The treatment of recurrent brain metastases with stereotactic radiosurgery.

Abstract

Between May 1986 and August 1989, we treated 18 patients with 21 recurrent or persistent brain metastases with stereotactic radiosurgery using a modified linear accelerator. To be eligible for radiosurgery, patients had to have a performance status of greater than or equal to 70% and have no evidence of (or stable) systemic disease. All but one patient had received prior radiotherapy, and were treated with stereotactic radiosurgery at the time of recurrence. Polar lesions were treated only if the patient had undergone and failed previous complete surgical resection (10 patients). Single doses of radiation (900 to 2,500 cGy) were delivered to limited volumes (less than 27 cm3) using a modified 6MV linear accelerator. The most common histology of the metastatic lesion was carcinoma of the lung (seven patients), followed by carcinoma of the breast (four patients), and melanoma (four patients). With median follow-up of 9 months (range, 1 to 39), all tumors have been controlled in the radiosurgery field. Two patients failed in the immediate margin of the treated volume and were subsequently treated with surgery and implantation of 125I to control the disease. Radiographic response was dramatic and rapid in the patients with adenocarcinoma, while slight reduction and stabilization occurred in those patients with melanoma, renal cell carcinoma, and sarcoma. The majority of patients improved neurologically following treatment, and were able to be withdrawn from corticosteroid therapy. Complications were limited and transient in nature and no cases of symptomatic radiation necrosis occurred in any patient despite previous exposure to radiotherapy. Stereotactic radiosurgery is an effective and relatively safe treatment for recurrent solitary metastases and is an appealing technique for the initial management of deep-seated lesions as a boost to whole brain radiotherapy.

Enhancement of replication of genetically engineered herpes simplex viruses by ionizing radiation: a new paradigm for destruction of therapeutically intractable tumors

“…) of R3616 or buffer with a Hamilton syringe; (3) mice subjected to ionizing radiation and either not injected or injected with buffer solution; and (4) control mice or mice administered R3616 and subjected to irradiation for 20 Gy at 1 day after infection or mock infection and with 25 Gy at 2 days after infection or mock infection. Although large for conventional clinical radiation fractionation protocols, fraction sizes of 20-25 Gy are employed in stereotactic radiosurgery [17][18][19] and preliminary experiments suggest that smaller radiation doses will also be effective. The tumor mass was measured biweekly for 60 days or at least until the tumor mass reached 2000 mm 3 .…”

“…Although large for conventional clinical radiation fractionation protocols, fraction sizes of 20-25 Gy are employed in stereotactic radiosurgery. [17][18][19] The tumor mass was measured biweekly for 60 days or at least until the tumor mass reached 2000 mm 3 . Tumor volumes were calculated using the formula (length × width × height)/2 which is derived from the formula for an ellipsoid ( d 3 )/6.…”

Feasibility of frameless single-fraction stereotactic radiosurgery for spinal lesions

“…Radiosurgery has been reported in the treatment of many different intracranial lesions, both benign and malignant, and is widely accepted as safe and effective. 5,9,20,27,28,34 Stereotactic radiosurgery offers a method for delivering high-dose radiation in a single or limited number of fractions to a small volume encompassing the tumor while minimizing the dose to adjacent normal structures. The authors of a study originating from the University of Arizona in 1996 demonstrated that spinal stereotactic radiosurgery involving the use of a body frame was both feasible and safe.…”

CyberKnife frameless single-fraction stereotactic radiosurgery for tumors of the sacrum

“…Radiosurgery has been used to treat many different intracranial lesions, both benign and malignant, and is widely accepted as both safe and effective. 4,6,18,24,25,29 There is reason to believe that radiosurgery in which similar doses are used would be equally efficacious in the treatment of sacral lesions.…”