A multi-institutional experience with stereotactic radiosurgery for solitary brain metastasis

Validation of the RTOG recursive partitioning analysis (RPA) classification for brain metastases

PURPOSE

The Radiation Therapy Oncology Group (RTOG) previously developed three prognostic classes for brain metastases using recursive partitioning analysis (RPA) of a large database. These classes were based on Karnofsky performance status (KPS), primary tumor status, presence of extracranial system metastases, and age. An analysis of RTOG 91-04, a randomized study comparing two dose-fractionation schemes with a comparison to the established RTOG database, was considered important to validate the RPA classes.

METHODS AND MATERIALS

A total of 445 patients were randomized on RTOG 91-04, a Phase III study of accelerated hyperfractionation versus accelerated fractionation. No difference was observed between the two treatment arms with respect to survival. Four hundred thirty-two patients were included in this analysis. The majority of the patients were under age 65, had KPS 70-80, primary tumor controlled, and brain-only metastases. The initial RPA had three classes, but only patients in RPA Classes I and II were eligible for RTOG 91-04.

RESULTS

For RPA Class I, the median survival time was 6. 2 months and 7.1 months for 91-04 and the database, respectively. The 1-year survival was 29% for 91-04 versus 32% for the database. There was no significant difference in the two survival distributions (p = 0.72). For RPA Class II, the median survival time was 3.8 months for 91-04 versus 4.2 months for the database. The 1-year survival was 12% and 16% for 91-04 and the database, respectively (p = 0.22).

CONCLUSION

This analysis indicates that the RPA classes are valid and reliable for historical comparisons. Both the RTOG and other clinical trial organizers should currently utilize this RPA classification as a stratification factor for clinical trials.

Stereotactic radiosurgery for brain metastases from breast cancer

BACKGROUND

Stereotactic radiosurgery is an alternative to resection or to radiotherapy alone for patients with brain metastases. Outcomes after radiosurgery for patients with brain metastases specifically from breast cancer have not been defined.

METHODS

We retrospectively studied survival and tumor control for all patients with brain metastases from breast cancer who underwent gamma knife stereotactic radiosurgery at the University of Pittsburgh. Univariate and multivariate analyses were used to determine which prognostic factors significantly affected survival.

RESULTS

Thirty patients underwent radiosurgery between 1990 and 1997. A total of 58 metastases were treated. The median length of survival for all patients was 13 months from radiosurgery and 18 months from diagnosis of brain metastases. The tumor control rate on follow-up imaging was 93%. On multivariate analysis, the only factor that correlated with longer survival was the absence of multiple brain metastases. Age, presence of systemic disease, previous whole brain radiation, location, and total tumor volume did not significantly affect survival. Four patients had tumors with evidence of radiation-induced edema after radiosurgery but did not require resection. Two patients underwent delayed resection for tumor growth after radiosurgery.

CONCLUSIONS

Stereotactic radiosurgery is an effective treatment for brain metastases from breast cancer and is associated with a low complication rate.

Increased tumor cures using combined radiosurgery and BCNU in the treatment of 9l glioma in the rat brain

PURPOSE

Radiosurgery refers to the delivery of high, single focused beams of ionizing radiation to defined intracranial lesions. 1,3 Bis[2-chloroethyl]-1-nitrosourea (BCNU) and cis-diammine-1, 1-cyclobutane-dicarboxylate platinum (II) (carboplatin) are commonly used cytotoxic agents for the treatment of malignant gliomas of the brain. Drug therapies have exhibited a modest enhanced cell killing when combined with radiation in experimental animal tumor systems. The purpose of the present study was to investigate the role of cytotoxic drugs, such as BCNU and carboplatin, in combination with a single high dose of radiosurgery on the tumor control rates of 9L tumors in the rat brain.

METHODS AND MATERIALS

Combined radiosurgery (25 Gy single dose) and/or chemotherapy (a single dose of BCNU, 7 mg/kg, i.p. 1.5 or 16 h prior to or 16 h after irradiation or a single dose of carboplatin, 30 mg/kg, administered either 1 h or 4 h prior to irradiation) was delivered 12 days after stereotactic tumor implantation. For dose escalation study, 4-10 mg/kg of BCNU was used.

RESULTS

The radiation alone group showed a dose-dependent survival. A single dose of 25 Gy to the control group resulted in an increase of the median survival time from 20 days to 42 days, but all animals died of the tumor in 50 days. A significant prolongation of the median survival time of animals was more than 100 days, resulting in animal cures of 50% or more when combined with radiosurgery (25 Gy) and BCNU (7 mg/kg). BCNU alone did not prolong the median survival time of the animal with the 9L brain tumor. In contrast, there was no survival improvement when the animals were treated with combined radiosurgery and carboplatin. None of the long-term surviving animals showed any significant brain tissue damage as evaluated by histopathology and clinical observations.

CONCLUSION

The data clearly suggest that the combined modalities of radiosurgery and concomitant BCNU represent an effective therapeutic regimen in the treatment of radioresistant human malignant gliomas of the brain. This study represents the first experimental report of the effectiveness of combined chemotherapy and radiosurgery.

Single dose radiosurgical treatment of recurrent previously irradiated primary brain tumors and brain metastases: final report of RTOG protocol 90-05

PURPOSE

To determine the maximum tolerated dose of single fraction radiosurgery in patients with recurrent previously irradiated primary brain tumors and brain metastases.

METHODS AND MATERIALS

Adults with cerebral or cerebellar solitary non-brainstem tumors </= 40 mm in maximum diameter were eligible. Initial radiosurgical doses were 18 Gy for tumors </= 20 mm, 15 Gy for those 21-30 mm, and 12 Gy for those 31-40 mm in maximum diameter. Dose was prescribed to the 50-90% isodose line. Doses were escalated in 3 Gy increments providing the incidence of irreversible grade 3 (severe) or any grade 4 (life threatening) or grade 5 (fatal) Radiation Therapy Oncology Group (RTOG) central nervous system (CNS) toxicity (unacceptable CNS toxicity) was < 20% within 3 months of radiosurgery. Chronic CNS toxicity was also assessed.

RESULTS

Between 1990-1994, 156 analyzable patients were entered, 36% of whom had recurrent primary brain tumors (median prior dose 60 Gy) and 64% recurrent brain metastases (median prior dose 30 Gy). The maximum tolerated doses were 24 Gy, 18 Gy, and 15 Gy for tumors </= 20 mm, 21-30 mm, and 31-40 mm in maximum diameter, respectively. However, for tumors < 20 mm, investigators' reluctance to escalate to 27 Gy, rather than excessive toxicity, determined the maximum tolerated dose. In a multivariate analysis, maximum tumor diameter was one variable associated with a significantly increased risk of grade 3, 4, or 5 neurotoxicity. Tumors 21-40 mm were 7.3 to 16 times more likely to develop grade 3-5 neurotoxicity compared to tumors < 20 mm. Other variables significantly associated with grade 3-5 neurotoxicity were tumor dose and Karnofsky Performance Status. The actuarial incidence of radionecrosis was 5%, 8%, 9%, and 11% at 6, 12, 18, and 24 months following radiosurgery, respectively. Forty-eight percent of patients developed tumor progression within the radiosurgical target volume. A multivariate analysis revealed two variables that were significantly associated with an increased risk of local progression, i.e. progression in the radiosurgical target volume. Patients with primary brain tumors (versus brain metastases) had a 2.85 greater risk of local progression. Those treated on a linear accelerator (versus the Gamma Knife) had a 2.84 greater risk of local progression. Of note, 61 % of Gamma Knife treated patients had recurrent primary brain tumors compared to 30% of patients treated with a linear accelerator.

CONCLUSIONS

The maximum tolerated doses of single fraction radiosurgery were defined for this population of patients as 24 Gy, 18 Gy, and 15 Gy for tumors </= 20 mm, 21-30 mm, and 31-40 mm in maximum diameter. Unacceptable CNS toxicity was more likely in patients with larger tumors, whereas local tumor control was most dependent on the type of recurrent tumor and the treatment unit.

Radiosurgical salvage therapy for patients presenting with recurrence of metastatic disease to the brain

OBJECTIVE

Radiosurgery has emerged as an important modality in the management of metastatic disease to the brain. A number of groups have published results suggesting that high local control rates can be achieved, with improvements in overall survival that rival the results of open surgical treatment. Typically, however, whole-brain radiotherapy has been used in the salvage therapy of patients who have undergone previous craniotomy or radiosurgery. We describe our experience with radiosurgical salvage in this group of patients.

METHODS

From August 1994 to February 1999, 190 patients with brain metastasis were treated with gamma unit radiosurgery at our institution. A subset of 45 patients, who underwent radiosurgical salvage for new tumors in a region remote from an initially treated tumor, form the population base for this study. The usual criteria for repeat treatment were recurrence with five or fewer discrete lesions outside of the previously treated radiosurgical volume and Karnofsky Performance Scale score of at least 70. Survival and freedom from progression were measured from the time of radiosurgical treatment and were computed by the Kaplan-Meier product-limit method. Two or more curves were compared using the log-rank method.

RESULTS

In this subgroup of patients, a total of 176 tumors were treated. The median time from first radiosurgical procedure to first salvage was 17.4 weeks. Median survival from the second radiosurgical intervention was 28 weeks. Of the 45 study patients, 34 patients underwent a single salvage procedure, 10 patients underwent two salvage procedures, and 1 patient had three salvage procedures. The actuarial freedom from progression for treated tumors at 52 weeks was 92.4%. Patients undergoing upfront whole-brain irradiation were less likely to require salvage therapy (P = 0.008). There were 33 deaths after salvage radiosurgery during the reporting period. Central nervous system causes accounted for 13 deaths, whereas 19 deaths resulted from systemic disease. The cause of death in one patient could not be determined. No statistically significant advantage in overall survival could be demonstrated in patients treated with whole-brain irradiation.

CONCLUSION

Radiosurgical salvage represents a valuable means of treatment for central nervous system recurrence for patients who have undergone previous treatment for metastatic disease to the brain. Whole-brain irradiation may reduce the need for salvage therapy, but no advantage in overall survival could be demonstrated in this subgroup.

Radiosurgery for brain metastases: a score index for predicting prognosis

PURPOSE

To analyze a prognostic score index for patients with brain metastases submitted to stereotactic radiosurgery (the Score Index for Radiosurgery in Brain Metastases [SIR]).

METHODS AND MATERIALS

Actuarial survival of 65 brain metastases patients treated with radiosurgery between July 1993 and December 1997 was retrospectively analyzed. Prognostic factors included age, Karnofsky performance status (KPS), extracranial disease status, number of brain lesions, largest brain lesion volume, lesions site, and receiving or not whole brain irradiation. The SIR was obtained through summation of the previously noted first five prognostic factors. Kaplan-Meier actuarial survival curves for all prognostic factors, SIR, and recursive partitioning analysis (RPA) (RTOG prognostic score) were calculated. Survival curves of subsets were compared by log-rank test. Application of the Cox model was utilized to identify any correlation between prognostic factors, prognostic scores, and survival.

RESULTS

Median overall survival from radiosurgery was 6.8 months. Utilizing univariate analysis, extracranial disease status, KPS, number of brain lesions, largest brain lesion volume, RPA, and SIR were significantly correlated with prognosis. Median survival for the RPA classes 1, 2, and 3 was 20.19 months, 7.75 months, and 3. 38 months respectively (p = 0.0131). Median survival for patients, grouped under SIR from 1 to 3, 4 to 7, and 8 to 10, was 2.91 months, 7.00 months, and 31.38 months respectively (p = 0.0001). Using the Cox model, extracranial disease status and KPS demonstrated significant correlation with prognosis (p = 0.0001 and 0.0004 respectively). Multivariate analysis also demonstrated significance for SIR and RPA when tested individually (p = 0.0001 and 0.0040 respectively). Applying the Cox Model to both SIR and RPA, only SIR reached independent significance (p = 0.0004).

CONCLUSIONS

Systemic disease status, KPS, SIR, and RPA are reliable prognostic factors for patients with brain metastases submitted to radiosurgery. Applying SIR and RPA classifications to our patients' data, SIR demonstrated better accuracy in predicting prognosis. SIR should be further tested with larger patient accrual and for all patients with brain metastases subjected or not to stereotactic radiosurgery.

Radiosurgery: where we were, are, and may be in the third millennium

Radiosurgery will celebrate its Golden Jubilee in the year 2001. More than 100,000 patients throughout the world have undergone radiosurgery since Lars Leksell first described the technique in 1951. Rapid developments in neuroimaging and even robotic technology in the past decade have contributed to improved outcomes and wider applications for radiosurgery. A variety of different radiosurgical techniques have been developed in the past two decades. Numerous studies have examined the benefits and risks of radiosurgery performed with various devices. The long-term results of radiosurgery are now available, and these results have established radiosurgery as an effective noninvasive treatment method for intracranial vascular malformations and many tumors. Additional applications of radiosurgery for the treatment of malignant tumors and functional disorders are being assessed. Radiosurgery is an impressive combination of minimally invasive technologies administered by a multidisciplinary team of surgeons, oncologists, medical physicists, and engineers.

Linear accelerator radiosurgery in the management of brain tumours

Radiosurgery is an increasingly popular method for treating a variety of intracranial tumours. A great deal of treatment data has been accumulated suggesting that radiosurgery may be the treatment of choice for small acoustic schwannomas. Moreover, radiosurgery promises excellent tumour control and minimal risk in the treatment of small meningiomas in risky surgical locations such as the cavernous sinus. Radiosurgery offers superior local control rates for many metastatic neoplasms and has promise as an adjuvant 'boost' technique in certain malignant gliomas. This article presents a brief description of the linear accelerator, LINAC, radiosurgical technique, followed by a review of the more common applications of stereotactic radiosurgery in the treatment of intracranial neoplastic disease.

Prognostic factors in brain metastases: should patients be selected for aggressive treatment according to recursive partitioning analysis (RPA) classes?

PURPOSE

To determine whether or not Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) derived prognostic classes for patients with brain metastases are generally applicable and can be recommended as rational strategy for patient selection for future clinical trials. Inclusion of time to non-CNS death as additional endpoint besides death from any cause might result in further valuable information, as survival limitation due to uncontrolled extracranial disease can be explored.

METHODS

We performed a retrospective analysis of prognostic factors for survival and time to non-CNS death in 528 patients treated at a single institution with radiotherapy or surgery plus radiotherapy for brain metastases. For this purpose, patients were divided into groups with Karnofsky performance status (KPS) <70% and KPS > or =70%, as proposed by the RTOG.

RESULTS

Median overall survival was 2.9 months (2.0 months for patients with KPS <70% and 3.6 months for patients with KPS > or =70%, p < 0.001). We did not find other variables splitting patients with KPS <70% in different prognostic groups. However, advanced age, multiple brain metastases, presence of extracranial metastases, and uncontrolled primary tumor each predicted shorter survival in patients with KPS > or =70%. When grouped into the original RTOG RPA classes, our data set split into three subgroups with different prognosis and median survival times of 10.5, 3.5, and 2 months, respectively (p < 0.05). Only 3% of patients fell into the most favorable group. Median time to non-CNS death was 4.1 months (12.9 months in RPA class I, 4.9 months in RPA class II, and 3.8 months in RPA class III, respectively, p > 0.05 for RPA class II versus III). However, it was 8.5 months in RPA class II patients with controlled primary tumor, which was found to be the only prognostic factor for time to non-CNS death in patients with KPS > or =70%. In patients with KPS <70%, no statistically significant prognostic factors were identified for this endpoint.

CONCLUSIONS

Despite some differences, this analysis essentially confirmed the value of RPA-derived prognostic classes, as published by the RTOG, when survival was chosen as endpoint. RPA class I patients seem to be most likely to profit from aggressive treatment strategies and should be included in appropriate clinical trials. However, their number appears to be very limited. Considering time to non-CNS death, our results suggest that certain patients in RPA class II also might benefit from increased local control of brain metastases.

Stereotactically delivered cranial radiation therapy: a ten-year experience of linac-based radiosurgery in the UK

In 1989, linear accelerator (linac)-based cranial stereotactic radiation therapy ('radiosurgery') was introduced in the UK at St Bartholomew's Hospital; a new, relocatable stereotactic frame was first used at the same time, allowing fractionated stereotactic radiotherapy. In the first decade of clinical practice using this technology, some 200 patients with blood vessel tumours/malformations have been treated, together with another 200 suffering from other conditions. The usefulness of this technique for cerebral arteriovenous malformations (AVM) has been demonstrated, and also a significant cure rate for AVM of >3 cm diameter (which is larger than for those previously reported after treatment on the gamma unit), albeit attended by a higher complication rate. The epilepsy associated with AVM is much improved by successful radiotherapy. The usefulness of radiosurgery for glomus tumours has been confirmed and new data published on the efficacy of the technique for haemangioblastoma, with new radiation therapy strategies designed for patients with von Hippel-Lindau disease. The acoustic neuroma treatment results have included improvements in hearing (a result not reported in the gamma unit literature), which are ascribed to the lower internal dose gradient within the target volume. Fractionation will, it is argued, also lead to sparing of the special sensory cochlear nerve. The risks of radiosurgery to the brainstem for chordoma of the mid-clivus are reduced by using a 'spacer' technique for the prepontine space. For meningiomas involving the cavernous sinus, conventionally fractionated radiotherapy is recommended when the meningeal base diameter exceeds 3.0 cm and radiosurgery (utilizing fractionation where appropriate) is advised for smaller lesions. Thus far, radiosurgery indications for pituitary adenomas have been restricted to recurrences after conventional radiotherapy, usually those in the cavernous sinus. In therapy for recurrent craniopharyngioma, it is argued that fractionation delivered via the relocatable frame will be important, particularly when the disease envelops the optic chiasma. For semicystic/semisolid craniopharyngiomas, the stereotactic delivery of colloidal yttrium-90 into a cystic element is useful, while stereotactic radiosurgery is delivered to the solid component. Staff at this centre consider that radiosurgery for low-grade gliomas, perhaps as boost therapy after conventional fractionation, is worthy of more research. We have been extremely selective in the use of radiosurgery for brain metastases (2% of patients, compared with about 30% in some Gamma Knife units), but future indications may become broader, probably using it as a booster technique after whole-brain conventionally-fractionated radiotherapy. Positron emission tomography scanning, co-registered with magnetic resonance imaging, allows the 'boost' concept in radiosurgery to become a sophisticated and accurate reality. Post-radiosurgical sequelae have been placed within a standard framework classification. New observations are being made with regard to subacute reactions: late-responding intrinsic and extra-axial tumours may swell in the subacute period, prior to shrinkage, and be attended by symptomatic surrounding brain oedema.

Treatment outcome for patients with primary nonsmall-cell lung cancer and synchronous brain metastasis

The purpose of this study was to evaluate the outcome of treatment for patients with newly diagnosed nonsmall-cell lung cancer (NSCLC) with an isolated, single, synchronous brain metastasis. A retrospective review was performed evaluating any patient diagnosed between 1982 and 1996 at the Cleveland Clinic Foundation with NSCLC metastatic only to the brain. Patients with multiple brain metastases or with systemic metastases to any other organ were excluded. Survival was measured from the date of the first treatment for malignancy. All hospital records were thoroughly reviewed in a retrospective manner. Thirty-three patients were identified who met the study criteria. Twelve patients had primary disease limited to the lung and hilar nodes, and 21 had more advanced primary disease with involvement of the mediastinum. Treatment of the chest was considered aggressive in 13 patients and palliative in 15. The primary tumor was observed in 5 patients. The management of the brain metastasis was as follows: 21 patients underwent surgical resection and postoperative whole brain radiotherapy (WBRT), 5 underwent stereotactic radiosurgery (SRS) and WBRT, 3 had resection alone, 2 had SRS alone, and 2 underwent WBRT alone. The median overall and disease-free survival for all patients was 6.9 months and 3.3 months, respectively. Overall survival was markedly improved with the addition of WBRT (P = 0.002) and with the aggressive management of the primary tumor (P = 0.005). A total of 9 patients experienced CNS failure, including both patients receiving WBRT alone. CNS failures were divided as follows: 3 local, 5 distant, and 1 local and distant. Two of the 4 patients with a local failure were salvaged, and ultimate local control of the original brain metastasis was achieved in 93.6% of cases. Survival remains poor for patients with Stage IV NSCLC even when metastatic disease is limited to a single site within the brain; however, aggressive therapy of both the lung primary and the brain metastasis may provide a survival advantage. Excellent local control of single brain metastases was achieved with a combination of WBRT with either surgical resection or SRS.

Dose optimization and indication of Linac radiosurgery for brain metastases

PURPOSE

The authors have examined treatment effects of linear accelerator based radiosurgery for brain metastases. Optimal doses and indications were determined in an attempt to improve the quality of life for terminal cancer patients.

METHODS AND MATERIALS

Ninety-two patients with 162 lesions were treated with Linac radiosurgery for brain metastases between April 1993 and September 1998. To determine prognostic factors, risk factors for recurrence, and appearance of new lesions, univariate and multivariate analyses were performed. To compare the local control between the high-dose (minimum dose > or =25 Gy: prescribed to the 50-80% isodose line) and low-dose (minimum dose <25 Gy) irradiated groups, matched-pairs analysis was performed.

RESULTS

Median survival time was 11 months. In univariate analysis, extracranial tumor activity (p<0.001) and Karnofsky Performance Status (KPS) (p = 0.036) were two significant predictors of survival. In multivariate analysis, the status of an extracranial tumor was the single significant predictor of survival (p = 0.005). Minimum dose was the single most significant predictor of local recurrence in univariate, multivariate, and matched-pairs analyses (p<0.05). As to the appearance of new lesions, activity of extracranial tumors was a significant predictor (p<0.05). Side effects due to radiosurgery were experienced in 4 of 92 cases (4.3%).

CONCLUSIONS

We concluded that brain metastases patients should be irradiated with > or =25 Gy, when extracranial lesions are stable and longer survival is expected. Combined surgery and conventional radiation may have little advantage over radiosurgery alone when metastatic brain tumors are small and extracranial tumors are well controlled. When extracranial tumors are progressive, the rate of appearance of new lesions in other nonirradiated locations becomes higher. In such cases, careful follow-up is required and a combination with whole brain irradiation should be considered.

Stereotactic radiosurgery for brainstem metastases

OBJECT

Brainstem metastases portend a dismal prognosis. Surgical resection is not part of routine management and radiation therapy has offered little clinical benefit. Radiosurgery provides a safe and effective treatment for many patients with brain metastasis, but its role in the brainstem has not been evaluated. In this study the authors examine the role of radiosurgery in the treatment of brainstem metastases.

METHODS

The authors reviewed the outcomes after stereotactic radiosurgery in 26 patients with 27 brainstem metastases. Tumor locations included the pons (21 tumors) and midbrain (six tumors): 14 patients had additional tumors in other locations. Twenty patients presented with brainstem signs. The median dose to the tumor margin was 16 Gy (range 12-20 Gy). Twenty-four patients received fractionated whole-brain radiation therapy (WBRT) and 12 underwent additional chemotherapy or immunotherapy. The median follow-up time in these patients was 9.5 months (range 1-43 months). After radiosurgery, the local control rate in brainstem tumors was 95%. In one patient in whom the tumor initially decreased in size, tumor enlargement was seen 7 months later. The median survival time was 11 months after diagnosis and 9 months after radiosurgery. Thirteen patients improved, 10 were stable, and three deteriorated. Eventually, 22 patients died, 18 of progression of their extracranial disease, three of new tumor growth (including one hemorrhage into a new brain metastasis), and one of extracranial disease plus new brain tumor growth.

CONCLUSIONS

Although they have slightly lower than the expected survival rates of patients with nonbrainstem tumors, patients with brainstem metastases may achieve effective palliation after stereotactic radiosurgery and WBRT.

Stereotactic radiosurgery plus whole brain radiotherapy versus radiotherapy alone for patients with multiple brain metastases

PURPOSE

Multiple brain metastases are a common health problem, frequently diagnosed in patients with cancer. The prognosis, even after treatment with whole brain radiation therapy (WBRT), is poor with average expected survivals less than 6 months. Retrospective series of stereotactic radiosurgery have shown local control and survival benefits in case series of patients with solitary brain metastases. We hypothesized that radiosurgery plus WBRT would provide improved local brain tumor control over WBRT alone in patients with two to four brain metastases.

METHODS

Patients with two to four brain metastases (all < or =25 mm diameter and known primary tumor type) were randomized to initial brain tumor management with WBRT alone (30 Gy in 12 fractions) or WBRT plus radiosurgery. Extent of extracranial cancer, tumor diameters on MRI scan, and functional status were recorded before and after initial care.

RESULTS

The study was stopped at an interim evaluation at 60% accrual. Twenty-seven patients were randomized (14 to WBRT alone and 13 to WBRT plus radiosurgery). The groups were well matched to age, sex, tumor type, number of tumors, and extent of extracranial disease. The rate of local failure at 1 year was 100% after WBRT alone but only 8% in patients who had boost radiosurgery. The median time to local failure was 6 months after WBRT alone (95% confidence interval [CI], 3.5-8.5) in comparison to 36 months (95% CI, 15.6-57) after WBRT plus radiosurgery (p = 0.0005). The median time to any brain failure was improved in the radiosurgery group (p = 0.002). Tumor control did not depend on histology (p = 0.85), number of initial brain metastases (p = 0.25), or extent of extracranial disease (p = 0.26). Patients who received WBRT alone lived a median of 7.5 months, while those who received WBRT plus radiosurgery lived 11 months (p = 0.22). Survival did not depend on histology or number of tumors, but was related to extent of extracranial disease (p = 0.02). There was no neurologic or systemic morbidity related to stereotactic radiosurgery.

CONCLUSIONS

Combined WBRT and radiosurgery for patients with two to four brain metastases significantly improves control of brain disease. WBRT alone does not provide lasting and effective care for most patients.

Surgery and radiotherapy compared with gamma knife radiosurgery in the treatment of solitary cerebral metastases of small diameter

OBJECT

The aim of this retrospective study was to compare treatment results of surgery plus whole-brain radiation therapy (WBRT) with gamma knife radiosurgery alone as the primary treatment for solitary cerebral metastases suitable for radiosurgical treatment.

METHODS

Patients who had a single circumscribed tumor that was 3.5 cm or smaller in diameter were included. Treatment results were compared between microsurgery plus WBRT (52 patients, median tumor dose 50 Gy) and radiosurgery alone (56 patients, median prescribed tumor dose 22 Gy). In case of local/distant tumor recurrence in the radiosurgery group, additional radiosurgical treatment was administered in patients with stable systemic disease. Survival time was analyzed using the Kaplan-Meier method, and prognostic factors were obtained from the Cox model. The patient groups did not differ in terms of age, gender, pretreatment Karnofsky Performance Scale (KPS) score, duration of symptoms, tumor location, histological findings, status of the primary tumor, time to metastasis, and cause of death. Patients who suffered from larger lesions underwent surgery (p < 0.01). The 1-year survival rate (median survival) was 53% (68 weeks) in the surgical group and 43% (35 weeks) in the radiosurgical group (p = 0.19). The 1-year local tumor control rates after surgery and radiosurgery were 75% and 83%, respectively (p = 0.49), and the 1-year neurological death rates in these groups were 37% and 39% (p = 0.8). Shorter overall survival time in the radiosurgery group was related to higher systemic death rates. A pretreatment KPS score of less than 70 was a predictor of unfavorable survival. Perioperative morbidity and mortality rates were 7.7% and 1.6% in the resection group, and 8.9% and 1.2% in the radiosurgery group, respectively. Four patients presented with transient radiogenic complications after radiosurgery.

CONCLUSIONS

Radiosurgery alone can result in local tumor control rates as good as those for surgery plus WBRT in selected patients. Radiosurgery should not be routinely combined with radiotherapy.

Cytopathologic evaluation of lung carcinomas presenting as brain metastasis

Brain metastasis is an uncommon initial presentation of lung carcinoma. One arm of this analysis is a retrospective review of 137 cases of surgically diagnosed solitary brain metastasis, which were eventually found to be of lung origin, encountered at Hines VA Hospital during the period 1958 to 1996. The second arm is composed of fine-needle aspiration biopsy specimens of primary lung tumor in 23 patients with an initial clinical diagnosis of brain metastasis and without the benefit of surgery, seen from 1981 through 1996. Our results in both analyses indicate that pulmonary adenocarcinoma is the predominant primary tumor that initially manifests as a brain metastasis, approaching 76% (107 and 17 cases, respectively), followed by small-cell carcinoma at 20% (24 and five cases, respectively) and large-cell undifferentiated carcinoma and squamous-cell carcinoma at 2% each. The predominance of adenocarcinoma as a source of brain metastasis in lung cancer patients probably reflects its rising incidence overall of late. Collateral findings also suggest that surgical resection of a solitary and small brain metastasis as well as of a discrete lung primary, whenever feasible, as the most effective procedure to improve survival and quality of life of patients.

MR imaging response of brain metastases after gamma knife stereotactic radiosurgery

PURPOSE

To characterize the magnetic resonance (MR) imaging response of brain metastases after gamma knife stereotactic radiosurgery and determine whether imaging features and tumor response rates correlate with local tumor control and survival.

MATERIALS AND METHODS

Serial MR examinations were performed in 48 patients (25 men, 23 women; mean age, 58 years) with 78 lesions. Pretreatment and follow-up enhancing lesion volumes and imaging features were assessed. Rates of response to stereotactic radiosurgery were calculated. Prognostic imaging features affecting local control and survival were analyzed.

RESULTS

Local tumor control was achieved in 66 (90%) of 73 metastases at 20 weeks after stereotactic radiosurgery; 61% maintained local control at 2 years. A homogeneous baseline enhancement pattern and initial good response rate (> 50% lesion volume reduction) predicted local control. Five metastases demonstrated a transient volume increase after treatment. The median survival time after stereotactic radiosurgery was 53 weeks and correlated with systemic disease burden and primary tumor type.

CONCLUSION

Baseline homogeneous tumor enhancement and initial good response correlate with local control. Initial lesion growth does not preclude local control and may represent radiation-related change. Recognition of these serial MR imaging findings may guide image interpretation and influence treatment in patients with stereotactic radiosurgery-treated metastases.

Serial evaluation of patients with brain tumors using volume MRI and 3D 1H MRSI

Patients with brain tumors are routinely monitored for tumor progression and response to therapy using magnetic resonance imaging (MRI). Although serial changes in gadolinium enhancing lesions provide valuable information for making treatment decisions, they do not address the fate of non-enhancing lesions and are unable to distinguish treatment induced necrosis from residual or recurrent tumor. The introduction of a non-invasive methodology, which could identify an active tumor more reliably, would have a major impact upon patient care and evaluation of new therapies. There is now compelling evidence that magnetic resonance spectroscopic imaging (MRSI) can provide such information as an add-on to a conventional MRI examination. We discuss data acquisition and analysis procedures which are required to perform such serial MRI-MRSI examinations and compare their results with data from histology, contrast enhanced MRI, MR cerebral blood volume imaging and FDG-PET. Applications to the serial assessment of response to therapy are illustrated by considering populations of patients being treated with brachytherapy and gamma knife radiosurgery.

Prognostic factor analysis for multiple brain metastases after gamma knife radiosurgery: results in 97 patients

Stereotactic radiosurgery (SR) is being used with increasing frequency in the treatment of brain metastases. This study provides data from a clinical experience with radiosurgery in the treatment of cases with multiple metastases and identifies parameters that may be useful in the proper selection and therapy of these patients. From January 1993 to April 1997, 97 patients (43 women and 54 men; median age 58 years) suffering from multiple brain metastases (median 3; range 2-4) in MRI scans, received SR with the Gamma Knife. The median dose at the tumor margin was 20 Gy (range 17-30 Gy). Median tumor volume was 3900 cmm (range 100-10,000). Different forms of hemiparesis, focal and generalized seizures, cognitive deficit, headache, dizziness and ataxia had been the predominant neurological symptoms. Major histologies included lung carcinoma (44%), breast cancer (21%), renal cell carcinoma (10%), colorectal cancer (8%), and melanoma (7%). The median survival time was 6 months after SR. The actual one-year survival rate was 26%. In univariate and multivariate analysis, a higher Karnofsky performance rating and absence of extracranial metastases had a significantly positive effect on survival. Local tumor control was achieved in 94% of the patients. Complications included the onset of peritumoral edema (n = 5) and necrosis (n = 1). SR induces a significant tumor remission accompanied by neurological improvement and, therefore, provides the opportunity for prolonged high quality survival. We conclude that radiosurgical treatment of multiple brain metastases leads to an equivalent rate of survival when compared to the historic experience of patients treated with whole brain radiotherapy. Patients presenting initially with a higher Karnofsky performance rating and without extracranial metastases had a median survival time of nine months. Each such case should therefore be evaluated based on these factors to determine an optimal treatment regimen.

Identification of prognostic factors in patients with brain metastases: a review of 1292 patients

PURPOSE

Prognostic factors in 1292 patients with brain metastases, treated in a single institution were identified in order to determine subgroups of patients suitable for selection in future trials.

MATERIALS AND METHODS

From January 1981 through December 1990, 1292 patients with CT-diagnosed brain metastases were referred to the Department of Radiation Oncology, Daniel den Hoed Cancer Center, Rotterdam. The majority of patients were treated with whole brain radiotherapy (84%), the remainder were treated with steroids only or surgery and radiotherapy. Information on potential prognostic factors (age, sex, performance status, number and distribution of brain metastases, site of primary tumor, histology, interval between primary tumor and brain metastases, systemic tumor activity, serum lactate dehydrogenase, response to steroid treatment, and treatment modality) was collected. Univariate and multivariate analyses were performed to determine significant prognostic factors. Results were compared with literature findings using a review of prognostic factors in 18 published reports.

RESULTS

Overall median survival was 3.4 months, with 6-month, 1-year, and 2-year survival percentages of 36%, 12%, and 4% respectively. Survival was statistically significantly different between treatment modalities, with median survival of 1.3 months in patients treated with steroids only, 3.6 months in patients treated with radiotherapy, and 8.9 months in patients treated with neurosurgery followed by radiotherapy (p < 0.0001). Multivariate analysis confirmed literature findings of the major prognostic value of treatment modality on survival of patients with brain metastases. Performance status, response to steroid treatment, systemic tumor activity, and serum lactate dehydrogenase were independent prognostic factors with the strongest impact on survival, second only to treatment modality. Site of primary tumor, age, and number of brain metastases were also identified as prognostic factors in our material, although with lesser importance. In patients with lung primaries, sex was found to have significant impact on survival. In patients with breast primaries, interval between primary tumor and development of brain metastases appeared to be a statistically significant prognostic factor. Histology in patients with lung primaries and distribution of brain metastases were not found to be statistically significant in multivariate analysis.

CONCLUSIONS

In this large database, the value of established prognostic factors was confirmed and, furthermore, some less well-recognized parameters such as response to steroid treatment, serum lactate dehydrogenase, age, sex in lung primaries, and site of primary tumor were established. From the three strongest prognostic factors--performance status, response to steroids, and evidence of systemic disease--simple identification of favorable and unfavorable subgroups of patients with brain metastases can be constructed.

Radiosurgery for brain metastases: is whole brain radiotherapy necessary?

PURPOSE

Because whole brain radiotherapy (WBRT) may cause dementia in long-term survivors, selected patients with brain metastases may benefit from initial treatment with radiosurgery (RS) alone reserving WBRT for salvage as needed. We reviewed results of RS +/- WBRT in patients with newly diagnosed brain metastasis to provide background for a prospective trial.

METHODS AND MATERIALS

Patients with single or multiple brain metastases managed initially with RS alone vs. RS + WBRT (62 vs. 43 patients) from 1991 through February 1997 were retrospectively reviewed. The use of upfront WBRT depended on physician preference and referral patterns. Survival, freedom from progression (FFP) endpoints, and brain control allowing for successful salvage therapy were measured from the date of diagnosis of brain metastases. Actuarial curves were estimated using the Kaplan-Meier method. Analyses to adjust for known prognostic factors were performed using the Cox proportional hazards model (CPHM) stratified by primary site.

RESULTS

Survival and local FFP were the same for RS alone vs. RS + WBRT (median survival 11.3 vs. 11.1 months and 1-year local FFP by patient 71% vs. 79%, respectively). Brain FFP (scoring new metastases and/or local failure) was significantly worse for RS alone vs. RS + WBRT (28% vs. 69% at 1 year; CPHM adjustedp = 0.03 and hazard ratio = 0.476). However, brain control allowing for successful salvage of a first failure was not significantly different for RS alone vs. RS + WBRT (62% vs. 73% at 1 year; CPHM adjusted p = 0.56).

CONCLUSIONS

The omission of WBRT in the initial management of patients treated with RS for up to 4 brain metastases does not appear to compromise survival or intracranial control allowing for salvage therapy as indicated. A randomized trial of RS vs. RS + WBRT is needed to assess survival, quality of life, and cost in good-prognosis patients with newly diagnosed brain metastases.

The Mayo Clinic gamma knife experience: indications and initial results

OBJECTIVE

To review the results and expectations of contemporary stereotactic radiosurgery.

MATERIAL AND METHODS

We conducted a retrospective analysis of 1,033 consecutive patients who underwent gamma knife radiosurgery at Mayo Clinic Rochester between January 1990 and January 1998.

RESULTS

The number of patients undergoing radiosurgery increased from 57 in 1990 to 216 in 1997. Of 97 patients with arteriovenous malformations who underwent follow-up angiography 2 years or more after a single radiosurgical procedure, 72 (74%) had complete obliteration of the vascular malformation. Of 209 patients who underwent radiosurgery for benign tumors (schwannomas, meningiomas, or pituitary adenomas) and had radiologic studies after 2 years or more of follow-up, tumor growth control was noted in 200 (96%). Tumor growth was also controlled in 90% of brain metastatic lesions at a median of 7 months after radiosurgery. Of 20 patients with trigeminal neuralgia and follow-up for more than 2 months, 14 (70%) were free of pain after radiosurgery.

CONCLUSION

Radiosurgery is a safe and effective management strategy for a wide variety of intracranial disorders. Use of radiosurgical treatment should continue to increase as more data become available on the long-term results of this procedure.

Fractionated stereotactic radiotherapy of small intracranial malignancies

PURPOSE

To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) in patients with small intracranial malignancies.

METHODS AND MATERIALS

From July 1991 to March 1997, 80 patients with a total of 121 brain or skull-base tumors were treated with FSRT alone, and were followed for periods ranging from 3 to 62 months (median 9.8). The majority of patients received 42 Gy in 7 fractions over 2.3 weeks, but in July 1993, protocols using smaller fraction doses were introduced for patients whose radiation-field diameters were larger than 3 cm or whose tumors were close to critical normal tissues.

RESULTS

For 64 patients with metastatic brain tumors the overall median survival was 8.3 months and 1-year actuarial survival rate was 33%. Significant prognostic factors were: the presence of extracranial tumors, pre-treatment performance status, and the lung as a primary site. Patients without extracranial tumors prior to FSRT had a median survival of 21.2 months. For seven patients with high-grade glioma, 1-year actuarial local control rate was 75%, with a median survival of 10.3 months. For patients with skull-base tumors the local control was achieved in 6 of 6 patients (100%), with a median survival of 30.7 months. No one suffered from acute complications, but three patients, two of whom had undergone FSRT as the third course of radiotherapy, developed late radiation injuries.

CONCLUSION

Overall high local control and low morbidity rates suggest that FSRT is an effective and safe modality, even for those with a history of prior irradiation. However, patients with risk factors should be treated with smaller fraction doses.

Patient selection criteria for the treatment of brain metastases with stereotactic radiosurgery

In this study we evaluate prognostic factors that predict local-regional control and survival following stereotactic radiosurgery (SRS) in patients with brain metastasis and establish guidelines for patient selection. Our evaluation is based on 73 patients with brain metastasis treated with SRS at the University of Minnesota between March 1991 and November 1995. The ability of stereotactic radiosurgery to improve local control in patients with brain metastases is confirmed in our study in which only 6 of 62 patients failed locally after SRS, with an actuarial local progression-free survival of 80% at 2 years. Variables that predicted worse prognosis were larger tumor size (p = 0.05) for local progression-free survival and multiplicity of metastasis (p = 0.03) and infratentorial location of metastases (p = 0.006) for regional progression-free survival. Absence of extracranial disease, KPS > or = 70, and single intracranial metastasis were significant predictors of longer survival. Patients who fulfill all three criteria will survive longer after SRS (MS = 17.7 months) and will most likely benefit from the increase local control in the brain achieved by SRS. Survival in patients who do not meet any of these criteria is very poor (MS = 1.5 months), and these patients are less likely to benefit from this treatment. Careful selection of patients for SRS is warranted.

Stereotactic radiosurgery for cerebral metastatic melanoma: factors affecting local disease control and survival

PURPOSE

The development of a brain metastasis represents an ominous event for patients with malignant melanoma. We evaluated results after stereotactic radiosurgery (SR) for patients with metastastic melanoma to identify patient outcomes and factors for survival.

METHODS

The authors reviewed the management results of 60 consecutive patients with melanoma metastases, with a total of 118 melanoma brain metastases, undergoing SR during a 9-year interval. Of these, 51 also had whole-brain radiation therapy (WBRT). A total of 118 tumors of mean volume of 2.95 ml (range, 0.1-25.5 ml) were treated by SR with a mean margin dose of 16.4 Gy (range, 10 to 20 Gy). Univariate and multivariate analyses were used to determine significant prognostic factors affecting survival in 60 patients.

RESULTS

Median survival was 7 months after SR in all 60 patients and 10 months from brain tumor diagnosis (mean follow-up period, 9.3 months). Lack of active systemic disease and a solitary metastasis were associated with improved survival in multivariate analysis (median, 15 months). The imaging-defined local control rate of evaluable tumors (n = 72) was 90% (disappearance = 11%, shrinkage = 44%, and stable = 35%). Local recurrence developed in 7 patients and remote brain disease developed in 14 patients. WBRT combined with radiosurgery did not improve survival nor local tumor control. New brain metastases developed less often when WBRT was added to SR (23% vs. 44%), but this difference was not significant. Only 4 patients (7%) died from progression of a radiosurgery-managed tumor. No patient developed a delayed radiation-related complication, but 3 patients developed delayed intratumoral hemorrhage at the radiosurgery site, 2 of whom had new symptoms.

CONCLUSIONS

Stereotactic radiosurgery for melanoma brain metastasis is effective and is associated with few complications. The use of radiosurgery alone is an appropriate management strategy for many patients with solitary tumors.

Radiographic findings and morbidity in patients treated with stereotactic radiosurgery

PURPOSE

To determine the prognostic significance of pretreatment edema, lesion size and location on morbidity following stereotactic radiosurgery (SRS).

METHODS AND MATERIALS

Forty-seven evaluable patients with 63 lesions were treated on a 6-MV linear accelerator radiosurgery system at Memorial Sloan Kettering Cancer Center. All patients received a 10-mg intravenous bolus of dexamethasone sodium phosphate (Decadron) prior to SRS. Thirteen patients were treated for asymptomatic lesions while 34 were treated because of neurologic symptoms. The median dose delivered was 1800 cGy and the median prescription isodose curve was 85%. Pretreatment edema was measured on a transaxial T2-weighted MR image acquired within 1 month of the SRS.

RESULTS

Ten patients experienced morbidity as a result of their treatment. The complication rate was measured by neurologic events following SRS and was not significantly influenced by the extent of peritumoral edema. Lesion size was also unrelated to the development of post-treatment symptoms as assessed by the ease of tapering steroids. The only parameter found to influence post-SRS complications was lesion location. Four of six (66%) patients treated to lesions in the motor cortex suffered post-SRS seizure activity, whereas only 6 of 37 (16%) patients treated to lesions elsewhere in the brain parenchyma experienced seizure activity.

CONCLUSION

The presence of pretreatment edema and lesion size are not predictors of post-SRS complication rates or the ability to taper Decadron. Lesion location is predictive of post-SRS seizure activity.

Stereotactic radiosurgery for brain metastasis from renal cell carcinoma

BACKGROUND

The authors evaluated results after stereotactic radiosurgery (SR) for brain metastases from renal cell carcinoma (RCC) and identified factors associated with improved survival and tumor control.

METHODS

The authors reviewed the management results from a total of 52 RCC brain metastases in 35 consecutive patients who underwent stereotactic radiosurgery (SR) during a 9-year interval. Twenty-eight patients also underwent whole brain radiation therapy (WBRT). The mean tumor volume was 2.4 mL (range, 0.1-14.1 mL). The mean dose delivered to the tumor margin was 17 gray (Gy) (range, 13-20 Gy). Univariate and multivariate testing was performed to determine significant prognostic factors.

RESULTS

The median survival was 11 months after SR and 14 months after brain tumor diagnosis. Only 2 patients (8%) died of progression of the irradiated tumor. Age < 55 years, lack of active systemic disease, and use of chemotherapy and/or immunotherapy after SR were significant favorable prognostic factors in multivariate testing. Post-SR imaging was evaluated in 26 patients (39 tumors). The local control rate from the 39 treated tumors imaged was 90% (tumor disappearance, 21%; tumor regression, 44%; and stable disease, 26%). Local recurrence developed in 3 patients (4 lesions) and remote brain disease in 12 patients. No patient developed a new focal neurologic deficit due to SR. Patients were classified into two groups: SR with and SR without WBRT. The addition of WBRT to SR did not improve survival. Distant failure occurred similarly in both groups (46% vs. 50%). WBRT combined with SR may contribute to local control, but did not prevent the development of new remote tumors.

CONCLUSIONS

SR for brain metastasis from RCC results in brain disease control in the majority of patients and was associated with few complications. Early detection of brain metastases and treatment with SR provides extended quality survival.

[Radiosurgery of single brain metastasis without combined total cerebral irradiation. Results of a consecutive series of 12 cases]

PURPOSE

To evaluate the usefulness of radiosurgery without whole brain irradiation for a solitary brain metastasis.

PATIENTS AND METHODS

Between December 1994 and November 1996, 12 patients were treated for a single brain metastasis by radiosurgery alone. Median age was 53, and 10 patients had a Karnofsky performance status above 70. Half the patients had active extracranial disease at the time of radiosurgery. Stereotactic radiosurgery delivered a single dose of 20 Gy (specified at the isocenter with a 70% isodose reference curve). Evaluation of results was performed according to local control, survival, evolution of performance status, as well as evolution of neurologic symptoms.

RESULTS

No patient had immediate toxicity. One month later, ten patients showed improvement in their neurologic impairments, and none had progression of the cerebral lesion according to CT scan evaluation (diminution for seven patients, and stabilization for five). Local control rate was 58%, and median time to failure was 4 months. The overall median survival time was 10 months. Three patients were alive, with good performance status, and six died following cerebral progression.

CONCLUSION

These poor results in terms of local control are in favor of supplementary whole brain irradiation, except for particular cases.

Radiosurgery without whole brain radiotherapy in melanoma brain metastases. Club de Cancérologie Cutanée

To evaluate the effectiveness of radiosurgery without whole brain radiotherapy in the palliative treatment of melanoma brain metastases, we retrospectively assessed the results in 35 patients: 4 with a solitary brain metastasis, 13 with a single brain metastasis and metastases elsewhere and 18 with multiple brain metastases. The local control rate was 98.2% (55/56 metastases) at 3 months. Median survival was 22 months in patients with a solitary brain metastasis, 7.5 months in patients with a single brain metastasis and metastases elsewhere, and 4 months in patients with multiple brain metastases. Complications were unusual and surgery was required in 2 of 35 patients. These results show for the first time that melanoma patients with a unique brain metastasis with or without metastases elsewhere clearly benefit from tumour control easily obtained by radiosurgery. Although the comparison of radiosurgery with surgery and/or whole brain radiotherapy cannot be adequately addressed, radiosurgery alone seems to provide similar results with lower morbidity and impact on quality of life.

[Importance of radiotherapy in stereotactic conditions (radiosurgery) in brain metastasis: experience and results of the Hôpital Pitié-Salpêtrière Group]

PURPOSE

Retrospective analysis of the influence of clinical and technical factors on local control and survival after radiosurgery for brain metastasis.

PATIENTS AND METHODS

From January 1994 to December 1996, 42 patients presenting with 71 metastases underwent radiosurgery for brain metastasis. The median age was 56 years and the median Karnofsky index 80. Primary sites included: lung (20 patients), kidney (seven), breast (five), colon (two), melanoma (three), osteosarcoma (one) and it was unknown for three patients. Seventeen patients had extracranial metastasis. Twenty-four patients were treated at recurrence which occurred after whole brain irradiation (12 patients), surgical excision (four) or after both treatments (eight). Thirty-six sessions of radiosurgery have been realized for one metastasis and 13 for two, three or four lesions. The median metastasis diameter was 21 mm and the median volume 1.7 cm3. The median peripheral dose to the lesion was 14 Gy, and the median dose at the isocenter 20 Gy.

RESULTS

Sixty-five metastases were evaluable for response analysis. The overall local control rate was 82% and the 1-year actuarial rate was 72%. In univariate analysis, theoretical radioresistance (P = 0.001), diameter less than 3 cm (P = 0.039) and initial treatment with radiosurgery (P = 0.041) were significantly associated with increased local control. Only the first two factors remained significant in multivariate analysis. No prognostic factor of overall survival was identified. The median survival was 12 months. Six patients had a symptomatic oedema (RTOG grade 2), only one of which requiring a surgical excision.

CONCLUSION

In conclusion, 14 Gy delivered at the periphery of metastasis seems to be a sufficient dose to control most brain metastases, with a minimal toxicity. Better results were obtained for lesions initially treated with radiosurgery, theoretically radioresistant and with a diameter less than 3 cm.

Is it time to reevaluate our approach to the treatment of brain metastases in patients with non-small cell lung cancer?

Brain metastases from non-small cell lung cancer develop in approximately one-third of patients. If not treated, neurological deterioration occurs quickly. Treatment with whole brain irradiation is advisable to palliate symptoms but despite this treatment, survival remains poor at 3-6 months. Recently, aggressive approaches with surgical resection and stereotactic radiosurgery have dramatically improved the control of brain metastases resulting in a meaningful survival advantage for a subset of eligible patients. New evidence also suggests a possible role for chemotherapy in the treatment of brain metastases. With several options now available to treat brain metastases proper patient selection is needed. This article will stratify patients with brain metastases and discuss the treatment modalities for each category.

Patterns of relapse and late toxicity after resection and whole-brain radiotherapy for solitary brain metastases

BACKGROUND

This retrospective analysis was performed in order to evaluate the pattern of relapse and the risk of late toxicity for solitary brain metastases treated with surgery and whole-brain radiotherapy and to correlate the results with those from radiosurgical trials.

PATIENTS AND METHODS

From a total of 66 patients, 52 received 10 x 3 Gy and 10 were treated with 20 x 2 Gy whole-brain radiotherapy after resection of their brain metastases.

RESULTS

The actuarial probability of relapse was 27% and 55% after 1 and 2 year(s), respectively. The local relapse rate (at the original site of resected brain metastases) was rather high for melanoma, non-breast adenocarcinoma, and squamous-cell carcinoma. No local relapse occurred in breast cancer and small-cell carcinoma. Failure elsewhere in the brain seemed to be influenced by extracranial disease activity. Size of brain metastases and total dose showed no correlation with relapse rate. Occurrence of brain relapse was not associated with a reduced survival time, because 10/15 patients who developed a relapse received salvage therapy. Of the patients, 11 had symptoms of late radiation toxicity (the actuarial probability was 42% after 2 years).

CONCLUSIONS

Most results of surgical and radiosurgical studies are comparable to ours. Several randomized trials investigate surgical resection versus radiosurgery, as well as the effects of additional whole-brain radiotherapy in order to define the treatment of choice. Some data support the adjuvant application of 10 x 3 Gy over 2 weeks as a reasonable compromise when local control, toxicity, and treatment time have to be considered.

Radiotherapeutic Management of Brain Metastases from Breast Cancer

We have reviewed the medical records of 28 breast cancer patients with brainmetastases who were treated with radiotherapy at our clinic from 1980 through 1994(4 patients, postoperatively; 24 patients, radiotherapy alone). Radiotherapy was delivered as whole brain irradiation using lateral opposed 10 MV X-rays. Tenpatients received an additional boost to a reduced field. One patient was treated with localized stereotactic irradiation alone. The radiation dose for tumorsranged from 32 Gy to 60 Gy(mean, 49 Gy)in 2 or 3 Gy daily fractionated doses. The brain was the first site of metastatic involvement in only two patients. In the 26 evaluable patients, neurologic functional improvement was achieved in 24 patients(92%)with complete response(CR)in 12 patients(46%)and partial response(PR)in 12 patients(46%). The survival rates from the initial treatment were 39% at 5 years and 16% at 10 years(median survival time, 50 months), and those after treatment of brain metastases were 29% at one year and 18% at 2 years(median survival time, 6 months). Performance status tended to be associated with survival(p=0.10), and the presence of liver metastasis was the most important risk factor concerning survival(p=0.056). Two patients suffered severe chronic complications.One patient developed severe dementia after whole brain irradiation with a total dose of 45 Gy in 3 Gy daily fractionated dose, and another patient developed widespread brain necrosis after combined radiotherapy with intrathecal local infusion of methotrexate. Radiotherapeutic management is useful for breast cancer patients with brain metastasis, and long-term survival may also be possible even if patients have preexisting extracranial metastases, except for hepatic involvement. Radiation-related complications should therefore be avoided in these patients.

Focal, high dose, and fractionated modified stereotactic radiation therapy for lung carcinoma patients: a preliminary experience

BACKGROUND

Stereotactic radiation therapy is highly effective in the treatment of small brain metastases, regardless of the histology. This suggests that small extracranial malignancies may be curable with similar radiation therapy. The authors developed a novel treatment unit for administering such therapy.

METHODS

The unit consisted of a linear accelerator (linac), an X-ray simulator (X-S), computed tomography (CT), and a table. The gantry axes of the three machines were coaxial and could be matched by rotating the table. Patients were instructed to perform shallow respiration with oxygen. The motion of the tumor was monitored with the X-S. When the motion was slight enough, the table was rotated to the CT. To include all geometric movement on the CT images, each scan was made while the patient was performing shallow respiration. After the CT positioning, the table was rotated to the linac, and non-coplanar treatment was given. Beginning in October 1994, 45 patients with 23 primary or 43 metastatic lung carcinomas were treated. Radiation doses at the 80% isodose line were 30-75 gray in 5-15 fractions over 1-3 weeks with or without conventional radiation therapy.

RESULTS

The treatment was performed with no or minimal adverse acute symptoms. The daily treatment time was short. During a median follow-up of 11 months, local progression occurred in 2 of 66 lesions. Interstitial changes in the lung were limited.

CONCLUSIONS

With this unit and procedure, focal radiation therapy similar to stereotactic radiation therapy is possible for extracranial sites. The preliminary experience appeared safe and promising, and further exploration of this approach is warranted.

Clinical study of renal cell carcinoma with brain metastasis

BACKGROUND

The clinical outcome of patients with renal cell carcinoma with brain metastasis was analyzed.

METHODS

Nine patients (median age, 60 years) with primary renal cell carcinoma and distant metastasis, including brain metastasis, were treated. The median time to the development of brain metastasis was 15 months after the initial visit. Patients with poor performance status or progressive disease were treated with interferon or conservative therapy alone. Patients with good performance status and other well-controlled metastatic foci were treated either with radiotherapy, or by tumorectomy of brain metastasis, or both. The median follow-up was 26 months after the initial visit.

RESULTS

The 1-year, cause-specific survival rate was 17%. Of the 5 patients treated with alpha-interferon alone, all died of disease after the treatments, without improvement of performance status, 1 to 4 months after the diagnosis of brain metastasis. Two of 4 patients who underwent radiotherapy were treated with a combination of gamma-knife and tumorectomy of brain metastasis. They remained alive 10 and 22 months after diagnosis of brain metastasis. The 2 patients who underwent the combination treatment of gamma-knife and tumorectomy showed improvement of their performance status after these treatments for brain metastasis.

CONCLUSION

Brain metastasis is an unfavorable prognostic factor in renal cell carcinoma. Although a larger number of patients would be necessary to demonstrate the definitive effects of gamma-knife treatment, our results suggest that the combination of gamma-knife and tumorectomy of brain metastases may be recommended for selected patients with good performance status and other well-controlled metastatic foci.

[Radiosurgery of brain metastasis]

Radiosurgery has recently provided an alternative to conventional therapy for the treatment of brain metastases. This non-invasive technique delivers a single large fraction of ionizing radiation to a well-defined small intracranial target as brain metastases. After a computerized tomography (CT) with stereotactic frame in place for tumor localization, a dosimetric study was performed. The sharp dose gradient of radiation reduces the dose to the surrounding normal structures at a minimal level (> 10%). The prescribed dose at the periphery of the lesion varies from 8 to 27 Gy with a combined whole brain irradiation and from 20 to 35 Gy without any irradiation. Radiosurgery has been reported to be highly efficacious with a local control rate of 86% (not increased size without local recurrence). Brain metastases from melanoma and renal carcinoma are usually resistant to conventional irradiation and are highly sensitive with this technique. The morbidity is very low with a symptomatic edema rate of 5-10% at 2 years, resolved with corticosteroids. A radiation necrosis has been reported in less than 5% of cases. The patients with a good performance status, without any extracranial metastasis and with a solitary brain metastases have presented the best survival rate. New brain metastases have occurred in 20 to 30% of the cases during the follow-up. Eleven to 25% of patients died from their intracranial disease and the others from the extracranial evolution of the cancer. The median survival was still poor, ranging from 8 to 12 months. Radiosurgery is a good choice for surgically inaccessible and recurrent tumors. It represents an alternative to the neurosurgery with or without whole brain irradiation, taking into account different prognostic factors and morbidity rate. The local control and the survival rates without neurologic symptom should be considered the major endpoints of different ongoing randomized studies for evaluating the role of the radiosurgery.

Clinical management of brain metastasis

Brain metastasis is a common complication occurring in about 15-20% of all cancer patients. For the initial management, distinguishing between three types of presentation is essential: de novo brain metastasis, simultaneous presentation of both brain metastasis and the primary tumour (usually lung carcinoma), and the presentation of a patient known to have systemic cancer developing a brain metastasis. For de novo brain metastasis, surgery is required, and detecting the primary tumour is of limited value. For simultaneous presentation, both a craniotomy and a thoracotomy may be indicated and may lead to cure in a number of cases. For a sequential presentation, the outcome is determined by a number of independent prognostic factors: age, performance status, and the extent of metastatic disease. In relatively young patients with a single brain metastasis, good performance status and no progression of systemic disease, treatment by either surgery or radiosurgery in combination with whole brain radiation therapy is indicated. Otherwise, as in multiple brain metastases, radiation therapy only is the main treatment. For symptomatic therapy of brain oedema or increased intracranial pressure, dexamethasone is administered. The standard doses of dexamethasone may vary between 4 and 16 mg/day, depending on the severity of symptoms.