Normal tissue exposure and second malignancy risk in vertebral-body-sparing craniospinal irradiation

Shifting Strategies in the Treatment of Pediatric Craniopharyngioma

PURPOSE OF REVIEW

Craniopharyngiomas represent one of the most challenging diseases to treat. Despite their benign histology, and after many decades of surgical experience and technological advancements, there is still no clear consensus regarding the most effective management for this tumor. Due to their location and aggressive local characteristics, purely surgical approaches all too often result in unacceptable morbidity.

RECENT FINDINGS

Partial resection combined with radiation therapy results in similar control rates when compared to aggressive surgery, while also minimalizing the neuro-endocrinological morbidity. In this manuscript, we describe the historical progression of the shifting strategies in the management of pediatric craniopharyngioma. Time has also altered our expectations for outcomes, evolving from purely morbidity and mortality to simple Glasgow Outcomes Scales, now to formal neuro-psychometric and quality of life data.

Late Effects of Craniospinal Irradiation Using Electron Spinal Fields for Pediatric Patients With Cancer

PURPOSE

For children, craniospinal irradiation (CSI) with photons is associated with significant toxic effects. The use of electrons for spinal fields is hypothesized to spare anterior structures but the long-term effects remain uncertain. We studied late effects of CSI using electrons for spinal radiation therapy (RT).

METHODS AND MATERIALS

Records of 84 consecutive patients treated with CSI using electrons for the spine at a single institution between 1983 and 2014 were reviewed. Median age at RT was 5 (range, 1-14) years. The most common histologies were medulloblastoma/primitive neuroectodermal tumor (59%) and ependymoma (8%). The median prescribed dose to the entire spine was 30 Gy (range, 6-45). A subset of 48 (57%) patients aged 2 to 14 at RT with clinical follow-up for ≥5 years was analyzed for late effects. Height z scores adjusted for age before and after CSI were assessed using stature-for-age charts and compared with a t test.

RESULTS

At median follow-up of 19 years (range, 0-38 years), the median survival was 22 years (95% confidence interval, 12-28 years) after RT, with 47 patients (56%) alive at last follow-up. On subset analysis for late effects, 19 (40%) patients developed hypothyroidism and 5 (10%) developed secondary malignancies. Other complications reported were esophageal stricture and periaortic hemorrhage in 1 and restrictive pulmonary disease in 1 patient. Median height z score before treatment was -0.4 (36th percentile; interquartile range, -1.0 to 0.0) and at last follow-up was -2.2 (first percentile; interquartile range, -3.1 to -1.6; P < .001). Of 44 patients with spinal curvature assessments, 15 (34%) had scoliosis with median Cobb angle 15° (range, 10°-35°) and 1 (2%) required surgery.

CONCLUSIONS

Frequent musculoskeletal toxic effects and predominantly decreased height were seen with long-term follow-up. Scoliosis and hypothyroidism were each seen in at least one-third of long-term survivors. However, clinically evident esophageal, pulmonary, and cardiac toxic effects were infrequent.