a medical physicist will work closely together to plan the appropriate radioactive materials to use, their placement, and the dosage. The placement is done under general anesthesia, and the child stays in the hospital for the amount of time needed to deliver the correct dose of radiation (often 2 to 4 days). The child and the hospital room are monitored for radiation, and a parent staying with the child usually wears a radiation badge or other device for monitoring, as well. Surgery to remove the plaque usually takes less than an hour, and your child may be able to go home the same day. The full effect of the radiation on the tumor is not seen for several months.

Chemotherapy

Until the 1990s, systemic (intravenous) chemotherapy was primarily used to treat retinoblastoma that had spread outside the eye. To prevent the long-term problems that can occur after enucleation or radiation, more doctors are now using chemotherapy to treat intraocular (within the eye) retinoblastoma. The decision to use chemotherapy is complex and depends on a number of factors, including your child’s age; family history; the number, size, and location of tumors; and the ability of the ophthalmologist to use local treatments. Chemotherapy works better for smaller tumors and for tumors that have not spread.

For intraocular retinoblastoma, intravenous chemotherapy is generally used in conjunction with local therapies (e.g., cryotherapy, thermotherapy, laser photocoagulation, plaque radiation therapy) to shrink the tumor and help prevent new ones from growing. This is called chemoreduction therapy. This technique can help avoid the use of enucleation or external beam radiation.

Chemotherapy is also sometimes delivered directly to the eye. The ophthalmologist can do this in a variety of ways. The most common method is directly injecting chemotherapy drugs into the vitreous to try to attack small pieces of tumor; this method is called selective intra-arterial chemotherapy.

Another way to administer chemotherapy is through the arteries. In this case, an interventional neuroradiologist puts a fine catheter into the femoral artery in the groin area and, using a special type of x-ray guidance called fluoroscopy, feeds the catheter all the way into the ophthalmic artery in the eye. The ophthalmologist then injects the chemotherapy into this artery.

The chemotherapy drugs most commonly used intravenously to treat retinoblastoma are vincristine, etoposide, carboplatin, cyclophosphamide, and doxorubicin. Melphalan, topotecan, and carboplatin are delivered via intra-arterial chemotherapy. For more information about these drugs, see Chapter 15, Chemotherapy.

Jayden was diagnosed at 15 months with retinoblastoma. Because his tumor was so large and had spread to his optic nerve, he had two high-dose rounds of IV chemotherapy in July and August and then he had the enucleation of his right eye in September. The tumor caused enough pain and swelling that he stopped talking. He went back to using the sign language I taught him as a baby. To help relieve the pain and pressure, I gave him oxycodone, steroids, and dilating eye drops. The chemotherapy reduced the size of the tumor dramatically. Three days after the surgery he was talking, smiling, and playing again. Afterwards, he had 4 months of standard chemotherapy and finished in January. He just celebrated one year off treatment and he is doing very well.

PrognosisInformation on standard treatments

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