Survival after surgery and stereotactic radiosurgery for patients with multiple intracranial metastases: results of a single-center retrospective study

Abstract

Object Patients with systemic cancer and a single brain metastasis who undergo treatment with resection plus radiotherapy live longer and have a better quality of life than those treated with radiotherapy alone. Historically, whole-brain radiotherapy (WBRT) has been the mainstay of radiation therapy; however, it is associated with significant delayed neurocognitive sequelae. In this study, the authors looked at survival in patients with single and multiple intracranial metastases who had undergone surgery and adjuvant stereotactic radiosurgery (SRS) to the tumor bed and synchronous lesions. Methods The authors retrospectively reviewed the records from an 8-year period at a single institution for consecutive patients with brain metastases treated via complete resection of dominant lesions and adjuvant radiosurgery. The cohort was analyzed for time to local progression, synchronous lesion progression, new intracranial lesion development, systemic progression, and overall survival. The Kaplan-Meier method (stratified by age, sex, tumor histology, and number of intracranial lesions prior to surgery) was used to calculate both progression-free and overall survival. A Cox proportional-hazards regression model was also fitted with the number of intracranial lesions as the predictor and survival as the outcome controlling for disease severity, age, sex, and primary histology. Results The median overall follow-up among the 150-person cohort eligible for analysis was 17 months. Patients had an average age of 46.2 years (range 16–82 years), and 62.7% were female. The mean (± standard deviation) number of intracranial lesions per patient was 2.5 ± 2.3. The mean time between surgery and stereotactic radiosurgery (SRS) was 3.2 ± 4.1 weeks. Primary cancers included lung cancer (43.3%), breast cancer (21.3%), melanoma (10.0%), renal cell carcinoma (6.7%), and colon cancer (6.7%). The average number of isocenters per treated lesion was 7.6 ± 6.6, and the average treatment dose was 17.8 ± 2.8 Gy. One-year survival for patients in this cohort was 52%, and the 1-year local control rate was 77%. The median (±standard error) overall survival was 13.2 ± 1.9 months. There was no difference in survival between patients with a single lesion and those with multiple lesions (p = 0.319) after controlling for age, sex, and histology of primary tumor. Patients with primary breast histology had the greatest overall median survival (22.9 ± 6.2 months); patients with colorectal cancer had the shortest overall median survival (5.3 ± 1.8 months). The most common cause of death in this series was systemic progression (79%). Conclusions These results confirm that 1-year survival for patients with multiple intracranial metastases treated with resection followed by SRS to both the tumor bed and synchronous lesions is similar to established outcomes for patients with a single intracranial metastasis.

Stereotactic radiosurgery versus whole-brain radiotherapy after intracranial metastasis resection: a systematic review and meta-analysis

“…Breast cancer metastases have been shown to have a particularly high rate of LMD [32–34]. Additionally, many studies reported on the adverse side effects of WBRT, including physical symptoms such as alopecia, somnolence, hearing loss, skin changes, and neurocognitive decline, manifested as memory loss and learning impairment [2, 7, 18, 26]. In particular, the cognitive decline following WBRT has been linked to leukoencephalopathy, which is supported by the increased risk for leukoencephalopathy in patients receiving post-operative WBRT [20, 35] Another study, evaluating 59 patients treated with primary SRS, found that even after multiple courses of SRS, quality of life (QOL), measured with the EQ-5D instrument, was preserved in 77% of patients at 12 month follow-up [36].…”

“…Approximately, 20–40% of cancer patients with primary extracranial cancer will develop brain metastases during the course of their disease [6]. In the United States alone, this represents about 98,000 to 170,000 new diagnoses each year [6, 7]. Median survival without treatment is estimated at 1 month, and increases to 3–12 months when cranial radiation therapy is used [8].…”

“…Traditionally, the standard of care for patients with solitary brain metastasis has been resection plus whole-brain radiotherapy (WBRT) [4, 7]. Resection allows for histopathological examination of the tissue and has been shown to improve neurological symptoms, functional independence, and survival [5].…”

“…Furthermore, WBRT is associated with both short and long-term neurological complications, such as radiation-induced edema, leukoencephalopathy, and cognitive deficits [2, 7, 10]. Given that patients with systemic cancer are now living longer due to improved extracranial anti-tumor strategies, concerns related to these delayed, radiation-induced neurotoxic effects are prompting neuro-oncologists to assess alternatives to WBRT [4, 14].…”

“…Many centers are therefore using targeted techniques with limited radiation exposure, such as stereotactic radiosurgery (SRS). SRS is associated with fewer global cognitive side effects, CNS preservation, and better quality-of-life [2, 4, 7, 15]. …”