Wilm’s Tumor: Employment Of Radiation Therapy

Radiation therapy is another effective technique used to exterminate tumor cells while keeping in mind that healthy cells and tissues are kept from any damage or injury. The appropriate administration of radiation therapy depends upon the outlook and condition of cancer.

Sometimes, radiotherapy is given before chemotherapy especially when the tumor is of high risk while at other times it is given after chemotherapy.

What is Radiotherapy?

Radiation therapy is the procedure, which possibly treats cancer by employing either X-rays or high-energy radiations emitted from a specific device. The treatment is almost like an X-ray except that the radiation dose is much higher. Bodies of the children are very sensitive to these radiations.

Methods of Radiotherapy:

There are two ways in which the radiotherapy is given.

  • External Radiation Therapy:

It refers to the administration of high energy radiations into the affected part of the body using a device that gives out this radiation and is kept outside the body.

  • Internal Radiation Therapy:

The method of radiation therapy involves the insertion of a small piece of radioactive material into the body, specifically in the abdominal cavity as in the case of Wilms’ tumor. This radioactive material/probe will give out radiation that will reach cancer cells and will tend to kill them.

The radioactive substance is more often made available in the body by sealing in:

  • Needles
  • Seeds
  • Wires
  • Catheters

This type of therapy is also termed as brachytherapy.

Targeted regions of Radiotherapy for Wilm’s tumor:

Depending upon the spread of cancer, radiotherapy is given to the possibly affected areas. It is given to the abdomen, but it can also be given to the chest cavity and other tumor-invaded areas.

The region of the tumor-invaded kidney is especially subjected to radiotherapy. Radiotherapy procedure is chosen based on certain aspects including the type of tumor, whether surgery has been performed, and whether a biopsy has been done before surgery.

Reason of employment of Radiotherapy for Wilm’s tumor:

Radiotherapy is given to the patient in cases when the tumor is large enough to hinder the process of surgery. So radiation therapy is given to the child in the affected regions (kidneys and other tumor-invaded areas in case of Wilms’ tumor) along with chemotherapy. Just to shrink the tumor to a size that can be conveniently removed through surgery.

Radiotherapy is also used after surgery to destroy or exterminate any remnants of the treated tumor; that may invade other regions of the body. Radiotherapy is made use of while treating either the advanced stages of Wilm’s tumor (stages III, IV, and V) or early stage of tumors with unfavorable histology.

Radiotherapy procedure:

An experienced radiation oncologist tackles the child’s cancer with great care and makes targeted radiotherapy as effective as possible.

  • The radiation oncologist makes the child lie on a table for about 15 to 30 minutes while a machine sends radiation to the child at a precisely targeted angle.
  • The procedure is not uncomfortable for the child; however, younger children may be sedated while being subjected to radiation.
  • Radiation therapy, if not done with care and attention, may cause damage to healthy cells, which may result in the initiation of a new tumor in addition to the existing ones.

Short-term side effects of radiotherapy:

Possible side effects of radiation therapy to the abdomen in case of Wilm’s tumor include:

  • Fatigue
  • Mild skin reactions due to the exposure of skin to high-energy radiation
  • Upset stomach
  • Loose bowel movements

However, all these ill effects are short-term and can be treated by administering relevant medicines. To avoid the maximum side effects while dealing with radiation therapy, the oncologist should take care in administering the appropriate dosage of radiation in the child. The ill effects can also be minimized by dividing the total dose to be given over days so that the child stays on the safe side of the radiation limit.

Modern techniques of Radiotherapy for Wilm’s tumor:

Some of the modern techniques of radiation therapy, that target the radiation with more precision, include the following:

  • Three-Dimensional Conformal Radiation Therapy (3D-CRT):

3D-CRT makes use of the results of imaging tests such as MRI to deliver the radiation into the body with more accuracy and precision. By observing the MRI image of the child’s body and consequently the exact location of the tumor, the radiation can be administered with more precision and exactly at the targeted point.

Each beam of radiation is itself very weak; however, the machine emitting the radiation converges the beams right on the tumor. In this way, the radiation is strengthened as it reaches the required target, and stray rays do not damage the nearby exposed tissues.

During the whole procedure, the child is sedated or more often he/she is confined in a plastic mold resembling the body shape to keep him/her throughout in the same position. It is done to facilitate the therapy.

  • Intensity Modulated Radiation Therapy (IMRT):

IMRT is a modernized and advanced form of three-dimensional radiotherapy, which has now been taken up by doctors/oncologists as a better and more effective way of administering radiotherapy.

By using this procedure, the radiation beams are not only aimed at the tumor from different angles but their intensities are also tailored to target the affected area specifically. It also helps to keep healthy tissues from being damaged. Hence, side effects are minimized.

Major Side Effects:

Radiation therapy, if not handled with proper precautionary measures, can result in severely drastic results often generating a new tumor in either healthy tissues or already treated ones. Major side effects are given as follows:

  • The skin of the areas exposed to radiation may appear sunburnt and may take several months to recover.
  • Hair loss observed in the skin exposed to radiation.
  • Radiation directed to the abdomen may disturb the digestive system resulting in nausea, vomiting, and diarrhea.
  • Excessive exposure to radiation can also produce consequences like stunted growth in young children. Healthy body tissues can also be damaged, and their growth may be affected.
  • New cancer/tumor may generate when the radiation disturbs DNA structure. The appearance of cancer is usually after several years. However, it usually doesn’t occur in the treatment of Wilms’ tumor as the exposure to the radiation is quite low and is limited to the abdominal region most of the time.

Questions to Ask Your Doctor

  • How much is the time taken to complete a session of radiotherapy?
  • Would you mind explaining to me why you want to give radiotherapy to my child?
  • To which areas you are going to give radiotherapy?
  • Are you going to use internal radiotherapy or external radiotherapy?
  • What are the possible side effects of radiotherapy?
  • Are there any long-term side effects of this therapy?
  • What are the chances that new cancer will turn out?
  • What other procedures are to be followed along with radiotherapy?
  • What are the precautions before or after the radiotherapy?
  • Is this treatment going to affect my child’s social life?
  • Are you going to sedate my child during the therapy session?

Conclusion:

Radiotherapy uses high energy particles or rays to destroy cancer cells. It is performed in the later or advanced stages of Wilm’s tumor i.e. III, IV and V for five days a week for almost two weeks. There are two methods in which radiation therapy is given. The external beam radiation therapy provides radiation from outside the body, particularly on the cancer cells.

References:

  1. Radiation therapy for Wilm’s tumor
  2. Treatment by stage and type of Wilms tumor
  3. RADIATION THERAPY FOR FAVORABLE HISTOLOGY WILMS TUMOR: PREVENTION OF FLANK RECURRENCE DID NOT IMPROVE SURVIVAL ON NATIONAL WILMS TUMOR STUDIES 3 AND 4
  4. Radiotherapy to the whole abdomen for Wilms tumour for children
  5. Radiation therapy in Wilms cancer