From 1968 to 1994, 55 children received megavoltage RT at our institution as part of treatment for
Wilms' tumor. A total of 42 (76.4%) have survived and have a minimum follow-up of 5 years. There were 25 female and 17 male patients with a median age at diagnosis of 48 months (range, 7-126 months). There were 12 Stage I, eight Stage II, 15 Stage III, six Stage IV, and one Stage V patient. RT was delivered to the hemiabdomen in 36 and whole abdomen in six patients. RT dose was 1000-1200 cGy (Group A) in 12, 1201-2399 cGy (Group B) in 11, and 2400-4000 cGy (Group C) in 19. Whole-lung RT was delivered to 13 patients either at diagnosis or pulmonary relapse. All patients received
chemotherapy; the most common agents were
actinomycin-D/
vincristine/
adriamycin in 13 and
actinomycin-D/
vincristine in 18. Median follow-up was 181 months (range, 60-306 months).
RESULTS: Of 42 patients, 13 (31.0%) did not have late effects of treatment. The number of patients who developed muscular hypoplasia, limb length inequality,
kyphosis, and iliac wing hypoplasia were seven (16.7%), five (11.9%), three (7.1%), and three (7.1%), respectively.
Scoliosis was seen in 18 (42.9%) with only one patient requiring orthopedic intervention. Median time to development of
scoliosis was 102 months, with a range of 16-146 months. The actuarial incidence of
scoliosis at 5, 10, and 15 years after RT was 4.8 +/- 3.3%, 51.8 +/- 9.0%, and 56.7 +/- 9.3%, respectively. Only one of 12 Group A patients developed
scoliosis. The 10- and 15-year actuarial incidences of
scoliosis for Group A and B patients were 37.7 +/- 12.4% and 37.7 +/- 12.4%, whereas for Group C patients the incidences were 65.8 +/- 12.0% and 74.4 +/- 11. 7% (p = 0.03, log rank test). The actuarial incidence of bowel obstruction at 5, 10, and 15 years was 9.5 +/- 4.5%, 13.0 +/- 5.6%, and 17.0 +/- 6.5%. Of 23 patients, five irradiated within 10 days of surgery and one of 19 irradiated after 10 days developed bowel obstruction (p = 0.09, log rank test). Three patients developed
hypertension with normal blood
urea nitrogen (BUN) and
creatinine levels; another patient had
chronic renal insufficiency in a nonirradiated kidney. One patient developed diffuse
interstitial pneumonitis. Of the 19 female patients who have reached puberty, three have given birth, and 15 have regular and one has irregular menstrual periods. Four patients developed
benign neoplasms; three were in the RT field (two
osteochondroma, one
lipoma) and one outside (
cervical intraepithelial neoplasia II). There were three
second malignancies (
chronic myelogenous leukemia at 9 years,
osteosarcoma at 11 years, and
breast cancer at 25 years after initial diagnosis of
nephroblastoma); both solid
malignancies occurred in the RT field.
CONCLUSIONS: Late effects of
therapy were seen in more than two thirds of children treated for
Wilms' tumor. Children treated with lower doses (<2400 cGy) had a lower incidence of
scoliosis compared with those who received more than 2400 cGy. There is also a suggestion that the incidence is lower in patients who received 1000-1200 cGy. Severe physical and functional
deformity from RT was uncommon.