Results of post-operative or exclusive radiotherapy in grade I and grade II cerebellar astrocytoma patients

Long-term Follow-up of Pediatric Benign Cerebellar Astrocytomas

BACKGROUND

The long-term prognosis of cerebellar astrocytomas needs to be reviewed.

OBJECTIVE

To elucidate the factors influencing tumor recurrence or progression and to determine how long these patient with cerebellar astrocytomas require surveillance with neuroimaging.

METHODS

A retrospective review of 101 children surgically treated for a cerebellar astrocytoma and followed up for < 10 years was performed.

RESULTS

Mean follow-up was 18.4 years. Total resection confirmed by postoperative imaging was performed in 51 patients (50.5%; group A). Twenty-three patients (22.8%) had surgical total resection; however, equivocal residual tumor was found on postoperative imaging (group B). Subtotal resection leaving a portion of brainstem or cerebellar peduncle was performed in 27 patients (26.7; group C). Of these 50 residual tumors, 16 (32%) showed spontaneous regression and 8 (16%) showed arrested growth. Radiographic recurrence or progression was noted in 29 patients (28.7%). Only 3 of 51 patients (5.9%) of group A with total resection had recurrence, whereas 26 of 50 residual tumors (52%; groups B and C) progressed. The only factor affecting recurrence or progression by multivariate analysis was the extent of surgical resection. All tumor recurrence or progression except for 1 (96.6%) occurred within 8 years from the original surgery (range, 2–132 months).

CONCLUSIONS

Overall prognosis of cerebellar astrocytomas is good; the 10-year survival rate was 100% and recurrence- or progression-free rate was 71.3% in our cohort. Almost half of residual tumors showed spontaneous regression or arrested growth in the long term. Eight to 10 years is considered to be a reasonable follow-up period by neuroimaging.

Low-grade astrocytoma--a retrospective analysis of 102 patients

One hundred and two patients (57 males, 45 females, median age 17 years) with histologically proven low-grade astrocytoma (grades I, II) treated between 1978 and 1994 were retrospectively analyzed at the King Faisal Specialist Hospital & Research Center. Microscopic investigation showed 50 patients (48%) with grade I tumors as opposed to 52 patients (52%) with grade II tumors. Fifteen patients (15%) had complete surgical excision, 55 (52%) had partial excision and 32 (31%) had biopsy only; 68 patients (66%) received external radiotherapy with a median dose of 54 Gy (range 45-68.5 Gy). With a median follow-up of 3.3 years, the 5 and 10 years, overall actuarial survival rates were 78% and 62%, respectively while the progression-free survival rates at 5 and 10 years were 69%, and 35%, respectively. Age and performance status were significant prognostic factors in terms of overall survival on univariate (p = 0.05 and 0.05, respectively) and multivariate analysis (p = 0.005 and 0.006, respectively).

Benign cerebellar astrocytomas in children

OBJECT

Cerebellar astrocytomas are benign tumors of childhood known to be associated with excellent long-term survival in patients in whom complete surgical resection is possible. However, the roles of other factors--clinical, radiological, histological, and therapeutic--in the survival of the patient, tumor recurrence, and long-term patient outcome remain imprecise. The goal of this study was to examine these factors and their relationships.

METHODS

To clarify these issues a retrospective review was conducted of 168 children who were surgically treated for a cerebellar astrocytoma at Hôpital Necker-Enfants Malades between 1955 and 1995. These patients' clinical files were examined, the histological characteristics of their tumors were reviewed, and their outcomes were assessed according to Bloom's scale and the Wechsler intelligence quotient test. Of the 168 patients in the study, 91 were male and 77 were female with a mean age of 6.9 years and a mean follow up lasting 7.7 years. Tumors were identified as being strictly located in the cerebellum in 76.2% of the patients and as involving the brainstem (referred to as the "transitional form") in 23.8% of the patients. Complete surgical excision was possible in 88.7% of cases. There was a total mortality rate of 4.2% and a tumor recurrence rate of 9.5%. Fifty-eight percent of the patients had no neurological sequelae at follow-up evaluation. Pejorative factors that were discovered by multivariate analysis to be important included: a long preoperative duration of symptoms and the transitional form of tumor with respect to survival; incomplete tumor excision with respect to an increased risk of recurrence; and a long preoperative duration of symptoms, an early epoch during which surgery was performed (1955-1974), severe ventricular dilation, and the transitional form of tumor with respect to a poorer long-term patient outcome.

CONCLUSIONS

The presence of brainstem involvement (tumor in the transitional form) emerged as a significant negative prognostic factor and should be treated as a distinct nosological entity. The extent of surgical excision has a significant bearing on the risk of tumor recurrence.

Cerebellar astrocytoma: experience with 54 cases surgically treated at the Mayo Clinic, Rochester, Minnesota, from 1978 to 1990

A comprehensive review of the literature has shown that the treatment of choice for cerebellar astrocytomas has primarily been gross-total resection of the mass and gross-total resection of the enhancing portion of pilocytic astrocytomas. Most large scale studies of postresection survival rates of patients with cerebellar astrocytomas were conducted when computerized tomography (CT) and magnetic resonance (MR) imaging were not readily available. It has been shown that postoperative CT scans or MR images are more reliable than the surgeon's estimate of the degree of tumor resection at the time of surgery. It is not possible, therefore, to make an accurate determination regarding a postresection prognosis based on the degree of suspected tumor resection without the availability of appropriate radiographic imaging. In this study, the authors retrospectively evaluated the treatment of 54 patients with cerebellar astrocytoma who underwent surgery at the Mayo Clinic in Rochester, Minnesota, from 1978 through 1990. Preoperative and postoperative CT scans or MR images were available in all 54 patients.

Cerebellar astrocytoma: experience with 54 cases surgically treated at the Mayo Clinic, Rochester, Minnesota from 1978 to 1990

A comprehensive review of the literature has shown that the treatment of choice for cerebellar astrocytomas has primarily been gross-total resection of the mass and gross-total resection of the enhancing portion of pilocytic astrocytomas. Most large scale studies of postresection survival rates of patients with cerebellar astrocytomas were conducted when computerized tomography (CT) or magnetic resonance (MR) imaging was not readily available. It has been shown that postoperative CT scans or MR images are more reliable than the surgeon's estimate of the degree of tumor resection at the time of surgery. It is not possible, therefore, to make an accurate determination regarding a postresection prognosis based on the degree of suspected tumor resection without the availability of appropriate radiographic imaging. In this study, the authors retrospectively evaluated the treatment of 54 patients with cerebellar astrocytoma who underwent surgery at the Mayo Clinic in Rochester, Minnesota from 1978 through 1990. Preoperative and postoperative CT scans or MR images were available in all 54 patients.