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Title: Modeling radiation dosimetry to predict cognitive outcomes in pediatric patients with CNS embryonal tumors including medulloblastoma

Abstract

Purpose: Model the effects of radiation dosimetry on IQ among pediatric patients with central nervous system (CNS) tumors. Methods and Materials: Pediatric patients with CNS embryonal tumors (n = 39) were prospectively evaluated with serial cognitive testing, before and after treatment with postoperative, risk-adapted craniospinal irradiation (CSI) and conformal primary-site irradiation, followed by chemotherapy. Differential dose-volume data for 5 brain volumes (total brain, supratentorial brain, infratentorial brain, and left and right temporal lobes) were correlated with IQ after surgery and at follow-up by use of linear regression. Results: When the dose distribution was partitioned into 2 levels, both had a significantly negative effect on longitudinal IQ across all 5 brain volumes. When the dose distribution was partitioned into 3 levels (low, medium, and high), exposure to the supratentorial brain appeared to have the most significant impact. For most models, each Gy of exposure had a similar effect on IQ decline, regardless of dose level. Conclusions: Our results suggest that radiation dosimetry data from 5 brain volumes can be used to predict decline in longitudinal IQ. Despite measures to reduce radiation dose and treatment volume, the volume that receives the highest dose continues to have the greatest effect, which supports currentmore » volume-reduction efforts.« less

Authors:
 [1];  [2];  [3];  [2];  [2];  [3];  [4];  [5]
  1. Division of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, TN (United States). E-mail: thomas.merchant@stjude.org
  2. Division of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, TN (United States)
  3. Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN (United States)
  4. Department of Hematology Oncology, St. Jude Children's Research Hospital, Memphis, TN (United States)
  5. Division of Behavioral Medicine, St. Jude Children's Research Hospital, Memphis, TN (United States)
Publication Date:
OSTI Identifier:
20793477
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 65; Journal Issue: 1; Other Information: DOI: 10.1016/j.ijrobp.2005.10.038; PII: S0360-3016(05)02953-6; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BRAIN; CARCINOMAS; CHEMOTHERAPY; DOSIMETRY; IRRADIATION; PATIENTS; RADIATION DOSE DISTRIBUTIONS; RADIATION DOSES; SURGERY

Citation Formats

Merchant, Thomas E., Kiehna, Erin N., Li Chenghong, Shukla, Hemant, Sengupta, Saikat, Xiong Xiaoping, Gajjar, Amar, and Mulhern, Raymond K.. Modeling radiation dosimetry to predict cognitive outcomes in pediatric patients with CNS embryonal tumors including medulloblastoma. United States: N. p., 2006. Web. doi:10.1016/J.IJROBP.2005.1.
Merchant, Thomas E., Kiehna, Erin N., Li Chenghong, Shukla, Hemant, Sengupta, Saikat, Xiong Xiaoping, Gajjar, Amar, & Mulhern, Raymond K.. Modeling radiation dosimetry to predict cognitive outcomes in pediatric patients with CNS embryonal tumors including medulloblastoma. United States. doi:10.1016/J.IJROBP.2005.1.
Merchant, Thomas E., Kiehna, Erin N., Li Chenghong, Shukla, Hemant, Sengupta, Saikat, Xiong Xiaoping, Gajjar, Amar, and Mulhern, Raymond K.. Mon . "Modeling radiation dosimetry to predict cognitive outcomes in pediatric patients with CNS embryonal tumors including medulloblastoma". United States. doi:10.1016/J.IJROBP.2005.1.
@article{osti_20793477,
title = {Modeling radiation dosimetry to predict cognitive outcomes in pediatric patients with CNS embryonal tumors including medulloblastoma},
author = {Merchant, Thomas E. and Kiehna, Erin N. and Li Chenghong and Shukla, Hemant and Sengupta, Saikat and Xiong Xiaoping and Gajjar, Amar and Mulhern, Raymond K.},
abstractNote = {Purpose: Model the effects of radiation dosimetry on IQ among pediatric patients with central nervous system (CNS) tumors. Methods and Materials: Pediatric patients with CNS embryonal tumors (n = 39) were prospectively evaluated with serial cognitive testing, before and after treatment with postoperative, risk-adapted craniospinal irradiation (CSI) and conformal primary-site irradiation, followed by chemotherapy. Differential dose-volume data for 5 brain volumes (total brain, supratentorial brain, infratentorial brain, and left and right temporal lobes) were correlated with IQ after surgery and at follow-up by use of linear regression. Results: When the dose distribution was partitioned into 2 levels, both had a significantly negative effect on longitudinal IQ across all 5 brain volumes. When the dose distribution was partitioned into 3 levels (low, medium, and high), exposure to the supratentorial brain appeared to have the most significant impact. For most models, each Gy of exposure had a similar effect on IQ decline, regardless of dose level. Conclusions: Our results suggest that radiation dosimetry data from 5 brain volumes can be used to predict decline in longitudinal IQ. Despite measures to reduce radiation dose and treatment volume, the volume that receives the highest dose continues to have the greatest effect, which supports current volume-reduction efforts.},
doi = {10.1016/J.IJROBP.2005.1},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 1,
volume = 65,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2006},
month = {Mon May 01 00:00:00 EDT 2006}
}
  • Purpose: To report, from a longitudinal study, cognitive outcome in pediatric patients treated with proton radiation therapy (PRT) for central nervous system (CNS) tumors. Methods and Materials: Sixty patients receiving PRT for medulloblastoma (38.3%), gliomas (18.3%), craniopharyngioma (15.0%), ependymoma (11.7%), and other CNS tumors (16.7%) were administered age-appropriate measures of cognitive abilities at or near PRT initiation (baseline) and afterward (follow-up). Patients were aged ≥6 years at baseline to ensure consistency in neurocognitive measures. Results: Mean age was 12.3 years at baseline; mean follow-up interval was 2.5 years. Treatment included prior surgical resection (76.7%) and chemotherapy (61.7%). Proton radiation therapy included craniospinal irradiationmore » (46.7%) and partial brain radiation (53.3%). At baseline, mean Wechsler Full Scale IQ was 104.6; means of all 4 Index scores were also in the average range. At follow-up, no significant change was observed in mean Wechsler Full Scale IQ, Verbal Comprehension, Perceptual Reasoning/Organization, or Working Memory. However, Processing Speed scores declined significantly (mean 5.2 points), with a significantly greater decline for subjects aged <12 years at baseline and those with the highest baseline scores. Cognitive outcome was not significantly related to gender, extent of radiation, radiation dose, tumor location, histology, socioeconomic status, chemotherapy, or history of surgical resection. Conclusions: Early cognitive outcomes after PRT for pediatric CNS tumors are encouraging, compared with published outcomes from photon radiation therapy.« less
  • Purpose: To report the early outcomes for very young children with medulloblastoma or supratentorial primitive neuroectodermal tumor (SPNET) treated with upfront chemotherapy followed by 3-dimensional proton radiation therapy (3D-CPT). Methods and Materials: All patients aged <60 months with medulloblastoma or SPNET treated with chemotherapy before 3D-CPT from 2002 to 2010 at our institution were included. All patients underwent maximal surgical resection, chemotherapy, and adjuvant 3D-CPT with either craniospinal irradiation followed by involved-field radiation therapy or involved-field radiation therapy alone. Results: Fifteen patients (median age at diagnosis, 35 months) were treated with high-dose chemotherapy and 3D-CPT. Twelve of 15 patients hadmore » medulloblastoma; 3 of 15 patients had SPNET. Median time from surgery to initiation of radiation was 219 days. Median craniospinal irradiation dose was 21.6 Gy (relative biologic effectiveness); median boost dose was 54.0 Gy (relative biologic effectiveness). At a median of 39 months from completion of radiation, 1 of 15 was deceased after a local failure, 1 of 15 had died from a non-disease-related cause, and the remaining 13 of 15 patients were alive without evidence of disease recurrence. Ototoxicity and endocrinopathies were the most common long-term toxicities, with 2 of 15 children requiring hearing aids and 3 of 15 requiring exogenous hormones. Conclusions: Proton radiation after chemotherapy resulted in good disease outcomes for a small cohort of very young patients with medulloblastoma and SPNET. Longer follow-up and larger numbers of patients are needed to assess long-term outcomes and late toxicity.« less
  • Purpose: To report on acute toxicity, longitudinal cognitive function, and early clinical outcomes in children with average-risk medulloblastoma. Methods and Materials: Twenty children {>=}5 years of age classified as having average-risk medulloblastoma were accrued on a prospective protocol of hyperfractionated radiation therapy (HFRT) alone. Radiotherapy was delivered with two daily fractions (1 Gy/fraction, 6 to 8 hours apart, 5 days/week), initially to the neuraxis (36 Gy/36 fractions), followed by conformal tumor bed boost (32 Gy/32 fractions) for a total tumor bed dose of 68 Gy/68 fractions over 6 to 7 weeks. Cognitive function was prospectively assessed longitudinally (pretreatment and atmore » specified posttreatment follow-up visits) with the Wechsler Intelligence Scale for Children to give verbal quotient, performance quotient, and full-scale intelligence quotient (FSIQ). Results: The median age of the study cohort was 8 years (range, 5-14 years), representing a slightly older cohort. Acute hematologic toxicity was mild and self-limiting. Eight (40%) children had subnormal intelligence (FSIQ <85), including 3 (15%) with mild mental retardation (FSIQ 56-70) even before radiotherapy. Cognitive functioning for all tested domains was preserved in children evaluable at 3 months, 1 year, and 2 years after completion of HFRT, with no significant decline over time. Age at diagnosis or baseline FSIQ did not have a significant impact on longitudinal cognitive function. At a median follow-up time of 33 months (range, 16-58 months), 3 patients had died (2 of relapse and 1 of accidental burns), resulting in 3-year relapse-free survival and overall survival of 83.5% and 83.2%, respectively. Conclusion: HFRT without upfront chemotherapy has an acceptable acute toxicity profile, without an unduly increased risk of relapse, with preserved cognitive functioning in children with average-risk medulloblastoma.« less
  • Purpose: Patients with brain metastases may experience treatment-related cognitive deficits. In this study, we prospectively assessed the self-reported cognitive abilities of patients with brain metastases from any solid primary cancer before and after irradiation of the brain. Methods and Materials: The treatment group (TG) consisted of adult patients (n=50) with brain metastases who received whole or partial irradiation of the brain without having received prior radiation therapy (RT). The control group (CG) consisted of breast cancer patients (n=27) without cranial involvement who were treated with adjuvant RT. Patients were recruited between May 2008 and December 2010. Self-reported cognitive abilities weremore » acquired before RT and 6 weeks, 3 months, and 6 months after irradiation. The information regarding the neurocognitive status was collected by use of the German questionnaires for self-perceived deficits in attention (FEDA) and subjectively experienced everyday memory performance (FEAG). Results: The baseline data showed a high proportion of self-perceived neurocognitive deficits in both groups. A comparison between the TG and the CG regarding the course of self-reported outcomes after RT showed significant between-group differences for the FEDA scales 2 and 3: fatigue and retardation of daily living activities (P=.002) and decrease in motivation (P=.032) with an increase of attention deficits in the TG, but not in the CG. There was a trend towards significance in FEDA scale 1: distractibility and retardation of mental processes (P=.059) between the TG and the CG. The FEAG assessment presented no significant differences. An additional subgroup analysis within the TG was carried out. FEDA scale 3 showed significant differences in the time-related progress between patients with whole-brain RT and those receiving hypofractionated stereotactic RT (P=.025), with less decrease in motivation in the latter group. Conclusion: Self-reported attention declined in patients with brain metastases after RT to the brain, whereas it remained relatively stable in breast cancer patients.« less
  • Purpose: Cognitive decline is a recognized effect of radiation therapy (RT) in children treated for brain tumors. The importance of the cerebellum and its contribution to cognition have been recognized; however, the effect of RT on cerebellum-linked neurocognitive deficits has yet to be explored. Methods and Materials: Seventy-six children (39 males) at a median 3.3 years of age (range, 1-17 years old) were irradiated for infratentorial ependymoma from 1997 to 2008. The total prescribed dose was 54 to 59.4 Gy administered to the postoperative tumor bed with 5- or 10-mm clinical target volume margin. Age-appropriate cognitive and academic testing was performed prior tomore » the start of RT and was then repeated at 6 months and annually throughout 5 years. The anterior and posterior cerebellum and other normal brain volumes were contoured on postcontrast, T1-weighted postoperative magnetic resonance images registered to treatment planning computed tomography images. Mean doses were calculated and used with time after RT and other clinical covariates to model their effect on neurocognitive test scores. Results: Considering only the statistically significant rates in longitudinal changes for test scores and models that included mean dose, there was a correlation between mean infratentorial dose and intelligence quotient (IQ; −0.190 patients/Gy/year; P=.001), math (−0.164 patients/Gy/year; P=.010), reading (−0.137 patients/Gy/year; P=.011), and spelling scores (−0.147 patients/Gy/year; P=.012), where Gy was measured as the difference between the mean dose received by an individual patient and the mean dose received by the patient group. There was a correlation between mean anterior cerebellum dose and IQ scores (−0.116 patients/Gy/year; P=.042) and mean posterior cerebellum dose and IQ (−0.150 patients/Gy/year; P=.002), math (−0.120 patients/Gy/year; P=.023), reading (−0.111 patients/Gy/year; P=.012), and spelling (−0.117 patients/Gy/year; P=.015) scores. Conclusions: Sparing portions of the cerebellum should be considered in RT planning for children with infratentorial ependymoma because of the potential impact of radiation dose on cognitive function.« less