Hypothyroidism after craniospinal irradiation with proton or photon therapy in patients with medulloblastoma.

BACKGROUND: Craniospinal irradiation (CSI) often results in endocrine deficiencies in children with medulloblastoma due to irradiation of the hypothalamic-pituitary axis (HPA) or the thyroid gland. CSI with Proton radiation therapy (PRT) has the potential to decrease the risk of hypothyroidism by reduction in radiation dose to these organs. This study compares the risk for hypothyroidism in patients with medulloblastoma treated with Photon radiation therapy (XRT) or PRT. METHODS: The records of patients with medulloblastoma diagnosed at a single institution between 1997 and 2014 who received CSI were, retrospectively, reviewed. Ninety-five patients (54 XRT and 41 PRT) who had baseline and yearly follow-up thyroid studies were included. We used interval censored Cox regression to calculate hazard ratios of developing any, primary, and central hypothyroidism. RESULTS: With a median time to last thyroid studies post radiation of 3.8 years in PRT and 9.6 years in XRT, 33/95 (34.7%) patients developed hypothyroidism (median time to hypothyroidism: 2.6 years). Hypothyroidism developed in 25/54 (46.3%) who received XRT vs. 8/41 (19%) in the PRT group (HR =1.85, p = .14). Primary hypothyroidism developed in 15/95 (15.8%) patients: 12/54 (22.2%) after XRT and 3/41 (7.3%) after PRT (HR =2.1, p = .27). Central hypothyroidism developed in 17/95 (18.0%) patients: 13/54 (24.0%) after XRT and 4/41 (9.8%) after PRT (HR =2.16, p = .18). CONCLUSIONS: The use of PRT in patients with medulloblastoma was associated with numerically lower but not significantly lower risk of hypothyroidism. Further studies including larger numbers and longer follow up must be performed to assess whether lower radiation doses achieved with PRT show statistically significant differences.

Predictors of Suboptimal Follow-up in Pediatric Cancer Survivors.

Attendance to follow-up care after completion of cancer treatment is an understudied area. We examined demographic, clinical, and socioeconomic predictors of follow-up by pediatric cancer patients at a large center in 442 newly diagnosed patients using multivariable logistic regression analyses. Patients who did not return to clinic for at least 1000 days were considered lost to follow-up. Two hundred forty-two (54.8%) patients were lost. In multivariable analyses, the following variables were independent predictors of being lost to follow-up: treatment with surgery alone (odds ratio [OR]=6.7; 95% confidence interval [CI], 3.1-14.9), older age at diagnosis (reference, 0 to 4; ages, 5 to 9: OR=1.8, 95% CI, 1.1-3; ages, 10 to 14: OR=3.3; CI, 1.8-6.1; and ages, 15 and above: OR=4.8; CI, 2.1-11.7), lack of history of stem cell transplantation (OR=2, 95% CI, 1.04-3.7) and lack of insurance (OR=3.4; CI, 1.2-9.2). Hispanic patients had the best follow-up rates (53.7%) compared to whites and blacks (P=0.03). Attendance to long-term follow-up care is suboptimal in childhood cancer survivors. Predictors that were associated with nonattendance can be used to design targeted interventions to improve follow-up care for survivors of pediatric cancer.

Scoliosis in Children Treated With Photon Craniospinal Irradiation for Medulloblastoma.

PURPOSE: Scoliosis is a well-recognized complication after abdominal radiation therapy but not reported frequently after craniospinal irradiation (CSI). We examined the incidence and risk factors for scoliosis after CSI in long-term survivors with medulloblastoma. METHODS AND MATERIALS: The records of patients with medulloblastoma seen at one institution from 1996 to 2006 were analyzed for the use of CSI and development of scoliosis as documented on physical examination and spinal imaging. RESULTS: We identified 35 children with medulloblastoma who were ≤12 years of age at time of CSI with a median 14.3 years (range, 5.8-19.3 years) of follow-up. Twenty-seven (77.1%) were male, and median age at CSI was 6.8 years (range, 2.8-12 years). The cumulative incidence of scoliosis at 15 years was 34.6%. The median time to develop scoliosis was 7.1 years (range, 5-11.7 years) after CSI. Treatment with high dose CSI (34.2-40 Gy) and presence of hemiplegia or hemiparesis were found to be risk factors for development of scoliosis. CONCLUSIONS: Scoliosis is an underreported complication of photon craniospinal irradiation.

Comparison of height and weight after 12 vs. 18 Gy cranial radiation therapy in pediatric acute lymphoblastic leukemia (ALL) patients.

PURPOSE: To compare the effect of 12 versus 18 Gy cranial radiation therapy (RT) on height and weight indices among pediatric patients with acute lymphoblastic leukemia (ALL). METHODS AND MATERIALS: Records of children with ALL who were 2 to 14 years old at the time of RT and were treated at a single institution between 2000 and 2011 were reviewed. Patients' height, weight, and body mass index were converted into z-scores using the Centers for Disease Control growth charts to normalize the values to number of standard deviations from the mean. These values were measured at the pre-RT clinic visit and subsequent yearly intervals. The z-scores of the growth indices were fitted into a generalizing estimating equations model and analyzed by various clinical factors. RESULTS: A total of 48 patients met the study criteria, including 32 boys and 16 girls. The median age at the time of RT was 7 years (range, 2-14 years). Patients were separated into 2 dose groups: 12 Gy (n = 30) and 18 Gy (n = 18). Median follow-up was 4.9 years (range, 3.0-11.8 years) and 6.0 years (range, 3.1-10.5 years) and the median pre-RT height z-scores were -0.55 (range, -2.2 to 1.4) and -0.85 (range, -3.1 to 0.8) for the 2 groups, respectively (P = .65). Patients who received 18 Gy had a significant difference in change in height compared with those who received 12 Gy, who were able to maintain normal growth during the first 3 years of follow-up. This did not appear to be sex-specific, and there was no difference in change in weight or body mass index. CONCLUSIONS: Compared with 18 Gy, patients with ALL who received 12 Gy of cranial RT had less height impairment in the first 3 years post-RT, but further prospective studies are needed.

Human papillomavirus vaccination in female pediatric cancer survivors.

STUDY OBJECTIVE: Survivors of childhood malignancy may be at increased risk for HPV infection for biological and cognitive/behavioral reasons. HPV vaccination is currently recommended for females 11-12 years old with catch up vaccination up to age 26 years. The objective of this cross-sectional study was to determine the prevalence of HPV vaccination among female pediatric cancer survivors, age 11-18 years, at Texas Children's Hospital. STUDY DESIGN, SETTING, AND PARTICIPANTS: A 42-question survey was distributed to parents/guardians of 172 long-term cancer survivors from August-November of 2010. Data were analyzed using frequencies, t-tests, and chi-square analyses. MAIN OUTCOME MEASURES: Prevalence of HPV vaccination (intention and completion). RESULTS: Sixty-six persons (38%) responded. The median current age of survivors was 14 years. Most were white/non-Hispanic (48%) or white/Hispanic (37%). Seventy-one percent had discussed HPV vaccination with a healthcare provider. The overall rate of HPV vaccination (≥ 1 dose) was 32%, including 5% of those age 11-12 years (n = 1 of 21), 36% of those age 13-17 years (n = 13 of 36), and 78% of those age 18 years (n = 7 of 9). Of those whose children had not been immunized, 36% intended to do so in the future. Factors associated with HPV vaccination included age ≥13 years, report of sexual activity, and report of having discussed HPV vaccination with a healthcare provider. CONCLUSION: The rate of HPV vaccination among female pediatric cancer survivors is not appreciably different than that seen in the general population.