Results of linear accelerator-based radiosurgery for intracranial meningiomas

OBJECTIVE

We report the outcomes of patients treated with linear accelerator-based radiosurgery for intracranial meningiomas at our institution.

METHODS

We reviewed 127 patients with 155 meningiomas treated with stereotactic radiosurgery (SRS) at the study institutions between October 1988 and December 1995.

RESULTS

There were 86 female and 41 male patients (median age, 61.5 yr; range, 19.9-87.9 yr). The median follow-up period was 31 months (range, 1.2-79.8 mo). The median tumor volume was 4.1 cc (range, 0.16-51.2 cc), and the median marginal dose was 15 Gy (range, 9-20 Gy). The tumor locations were as follows: convexity, 31 tumors; parasagittal/falcine, 39 tumors; cranial base, 82 tumors; and ventricular/pineal, 3 tumors. There were 106 benign, 26 atypical, and 18 malignant meningiomas and 5 cases of meningiomatosis. SRS was performed on 48 lesions as the initial treatment and on 107 lesions as adjunct therapy. Freedom from progression was observed in 107 patients (84.3%) at a median time of 22.9 months (range, 1.2-79.8 mo). Twenty patients (15.7%) had disease progression (16 marginal [12.6%] and 4 local [3.1%]) at a median time of 19.6 months (range, 4.1-69.3 mo); the median time for freedom from progression for the benign, atypical, and malignant meningiomas was 20.9, 24.4, and 13.9 months, respectively. Actuarial tumor control for the patients with benign meningiomas was 100, 92.9, 89.3, 89.3, and 89.3% at 1, 2, 3, 4, and 5 years, respectively. Six patients (4.7%) had permanent complications attributable to SRS (median time, 10.3 mo; range, 4.3-18.0 mo); 13 patients died as a result of causes related to the meningiomas (median, 17.5 mo; range, 4.3-37.3 mo). The 1-, 2-, 3-, 4-, and 5-year survival probability for the entire group of patients was 90.3, 82.6, 73.6, 70.5, and 68.2%, respectively; for patients with benign meningiomas, excluding death resulting from intercurrent disease, the survival probability was 97.6, 94.8, 91.0, 91.0, and 91.0%, respectively. The 1-, 2-, 3-, and 4-year survival probability for the patients with atypical and malignant meningiomas was 91.7, 83.3, 83.3, and 83.3% and 92.3, 64.6, 43.1, and 21.5%, respectively.

CONCLUSION

Even though complications from SRS are expected more frequently with large tumors near critical structures, SRS is a safe and effective means of treating selected meningiomas.

Radiosurgery for primary malignant brain tumors

Despite the ability of surgery, radiotherapy, and chemotherapy to prolong survival in patients with glioblastoma multiforme (GBM), most patients succumb to their disease, usually as a result of local tumor persistence or recurrence. Stereotactic radiosurgery (SRS) allows a substantial increase in total dose at sites of greatest tumor cell density while sparing most of the normal brain, resulting in significantly improved survival. SRS was designed as a technique to deliver a large single dose of radiation to a small and focal target: two of its hallmarks are the focal distribution of dose and the inverse relationship between dose and volume. Acute complications of SRS are related to edema and are manifested as a worsening of pre-existing symptoms: seizure, aphasia, and motor deficits--these are treatable with steroids and are transient in the majority of cases. The actuarial risk of undergoing reoperation was 33% at 12 months and 48% at 24 months, following SRS. Patterns of failure were similar following brachytherapy or SRS as treatment for recurrent GBM with most patients experiencing marginal failure outside the original treatment volume. Patients with small (< 30 mm diameter), radiographically distinct and focally recurrent GBM should be considered for SRS. Larger lesions (> 30 mm diameter), especially those adjacent to eloquent cortex or critical white matter pathways, must be evaluated with caution. The potential for acute toxicity associated with SRS increases substantially for larger lesions. There is a significant survival advantage using SRS in many patients with gliomas, especially if appropriately used with surgery and other adjuvant therapy.

Survival results from a phase I study of etanidazole (SR2508) and radiotherapy in patients with malignant glioma

PURPOSE

To report the survival results from a previous Phase I study of etanidazole (ETA) and radiotherapy in patients with glioblastoma multiforme (GBM n = 50) or anaplastic astrocytoma (AA n = 19) and examine survival according to age, Karnofsky performance status (KPS), and implant status.

PATIENTS AND METHODS

In a previous Phase I study, 70 previously untreated patients (median age 49) with malignant gliomas were accrued. One patient was excluded from analysis because pathology was unverifiable. All had KPS > or = 70. Prior to initiation of treatment, patients were stratified according to whether they were candidates for interstitial implantation. The implant patients (IMP n = 14) received accelerated fractionation radiotherapy (XRT) 2 Gy BID (6 hours apart) to 40 Gy in 2 weeks with ETA 2 gm/m2 x 6 doses, a 2 week break, and then interstitial implant for an additional 50 Gy (4-7 days) with a continuous infusion of ETA over 90-96 hours. There were 55 patients treated on two sequentially conducted non-implant arms. These patients started with accelerated fractionation XRT 2 Gy BID (6 hours apart) to 40 Gy in 2 weeks with ETA 2 gm/m2 x 4-5 doses/week. Non-IMP1 arm (n = 41) received a 2-week break before standard fractionated boost XRT of 2 Gy/day for 2 weeks to a total dose of 60 Gy with ETA. Non-IMP2 arm (n = 14) did not have the 2-week break. All patients had plasma pharmacokinetic monitoring of ETA. Subsequent follow-up study provided information regarding long-term survival status of this group of patients. The Phase I toxicity evaluation was conducted according to the RTOG toxicity scale and was found well tolerated in both groups. Overall actuarial survival was plotted for all patients, by histologic group, and by implant status. Subset analyses of GBM patients by age (< or = 49 or > 49 years), KPS (< or = 80 or > 80) and implant versus non-implant were also performed.

RESULTS

Median survival of GBM patients was 1.1 years and that of anaplastic astrocytoma patients was 3.1 years (p = 0.0001). In GBM patients, KPS > 80, implanted patients, and age < or = 49 were factors found not to be associated with a statistically improved survival.

CONCLUSION

The results of survival in this Phase I etanidazole study of patients with anaplastic astrocytoma are comparable to the results from other studies using bromodeoxyuridine, iododeoxyuridine, or procarbazine, lomustine (CCNU), and vincristine. The use of etanidazole with accelerated radiotherapy does not appear to improve survival in patients with glioblastoma multiforme compared to those treated with conventional therapies.

Development and implementation of intraoperative magnetic resonance imaging and its neurosurgical applications

OBJECTIVE

We describe the development and implementation of a new open configuration magnetic resonance imaging (MRI) system, with which neurosurgical procedures can be performed using image guidance. Our initial neurosurgical experience consists of 140 cases, including 63 stereotactic biopsies, 16 cyst drainages, 55 craniotomies, 3 thermal ablations, and 3 laminectomies. The surgical advantages derived from this new modality are presented.

METHODS

The 0.5-T intraoperative MRI system (SIGNA SP, Boston, MA), developed by General Electric Medical Systems in collaboration with the Brigham and Women's Hospital, has a vertical gap within its magnet, providing the physical space for surgery. Images are viewed on monitors located within this gap and can also be acquired in conjunction with optical tracking of surgical instruments, establishing accurate intraoperative correlations between instrument position and anatomic structures.

RESULTS

A wide range of standard neurosurgical procedures can be performed using intraoperative MRI. The images obtained are clear and provide accurate and immediate information to use in the planning and assessment of the progress of the surgery.

CONCLUSION

Intraoperative MRI allows lesions to be precisely localized and targeted, and the progress of a procedure can be immediately evaluated. The constantly updated images help to eliminate errors that can arise during frame-based and frameless stereotactic surgery when anatomic structures alter their position because of shifting or displacement of brain parenchyma but are correlated with images obtained preoperatively. Intraoperative MRI is particularly helpful in determining tumor margins, optimizing surgical approaches, achieving complete resection of intracerebral lesions, and monitoring potential intraoperative complications.

rhIGF-I administration reduces insulin requirements, decreases growth hormone secretion, and improves the lipid profile in adults with IDDM

IDDM is associated with elevated circulating levels of growth hormone (GH) and reduced insulin-like growth factor I (IGF-I). GH antagonizes the action of insulin-increasing insulin requirements in IDDM. The effects of subcutaneously administered rhIGF-I on glycemic control, insulin requirements, and GH secretion were studied in eight adults with IDDM. Patients received either placebo or rhIGF-I (50 microg/kg b.i.d.) for 19 days in a randomized, double-blind, parallel-design, placebo-controlled trial. Overnight GH, plasma glucose, free insulin, IGF-I, fructosamine, and lipid profiles were assessed during this period. rhIGF-I therapy increased IGF-I concentration from 117.1 +/- 14.2 (mean +/- SE) ng/ml (baseline) to 310.5 +/- 40.6 and 257.1 +/- 41.2 ng/ml on day 5 (P < 0.01 vs. baseline) and day 20 (P < 0.01 vs. baseline), respectively. After 19 days of rhIGF-I treatment, fructosamine concentrations were unchanged compared with baseline (439 +/- 32 vs. 429 +/- 35 micromol/l, day -1 vs. day 20, respectively), yet insulin requirements were decreased by approximately 45% (0.67 +/- 0.08 vs. 0.36 +/- 0.07 U x kg(-1) x day(-1), day -1 vs. day 19, respectively, P < 0.005). After 4 days of rhIGF-I therapy, there was a decrease in free insulin levels (8.38 +/- 1.47 vs. 4.98 +/- 0.84 mU/l, P < 0.05), mean overnight GH concentration (12.6 +/- 3.3 vs. 3.8 +/- 2.1 mU/l, P = 0.05), and total cholesterol and triglycerides (4.68 +/- 0.31 vs. 4.25 +/- 0.35 mmol/l, P < 0.05, 1.27 +/- 0.19 vs. 0.95 +/- 0.21 mmol/l, P < 0.001, respectively). There was no change in any variable in the placebo-treated patients. This study demonstrates that subcutaneous administration of rhIGF-I decreases insulin requirements and improves the plasma lipid profile while maintaining glycemic control in adults with IDDM. The excess nocturnal release of GH, characteristic of IDDM, is also decreased by rhIGF-I therapy.

Permanent low-activity iodine-125 implants for cerebral metastases

Beginning in 1987, selected patients with metastatic brain tumors were treated with permanent implants of low-activity radioactive iodine-125(125I) seeds. These patients underwent craniotomy, gross total resection of the metastatic lesion, and placement of the seeds. In general, criteria for treatment included the presence of a recurrent tumor with a volume too large to permit radiosurgery, and a Karnofsky Performance Score of 70 or higher. Thirteen patients underwent 14 implant procedures; all received external whole-brain radiotherapy. Implant dose ranged from 43 Gy to 132 Gy, with a mean of 83 Gy. Survival after implantation ranged from 2 weeks to almost 9 years, with a median of 9 months. Clinical and radiographic local control was obtained in 9 patients. Two patients died of acute, postoperative complications within a month of implantation, so no information regarding tumor control is available for them. Late complications included a bone flap infection in one patient and a CSF leak in another; both were treated without further sequelae. These results demonstrate that permanent 125I implants can results in good survival and quality of life, and occasionally can yield long-term survival. Potentially, it is a cost-effective treatment in that a separate procedure for stereotactic implantation or radiosurgery is not needed, as is the case with the use of temporary high-activity seeds. The permanent implantation itself adds less than 10 minutes to the craniotomy, and the risk of symptomatic radiation necrosis is low. We recommend consideration of this procedure in patients harboring large, recurrent metastatic tumors that require further surgery.

First coitus for adolescents: understanding why and when

BACKGROUND

Correlates of initiation of coitus for teenagers were examined, and participants were asked their reasons for initiating or postponing the onset of coitus.

METHODS

Questionnaires were completed privately by 218 patients aged 13 to 18 years. Questions explored the reasons adolescents cite for their sexual decisions and the role of peer influence in these decisions.

RESULTS

Correlation was noted in young teenagers between perception of peer sexual behavior and participant's initiation of coitus. Reasons stated for engaging in first intercourse reflect both active choices and loss of control. Reasons for refraining included fear of pregnancy and sexually transmitted diseases, lack of developmental readiness and opportunity, and social sanctions. Morality was cited infrequently as a reason for postponing sexual behavior.

CONCLUSIONS

Results suggest that sexuality education should address the direct and curious questions of younger teenagers about sexuality, help youth define strategies that they can use to evaluate and resist peer pressure, and give more generalized attention to ways of helping youth feel competent. Physicians and other health educators might focus on helping older youth define how and when they know they are ready to have intercourse, consider ways of expressing sexuality that do not jeopardize health, and improve communication skills when talking with friends and potential partners about sexual issues.

Prostate pathology case study seminar

Great strides have been made in the past decade in our understanding of the pathology of the prostate. Diagnostic criteria have been proposed, debated, and refined for a number of entities, including prostatic intraepithelial neoplasia, atypical adenomatous hyperplasia, basal cell proliferations, postatrophic hyperplasia, verumontanum mucosal gland hyperplasia, and numerous new variants of prostatic adenocarcinoma such as ductal adenocarcinoma, mucinous carcinoma, signet ring cell carcinoma, and lymphoepithelioma-like carcinoma. This report presents a series of case studies in prostate pathology which illustrate some of the contemporary issues which confront the pathologist and urologist.

The influence of Harvey Cushing on neuroradiologic therapy

Harvey Cushing was largely responsible for the establishment of neurosurgery as a separate discipline. He demonstrated how careful attention to technique could make surgery acceptably safe, established classifications and clinical-pathologic correlations of a wide variety of tumors, and trained dozens of future neurosurgical department heads. Less well known, however, is Cushing's contribution to the early clinical use of radiation therapy for a variety of intracranial disorders. With the aid of his meticulous clinical follow-up, large case volume, and willingness to try new treatment methods, he demonstrated the utility of therapeutic radiation in patients with pituitary tumor, medulloblastoma, and arteriovenous malformation. His less impressive results with the irradiation of patients with glioma are also worthy of note and include trials of brachytherapy. Neurosurgeons and radiation oncologists exploring new methods of delivering therapeutic radiation to the central nervous system should be aware of the lessons learned from Cushing's experience.

Fractionated stereotactic radiotherapy for the treatment of acoustic neuromas: preliminary results

PURPOSE

To evaluate the efficacy and toxicity of fractionated, stereotactic radiotherapy (SRT) for acoustic neuromas.

METHODS AND MATERIALS

Twelve patients with acoustic neuroma were treated with SRT between June 1992 and October 1994. Follow-up ranged from 16-44 months. Patient age ranged from 27-70 (median: 45). Eight patients were treated with primary SRT and four patients were treated after primary surgical intervention for recurrent [3] or persistent [1] disease. Tumor volumes were 1.2-18.4 cm3 (median: 10.1 cm3). Collimator sizes ranged from 30-50 mm (median: 37.5). Tumors received 1.8 Gy/day normalized to the 95% isodose line. Patients received a minimum prescribed dose of 54 Gy in 27-30 fractions over a 6-week period.

RESULTS

After a median follow-up of 26.5 months, local control was obtained in 12 out of 12 lesions. Tumor regression was noted in three patients, and tumor stabilization was found in the remaining nine patients. No patient developed a new cranial nerve deficit. One patients developed worsening of preexisting Vth cranial neuropathy and another experienced a decrease in hearing. However, all nine patients with useful hearing prior to SRT maintained useful hearing at last follow-up.

CONCLUSIONS

Stereotactic radiotherapy provided excellent local control without new cranial nerve deficits. These results must be viewed as tentative in nature because of the small number of patients and the short median follow-up period.

Clinical strategies to reduce utilization of chest physiotherapy without compromising patient care

BACKGROUND

There is widespread interest in the evaluation of clinical strategies that safely reduce health-care costs. Elimination of inappropriate chest physiotherapy may represent one of those strategies.

SETTING

An academic community hospital.

METHODS

One-hundred one patients receiving chest physiotherapy were prospectively randomized to continue their chest physiotherapy or to inform their physicians that the order for the chest physiotherapy may have been inappropriate.

RESULTS

Patients who were randomized to have their chest physiotherapy discontinued received 45% fewer chest physiotherapy treatments than control patients (p < 0.01). There was no increase in the mortality rate or length of hospital stay associated with the reduction in chest physiotherapy in carefully selected patients. The estimated cost savings would be $319,000, which is 50 times greater than the cost associated with the intervention.

CONCLUSION

Chest physiotherapy is frequently provided to patients for inappropriate indications. Reducing chest physiotherapy for these patients may significantly reduce respiratory therapy costs without increasing length of stay or mortality rates.

Cardioactive compounds from Eremophila species

The isolation and identification of two cardioactive compounds from two Eremophila species (Myoporaceae) considered important in the pharmacopoeia of the Australian Aboriginal people is described. Verbascoside, isolated from the methanol and water extracts of E. alternifolia leaves, mediated significant increases in chronotropism, inotropism and coronary perfusion rate (CPR) in the Langendorff rat heart. Geniposidic acid, isolated from the methanol extract of E. longifolia leaves, mediated an inhibitory effect with significant negative chronotropism, negative inotropism and CPR.

Recurrent brain metastases

Metastases of the brain are the most frequent metastatic neurologic complication of systemic cancer and are second only to metabolic encephalopathies as a cause of central nervous system dysfunction in cancer patients. Despite recent significant advances in the diagnosis and treatment of metastases to the brain, many patients will suffer from recurrence. Future advances in the use of chemotherapy, radiosurgery, and newer cancer therapy techniques may lead to further increases in the efficacy of treatment for recurrent brain metastases.

Radiosurgery for hemangioblastoma: results of a multiinstitutional experience

PURPOSE

Between June 1988 and June 1994. 38 hemangioblastomas were treated with stereotactic radiosurgery (SR) at three SR centers to evaluate the efficacy and potential toxicity of this therapeutic modality as an adjuvant or alternative treatment to surgical resection.

METHODS AND MATERIALS

SR was performed using either a 201-cobalt source unit or a dedicated SR linear accelerator. Of the 18 primary tumors treated, 16 had no prior history of surgical resection and were treated definitively with SR and two primary lesions were subtotally resected and subsequently treated with SR. Twenty lesions were treated with SR after prior surgical failure (17 tumors) or failure after prior surgery and conventional radiotherapy (three tumors). Eight patients were treated with SR for multifocal disease (total, 24 known tumors). SR tumor volumes measured 0.05 to 12 cc (median: 0.97 cc). Minimum tumor doses ranged from 12 to 20 Gy (median: 15.5 Gy).

RESULTS

Median follow-up from the time of SR was 24.5 months (range: 6-77 months). The 2-year actuarial over-all survival was 88 +/- 15% (95% confidence interval). Two-year actuarial freedom from progression was 86 +/- 12% (95% confidence interval). The median tumor volume of the lesions that failed to be controlled by SR was 7.85 cc (range: 3.20-10.53 cc) compared to 0.67 cc (range: 0.05-12 cc) for controlled lesions (p - 0.0023). The lesions that failed to be controlled by SR received a median minimum tumor dose of 14 Gy (range: 13-17 Gy) compared to 16 Gy (range: 12-20 Gy) for controlled lesions (p = 0.0239). Seventy-eight percent of the surviving patients remained neurologically stable or clinically improved. There were no significant permanent complications directly attributable to SR.

CONCLUSIONS

This report documents the largest experience in the literature of the use of SR in the treatment of hemangioblastoma. We conclude that SR: (a) controls the majority of primary and recurrent hemangioblastomas; (b) offers the ability to treat multiple lesions in a single treatment session, which is particularly important for patients with Von Hippel-Lindau Syndrome; and that (c) better control rates are associated with higher doses and smaller tumor volumes.

Magnetic resonance imaging therapy. Intraoperative MR imaging

The field of image-guided neurosurgery has developed under the premise that integrating the enhanced discrimination powers of CT scan and MR imaging into the operating room improves the accuracy, safety and precision of neurosurgery, and expand the realm of surgically treatable lesions. Through cooperation between General Electric Corporation and the Brigham and Women's Hospital, and open-configuration MR suite was designed and implemented to attain these goals through real-time, intraoperative MR imaging in a true surgical suite. This system allows intraoperative acquisition of MR images without moving the patient, online image-guided stereotaxy without preoperative imaging, and "real-time" tracking of instruments in the operative field registered to the MR images. The design and implementation of neurosurgery in the open-configuration MR imaging suite are summarized in this article.