Introduction

Adolescent females with idiopathic scoliosis are exposed to substantial amounts of radiation during treatment and follow-up for AIS. The purpose of this study was to determine the amount radiation exposure patients received during treatment for AIS and report the incidence of infertility and cancer in adulthood.

Material and Method: 219 consecutive AIS patients treated at Rigshospitalet, Copenhagen between 1983 and 1990 were identified and requested to return for clinical and radiographic examination. The incidence of cancer was determined through chart review and follow-up interviews. In addition, the subjects and age-matched controls were queried regarding infertility, age at first pregnancy and spontaneous abortions. Using X -ray reports that included patient position, mAs and kV used and the number of X-rays taken, a radiation physicist calculated the total radiation dose during treatment and follow-up adjusted for BMI and sex.

Results

159 (78%) patients participated in the follow up study, and medical charts were available in 209 patients. 2 patients had passed away, one due to cardiac arrest and one to breast cancer. 8 patients had emigrated. Radiation information was available in 211 patients. The mean calculated mean total radiation exposure was 1.58 mSv (0,44–6,9). An average of 16.3 (range, 8–34) X-rays were taken during treatment. The rate of infertility (10%) and spontaneous abortion (23%) is similar to the normal controls. The AIS patients had an average of 1.4 children, which is 1 child less than the 2.5 children in the control cohort. Nine (4.3%) AIS patients developed cancer, mostly breast (3) and endometrial (4). Risk Ratio for cancer = 20.93 (95% CI:2.67–164.19) p = 0.000132. The patients with endometrial cancers have a low BMI 16.4 (15.9–16.6) at first radiation exposure, and the patients with breast cancers were older with BMI 20.4 (18.0–22.4). The incidence of cancer in this cohort is 17 times greater than the incidence of 0.25% in an age-sex matched cohort from the Danish Cancer Society Annual Report.

Conclusion

The infertility and spontaneous abortion rate was similar between AIS patients and an age matched cohort. The cancer rate in the AIS patients is 17 times higher than expected compared with the age-matched Danish population.

Table 1

Summary of demographic characteristics

	AIS patients	Controls
*Both patient and partner infertile.
N	165	100
Responders	95 (57,6%)	65 (65%)
Female	91	59
Age at end of treatment	14,3 years (12–18 years)
Age at questionnaire	37,6 years (33–47 years)	37,5 years (26–54 years)
Have you been pregnant	85 (89,5%)	54 (91,5%)
Infertility	11* (10,6%)	8 (12,3%)
Partner infertile	6* (6,3%)	5 (7,6%)
Spontaneous abortion	22 (22,9%)	14 (21,5%)
Age at 1 pregnancy	23,0 years (16–41 years)	26,0 years (20–40 years)
N of children	1,4 (1–4 children)	2,5 (1–4 children)

Table 2

Summary of demographic characteristics

	AIS patients
N	219
Data available	209*
Female	199
Age at follow-up	37,6 years (33–47 years)
BMI at treatment	19,56 (12,26–27,85)
N X-rays during treatment	16,3 (8–34)
Radiation dose pr exam	0,8–1,4 mSv
Cummulative radiation dose per year	2,4–5,6 mSv
Number of cancer	9
Endometrial cancer	4
Breast cancer	3
Lymphoma	1
Glioma	1