|
Advertisement |
|
|
||
 |
|
|||||
|
|||||
|
 |
||||||
|
||||||
|
||||||
|
Journal of Clinical Oncology, Vol 24, No 33 (November 20), 2006: pp. 5283-5290 © 2006 American Society of Clinical Oncology. DOI: 10.1200/JCO.2005.03.8547 Changes in Attentional Performance of Children and Young Adults With Localized Primary Brain Tumors After Conformal Radiation Therapy
From the Divisions of Radiation Oncology and Behavioral Medicine, Department of Biostatistics, St Jude Children's Research Hospital, Memphis, TN Address reprint requests to Thomas E. Merchant, DO, PhD, Department of Radiological Sciences, MS 220, St Jude Children's Research Hospital, 332 N Lauderdale, Memphis, TN 38105-2794; e-mail: thomas.merchant{at}stjude.org
Purpose To prospectively assess the impact of conformal radiation therapy (CRT) and demographic and clinical variables on four measures of attention in pediatric and young adult patients with localized primary brain tumors. Patients and Methods We prospectively evaluated 120 patients with primary brain tumors, ages 2 to 24.4 years (median, 9.2 years). Evaluations were done using the computerized Conners' Continuous Performance Test (CCPT). We analyzed errors of omission (inattentiveness), errors of commission (impulsivity), reaction time, and an overall index of performance before CRT, weekly during CRT, and serially up to 60 months after the start of CRT. Results Before CRT, patients exhibited mild inattentiveness. During CRT, impulsivity decreased significantly (P = .002). After CRT, inattentiveness increased significantly (P = .03), and global attention disorders were associated with craniopharyngioma (P < .0001), supratentorial tumors (P = .008), optic pathway and diencephalic tumors (P = .012), and subtotal resection of the tumor (P = .010). Conclusion Brain tumors and their treatment impair sustained attention and reaction time. A decline in impulsivity and relative stability of the other CCPT scores over the course of CRT demonstrated the absence of early radiation-related cognitive sequelae. Local tumor effects, initial surgical intervention, and focal irradiation of central structures contribute to long-lasting attentional problems in pediatric and young adult patients.
Higher order cognitive processing is regulated by the executive function system of the brain. Although these processes are primarily localized to the prefrontal region, they depend on widely distributed subcortical networks between the cortices, basal ganglia, and thalamus. Cognitive processing is exquisitely sensitive to multiple sources of brain damage, including genetic and metabolic disorders, hypoxic injury, toxin exposure, brain tumors, and traumatic injury. Acquired deficits in higher cognitive processing, such as attentional problems, are precursors to poor academic achievement, vocational failure, and a decline in intelligence quotient.1,2 These functions have been the focus of research designed to improve our understanding of the cognitive adverse effects of curative therapy for brain tumors in children.3 Identification of risk factors for attention deficits is important for it may identify susceptible patients and assist in the design of interventions to improve their outcome.4 Although most patients with brain tumors require multimodal treatment, radiation therapy (RT) has often been implicated as the primary cause of attention deficits and other neurocognitive sequelae to which younger children appear vulnerable.5-8 Possible risk factors for neurocognitive decline are numerous, and sole attribution of toxicity to any one modality, is not always justifiable based on the information available in the literature.9-13 To improve our understanding of the effects of RT in children with primary brain tumors and identify risk factors for neurocognitive sequelae, including attention deficits, we designed a prospective trial to evaluate neurocognitive abilities before, during, and after conformal RT (CRT). We assessed four neurocognitive functions (selective attention, sustained attention, impulsivity, and reaction time) by using Conners' Continuous Performance Test (CCPT),14 a computer-administered test commonly used to diagnose attention-deficit hyperactivity disorder in children 6 years of age or older. The CCPT has been standardized on normally developing children and adolescents and yields age- and sex-corrected scores. Because the CCPT has limited practice effects, we administered it before, during, and after CRT to identify early and late effects of irradiation on attentional abilities.14,15 We have already described our experience with changes in attentional performance that occurred during a 6- to 7-week course of CRT administered to 39 pediatric patients with localized primary brain tumors.16 In that study, we noted difficulties with sustained attention and slower reactions, predominantly in the youngest patients. Other studies have noted similar problems with focused attention, working memory, and cognitive processing.17 The purpose of this study was to evaluate attentional functioning before, during, and after CRT in a larger cohort; to determine whether any changes in attentional functioning occurred over this period; and to identify demographic (age, sex) and clinical factors (for example, tumor type, grade, and location; extent of surgical intervention; use of ventricular shunting) associated with the development of attentional problems.
Patient Selection Criteria Between June 1997 and January 2003, we enrolled 202 patients at St Jude Children's Research Hospital (Memphis, TN) on a phase II study of CRT for pediatric CNS tumors and quantification of radiation-related CNS effects. The purpose was to limit the volume of irradiation to minimize adverse effects and to evaluate patients serially for deficits in cognitive function. The study was limited to patients ages 1 to 24 years with localized primary brain tumors requiring only focal RT with no history of previous RT; whose Eastern Cooperative Oncology Group performance status was adequate (grade, 0 to 2);18 and who had given written informed consent approved by the institutional review board. Patients with diffuse pontine glioma and tumors conventionally treated with craniospinal irradiation were excluded.
A total of 202 patients were enrolled on the prospective treatment protocol and 111 were old enough at the time CRT began (approximate age
CRT Regimen All patients received CRT over 6 to 7 weeks; the total dose of radiation ranged from 54.0 Gy to 59.4 Gy, using conventional fractionation of 1.8 Gy per day. Dose and volume depended on the tumor type: ependymoma was irradiated to 59.4 Gy, using a 1-cm margin surrounding the tumor or the tumor and the tumor bed; low-grade astrocytoma and craniopharyngioma were irradiated to 54.0 Gy or 55.8 Gy with a clinical target volume of 1 cm; and high-grade astrocytoma was irradiated to 59.4 Gy using a 2-cm margin. Further details of our administration of CRT have been reported elsewhere.20
Neurocognitive Assessments The numbers of errors of omission and commission and reaction times were analyzed as age- and sex-corrected T-scores. A T-score of 50 with a standard deviation of 10 is a rescaled z-score that represents normal performance by healthy peers. Poor performance is indicated by high scores in the errors of omission and errors of commission categories (ie, more errors), low scores in the reaction time category (ie, abnormally slow responses), and high scores on the overall index. The overall index is calculated as an algorithm of the other scores, for which 0 represents a perfect set of responses, and a score of 11 or more is generally considered the clinical threshold for attentional problems (Table 2). Approximately 86% of healthy children in the general population will obtain an overall index score of 8 or less; scores between 8 and 11 are considered borderline indications of attentional problems.
Statistical Analysis The main goal of the analysis was to estimate the mean rate of change in the CCPT scores during the period of study (  60 months after the start of CRT) and to assess the influence of age and clinical variables (Table 1) on the rate of change. A linear mixed-effects model with random coefficients was used for the analysis.21 The response variable was the CCPT score. Each patient CCPT score and the time at which that score was obtained were used to create a regression line. The intercept of the line provided an estimate of the initial (pre-CRT) CCPT score, and the slope of the line indicated the rate of change of the CCPT score. The intercept and slope of an individual patient regression line were considered random effects and were used to form the estimating equations for the patient population. The resulting model was used to describe the longitudinal change in CCPT scores. When age at CRT was used to model the initial score and the change in scores over time, age was a dichotomous variable relative to the median age of our patient population. Time was a continuous variable in our analysis, and time = 0 indicated the start of CRT. Baseline measurements of CCPT were not taken for 20 patients younger than 6 years of age at the commencement of CRT, which may cause possible bias in estimation of baseline CCPT for patient population; however, our main goal for the analysis was to evaluate the rate of longitudinal change. We tested the significant effects of a given clinical or treatment variable on longitudinal change after CRT, which detects difference in slopes among the subgroups defined by the variable. We also compared the slope of the modeled score of such a subgroup against a slope of zero (which would represent no change). Statistical significance for our tests was defined as P < .05. P values were not adjusted for multiple comparisons; while this may increase type I errors in the analysis, it will reduce the probability that our analysis would overlook potential causes of attention disorders in this patient population.22
We analyzed a total of 801 CCPT evaluations from 120 patients. The longitudinal portion of the study (ie, pre- and post-CRT evaluations) included 376 serial examinations: 82 pre-CRT, 109 at 6 months, 70 at 12 months, 52 at 24 months, 37 at 36 months, 19 at 48 months, and 7 at 60 months after the start of CRT. One hundred of 120 patients were evaluated by 525 CCPT examinations administered weekly during CRT. The median follow-up period for the entire group was 23.9 months (range, –0.8 to 60.8 months). Variables that significantly affected attention are summarized in Table 3.
Age and diagnosis were not mutually exclusive. The mean ages of patients with craniopharyngioma, ependymoma, low-grade astrocytoma, and high-grade astrocytoma were 10.3, 8.4, 10.1, and 13.5 years, respectively. Patients with high-grade astrocytoma were significantly older than those with craniopharyngioma (P < .02), ependymoma (P < .001), and low-grade astrocytoma (P < .06). The location of the tumor was found to be significantly associated with both the age of the patient (P = .003, age analyzed at 10.5 years; P = .03, age analyzed at 7 years) and the degree of surgical resection (P = .0001).
Attention Before Irradiation An analysis of risk factors revealed that impulsivity was significantly higher in the following subgroups: male patients (P = .04); patients who had astrocytoma (v craniopharyngioma or ependymoma; P = .047); patients whose tumor was bilateral or left sided (versus right sided or midline; P = .032); and patients who experienced progression of symptoms before CRT (P = .049). Reaction time was slower in female patients (P = .015) and patients who had an infratentorial tumor (P = .017). The pre-CRT overall index showed evidence of global attention deficits in patients with high-grade astrocytoma or ependymoma (P = .025).
Attention During CRT
Inattention increased significantly in patients who underwent biopsy (P = .02). Significantly decreased impulsivity during CRT was associated with: female sex (P = .001), age 10.5 years or younger (P = .006; age 7 or younger, P < .0001), low-grade astrocytoma (P = .021), left sided (P = .0004) or bilateral tumors (P = .031), supratentorial tumors (P = .005), hemispheric tumors (P = .014), tumors that were examined by biopsy only (P = .02), absence of an Ommaya reservoir (P = .003), absence of hydrocephalus (P = .0006), and presence of a ventriculoperitoneal shunt (P = .003). Reactions became slower for patients 10.5 years or younger (P = .007; age 7 or younger, P = .0003). The difference in reaction time according to age was statistically significant (at the age of 10 years, P = .006; at the age of 7 years, P = .0004). The overall index increased in patients who had experienced progression of symptoms before CRT (P < .05), patients without shunted hydrocephalus (P = .007), patients age 10.5 years or younger (P = .042; age 7 or younger, P = .011), and those with craniopharyngioma or low-grade astrocytoma (P = .0495). The impact of age on the overall index was statistically significant (at the age of 7 years, P = .042).
Changes in Attention After CRT
An analysis of risk factors revealed that all of the following subgroups increased inattentiveness significantly: female sex (P = .016), diagnosis of craniopharyngioma (P = .010), low-grade (P = .036) or high-grade astrocytoma (P = .05), evidence of disease progression before CRT (P = .03), midline (P = .04) or right-sided tumors (P = .014), optic pathway or diencephalic tumors (P = .016), supratentorial tumors (P = .0035), subtotal resection of the tumor (P = .017), more than two surgical procedures (P = .0023), Ommaya reservoir (P = .02), or absence of hydrocephalus (P = .026). Reaction times became slower for patients with craniopharyngioma (P = .038; Fig 3) and in those who underwent subtotal resection (P = .031). Reaction times became faster in patients with ependymoma (P = .001; Fig 3), patients who underwent a gross total resection (P = .013), patients who underwent a single surgical procedure (P = .006), and patients older than 10.5 years (P = .024). The impact of diagnosis on the overall index is shown in Figure 4. An increasing overall index was associated with craniopharyngioma (P < .0001), optic pathway or diencephalic tumors (P = .012), supratentorial tumors (P = .008), subtotal resection (P = .010), more than two surgical procedures (P = .043), or an Ommaya reservoir (P = .006).
This study is one of the first to detail the development of an acquired attentional disorder among children and young adults who have experienced nontraumatic brain injury. Through serial evaluations, we were able to examine how the ability to focus and sustain attention in children with primary brain tumors changes during the 6- to 7-week period of CRT and the subsequent 5 years. The findings from this study confirm those we previously reported—that attentional abilities remain relatively stable over time after irradiation, with the exception of slower reaction times in younger patients.16 With additional examinations, we have found that performance in the younger patients stabilizes after CRT. A large patient population enabled us to perform a detailed analysis of clinical and treatment variables and to identify influences on patterns of attention in children with localized brain tumors. Our results demonstrated that performance is related to the type of tumor, location, comorbid effects, and initial surgical management.
Diagnosis Despite reports that RT has a limited effect on cognitive function28-30 in adults with low-grade astrocytoma, the role of RT in the treatment of pediatric low-grade astrocytoma remains controversial. Most of our patients with a low-grade astrocytoma received CRT because their tumors were located along the optic pathways or in the diencephalon. Children with midline and hemispheric tumors are at risk for tumor- and treatment-related brain injury.31 Despite the central location of the irradiated volume, these patients demonstrated only a slight increase in inattentiveness, without evidence of global dysfunction. This finding supports the observation that attention impairment in patients with low-grade astrocytoma31 are tumor related32 and highlights the importance of baseline testing and longitudinal follow-up. Worsening cognitive function after CRT has been described in patients with hemispheric high-grade astrocytoma, compared with that of patients with low-grade astrocytoma.33 We found no difference between attention and astrocytoma grade. Tumor laterality to the dominant hemisphere is a risk factor for cognitive dysfunction.33,34 Patients with ependymoma were significantly younger than those with other diagnoses and 89% underwent gross total resection. They initially exhibited more attentional problems and showed faster reaction times as they improved over time. Although patients with posterior fossa tumors who received whole brain irradiation have fared worse than their counterparts receiving surgery and chemotherapy,35 our data provides evidence that CRT has a limited effect on cognitive outcomes in this patient group.
Surgical Variables Congenital hydrocephalus causes impairments in cognitive skills, memory performance, information processing, and fine motor skills.36-42 Similar impairments have been found in patients with brain tumors and hydrocephalus.28,43 In addition, the duration of hydrocephalus before surgery has been implicated in long-term learning disabilities.28 We found that our patients with shunted hydrocephalus had faster response times, although patients with shunted hydrocephalus appear to perform significantly poorer on neurocognitive exams in other series.44,45 It appears that prompt treatment of hydrocephalus can limit long-term effects on attentiveness.
Conclusion
The authors indicated no potential conflicts of interest.
Supported by Cancer Center Grant No. CA21765 from the National Cancer Institute, by Research Project Grant No. RPG-99-252-01-CCE from the American Cancer Society, and by the American Lebanese Syrian Associated Charities (ALSAC). Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.
1. Reddick WE, White HA, Glass JO, et al: Developmental model relating white matter volume to neurocognitive deficits in pediatric brain tumor survivors. Cancer 97 : 2512 -2519, 2003[CrossRef][Medline] 2. Schatz J, Kramer JH, Ablin AR, et al: Visual attention in long-term survivors of leukemia receiving cranial radiation therapy. J Int Neuropsychol Soc 10 : 211 -220, 2004[CrossRef][Medline] 3. Reeves CB, Palmer SL, Reddick WE, et al: Attention and memory functioning among pediatric patients with medulloblastoma. J Pediatr Psychol 31 : 272 -280, 2005[CrossRef][Medline] 4. Butler RW, Mulhern RK: Neurocognitive interventions for children and adolescents surviving cancer. J Pediatr Psychol 30
: 65
-78, 2005 5. Chadderton RD, West CG, Schuller S, et al: Radiotherapy in the treatment of low-grade astrocytomas: II. The physical and cognitive sequelae. Childs Nerv Syst 11 : 443 -448, 1995[CrossRef][Medline] 6. Garcia-Perez A, Sierrasesumaga L, Narbona-Garcia J, et al: Neuropsychological evaluation of children with intracranial tumors: Impact of treatment modalities. Med Pediatr Oncol 23 : 116 -123, 1994[Medline] 7. Dennis M, Hetherington CR, Spiegler BJ: Memory and attention after childhood brain tumors. Med Pediatr Oncol 1 : 25 -33, 1998 (suppl)[Medline] 8. Silber JH, Radcliffe J, Peckham V, et al: Whole-brain irradiation and decline in intelligence: The influence of dose and age on IQ score. J Clin Oncol 10
: 1390
-1396, 1992 9. Riva D, Giorgi C: The cerebellum contributes to higher functions during development: Evidence from a series of children surgically treated for posterior fossa tumours. Brain 123
: 1051
-1061, 2000 10. Ronning C, Sundet K, Due-Tonnessen B, et al: Persistent cognitive dysfunction secondary to cerebellar injury in patients treated for posterior fossa tumors in childhood. Pediatr Neurosurg 41 : 15 -21, 2005[CrossRef][Medline] 11. Brookshire B, Copeland DR, Moore BD, et al: Pretreatment neuropsychological status and associated factors in children with primary brain tumors. Neurosurgery 27 : 887 -891, 1990[CrossRef][Medline] 12. Riva D, Pantaleoni C, Devoti M, et al: Late neuropsychological and behavioural outcome of children surgically treated for craniopharyngioma. Childs Nerv Syst 14 : 179 -184, 1998[CrossRef][Medline] 13. Carpentieri SC, Waber DP, Pomeroy SL, et al: Neuropsychological functioning after surgery in children treated for brain tumor. Neurosurgery 52 : 1348 -1356, 2003; discussion 1356-1357, 2003[CrossRef][Medline] 14. Conners CK: The Conners' continuous performance test. Toronto, Canada, Multi-Health Systems, 1995 15. Kirby EA, BandenBerg SP, Sullins W: Evaluation of a Continuous Performance Test for Assessing ADHD. Poster presented at the 101st Annual Convention of the American Psychological Association, Toronto, Canada, August 20-24, 1993 16. Merchant TE, Kiehna EN, Miles MA, et al: Acute effects of irradiation on cognition: Changes in attention on a computerized continuous performance test during radiotherapy in pediatric patients with localized primary brain tumors. Int J Radiat Oncol Biol Phys 53 : 1271 -1278, 2002[CrossRef][Medline] 17. Lilja AM, Portin RI, Hamalainen PI, et al: Short-term effects of radiotherapy on attention and memory performances in patients with brain tumors. Cancer 91 : 2361 -2368, 2001[CrossRef][Medline] 18. Oken MM, Creech RH, Tormey DC, et al: Toxicity and response criteria of the Eastern Cooperative Oncology Group. Am J Clin Oncol 5 : 649 -655, 1982[Medline] 19. Doxey D, Bruce D, Sklar F, et al: Posterior fossa syndrome: Identifiable risk factors and irreversible complications. Pediatr Neurosurg 31 : 131 -136, 1999[CrossRef][Medline] 20. Merchant TE, Zhu Y, Thompson SJ, et al: Preliminary results from a phase II trial of conformal radiation therapy for pediatric patients with localized low-grade astrocytoma and ependymoma. Int J Radiat Oncol Biol Phys 52 : 325 -332, 2002[CrossRef][Medline] 21. Verbeke G, Molenberghs G: Linear Mixed Models for Longitudinal Data. New York, NY, Springer-Verlag, 2000 22. Feise RJ: Do multiple outcome measures require p-value adjustment? BMC Medical Research Methodology 2 : 8 , 2002[CrossRef][Medline] 23. Honegger J, Barocka A, Sadri B, et al: Neuropsychological results of craniopharyngioma surgery in adults: A prospective study. Surg Neurol 50 : 19 -29, 1998[CrossRef][Medline] 24. Cavazzuti V, Fischer EG, Welch K, et al: Neurological and psychophysiological sequelae following different treatments of craniopharyngioma in children. J Neurosurg 59 : 409 -417, 1983[Medline] 25. Donnet A, Schmitt A, Dufour H, et al: Neuropsychological follow-up of twenty two adult patients after surgery for craniopharyngioma. Acta Neurochir 141 : 1049 -1054, 1999[CrossRef][Medline] 26. Carpentieri SC, Waber DP, Scott M, et al: Memory deficits among children with craniopharyngioma. Neurosurgery 49 : 1053 -1058, 2001[CrossRef][Medline] 27. Colangelo M, Ambrosio A, Ambrosio C: Neurological and behavioral sequelae following different approaches to craniopharyngioma: Long-term follow-up and therapeutic guidelines. Childs Nerv Syst 6 : 379 -382, 1990[CrossRef][Medline] 28. Yule SM, Hide TAH, Cranney M, et al: Low grade astrocytomas in the west of Scotland 1987-96: Treatment, outcome, and cognitive functioning. Arch Dis Child 84
: 61
-64, 2001 29. Brown PD, Buckner JC, O'Fallon JR, et al: Effects of radiotherapy on cognitive function in patients with low-grade glioma measured by the Folstein Mini-Mental State Examination. J Clin Oncol 21
: 2519
-2524, 2003 30. Vigliani MC, Sichez H, Poisson M, et al: A prospective study of cognitive functions following conventional radiotherapy for supratentorial gliomas in young adults: 4-year results. Int J Rad Onc 35 : 527 -533, 1996[CrossRef] 31. Ater JK, Moore BD, Francis DJ, et al: Correlation of medical and neurosurgical events with neuropsychological status in children at diagnosis of astrocytoma: Utilization of a neurological severity score. J Child Neurol 11
: 462
-469, 1996 32. Klein M, Heimans JJ, van der Ploeg HM, et al: Effects of radiotherapy and other treatment-related factors on mid-term to long-term cognitive sequelae in low-grade gliomas, a comparative study. Lancet 360 : 1361 -1368, 2002[CrossRef][Medline] 33. Hahn CA, Dunn RH, Logue PE, et al: Prospective study of neuropsychologic testing and quality-of-life assessment of adults with primary malignant brain tumors. Int J Radiat Oncol Biol Phys 55 : 992 -999, 2003[CrossRef][Medline] 34. Scheibel RS, Meyers CA, Levin VA: Cognitive dysfunction following surgery for intracerebral glioma: Influences of histopathology, lesion location and treatment. J Neurooncol 30 : 61 -69, 1996[CrossRef][Medline] 35. Copeland DR, deMoor C, Moore BD, et al: Neurocognitive development of children after a cerebellar tumor in infancy: A longitudinal study. J Clin Oncol 17
: 3476
-3486, 1999 36. Raimondi AJ, Soare P: Intellectual development in shunted hydrocephalic children. Am J Dis Child 127
: 664
-671, 1974 37. Lumenta CB, Skotarczak U: Long-term follow-up in 233 patients with congenital hydrocephalus. Childs Nerv Syst 11 : 173 -175, 1995[CrossRef][Medline] 38. Prigatano GP, Zeiner HK, Pollay M, et al: Neuropsychological functioning in children with shunted uncomplicated hydrocephalus. Childs Brain 10 : 112 -120, 1983[Medline] 39. Zeiner HK, Prigatano GP, Pollay M, et al: Ocular motility, visual acuity and dysfunction of neuropsychological impairment in children with shunted uncomplicated hydrocephalus. Childs Nerv Syst 1 : 115 -122, 1985[CrossRef][Medline] 40. Riva D, Milani N, Giorgi C, et al: Intelligence outcome in children with shunted hydrocephalus of different etiology. Childs Nerv Syst 10 : 70 -73, 1994[CrossRef][Medline] 41. Ding Y, Lai Q, McAllister JP, et al: Impaired motor learning in children with hydrocephalus. Pediatr Neurosurg 34 : 182 -189, 2001[CrossRef][Medline] 42. Ralph K, Moylan P, Canady A, et al: The effects of multiple shunt revisions on neuropsychological functioning and memory. Neurol Res 22 : 131 -136, 2000[Medline] 43. Merchant TE, Lee H, Zhu J, et al: The effects of hydrocephalus on intelligence quotient in children with localized infratentorial ependymoma before and after focal radiation therapy. J Neurosurg (Pediatrics 2) 101 : 159 -168, 2004 44. Brookshire BL, Fletcher JM, Bohan TP, et al: Verbal and nonverbal skill discrepancies in children with hydrocephalus: A five-year longitudinal follow-up. J Pediatr Psychol 20
: 785
-800, 1995 45. Hoppe-Hirsch E, Laroussinie F, Brunet L, et al: Late outcome of the surgical treatment of hydrocephalus. Childs Nerv Syst 14 : 97 -99, 1998[Medline] Submitted August 19, 2005; accepted September 6, 2006.
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|||||||||||
|
|||||||||||
|
|
Copyright © 2006 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|
TOP
ABSTRACT
INTRODUCTION
6 years) to complete the CCPT during therapy. An additional 20 patients became eligible to complete the CCPT during their post-CRT follow-up and were included in the longitudinal analysis. Eleven of the patients with high-grade astrocytoma who participated in the CCPT with the commencement of treatment were excluded from the analysis because of deteriorating neurologic condition and early death. Eighteen patients had significant visual deficits and two had significant motor deficits that prevented their participation. None of the patients had posterior fossa syndrome.
