Pediatric Oncology
Education Materials

Musculo-skeletal

Growth abnormalities and hypoplasia:

• Scoliosis and mild asymmetry of all musculoskeletal structures in the RT field can occur due to reduced growth of bone and paravertebral muscles

• Scoliosis is more likely for survivors of neuroblastoma than Wilms tumor
  

• NBL tumors are more likely to cross the midline than Wilms and impinge on the opposite kidney. Patients often received RT with 3D conformal fields and sparing renal tissue takes precedence over irradiating the vertebral bodies uniformly.  The dose of RT is also generally higher for NBL than Wilms and therefore skeletal asymmetry is more likely in NBL.
• There is likely to be a decrease in sitting height and modest decrease in standing height after abdominal RT
  

• These effects are more pronounced the younger the patient is at the time of RT

Increased risk of osteoporosis (especially involving the spine) and degenerative disease:

• Patients should avoid lifting heavy weights
• Bone density should be checked roughly 10 years before one would normally worry about osteoporosis
• Important to maintain bone density (Vit D, dairy servings in diet and exercise)

Hepatic

There is a small long term risk of veno-occlusive disease which consists of the clinical triad:

• hepatomegaly
• ascites
• icterus

Renal

Patients may have undergone nephrectomy when their primary NBL tumor was resected and therefore have less renal reserve.

Large primary abdominal NBL tumors that cross the midline may extend very close to the contralateral kidney.  RT to the tumor bed is likely to be associated with a significantly increased risk of chronic renal failure

If included in the RT treatment volume, stenosis of the contralateral renal artery may produce hypertension.

It is very important to check NBL survivor's blood pressure on a regular basis

Gonadal

Ovary:

Testis:
Primary gonadal failure is rare in survivors of NBL as whole abdominal RT is rarely if ever indicated.

Pelvic RT for a primary NBL arising in that region would be associated with a risk of gonadal failure

It would be anticipated that female patients who have abdominal RT for NBL - as with patients who received flank RT for Wilms are at increased risk for premature and low birth weight babies.

Secondary Neoplasms

• RT is associated with an increase risk of secondary malignancies
• Probably in the range of 3 - 5% long-term increased risk

Musculo-skeletal Growth

Scoliosis and asymmetry of all musculoskeletal structures in the RT field are likely to occur due to:

• Spinal deformity secondary to primary NBL tumor
• Surgically induced spinal asymmetry
• Reduced growth of bone and paravertebral muscles secondary to RT
  

There will be a decrease in sitting height and modest decrease in standing height after flank or abdominal RT depending on the age of the child at the time of therapy

If the child is very young, after RT to the thoracic spine there may be a mild restrictive problem due to reduced growth of the chest wall and ribs.

Pulmonary

RT to the thoracic spine may be associated with:

• A mild restrictive problem due to reduced growth of the spine, adjacent chest wall and ribs.
• Extensive primary NBL therapy may be associated with a risk of pneumonitis and subsequent lung fibrosis

Cervical spine RT is likely to be associated with a risk of hypothyroidism, thyroid nodules and papillary carcinoma of the thyroid.

Secondary Neoplasms

• Increased risk of secondary neoplasms
• Survivors should be discouraged from smoking.  A previous history of chest RT as a child gives a very high risk of lung cancer in survivors that smoke.
• Women who had chest RT as children are at increased risk for the development of breast cancer and require early screening.

• Secondary malignancy (AML)
• Infertility

• Renal toxicity
• Hearing loss

• Secondary AML (short latency period)

• Significant cardiac toxicity is very rare in neuroblastoma survivors

• Peripheral neuropathy