Radiation response and survival time in patients with glioblastoma multiforme

Quantitative imaging study of extent of surgical resection and prognosis of malignant astrocytomas

OBJECTIVE

This study used quantitative radiological imaging to determine the effect of surgical resection on postoperative survival of patients with malignant astrocytomas. Previous studies relied on the surgeons' impressions of the amount of tumor removed, which is a less reliable measure of the extent of resection.

METHODS

Information concerning possible prognostic factors was collected for 75 patients undergoing magnetic resonance imaging or computed tomography preoperatively and within 10 days postoperatively. Image analysis of the neuroradiological studies was conducted to quantify pre- and postoperative total tumor volumes and enhancing volumes. Univariate and multivariate proportional hazards models were used to analyze the regression of survival regarding 22 covariates that might affect survival. The covariates that were entered included age, gender, tumor grade, cumulative radiation dose, chemotherapy, seizures as a first symptom, Karnofsky performance status at presentation, pre- and postoperative total and enhancing tumor volumes, ratio of pre- to postoperative total and enhancing tumor volumes, tumor location, surgeon's impression of the degree of resection, and subsequent surgery.

RESULTS

There were 23 patients with anaplastic astrocytomas and 52 with glioblastomas multiforme. The estimated mean survival time was 27 months for patients undergoing gross total resection, 33 months for subtotal resection, and 13 months for open or stereotactic biopsy. Five factors that were significant predictors of survival in multivariate analysis were tumor grade, age, Karnofsky performance status, radiation dose, and postoperative complications (P < 0.05). In univariate analysis, tumor grade, radiation dose, age, Karnofsky status, complications, presence of enhancing tumor in postoperative imaging, and postoperative volume of enhancing tumor were significantly associated with survival (P < 0.05).

CONCLUSION

We conclude that the most important prognostic factors affecting survival of patients with anaplastic astrocytomas and glioblastomas multiforme are tumor grade, age, preoperative performance status, and radiation therapy. Postoperative complications adversely affect survival. Aggressive surgical resection did not impart a significant increase in survival time. Surgical resection may improve survival, but its importance is less than that of other factors and may be demonstrable only by larger studies.

Survival benefit of stereotactic radiosurgery for patients with malignant glial neoplasms

OBJECTIVE

During an 8-year interval, we evaluated the survival benefit of stereotactic radiosurgery performed in 64 patients with glioblastomas multiforme (GBM) and 43 patients with anaplastic astrocytomas (AA).

METHODS

Adjuvant radiosurgery was performed either before disease progression or for recurrent tumor at the time of disease progression. Clinical and imaging follow-up data were obtained for all patients. The diagnosis of GBM was obtained by performing craniotomies in 41 patients and by performing stereotactic biopsies in 23. The diagnosis of AA was obtained by performing craniotomies in 19 patients (44%) and by performing biopsies in 24.

RESULTS

Of the entire series, the median survival time after initial diagnosis for patients with GBM was 26 months (standard deviation [SD], 19 mo; range, 5-79 mo) and the median survival time after radiosurgery was 16 months (SD, 16 mo; range, 1-74 mo). The 2-year survival rate was 51%. No survival benefit was identified for patients who underwent intravenously administered chemotherapy in addition to radiosurgery (P = 0.97). After undergoing radiosurgery, 12 patients (19%) underwent craniotomies and resections and 4 (6%) underwent subsequent radiosurgery for regional or remote recurrence. For 45 patients who underwent radiosurgery as part of the initial management plan, the median survival time after diagnosis was 20 months. Of the entire series, the median survival time after diagnosis for patients with anaplastic astrocytomas was 32 months (SD, 23 mo; range 5-96 mo) and the median survival time after radiosurgery was 21 months (SD, 18 mo; range 3-93 mo). The 2-year survival rate was 67%. Ten patients (23%) underwent subsequent craniotomies at a mean of 8 months after initial surgery, and two underwent subsequent radiosurgery. There was no acute neurological morbidity after radiosurgery. Histologically proven radiation necrosis occurred in one patient with GBM (1.6%) and two patients with AA (4.7%). For 21 patients for whom radiosurgery was part of the initial management plan, the median survival time after diagnosis was 56 months.

CONCLUSION

In comparison to historical controls, improved survival benefit after radiosurgery was identified for patients with GBM and patients with AA. Although this survival benefit may be related to our selection of patients for radiosurgery based on their having smaller tumor volumes, no selection was made based on location. We observed that radiosurgery was safe and well tolerated. Its effectiveness as an adjuvant therapy deserves a properly stratified randomized trial.

External radiation of brain metastases from renal carcinoma: a retrospective study of 119 patients from the M. D. Anderson Cancer Center

PURPOSE

Approximately 10% of patients with metastatic renal cell carcinoma are diagnosed with brain metastases. Most of these patients receive palliative radiotherapy and die of progressive brain metastatic disease. This retrospective study examines the M. D. Anderson Cancer Center experience with such patients who received only whole brain radiation therapy (WBRT).

METHODS AND MATERIALS

Records of 200 patients with brain metastases from renal carcinoma who were treated at M. D. Anderson Cancer Center between 1976 and 1993 were reviewed. Of these patients, 119 received WBRT only and constitute the basis of this study. Different prognostic factors were analyzed.

RESULTS

Overall median survival time from diagnosis of the brain metastases was 4.4 months. Multiple brain tumors were treated in 70 patients (58.8%) who had a survival of 3.0 months compared with 4.4 months for patients having a single brain metastasis (p = 0.043). Among 117 patients the causes of death were neurologic in 90 (76%), systemic cancer in 19 (16%), and unknown in 9 (8%). Survival rates at 6 months, 1 year, and 2 years, were 33.6, 16.8, and 5.9%, respectively. Patients in whom brain metastases were diagnosed synchronously with a renal primary (n = 24) had a median survival time of 3.4 months compared with 3.2 months for those 95 who were diagnosed metachronously (p < 0.79, NS). In the Cox multivariate analysis of 13 possible prognostic factors, only a single brain metastasis (p = 0.0329), lack of distant metastases at the time of diagnosis (p = 0.0056), and tumor diameter < or = 2 cm (p < 0.0016) were statistically significant.

CONCLUSION

These unsatisfactory results with WBRT suggest that more aggressive approaches, such as surgery or radiosurgery should be applied whenever possible.