The physical, biologic, and clinical basis of radiosurgery

Stereotactic Radiosurgery as Treatment for Brain Metastases: An Update

Stereotactic radiosurgery (SRS) is a mainstay treatment option for brain metastasis (BM). While guidelines for SRS use have been outlined by professional societies, consideration of these guidelines should be weighed in the context of emerging literature, novel technology platforms, and contemporary treatment paradigms. Here, we review recent advances in prognostic scale development for SRS-treated BM patients and survival outcomes as a function of the number of BM and cumulative intracranial tumor volume. Focus is placed on the role of stereotactic laser thermal ablation in the management of BM that recur after SRS and the management of radiation necrosis. Neoadjuvant SRS prior to surgical resection as a means of minimizing leptomeningeal spread is also discussed.

Efficacy of Stereotactic Radiosurgery as Single or Combined Therapy for Brain Metastasis: A Systematic Review and Meta-Analysis

To determine the efficacy of stereotactic radiosurgery (SRS) in treating patients with brain metastases (BMs), a network meta-analysis (NMA) of randomized controlled trials (RCTs) and a direct comparison of cohort studies were performed. Relevant literature regarding the effectiveness of SRS alone and in combination with whole-brain radiotherapy (WBRT) and surgery was retrieved using systematic database searches up to April 2019. The patterns of overall survival (OS), one-year OS, progression-free survival (PFS), one-year local brain control (LBC), one-year distant brain control (DBC), neurological death (ND), and complication rate were analyzed. A total of 18 RCTs and 37 cohorts were included in the meta-analysis. Our data revealed that SRS carried a better OS than SRS+WBRT (p= 0.048) and WBRT (p= 0.041). Also, SRS+WBRT demonstrated a significantly improved PFS, LBC, and DBC compared to WBRT alone and SRS alone. Finally, SRS achieved the same LBC as high as surgery, but intracranial relapse occurred considerably more frequently in the absence of WBRT. However, there were not any significant differences in ND and toxicities between SRS and other groups. Therefore, SRS alone may be a better alternative since increased patient survival may outweigh the increased risk of brain tumor recurrence associated with it.

Stereotactic Radiosurgery for Neurosurgical Patients: A Historical Review and Current Perspectives

Today, stereotactic radiosurgery is an effective therapy for a variety of intracranial pathology that were treated solely with open neurosurgery in the past. The technique was developed from the combination of therapeutic radiation and stereotactic devices for the precise localization of intracranial targets. Although stereotactic radiosurgery was originally performed as a partnership between neurosurgeons and radiation oncologists, this partnership has weakened in recent years, with some procedures being performed without neurosurgeons. At the same time, neurosurgeons across the United States and Canada have found their stereotactic radiosurgery training during residency inadequate. Although neurosurgeons, residency directors, and department chairs agree that stereotactic radiosurgery education and exposure during neurosurgery training could be improved, a limited number of resources exist for this kind of education. This review describes the history of stereotactic radiosurgery, assesses the state of its use and education today, and provides recommendations for the improvement of neurosurgical education in stereotactic radiosurgery for the future.

Cranial stereotactic radiosurgery: current status of the initial paradigm shifter

The concept of stereotactic radiosurgery (SRS) was first described by Lars Leksell in 1951. It was proposed as a noninvasive alternative to open neurosurgical approaches to manage a variety of conditions. In the following decades, SRS emerged as a unique discipline involving a collegial partnership among neurosurgeons, radiation oncologists, and medical physicists. SRS relies on the precisely guided delivery of high-dose ionizing radiation to an intracranial target. The focused convergence of multiple beams yields a potent therapeutic effect on the target and a steep dose fall-off to surrounding structures, thereby minimizing the risk of collateral damage. SRS is typically administered in a single session but can be given in as many as five sessions or fractions. By providing an ablative effect noninvasively, SRS has altered the treatment paradigms for benign and malignant intracranial tumors, functional disorders, and vascular malformations. Literature on extensive intracranial radiosurgery has unequivocally demonstrated the favorable benefit-to-risk profile that SRS affords for appropriately selected patients. In a departure from conventional radiotherapeutic strategies, radiosurgical principles have recently been extended to extracranial indications such as lung, spine, and liver tumors. The paradigm shift resulting from radiosurgery continues to alter the landscape of related fields.

Radiosurgery for epilepsy: clinical experience and potential antiepileptic mechanisms

Stereotactic radiosurgery, well established in the noninvasive treatment of focal lesions that are otherwise difficult to access through open surgery, is an emerging technology in the treatment of focal epileptic lesions. Recent studies suggest that seizures from hypothalamic hamartomas and mesial temporal lobe epilepsy remit at clinically significant rates with radiosurgery, but large variations among different studies have raised questions about appropriate treatment protocols and mechanisms. Proposed anticonvulsant mechanisms include neuromodulatory effects or ischemic necrosis of epileptic tissue. An ongoing trial that directly compares efficacy, morbidities, and cost of radiosurgery versus open surgery for mesial temporal lobe epilepsy is underway.

Socioeconomic costs of open surgery and gamma knife radiosurgery for benign cranial base tumors

OBJECTIVE

The aim of this study was to evaluate the relative socioeconomic costs of benign cranial base tumors treated with open surgery and gamma knife radiosurgery.

METHODS

In a retrospective study, we studied 174 patients with benign cranial base tumors, less than 3 cm in diameter (or volume less than 30 ml), admitted in the past 5 years. Group A (n = 94) underwent open surgery for removal of the tumors, whereas Group B (n = 80) underwent gamma knife radiosurgery. The socioeconomic costs were evaluated by both direct and indirect cost. The direct costs comprised intensive care unit cost, ward cost, operating room cost, and outpatient visiting cost. The indirect costs included loss of workdays and mortality. The length of hospital stay, the number of lost workdays, surgical complications, mortality, and cost-effectiveness analysis were calculated as well. Student t test and chi test were used for statistical analysis.

RESULTS

The mean length of hospital stay for open surgery was 18.2 +/- 30.4 days including 5.0 +/- 14.7 days of intensive care unit stay and 13.0 +/- 15.2 days of ward stay, P < 0.01. The mean hospital stay for gamma knife was 2.2 +/- 0.9 days with no need of intensive care unit stay, P < 0.01. The mean loss of workdays for open surgery was 160 +/- 158 days and 8.0 +/- 9.0 days for gamma knife, P < 0.01. The gamma knife cost per hour (1435 US dollars) is higher than the open surgery cost per hour (450 US dollars), P < 0.01. The direct cost for gamma knife (9677 US dollars +/- 6700 US dollars) is higher than that for open surgery (5837 US dollars +/- 6587 US dollars), P < 0.01. Open surgery had more complication rates (31.2%) than gamma knife (3.8%). Open surgery had a mortality rate of 5.3%; there was no mortality for gamma knife. The indirect costs, including loss of workdays and mortality, were significantly higher for open surgery than for gamma knife, P < 0.01. Finally, the socioeconomic cost (34,453 US dollars +/- 97,277 US dollars) is higher for open surgery than for gamma knife (10,044 US dollars +/- 7481 US dollars), P < 0.01. The CEA is significantly higher in gamma knife (3762 US dollars/quality-adjusted life year) than in open surgery (8996 US dollars/quality-adjusted life year), P < 0.01.

CONCLUSION

Most of the socioeconomic loss with open surgery for benign cranial base tumors comes from the indirect costs of workdays lost and mortality. Gamma knife radiosurgery is a worthwhile treatment to our patients and to our society because it may shorten hospital stays and workdays lost and reduce complications, mortality, socioeconomic loss, and achieve better cost-effectiveness.

History of surgery for cerebrovascular disease in children. Part III. Arteriovenous malformations

✓ Arteriovenous malformations (AVMs) are the most common cause of intracerebral hemorrhage in children. In this paper the authors trace the historical evolution of the recognition, diagnosis, and treatment of pediatric intracerebral AVMs, and they summarize the contemporary approach and current controversies surrounding treatment of these lesions. Important distinctions between adult and pediatric AVMs are emphasized.

Improvement of radiological penumbra using intermediate energy photons (IEP) for stereotactic radiosurgery

Using efficient immobilization and dedicated beam collimation devices, stereotactic radiosurgery ensures highly conformal treatment of small tumours with limited microscopic extension. One contribution to normal tissue irradiation remains the radiological penumbra. This work aims at demonstrating that intermediate energy photons (IEP), above orthovoltage but below megavoltage, improve dose distribution for stereotactic radiosurgery for small irradiation field sizes due to a dramatic reduction of radiological penumbra. Two different simulation systems were used: (i) Monte Carlo simulation to investigate the dose distribution of monoenergetic IEP between 100 keV and 1 MeV in water phantom; (ii) the Pinnacle3 TPS including a virtual IEP unit to investigate the dosimetry benefit of treating with 11 non-coplanar beams a 2 cm tumour in the middle of a brain adjacent to a 1 mm critical structure. Radiological penumbrae below 300 microm are generated for field size below 2 x 2 cm2 using monoenergetic IEP beams between 200 and 400 keV. An 800 kV beam generated in a 0.5 mm tungsten target maximizes the photon intensity in this range. Pinnacle3 confirms the dramatic reduction in penumbra size. DVHs show for a constant dose distribution conformality, improved dose distribution homogeneity and better sparing of critical structures using a 800 kV beam compared to a 6 MV beam.

Effectiveness of stereotactic radiosurgery alone or in combination with whole brain radiotherapy compared to conventional surgery and/or whole brain radiotherapy for the treatment of one or more brain metastases: a systematic review and meta-analysis

PURPOSE

To assess the effectiveness of SRS alone or in combination with WBRT compared to surgery and/or WBRT in prolonging survival and improving the quality-of-life and functional status of patients with brain metastases.

METHODS AND MATERIALS

A meta-analysis of randomized controlled trials and concurrent cohort studies examining SRS versus SRS + WBRT, SRS versus WBRT +/- surgical resection, SRS versus surgical resection only, or SRS + WBRT versus WBRT was conducted. Trial registers, bibliographic databases, and reference lists from selected studies and recent issues of relevant journals were searched. Neuro-oncology specialists were also contacted. All studies were analyzed independently by two reviewers, applying validated critical appraisal techniques.

RESULTS

The review identified three RCTs and one cohort study. Among patients with multiple metastases, no difference in survival between those treated with WBRT + SRS and those treated with WBRT was found. However, in patients with one metastasis, a statistically significant difference, favoring those treated with WBRT + SRS, was observed. Regarding local tumor control at 24 months, rates were significantly higher in the WBRT + SRS treatment arm, regardless of the number of metastases.

CONCLUSIONS

Adding SRS to WBRT improves survival in patients with one brain metastasis. Combining SRS and WBRT improves local tumour control and functional independence in all patients.

Radiation safety and quality control in the cyclotron laboratory

Radiation safety was determined to maintain quality control in the cyclotron laboratory. Based on the results of 438 runs in the Faraday cup (20 microA for 10 min), 20 runs on 18O-water target (40 microA for 2 h) and 10 runs on 18O-gas targets (30 microA for 45 min), we have established that occupationally exposed workers remain 10 +/- 5 times below federal regulatory limits (FRLs) in the cyclotron vault, 30 +/- 8 times below FRL in the radiochemistry laboratory and 200 +/- 10 times below the FRL outside the cyclotron laboratory during beam operation. (The FRL for unrestricted area are <20 microSv in 1 h.) The non-occupationally exposed workers serving in offices in the vicinity of the cyclotron vault within 100 m distance remained 200 times below the FRL irrespective of beam being on or off, suggesting that routine beam operation of 40 microA for 2 h once a day during office hours is safe provided quality control and system performance measures as discussed in this report are strictly maintained.

Use of the Leksell Gamma Knife for localized small field lens irradiation in rodents

For most basic radiobiological research applications involving irradiation of small animals, it is difficult to achieve the same high precision dose distribution realized with human radiotherapy. The precision for irradiations performed with standard radiotherapy equipment is +/-2 mm in each dimension, and is adequate for most human treatment applications. For small animals such as rodents, whose organs and tissue structures may be an order of magnitude smaller than those of humans, the corresponding precision required is closer to +/-0.2 mm, if comparisons or extrapolations are to be made to human data. The Leksell Gamma Knife is a high precision radiosurgery irradiator, with precision in each dimension not exceeding 0.5 mm, and overall precision of 0.7 mm. It has recently been utilized to treat ocular melanoma and induce targeted lesions in the brains of small animals. This paper describes the dosimetry and a technique for performing irradiation of a single rat eye and lens with the Gamma Knife while allowing the contralateral eye and lens of the same rat to serve as the "control". The dosimetry was performed with a phantom in vitro utilizing a pinpoint ion chamber and thermoluminescent dosimeters, and verified by Monte Carlo simulations. We found that the contralateral eye received less than 5% of the administered dose for a 15 Gy exposure to the targeted eye. In addition, after 15 Gy irradiation 15 out of 16 animals developed cataracts in the irradiated target eyes, while 0 out of 16 contralateral eyes developed cataracts over a 6-month period of observation. Experiments at 5 and 10 Gy also confirmed the lack of cataractogenesis in the contralateral eye. Our results validate the use of the Gamma Knife for cataract studies in rodents, and confirmed the precision and utility of the instrument as a small animal irradiator for translational radiobiology experiments.

Delineation of brain metastases on CT images for planning radiosurgery: concerns regarding accuracy

Conformal radiotherapy requires confidence that the images used for target delineation accurately reflect the pathological dimensions of the target. Radiosurgery, which is a conformal radiotherapy technique, is often used to treat brain metastases. The images of brain metastases can be affected by the method of image acquisition. A prospective study was undertaken to evaluate the effect of delay on CT images of brain metastases selected for radiosurgical treatment. A median delay from contrast administration of 65 min resulted in an increase in the volume of the metastases in 86% of cases when compared with the volumes of the same metastases determined from CT images acquired immediately following the administration of contrast medium. The magnitude of the increase in volume was sufficient to cause radiosurgery planners to select larger collimator sizes for radiosurgery plans based on the delayed CT images in 92% of cases. No significant intraobserver or interobserver variation was found in the group of radiosurgery planners. Differences in image acquisition may account in part for the differences in local control reported in the radiosurgical treatment of brain metastases.

Concomitant boost of stratified target area with gamma knife radiosurgery: a treatment planning study

Conventional Gamma Knife Stereotactic Radiosurgery (GKSRS) has been focused on delivering a single peripheral dose to the gross target volume based on the anatomic information derived from the magnetic resonance or computed tomography (CT) studies. In this study, we developed a treatment planning approach that allows a boost dose to be delivered concomitantly to the desired subtarget area while maintaining the peripheral isodose coverage of the target volume. The subtarget area is defined as the high-risk or the tumor burden areas based on the functional imaging information such as the magnetic resonance spectroscopy (MRS) studies or the physician's clinical diagnosis. Treatment plan comparisons were carried out between the concomitant boost plans and the conventional treatment plans using dose volume histogram (DVH), tissue volume ratio (TVR), and the maximum dose to the peripheral dose ratio (MD/PD) analysis. Using the concomitant boost approach, more conformal and higher dose was delivered to the desired subtarget area while maintaining the peripheral isodose coverage of the gross target volume (GTV). Additionally, the dose to the normal brain tissue was found to be equivalent between the concomitant boost plans and the conventional plans. As a result, we conclude that concomitant boost of a stratified target area is feasible for GKSRS.

Brain metastases: treatment options to improve outcomes

In recent years, a broader base of treatment options has evolved to improve the outcome for patients with brain metastases. The selection of the most appropriate intervention for the individual patient is dependent on a careful evaluation of the extent of intracranial tumour, as well as an understanding of patient and tumour characteristics that are important determinants of prognosis. Recent analyses have confirmed good performance status, control of the primary tumour, absence of extracranial metastases and age less than 65 years to be predictors for longer survival. Medical therapy typically includes the use of corticosteroids, and some advances have been made in optimising the use of these agents. Prophylactic use of antiepileptic drugs in patients with brain metastases is generally discouraged. Chemotherapy was previously not considered to have a role in treating brain metastases, but has increasingly become an accepted treatment option. Recent clinical studies have evaluated the integration of chemotherapy with conventional treatments such as radiotherapy and the addition of biological response modifiers. In the past, radiotherapy has been the mainstay of treatment for brain metastases. A number of randomised controlled trials have explored external beam radiation therapy, radiation sensitisers, postoperative whole brain irradiation and prophylactic cranial irradiation. Significant improvements in survival have been demonstrated as a result of prophylactic cranial irradiation in patients with small-cell lung cancer, and improved local control of brain metastases has been achieved with postoperative whole brain irradiation. A number of studies have helped define a more efficient use of external beam irradiation. Radiosurgery in particular has been identified as an important advance in radiation treatment delivery and may provide an acceptable alternative to surgical resection in many patients. Conventional surgery has long had a role to play in establishing the diagnosis, guiding the choice of subsequent therapies and reversing life-threatening complications from brain metastases. The risks of surgery have been reduced with recent improvements in anaesthesia and intraoperative tumour localisation. Recent clinical studies have addressed the role of surgical resection in the management of patients with a single brain metastasis. Survival benefits have been demonstrated in patients undergoing surgical resection in addition to external beam radiation therapy. Despite the improvements achieved in the treatment of patients with brain metastases at first diagnosis, the question of retreatment may arise in due course. The therapeutic options available in this situation include re-operation, radiosurgery and brachytherapy.

Stereotactic radiosurgery and fractionated stereotactic radiotherapy for the treatment of acoustic schwannomas: comparative observations of 125 patients treated at one institution

BACKGROUND

Stereotactic radiosurgery (SRS) and, more recently, fractionated stereotactic radiotherapy (SRT) have been recognized as noninvasive alternatives to surgery for the treatment of acoustic schwannomas. We review our experience of acoustic tumor treatments at one institution using a gamma knife for SRS and the first commercial world installation of a dedicated linac for SRT.

METHODS

Patients were treated with SRS on the gamma knife or SRT on the linac from October 1994 through August 2000. Gamma knife technique involved a fixed-frame multiple shot/high conformality single treatment, whereas linac technique involved daily conventional fraction treatments involving a relocatable frame, fewer isocenters, and high conformality established by noncoplanar arc beam shaping and differential beam weighting.

RESULTS

Sixty-nine patients were treated on the gamma knife, and 56 patients were treated on the linac, with 1 NF-2 patient common to both units. Three patients were lost to follow-up, and in the remaining 122 patients, mean follow-up was 119 +/- 67 weeks for SRS patients and 115 +/- 96 weeks for SRT patients. Tumor control rates were high (> or =97%) for sporadic tumors in both groups but lower for NF-2 tumors in the SRT group. Cranial nerve morbidities were comparably low in both groups, with the exception of functional hearing preservation, which was 2.5-fold higher in patients who received conventional fraction SRT.

CONCLUSION

SRS and SRT represent comparable noninvasive treatments for acoustic schwannomas in both sporadic and NF-2 patient groups. At 1-year follow-up, a significantly higher rate of serviceable hearing preservation was achieved in SRT sporadic tumor patients and may therefore be preferable to alternatives including surgery, SRS, or possibly observation in patients with serviceable hearing.

Time-dependent astroglial changes after gamma knife radiosurgery in the rat forebrain

OBJECTIVE

Using an experimental rat model and a clinically relevant treatment dose, we performed gamma knife radiosurgery to define the hyperacute radiation effects in normal rat forebrain, the time dependence of the astrocytic reaction, and the participation of astrocytes in the healing process after single-dose gamma radiation injuries.

METHODS

Seventy-one rats underwent radiosurgical treatment (4-mm collimator) of the caudate-putamen nucleus (single-fraction maximal dose of 100 Gy) and were killed at times ranging from 3 hours to 90 days. Serial cryostat brain sections were processed with the immunohistochemical avidin-biotin complex technique, using anti-glial fibrillary acidic protein as the primary antibody (to identify astrocytes).

RESULTS

Vascular changes, including endothelial hyperplasia and vessel wall thickening, were identified as the earliest postradiation manifestations and continued throughout the observation period. Astrocytes reacted to the radiation injury with hyperplasia and hypertrophy. At earlier time points (3-24 h), proliferation was the predominant reaction. The expression of glial fibrillary acidic protein in the proliferating and hypertrophic astrocytes formed an initial peak in the adjacent corpus callosum 3 days after radiosurgery and peaked within the target site between 14 and 30 days. Astrocytic proliferation and hypertrophy were also observed in distant cortices (frontal, parietal, insular, and piriform cortices) and in the hippocampus. No necrosis was observed less than 30 days after irradiation. By Day 90, necrotic lesions with a mean diameter of 4 mm were identified, with glial scar at their peripheries. Astrocytic morphological features varied according to the distance from the necrosis. The irradiated side contained more glial fibrillary acidic protein-containing cells than did the nonirradiated contralateral side.

CONCLUSION

During the early phase after radiation, vasculopathy was the first morphological change and may serve as the initiating factor for subsequent changes. Reactive astrocytes appeared not only at the target site but also in the surrounding regions; the severity of injury was determined by the distance from the target.

A cost-effectiveness and cost-utility analysis of radiosurgery vs. resection for single-brain metastases

PURPOSE

The median survival of well-selected patients with single-brain metastases treated with whole-brain irradiation and resection or radiosurgery is comparable, although a randomized trial of these two modalities has not been performed. In this era of cost containment, it is imperative that health-care professionals make fiscally prudent decisions. The present environment necessitates a critical appraisal of apparently equi-efficacious therapeutic modalities, and it is within this context that we present a comparison of the actual costs of resection and radiosurgery for brain metastases.

METHODS AND MATERIALS

Survival and quality of life outcome data for radiation alone or with surgery were obtained from two randomized trials, and radiosurgical results were obtained from a multiinstitutional analysis that specifically evaluated patients meeting surgical criteria. Only linear accelerator radiosurgery data were considered. Cost analysis was performed from a societal view point, and the following parameters were evaluated: actual cost, cost ratios, cost effectiveness, incremental cost effectiveness, cost utility, incremental cost utility, and national cost burden. The computerized billing records for all patients undergoing resection or radiosurgery for single-brain metastases from January 1989 to July 1994 were reviewed. A total of 46 resections and 135 radiosurgery procedures were performed. During the same time period, 454 patients underwent whole-brain radiation alone. An analysis of the entire bill was performed for each procedure, and each itemized cost was assigned a proportionate figure. The relative cost ratios of resection and radiosurgery were compared using the Wilcoxon rank sum test. Cost effectiveness of each modality, defined as the cost per year of median survival, was evaluated. Incremental cost effectiveness, defined as the additional cost per year of incremental gain in median survival, compared to the next least expensive modality, was also determined. To calculate the societal or national impact of these practices, the proportion of patients potentially eligible for aggressive management was estimated and the financial impact was determined using various utilization ratios for radiosurgery and surgery.

RESULTS

Both resection and radiosurgery yielded superior survival and functional independence, compared to whole brain radiotherapy alone, with minor differences in outcome between the two modalities; resection resulted in a 1.8-fold increase in cost, compared to radiosurgery. The latter modality yielded superior cost outcomes on all measures, even when a sensitivity analysis of up to 50% was performed. A reversal estimate indicated that in order for surgery to yield equal cost effectiveness, its cost would have to decrease by 48% or median survival would have to improve by 108%. The average cost per week of survival was $310 for radiotherapy, $524 for resection plus radiation, and $270 for radiosurgery plus radiation.

CONCLUSIONS

For selected patients, aggressive strategies such as resection or radiosurgery are warranted, as they result in improved median survival and functional independence. Radiosurgery appears to be the more cost-effective procedure.

Radiotherapy for palliation of symptoms in incurable cancer

Approximately one half of prescribed radiotherapy is given for palliation of symptoms due to incurable cancer. Distressing symptoms including pain, bleeding, and obstruction can often be relieved with minimal toxic effects. Painful osseous metastasis is common in oncologic practice. Ninety percent of patients with symptomatic bone metastases obtain some pain relief with a lowdose, brief course of palliative radiotherapy. One half of the responding patients may experience complete pain relief. A single dose of 800 cGy in the setting of painful bone metastasis may provide pain control comparable to more protracted treatment at a higher dose of radiation. Patients with lytic disease in weight-bearing bones, particularly in the presence of cortical destruction, should be considered for prophylactic surgical stabilization of their condition. Routinely a brief, fractionated course of radiotherapy is given postoperatively. Pain due to multiple bone metastases uncontrolled by analgesics can be managed with single doses of halfbody irradiation. Doses of 600 cGy delivered to the upper half-body (above the umbilicus) and 800 cGy to the lower half-body (from the umbilicus to the middle of the femur) will provide some pain relief in 73% of patients. Half-body techniques have been investigated as prophylactic treatment, as a complement to local-field irradiation, and as fractionated rather than singledose therapy. Although intravenous administration of strontium 89 has been associated with myelosuppression, this treatment has been shown (a) to relieve pain due to bone metastasis and (b) to delay development of new painful sites. Recent data from phase III trials demonstrated that bisphosphonates have a role in reducing skeletal morbidity due to bone metastasis. Bone pain was reduced, and the incidence of pathologic fracture and the need for future radiotherapy was decreased. Radiotherapy relieves clinical symptoms in 70% to 90% of patients with brain metastases. Brief treatment schedules (e.g., 2000 cGy in five fractions over 1 week) are as effective as more prolonged therapy. Patients with solitary brain metastasis and no extracranial disease or controlled extracranial disease should be considered for surgical resection, because phase III data indicate enhanced survival with such an approach. Whole-brain radiotherapy is routinely administered postoperatively. A phase III study is examining the impact of accelerated fractionated doses of radiotherapy (two treatments per day) on survival of patients with brain metastases. Stereotaxic radiosurgical treatment is becoming increasingly available and permits delivery of radiation to metastatic intracranial tumor with minimal exposure of normal surrounding brain This treatment is most commonly used at the time of a solitary recurrence of disease in patients who previously received whole-brain radiotherapy. A role for this modality in newly diagnosed brain metastases remains to be defined. Chest symptoms are common in patients with locally advanced lung cancer and are effectively palliated with one 1000 cGy or two 850 cGy one fraction doses of radiation to the thoracic inlet and mediastinum. Chest pain and hemoptysis are more effectively palliated than cough and dyspnea. In patients with stage III cancer there is no compelling evidence that radiotherapy confers a survival advantage, and it may be reasonable to administer thoracic radiotherapy only when the patient has significant symptoms and the goal is to achieve control of these symptoms. Approximately 75% of the cases of superior vena cava syndrome are due to lung cancer, and small-cell lung cancer is the most common histologic type. A histologic diagnosis should be obtained before treatment is started, because detection of lymphoma or small-cell carcinoma would necessitate systemic therapy. Eighty percent of the patients with vena cava syndrome due to malignant disease achieve symptom relief with a brief, fractionated, palliative course of rad

Non-surgical treatment of vestibular schwannoma patients

The aim of the study was to evaluate the course of vestibular schwannoma (VS) when surgery was not attempted. The tumor may be slowly growing and surgery a risk for a patient. Twenty-eight patients out of 390 VS patients during years 1981-1995 were primarily recommended a non-surgical treatment. Another 3 patients refused the operation. Altogether 23 women and 8 men were evaluated. Their age varied from 30.6 to 74.6 years (median 56.7 years). Tumor size varied from 5 to 30 mm (median 15.0 mm) at the beginning of the follow-up. Patients symptoms, condition and other illnesses were recorded. Seven patients had neurofibromatosis 2 (3 of them had one hearing ear), 2 had severe mental problems, 5 patients had their only hearing ear and 11 patients were not recommended an operation because of their age and other illnesses. Patients were controlled with MRI at intervals from 1 to 3 years. The follow-up time varied from 1 to 20 years (median 2.0 years). The average tumor growth rate among unilateral VS patients was 0.035 cm/year and among bilateral tumors the average tumor growth rate was 0.015 cm/year. Two patients were later operated on, one 2 years after diagnosis because of the tumor growth and the other one 4 years after diagnosis-she had refused an operation earlier. Two patients could not be reached. Another patient had tumor growth but because of his illnesses he got a radiation beam instead of an operation. The majority of the patients could live fairly normal lives and required no treatment. Surgery is not the only alternative to VS patients. Wait-and-see policy is also a good alternative to those who have high operation risk or who refuse an operation.