Stereotactic radiosurgery as therapy for melanoma, renal carcinoma, and sarcoma brain metastases: Impact of added surgical resection and whole-brain radiotherapy

Management of melanoma brain metastases in the era of targeted therapy

Disseminated metastatic disease, including brain metastases, is commonly encountered in malignant melanoma. The classical treatment approach for melanoma brain metastases has been neurosurgical resection followed by whole brain radiotherapy. Traditionally, if lesions were either too numerous or surgical intervention would cause substantial neurologic deficits, patients were either treated with whole brain radiotherapy or referred to hospice and supportive care. Chemotherapy has not proven effective in treating brain metastases. Improvements in surgery, radiosurgery, and new drug discoveries have provided a wider range of treatment options. Additionally, recently discovered mutations in the melanoma genome have led to the development of "targeted therapy." These vastly improved options are resulting in novel treatment paradigms for approaching melanoma brain metastases in patients with and without systemic metastatic disease. It is therefore likely that improved survival can currently be achieved in at least a subset of melanoma patients with brain metastases.

Delayed surgical resections of brain metastases after gamma knife radiosurgery

Although brain metastases are one of the most frequently diagnosed sequelae of systemic malignancy, their optimal management still is not well defined. In that respect, the different diagnostic and therapeutic approaches of BMs patients is an issue for serious discussions. The treatment options include surgical excision, WBRT, radiosurgery, chemotherapy, immunotherapy, etc. Nowadays, the aforementioned treatment modalities are usually combined in different treatment schemes. More than one option is used for the same patient and combining these treatment modalities gives better results than when separately use them. The value of surgical excision of progressing brain metastases treated with gamma knife surgery (GKS) is not well investigated.With the present study, we aim to investigate the value of surgical excision of symptomatic brain lesions that have been previously treated with GKS.

Gamma knife radiosurgery as a therapeutic strategy for intracranial sarcomatous metastases

PURPOSE

To determine the indication and outcomes for Gamma Knife stereotactic radiosurgery (GKSRS) in the care of patients with intracranial sarcomatous metastases.

METHODS AND MATERIALS

Data from 21 patients who underwent radiosurgery for 60 sarcomatous intracranial metastases (54 parenchymal and 6 dural-based) were studied. Nine patients had radiosurgery for solitary tumors and 12 for multiple tumors. The primary pathology was metastatic leiomyosarcoma (4 patients), osteosarcoma (3 patients), soft-tissue sarcoma (5 patients), chondrosarcoma (2 patients), alveolar soft part sarcoma (2 patients), and rhabdomyosarcoma, Ewing's sarcoma, liposarcoma, neurofibrosarcoma, and synovial sarcoma (1 patient each). Twenty patients received multimodality management for their primary tumor, and 1 patient had no evidence of systemic disease. The mean tumor volume was 6.2 cm(3) (range, 0.07-40.9 cm(3)), and a median margin dose of 16 Gy was administered. Three patients had progressive intracranial disease despite fractionated whole-brain radiotherapy before SRS.

RESULTS

A local tumor control rate of 88% was achieved (including patients receiving boost, up-front, and salvage SRS). New remote brain metastases developed in 7 patients (33%). The median survival after diagnosis of intracranial metastasis was 16 months, and the 1-year survival rate was 61%.

CONCLUSIONS

Gamma Knife radiosurgery was a well-tolerated and initially effective therapy in the management of patients with sarcomatous intracranial metastases. However, many patients, including those who also received fractionated whole-brain radiotherapy, developed progressive new brain disease.

Brain metastases: current management and new developments

PURPOSE OF REVIEW

To review the state-of-the-art and new developments in the management of patients with brain metastases.

RECENT FINDINGS

Treatment decisions are based on prognostic factors to maximize neurologic function and survival, while avoiding unnecessary therapies. Whole-brain radiotherapy (WBRT) is the treatment of choice for patients with unfavorable prognostic factors. Stereotactic radiosurgery (SRS) or surgery is indicated for patients with favorable prognostic factors and limited brain disease. In single brain metastasis, the addition of either stereotactic radiosurgery or surgery to WBRT improves survival. The omission of WBRT after surgery or radiosurgery results in a worse local and distant control, though it does not affect survival. The incidence of neurocognitive deficits in long-term survivors after WBRT remains to be defined. New approaches to avoid cognitive deficits following WBRT are being investigated. The role of chemotherapy is limited. Molecularly targeted therapies are increasingly employed. Prophylaxis with WBRT is the standard in small-cell lung cancer.

SUMMARY

Many questions need future trials: the usefulness of new radiosensitizers; the role of local treatments after surgery; and the impact of molecularly targeted therapies on subgroups of patients with specific molecular profiles. Quality of life and cognitive functions are recognized as major endpoints in clinical trials.

Early brain tumor metastasis reduction following Gamma Knife surgery

OBJECT

Unlike whole-brain radiation therapy, Gamma Knife surgery (GKS) is delivered in a single session for the treatment of brain metastases. The extent to which GKS can facilitate early tumor control was the focus of this study.

METHODS

The authors reviewed 134 metastatic lesions in 82 patients treated with GKS at the University of Virginia who underwent follow-up MR imaging within 30 days or less of GKS. For accurate volumetry only tumors measuring 0.5 cm3 or greater in volume were included. Radiological review as well as tumor volumetry was performed to assess the tumor's response to GKS. Tumors were characterized as either enlarged (> 15% volume increase), stable (follow-up volume +/- 15% of the initial volume), or decreased (> 15% volume decrease). A multivariate analysis was performed to determine factors related to each volume outcome group.

RESULTS

Within the first month following GKS, a decrease was observed in 47.8% of the tumors. Tumor reduction varied according to carcinoma histopathological subtype, with 46.4% of non-small cell lung carcinomas, 70% of breast carcinomas, and 22.6% of melanomas showing volume reduction within 30 days after GKS. The mean volume decrease was 41.7%. For the remaining tumors, 41% were stable and 11.2% increased in volume. The overall analysis showed that there was a significant difference in percentage tumor change according to histopathological type (p < 0.001). There was a trend toward increased tumor reduction in those carcinoma types that are traditionally viewed as radiation sensitive (breast and non-small cell lung carcinomas).

CONCLUSIONS

Gamma Knife surgery can offer patients early substantial volume reduction in many brain metastases. In instances in which early volume reduction of limited intracranial disease is desired, GKS may be used alone or before whole brain radiation therapy.

CYBERKNIFE FOR BRAIN METASTASES OF MALIGNANT MELANOMA AND RENAL CELL CARCINOMA

OBJECTIVE

To evaluate the efficacy of CyberKnife (Accuray, Inc., Sunnyvale, CA) stereotactic radiosurgery (SRS) for patients with brain metastases of malignant melanoma and renal cell carcinoma.

METHODS

We conducted a retrospective review of all patients treated by image-guided radiosurgery at our institution between March 1999 and December 2005. Sixty-two patients with 145 brain metastases of renal cell carcinoma or melanoma were identified.

RESULTS

The median follow-up period was 10.5 months. Forty-four patients had malignant melanoma, and 18 patients had renal cell carcinoma. The median age was 57 years, and patients were classified as recursive partitioning analysis Class 1 (6 patients), 2 (52 patients) or 3 (4 patients). Thirty-three patients had been treated systemically with either chemotherapy or immunotherapy, and 33 patients were taking corticosteroids at the time of treatment. The mean tumor volume was 1.47 mL (range, 0.02–35.7 mL), and the mean prescribed dose was 20 Gy (range, 14–24 Gy). The median survival after SRS was 8.3 months. Actuarial survival at 6 and 12 months was 57 and 37%, respectively. On multivariate analysis, Karnofsky Performance Scale score (P &lt; 0.01) and previous immunotherapy/clinical trial (P = 0.01) significantly affected overall survival. One-year intracranial progression-free survival was 38%, and local control was 87%. Intracranial control was impacted by whole-brain radiotherapy (P = 0.01), previous chemotherapy (P = 0.01), and control of the primary at the time of SRS (P = 0.02). Surgical resection had no effect on intracranial or local control. Radiographic evidence of radiation necrosis developed in 4 patients (6%).

CONCLUSION

CyberKnife radiosurgery provided excellent local control with acceptable toxicity in patients with melanoma or renal cell brain metastases. Initial SRS alone appeared to be a reasonable option, as survival was dictated by systemic disease.