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

Stereotactic radiosurgery for pediatric intracranial arteriovenous malformations: the University of California at San Francisco experience

OBJECT

Stereotactic radiosurgery for arteriovenous malformations (AVMs) is an accepted treatment option, but few reports have been published on the results of this treatment in children. In this study the authors describe a series of pediatric patients with a minimum follow-up duration of 36 months.

METHODS

From 1991 to 1997, 40 children (26 boys and 14 girls) with AVMs were treated with radiosurgery at the University of California at San Francisco (UCSF). Follow-up information was available for 31 children (20 boys and 11 girls) in whom the median age at initial treatment was 11.2 years (range 3.4-17.5 years). The median follow-up duration was 60 months (range 6-99 months). Sixteen percent of the AVMs were Spetzler-Martin Grade II; 68%, Grade III; 10%, Grade IV; and 6%, Grade V. The mean volume of the AVMs was 5.37 cm3 and the median volume was 1.6 cm3. The mean marginal dose of radiation was 16.7 Gy and the median dose was 18 Gy (range 12-19 Gy). Angiography performed in 26 children confirmed obliteration of the AVM nidus in nine patients (35%), partial response in 16 patients (62%), and no response in one patient (4%). In five patients who refused angiography, magnetic resonance (MR) imaging revealed obliteration in two patients and partial response in three patients, bringing the overall obliteration rate associated with initial radiosurgery to 35%. Logistic regression analysis confirmed a significant correlation between marginal dose prescription and response (p = 0.025); in AVMs that received at least 18 Gy there was a 10-fold increase in the obliteration rate (63%) over AVMs that received a lower dose. Lesions smaller than 3 cm3 were associated with a six-fold increased obliteration rate (53%) over lesions larger than 3 cm3 (8%), but AVM volume was not a statistically significant predictor of response (p = 0.09). Twelve patients have since undergone repeated radiosurgery and are currently being followed up with serial MR imaging studies (in five cases, the AVM is now obliterated). During the follow-up period (1918 patient-months) there were eight hemorrhages in five patients, with a cumulative posttreatment hemorrhage rate of 3.2%/patient/year in the 1st year and a rate of 4.3%/patient/year over the first 3 years. There were two permanent neurological complications (6%) and no deaths in this study.

CONCLUSIONS

The lower overall obliteration rate reported in this series is most likely due to the larger mean AVM volumes treated at UCSF as well as conservative dose-volume prescriptions delivered to children. Significantly higher obliteration rates were observed when a marginal radiation dose of at least 18 Gy was delivered. The permanent complication rate is low and should encourage those treating children to use doses similar to those used in adults.

Analysis of repeat stereotactic radiosurgery for progressive primary and metastatic CNS tumors

PURPOSE

To identify and evaluate the pretreatment and patient factors that would predict for complications after repeat radiosurgery.

METHODS AND MATERIALS

The data from 26 patients who underwent re-irradiation with Gamma Knife surgery after a previous procedure in the same or subjacent location were available for evaluation. The range of follow-up was 1-45 months (mean 10). The mean minimal and maximal initial dose and volume for all 26 patients was 16.2 Gy (range 12-22), 31.0 Gy (range 22.2-40.0), and 12.4 cm(3) (range 1.20-70.84), respectively. The mean marginal and maximal repeated radiosurgery dose and volume for all 26 patients was 14.9 Gy (range 12-22.5), 29.7 Gy (range 18.0-45.0) and 12.8 cm(3) (range 1.10-39.20), respectively.

RESULTS

Tumor control was significantly better statistically (p = 0.0129) for benign tumors (6 of 6, 100% actuarial rate at 4 years) compared with malignant tumors (7 of 20, 35% actuarial rate at 3 years, 3 of 4 metastatic tumors and 2 of 10 primary malignant gliomas). The retreatment volume for radiosurgery correlated significantly with the probability of neurologic decline (any cause) (p = 0.0181).

CONCLUSION

Repeat radiosurgery can be performed for recurrent tumors with minimal central nervous system toxicity, especially for benign tumors, with reasonable tumor control.

Stage III non-small cell lung cancer and metachronous brain metastases

OBJECTIVES

This study was undertaken to identify management strategies that maximize survival of patients with stage III non-small cell lung cancer and metachronous brain metastases and to determine whether any apparent improved survival was due to treatment or simply to patient selection.

METHODS

Treatment evaluations of both primary non-small cell lung cancer and brain metastases were performed in 91 patients. Optimal treatment was identified by multivariable analysis. Propensity scoring and multivariable analysis were used to separate treatment benefit from patient selection.

RESULTS

Risk-unadjusted median, 12-, and 24-month survivals were 5.2 months, 22%, and 10%, respectively. Younger age (P =.006), good performance status (P =.003), stage IIIA (P =.001), lung resection (P =.02), no other systemic metastases at time of diagnosis of brain metastases (P =.02), and either metastasectomy (P <.001) or stereotactic radiosurgery (P <.001) predicted best survival. However, metastasectomy or stereotactic radiosurgery was more common after lung resection (P =.02) and in patients with good performance status (P =.006), no other systemic metastases at time of diagnosis of brain metastases (P =.01), and fewer brain metastases (P <.001), suggesting that the patients with the best risk profile were selected for aggressive therapy of both lung primary and brain metastases. Despite this selection, analysis of propensity-matched patients demonstrated the benefit of lung resection and metastasectomy or stereotactic radiosurgery (P <.001).

CONCLUSIONS

Younger patients with resected stage IIIA non-small cell lung cancer who have isolated metachronous brain metastases and good performance status do best when treated with metastasectomy or stereotactic radiosurgery. This survival benefit is a brain treatment effect, not the result of selecting the best patients for aggressive therapy.

Stereotactic single high dose irradiation of lung tumors under respiratory gating

PURPOSE

To investigate the feasibility of a stereotactic single high dose irradiation of lung tumors under respiratory gating and the clinical response.

METHODS AND MATERIALS

Twenty-three malignant lung tumors less than 40mm in diameter were treated by a single fractional irradiation.

RESULTS AND DISCUSSION

Local regrowth was seen in three of ten tumors irradiated less than 30Gy, the minimal dose. Only one regrowth was observed in the tumors treated by 30Gy of with a follow up length of 3-24 months. Apparently 30Gy is able to control the lung tumors with a diameter less than 40mm.

Influence of gamma knife radiosurgery on the quality of life in patients with brain metastases

Quality of life (QOL) is an important issue in the treatment of patients with brain metastases. With median survival times often less than 4 months, less invasive treatment options that maximize QOL parameters are essential. In recent years, stereotactic radiosurgery (SRS) has been commonly used as a noninvasive alternative to surgical resection for such patients. This prospective study was undertaken to evaluate QOL in patients undergoing SRS for brain metastases. Between 1999 and 2000, 20 patients with metastatic disease to the brain were evaluated and treated in our Gamma Knife unit. All patients performed the Spitzer QOL survey (10-point scale) both before stereotactic radiosurgery and at each follow-up visit. Primary sites of disease included lung (n = 10), breast (n = 5), melanoma (n = 2), thyroid (n = 1), uterine (n = 1), and kidney (n = 1). Fifteen (75%) had prior whole brain radiotherapy (median dose: 35 Gy). The median age and Karnofsky Performance Status were 58 years and 80, respectively. The median Spitzer score before SRS was 9 (range: 7-10), and the median follow-up time of the patients in this series was 7 months. The median posttreatment Spitzer score at 1 and 3 months after SRS was 9 (range: 5-10) and 8 (range: 4-10), respectively. Crude intracranial tumor control in this cohort of patients was 90%. Extracranial tumor progression was noted in 8 patients (40%), and in these patients, Spitzer scores tended to decrease in value. In those patients who had no evidence of intracranial or extracranial tumor progression, Spitzer scores remained either unchanged or improved. Gamma knife SRS is an appropriate treatment modality for maintaining QOL parameters in patients with brain metastases. Tumor progression both intracranially and extracranially influences QOL parameters. Confirmation of this finding will require further investigation.

Metastatic melanoma to the brain: prognostic factors after gamma knife radiosurgery

PURPOSE

To identify important prognostic factors predictive of survival and tumor control in patients with metastatic melanoma to the brain who underwent gamma knife radiosurgery.

METHODS AND MATERIALS

A total of 122 consecutive patients with 332 intracranial melanoma metastases underwent gamma knife radiosurgery over a 5-year period. Of these, 39 (32%) also received whole-brain irradiation (WBI). The median tumor volume was 0.8 cm(3) (range: 0.02-30.20 cm(3)), and the median prescribed dose was 20 Gy (range: 14-24 Gy). Median follow-up was 6.8 months. Univariate and multivariate analyses of survival and freedom from progression were performed using the following parameters: status of systemic disease, intracranial tumor volume, number of lesions, tumor location, Karnofsky performance status, gender, age, and WBI.

RESULTS

Overall median survival was 7.0 months from time of radiosurgery and 9.1 months from the onset of brain metastasis. In multivariate analysis, improved survival was noted in patients with total intracranial tumor volume <3 cm(3) (p = 0.003) and inactive systemic disease (p = 0.0065), whereas other parameters studied were of lesser importance (tumor location, p = 0.056, and Karnofsky performance status, p = 0.086), or of no significance (number of lesions, WBI, age, and gender). Freedom from subsequent brain metastasis depended on intracranial tumor volume (p = 0.0018) and status of systemic disease (p = 0.034).

CONCLUSIONS

Stereotactic radiosurgery is an effective treatment modality for patients with intracranial metastatic melanoma. Tumor volume and status of systemic disease are good independent predictors of survival and freedom from tumor progression.

Therapy for stage IIIB and stage IV non-small cell lung cancer

The treatment options for unresectable stage III NSCLC include definitive RT, chemotherapy, combined chemoradiotherapy, or supportive care. Compared with radiation alone or chemotherapy alone, the combination of chemotherapy and standard RT confers a modest survival benefit at the cost of increased toxicity for patients with an excellent performance status. For metastatic disease, combination chemotherapy--in particular, platinum-based regimens--improves symptom control and survival. Newer chemotherapeutic agents with higher response rates and favorable toxicity profiles are improving outcome even for the elderly and debilitated patients and those refractory to first-line chemotherapy. Evolving understanding of the molecular events in tumorigenesis is uncovering a host of promising targets for mechanism-based therapy. Many of these novel target modulators likely will require combination with conventional chemotherapy for optimal results.

Radiosurgery for brain metastases: the Tuebingen experience

PURPOSE

To retrospectively investigate the effectiveness of linear accelerator based radiosurgery (RS) in the treatment of brain metastases (BM).

MATERIAL AND METHODS

Of 55 patients with a total of 72 BM, 41 patients had a single brain metastasis and 14 patients had two or three metastases. Median tumour dose of 15Gy (range 8-20Gy) was prescribed to a median isodose surface of 90% (range 70-100%) encompassing the target volume.

RESULTS

The median survival time (MST) for all 55 patients was 7 months [95% confidence interval (CI), 5-10 months] and 2-year survival is 18%. There was no significant difference between patients who had one brain metastasis and those with either two or three metastases (log rank P=0.7565). Multivariate analysis in patients with a single BM showed that interval between primary diagnosis (PD) to BM, maximum size of metastasis, and histology (renal cell carcinoma and melanoma versus others) were independent prognostic factors influencing survival. Local control was obtained in 66/72 (92%) metastases. Actuarial local control at 24 months was 52%. Only age (<or=50 years vs >50 years) and histology (renal cell versus others) influenced local control in the univariate analysis in patients with a single BM. In multivariate analysis, size, histology (renal cell and melanoma versus others), activity of extracranial metastatic disease, age, interval from PD to BM and location (midline versus other) independently influenced local control, while the dose was not significant for our patient group. Only one patient developed radiographically suspected RS-induced necrosis after previous whole brain RT.

CONCLUSION

RS was effective and little toxic in BM. Identification of prognostic factors must be performed to gain knowledge on patients most likely to benefit from this procedure.

Risk of symptomatic brain tumor recurrence and neurologic deficit after radiosurgery alone in patients with newly diagnosed brain metastases: results and implications

PURPOSE

A single-institution experience using primary stereotactic radiosurgery (SRS) alone in the management of newly diagnosed brain metastases was analyzed to identify the risk of symptomatic brain tumor recurrence (BTR) and neurologic deficit associated with such a treatment strategy.

METHODS AND MATERIALS

Thirty-six patients were treated for newly diagnosed single/multiple brain metastases using SRS alone followed by planned observation. SRS minimum tumor dose ranged from 8 to 25 Gy (median: 20 Gy). Factors evaluated in analysis of treatment outcome included number of metastases, site of metastasis, primary tumor site, histology, extent of intracranial and extracranial disease, and interval to diagnosis of brain metastasis.

RESULTS

Median and 1-year survival for the entire group was 9 months and 36%, respectively. BTR anywhere in the brain occurred in 47% (17/36) of patients. Forty-seven percent of BTR (8/17) recurred at the site of original metastasis; 35% (6/17) recurred at both original [corrected] and distant sites in the brain, and 18% (3/17) recurred at distant only [corrected] brain sites. Seventy-one percent (12/17) of the patients were symptomatic at the time of recurrence, and 59% (10/17) had an associated neurologic deficit. Multivariate analysis found that only the extent of disease was a predictor of BTR. Patients who had disease limited to the brain only had a BTR rate of 80% (8/10) vs. 35% (9/26) who had disease involving the brain, primary site, and/or other extracranial metastatic sites (p = 0.03).

CONCLUSIONS

Use of primary SRS alone in this setting is associated with an increasingly significant risk of BTR with increasing survival time. In addition, the majority of such recurrences are symptomatic and associated with a neurologic deficit, a finding not analyzed in recently reported experiences withholding whole brain radiation therapy as part of the primary treatment of brain metastasis.

The radiation oncologist's perspective on stereotactic radiosurgery

Unfavorable gliomas: The basis for single-fraction stereotactic radiosurgery (SRS) is largely historical in nature and rooted in conventional thinking. This is derived from the original use of SRS in the treatment of arteriovenous malformations (AVMs), where the benefit of single-fraction high-dose radiation is clearly optimal in terms of addressing AVM obliteration kinetics. However, tumor cell kinetics are not the same as AVM obliteration kinetics and therefore may not be optimally addressed by single-fraction SRS. In addition, fractionated (F) SRS, as compared to single-fraction SRS, should allow for sparing of normal tissue damage. The relatively noninvasive nature of SRS allows for the potential of exploiting the use of FSRS and also allows for consideration of delivering FSRS in a split-course fashion. This provides an additional advantage over what can normally be achieved by use of stereotactic brachytherapy, in that sterotactic brachytherapy is likely to be performed only once in the course of a patient's primary treatment. This strategy exploits tumor and/or normal tissue cell kinetics, inclusive of attempting to counteract the initial accelerated tumor growth phase pre-CEBRT(conventional external beam radiation therapy), thereby decreasing the rate of clinical tumor progression during CEBRT. This split-course design should also help to counteract the effect of accelerated tumor repopulation post-CEBRT. Our unique experience with this approach in patients with unfavorable gliomas will be reviewed. Brain metastases: While whole brain radiation therapy (WBRT) remains a standard of care in patients with brain metastases, is potential neurocognitive morbidity remains a poorly understood concern. Despite this, and with an increasing role of surgery and/or SRS in the primary management of patients with brain metastasis, recently reported experiences withholding WBRT as part of primary therapy for brain metastases have not analyzed the potential effects on neurological functional status and/or neurocognition associated with the increased risk of brain tumor recurrence seen with such a strategy. We recently evaluated the risk of symptomatic brain tumor recurrence and associated neurologic deficit in 36 patients treated for newly diagnosed unresected brain metastases treated by Gamma Knife SRS alone followed by planned observation. Among the 17 patients (47%) developing brain tumor recurrence, 71% (12/17) were symptomatic and 59% (10/17) had an associated neurologic deficit. Also of interest, the author (WFR) performed a secondary analysis of a randomized phase III study of accelerated hyperfractionation (AH) versus standard accelerated fractionation (AF) in patients with unresected brain metastases. Control of brain metastases had a significant impact on MMSE. It is only among patients with 'uncontrolled" brain metastases that a drop in MMSE score is seen. Details of these studies, along with others, will be reviewed and implications with regards to the complementary role of WBRT in patients undergoing SRS for brain metastases will be discussed.

Stereotactic radiotherapy for solitary brain metastases

PURPOSE

Surgery is considered to be the treatment of choice for patients with solitary brain metastases. We report a single-centre experience of stereotactic radiotherapy (SRT)/radiosurgery as an alternative to surgery and define prognostic parameters that provide for a more rational selection of patients for appropriate treatment.

PATIENTS AND METHODS

Between 1990 and 1997, 96 patients with 106 brain metastases received SRT to a dose of 20 Gy in two fractions (range 20-30 Gy in 24 fractions) either alone or in combination with whole brain radiotherapy.

RESULTS

After SRT, 51% of patients had improvement in neurological function. The median survival of the 96 patients was 9 months. The Radiation Therapy Oncology Group prognostic grouping for patients with multiple brain metastases (prognostic factors: age, performance status, systemic metastases, status of primary tumour) was applicable to this cohort, with median survivals of 15, 8 and 2 months for favourable, intermediate and poor prognostic groups respectively.

CONCLUSION

SRT is a non-invasive method of treatment of solitary brain metastases and the outcome is comparable with the results obtained after surgical excision. Prognosis is determined by factors defined for patients with multiple brain metastases, with performance status being the most important. SRT/radiosurgery should be reserved for patients with favourable prognostic factors, with a Karnofsky performance status >70, who have a reasonable chance of good quality prolonged survival. In future trials, radiosurgery should be compared in terms of survival, quality of life and health economics to whole brain radiotherapy and surgery.

Diagnosis and management of brain metastases

In the past 15 years, significant advancement has been made in the diagnosis and treatment of brain metastases. The distinction between the management of single and multiple brain metastases is an important one. Although radiotherapy remains a mainstay of treatment, especially in multiple brain metastases, surgical resection and stereotactic radiosurgery also have their place in the management of selected patients. Rarely, interstitial radiation or chemotherapy also may be used to treat brain metastases in the setting of relapse.

Brain metastases

Metastatic tumors to the brain are an increasing cause of morbidity and mortality in patients with systemic cancers. Many new therapies used to treat systemic cancers do not penetrate the central nervous system (CNS) and do not protect patients from the development of brain metastases. Surgery, radiosurgery, and radiation therapy are all used to treat brain metastases. It is in our opinion a mistake to use only one or two of these modalities to the exclusion of other(s). The role of systemic chemotherapy is still limited, due to both the issues of drug delivery caused by the blood brain barrier and to the relative resistance of many of these tumors to chemotherapy. Traditionally, brain metastases have been grouped together regardless of the origin of the tumor and have been treated with a single algorithm. As we encounter more patients for whom treatment of the brain metastases is an important determinant of survival, we must tailor our treatment strategies to individual tumor types. Also, we must recognize differences in each tumor's sensitivity to chemotherapy and radiotherapy and differences in their biology.

Radiosurgery for brain metastases: who may not benefit?

PURPOSE

To select a group of patients with brain metastases for whom stereotactic radiosurgery (SRS) may not be beneficial.

PATIENTS, MATERIALS, AND METHODS

Actuarial survival of 87 patients with brain metastases treated with SRS between July 1993 and May 1999 was retrospectively analyzed under stratification by the Score Index for Stereotactic Radiosurgery for Brain Metastases (SIR). To identify the group of patients most likely to survive less than 6 months after SRS, Cox model survival curves were calculated for all SIR values, and Kaplan-Meier survival curves were calculated for two SIR subsets (0-5 and 6-10) and were compared by log-rank test.

RESULTS

Overall median survival after SRS was 6.88 months. The stratification of patients into two SIR subsets (0-5 and 6-10) sustained statistical significance regarding survival with p = 0.0001. The median survival time for the group of patients with SIR between 0 and 5 was 4.52 months (95% confidence interval of 2.82 to 5.84 months). Survival probability at 6 months for this group of patients with poor prognosis was 35.6%.

CONCLUSION

Patients with brain metastases and SIR of 5 or lower have an expected median survival of less than 6 months after treatment with radiosurgery. Thus, radiosurgery may not be beneficial for this group of patients.

Initial clinical experience with frameless stereotactic radiosurgery: analysis of accuracy and feasibility

PURPOSE

To report on preliminary clinical experience with a novel image-guided frameless stereotactic radiosurgery system.

METHODS AND MATERIALS

Fifteen patients ranging in age from 14 to 81 received radiosurgery using a commercially available frameless stereotactic radiosurgery system. Pathologic diagnoses included metastases (12), recurrent primary intracranial sarcoma (1), recurrent central nervous system (CNS) lymphoma (1), and medulloblastoma with supratentorial seeding (1). Treatment accuracy was assessed from image localization of the stereotactic reference array and reproducibility of biteplate reseating. We chose 0.3 mm vector translation error and 0.3 degree rotation about each axis as the maximum tolerated misalignment before treating each arc.

RESULTS

The biteplates were found on average to reseat with a reproducibility of 0.24 mm. The mean registration error from CT localization was found to be 0.5 mm, which predicts that the average error at isocenter was 0.82 mm. No patient treatment was delivered beyond the maximum tolerated misalignment. The radiosurgery treatment was delivered in approximately 25 min per patient.

CONCLUSION

Our initial clinical experience with stereotactic radiotherapy using the infrared camera guidance system was promising, demonstrating clinical feasibility and accuracy comparable to many frame-based systems.

Computed tomography-guided frameless stereotactic radiotherapy for stage I non-small cell lung cancer: a 5-year experience

PURPOSE

Stereotactic radiotherapy (SRT) is highly effective for brain metastases from non-small-cell lung cancers (NSCLCs). As such, primary lesions of NSCLC may also be treated effectively by similar focal high-dose SRT.

METHODS AND MATERIALS

Between October 1994 and June 1999, 50 patients with pathologically proven T1-2N0 M0 NSCLC were treated by CT-guided frameless SRT. Of these, 21 patients were medically inoperable and the remainder were medically operable but refused surgery. In most patients, SRT was 50-60 Gy in 5-10 fractions for 1-2 weeks. Eighteen patients also received conventional radiotherapy of 40-60 Gy in 20-33 fractions before SRT.

RESULTS

With a median follow-up period of 36 months (range 22-66), 30 patients were alive and disease free, 3 were alive with disease, 6 had died of disease, and 11 had died intercurrently. Local progression was not observed on follow-up CT scans in 47 (94%) of 50 patients. The 3-year overall survival rate was 66% in all 50 patients and 86% in the 29 medically operable patients. The 3-year cause-specific survival rate of all 50 patients was 88%. No definite adverse effects related to SRT were noted, except for 2 patients with a minor bone fracture and 6 patients with temporary pleural pain.

CONCLUSIONS

SRT is a very safe and effective treatment for Stage I NSCLC. Additional studies involving a larger patient population and longer follow-up periods are warranted to assess this new treatment for early-stage lung cancer.

Radiotherapy and radiosurgical management of brain metastases

Out of the various cancer treatment modalities available, radiotherapy is the most commonly used for managing metastatic disease in the brain. Until recent years, this was almost exclusively limited to whole-brain radiotherapy (WBRT). Radiosurgery has emerged as a powerful technique for controlling small to moderate-sized brain metastases (<4 cm in diameter). Tumor control rates with radiosurgery are superior to those with WBRT and appear to equal or surpass those with surgery plus WBRT in most studies. The choice among various radiation management strategies (radiosurgery alone, radiosurgery plus WBRT, or surgery followed by radiotherapy) should be based on the size and location of the brain metastases, the functional and neurologic status of the patient, the type of tumor, the tumor imaging characteristics, and the patient's concerns about the risks and side effects of the proposed treatment.

Radiosurgery for patients with brain metastases: a multi-institutional analysis, stratified by the RTOG recursive partitioning analysis method

PURPOSE

To estimate the potential improvement in survival for patients with brain metastases, stratified by the Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) class and treated with radiosurgery (RS) plus whole brain radiotherapy (WBRT).

METHODS AND MATERIALS

An analysis of the RS databases of 10 institutions identified patients with brain metastates treated with RS and WBRT. Patients were stratified into 1 of 3 RPA classes. Survival was evaluated using Kaplan-Meier estimates and proportional hazard regression analysis. A comparison of survival by class was carried out with the RTOG results in similar patients receiving WBRT alone.

RESULTS

Five hundred two patients were eligible (261 men and 241 women, median age 59 years, range 26-83). The overall median survival was 10.7 months. A higher Karnofsky performance status (p = 0.0001), a controlled primary (median survival = 11.6 vs. 8.8 months, p = 0.0023), absence of extracranial metastases (median survival 13.4 vs. 9.1 months, p = 0.0001), and lower RPA class (median survival 16.1 months for class I vs. 10.3 months for class II vs. 8.7 months for class III, p = 0.000007) predicted for improved survival. Gender, age, primary site, radiosurgery technique, and institution were not prognostic. The addition of RS boosted results in median survival (16.1, 10.3, and 8.7 months for classes I, II, and III, respectively) compared with the median survival (7.1, 4.2, and 2.3 months, p <0.05) observed in the RTOG RPA analysis for patients treated with WBRT alone.

CONCLUSION

In the absence of randomized data, these results suggest that RS may improve survival in patients with BM. The improvement in survival does not appear to be restricted by class for well-selected patients.

Radiosurgery for re-irradiation of brain metastasis: results in 54 patients

PURPOSE

To evaluate in terms of probabilities of local-regional control and survival, as well as of treatment-related toxicity, results of radiosurgery for brain metastasis arising in previously irradiated territory.

PATIENTS AND METHODS

Between January 1994 and March 2000, 54 consecutive patients presenting with 97 metastases relapsing after whole brain radiotherapy (WBRT) were treated with stereotactic radiotherapy. Median interval between the end of WBRT and radiosurgery was 9 months (range 2-70). Median age was 53 years (24-80), and median Karnofski performance status (KPS) 70 (60-100). Forty-seven patients had one radiosurgery, five had two and two had three. Median metastasis diameter and volume were 21 mm (6-59) and 1.2 cc (0.1-95.2), respectively. A Leksell stereotactic head frame (Leksell Model G, Elektra, Instrument, Tucker, GA) was applied under local anesthesia. Irradiation was delivered by a gantry mounted linear accelerator (linacs) (Saturne, General Electric). Median minimal dose delivered to the gross disease was 16.2 Gy (11.8-23), and median maximal dose 21.2 Gy (14- 42).

RESULTS

Median follow-up was 9 months (1-57). Five metastases recurred. One- and 2-year metastasis local control rates were 91.3 and 84% and 1- and 2-year brain control rates were 65 and 57%, respectively. Six patients died of brain metastasis evolution, and three of leptomeningeal carcinomatosis. One- and 2-year overall survival rates were 31 and 28%, respectively. According to univariate analysis, KPS, RPA class, SIR score and interval between WBRT and radiosurgery were prognostic factors of overall survival and brain free-disease survival. According to multivariate analysis, RPA was an independent factor of overall survival and brain free-disease survival, and the interval between WBRT and radiosurgery longer than 14 months was associated with longer brain free-disease survival. Side effects were minimal, with only two cases of headaches and two of grade 2 alopecia.

CONCLUSION

Salvage radiosurgery of metastasis recurring after whole brain irradiation is an effective and accurate treatment which could be proposed to patients with a KPS>70 and a primary tumour controlled or indolent. We recommend that a dose not exceeding 14 Gy should be delivered to an isodose representing 70% of the maximal dose since local control observed rate was similar to that previously published in literature with upper dose and side effects were minimal.

Radiosurgery for the treatment of recurrent central neurocytomas

OBJECTIVE

Central neurocytomas are benign neoplasms with neuronal differentiation typically located in the lateral ventricles of young adults. Although the treatment of choice is complete surgical excision, patients may experience local recurrence. Adjuvant therapy for patients with residual or recurrent tumor has included reoperation, radiotherapy, or chemotherapy. To avoid the side effects of conventional radiotherapy in young patients, we present a series of patients with clear evidence of tumor progression who were treated with gamma knife radiosurgery.

METHODS

Four patients (ages 20-49 yr; mean, 28 yr) who presented with an intraventricular mass on magnetic resonance imaging scans and underwent craniotomy for tumor resection were reviewed retrospectively. Histopathological analysis confirmed central neurocytoma in all cases. Each patient was followed up clinically and radiographically with serial magnetic resonance imaging. When radiographic signs of tumor progression were evident, patients were treated with radiosurgery.

RESULTS

Complete radiographic tumor resection was achieved in all patients. There were no major postoperative complications. Local tumor progression was detected on magnetic resonance imaging scans 9 to 25 months after surgery (median, 17.5 mo). All patients achieved complete response to radiosurgery with reduction in tumor size. There have been no complications from radiosurgery. Follow-up ranged from 12 to 28 months (mean, 16.5 mo) after radiosurgery, and from 24 to 84 months (mean, 54.5 mo) after initial presentation.

CONCLUSION

Radiosurgery with the gamma knife unit provides safe and effective adjuvant therapy after surgical resection of central neurocytomas. Radiosurgery may eliminate the need for reoperation and avoid the possible long-term side effects from conventional radiotherapy in young patients.

Relationship between pattern of enhancement and local control of brain metastases after radiosurgery

PURPOSE

A desired goal in the radiosurgery (RS) of brain metastases is improved local control. Our earlier retrospective review identified pattern of enhancement on day-of-treatment imaging as a prognostic indicator for freedom from progression (FFP) after RS in 219 brain metastases. The current study was performed to corroborate this preliminary finding.

METHODS AND MATERIALS

Records and imaging studies of patients treated with RS from 1991 to 1997 were reviewed. Each metastasis was categorized as homogeneously-, heterogeneously-, or ring-enhancing. Kaplan-Meier FFP was calculated from the date of RS to the first imaging showing tumor progression. Univariate and multivariate analyses were performed using Cox proportional hazard models stratified by primary site and type of RS (alone, as a boost, or for recurrence).

RESULTS

Of 682 lesions in 258 patients, 518 lesions in 193 patients were evaluable. Pattern of enhancement was homogeneous in 59%, heterogeneous in 32%, and ring-like in 8% of lesions. One-year FFP probabilities for homogeneously-, heterogeneously-, and ring-enhancing lesions were 90% (95% confidence interval, 84-93%), 76% (64-84%), and 57% (35-74%), respectively. The p-value for pattern of enhancement from the stratified multivariate analysis was 0.019 adjusting for RS dose and treatment period (1991-1994 vs. 1995-1997). Similar results were achieved adjusting for tumor volume instead of RS dose.

CONCLUSION

Pattern of enhancement is confirmed as a significant prognostic factor for FFP of brain metastases treated with RS, independent of dose and volume. A possible explanation is radioresistance of hypoxic tumor cells associated with necrotic regions, suggesting future investigations with radiosensitizers, hypoxic cell sensitizers, or strategies to improve tumor oxygenation.

Transient enlargement of contrast uptake on MRI after linear accelerator (linac) stereotactic radiosurgery for brain metastases

PURPOSE/OBJECTIVE

With the increasing number of patients successfully treated with stereotactic radiosurgery for brain metastases, decision making after therapy based on follow-up imaging findings becomes more and more important. Magnetic resonance imaging (MRI) is the most sensitive means for follow-up studies. The objective of this study was to investigate the treatment outcome of our radiosurgery program and to describe the response of brain metastases to contrast-enhanced MRI after linear accelerator (linac) stereotactic radiosurgery and identify factors to distinguish among local control and local failure.

METHODS AND MATERIALS

Using serial MRI, we followed the course of 87 brain metastases in 48 consecutive patients treated between September 1996 and November 1997 with linac-based radiosurgery with 15-MV photons. Treatment planning was performed on an MR data cube. For spherical metastases, radiosurgery was delivered using a 9 noncoplanar arc technique with circular-shaped collimators. For irregularly shaped targets, radiosurgery was delivered using a manually driven multi-leaf collimator with a leaf width of 1.5 mm projected to the isocenter. Median radiosurgery dose was 20 Gy prescribed to the 80% isodose. Together with whole brain radiotherapy (20 x 2 Gy, 5/w), a median radiosurgical dose of 15 Gy was delivered. Median follow-up was 8 (range 2--36) months. Factors influencing local control and survival rates were analyzed with respect to MRI response, and Kaplan-Meier curves were calculated.

RESULTS

Actuarial local tumor control was 91% at one and two years. Patient survival at one and two years was 30% and 18%. Median survival was 9 months. During follow-up in 70 (81%) of the 87 treated metastases, the contrast-enhancing volumes on T1W images were stable or disappeared partly or completely. A transient enlargement of contrast-enhancing volumes was observed in 11 (12%) of the 87 lesions treated, while a progressive enlargement due to local treatment failure was observed in 6 (7%) of the 87 treated metastases. Younger age, early contrast onset after radiosurgery, and previous chemotherapy were associated with this transient enlargement of contrast-enhancing lesion volume.

CONCLUSIONS

Linac-based radiosurgery is an effective, noninvasive, and safe treatment option for patients with brain metastases. A marked enlargement of the contrast-enhancing volume on T(1)-weighted MR images after radiosurgery is a sensitive predictor for, but not equivalent with, local failure. In as many as two-thirds of the cases with contrast enlargement in MRI follow-up, the contrast enlargement is transient with no need for further treatment. While some MRI findings are more likely if transient enlargement is present, a clear decision cannot be made based on MRI, and ultimately the clinical status dictates further action.

Palliative radiation therapy for gynaecological malignancies

Patients with advanced, recurrent, or metastatic gynaecological malignancies constitute a heterogenous population with diverse symptomatology. Progressive abdominopelvic disease can result in vaginal or diffuse pelvic bleeding, pain, and visceral or lymphovascular obstruction. Gynaecological cancer can also develop debilitating metastases, in particular to bone, central nervous system, or chest. Radiation therapy is a local-regional treatment modality, that, when applied judiciously, can lead to substantial symptomatic relief and tumour response. Individualized application is necessary, balancing efficacy and patient convenience versus treatment intensity, expected duration of palliation and potential toxicity. Important factors to consider are a patient's performance status, extent and sites of tumour, specific symptoms, and life expectancy. The optimal incorporation of radiotherapy is best achieved in the context of a multidisciplinary approach that addresses all facets of palliative care in patients with incurable gynaecological malignancies, to maximize their quality of life and functional level.

Intracranial metastases in patients with squamous cell carcinoma of the head and neck

BACKGROUND

Intracranial metastases are rarely clinically diagnosed in patients with head and neck squamous cell carcinoma. Only 7 patients with metastases to the cavernous sinus from head and neck squamous cell carcinomas have been reported.

METHODS

A retrospective study revealed 13 patients with intracranial metastases of head and neck squamous cell carcinoma. In a 53-year-old woman a cavernous sinus metastasis of a laryngeal carcinoma was histologically diagnosed by using a CT-guided surgical navigation system and was treated with stereotactic radiotherapy.

RESULTS

The mean survival was 4.3 months. Predictive factors for longer survival were absence of extracranial disease, age younger than 60 years, and treatment with radiotherapy.

CONCLUSIONS

The prognosis for patients with intracranial disease is poor. The current development of computer-assisted stereotactic navigation and stereotactic radiotherapy may facilitate surgical diagnostic exploration and improve treatment, especially in patients without extracranial disease.

Adjuvant treatment of brain metastases

With an incidence of 15/10(5) in the general population, brain metastases constitute a serious, debilitating complication in cancer patients. The majority of those patients suffer from more than one metastasis, but up to 30% to 40% present with a solitary lesion. Whole-brain radiotherapy (WBRT) extends median survival from 1 to 2 months for treatment with steroids only, to 4 to 6 months in most series. However, long-term survival (>1-2 years) is observed in up to 10% of patients with favorable prognostic factors, such as solitary lesions, good Karnofsky performance status, and absence of extracranial disease. For those patients, individually optimized treatment is worthwhile. For good-prognosis patients with controlled extracranial disease, surgery in combination with postoperative WBRT should be considered, especially when fast relief of symptoms is mandated. For surgically inaccessible solitary lesions below a size threshold of approximately 30 ccm, stereotactic radiosurgery (RS), although never compared to surgery in a randomized fashion, seems to yield comparable results and is the treatment of choice for more than one lesion in appropriately selected patients. Nevertheless, a number of questions concerning the optimal treatment regimens for brain metastases remain. These mainly concern the radiation dose, need for a combination of RS and WBRT, relative timing of different treatment modalities, and maximum number of brain metastases that can reasonably be treated with RS when long-term progression-free survival is the goal. However, RS is definitely an excellent option for salvage and palliation in patients with short life expectancy, as it is simultaneously noninvasive and cost-effective, with short hospitalization times.

Fractionated radiosurgery for brain metastases in 43 patients with breast carcinoma

About 15% of metastatic breast carcinoma patients are diagnosed with brain metastases. Historically, the majority are treated with palliative external whole-brain radiation with a median survival of 4 months. We examined stereotactic radiosurgery's effect on treatment outcome in such patients. Four hundred and fifty four consecutive patients with brain metastases were treated with stereotactic radiosurgery at Staten Island University Hospital, NY, between 1991 and 1999. The medical records of 60 women with histologically confirmed breast cancer were retrospectively reviewed. Forty-three patients (71%) received fractionated radiosurgery (4 x 600 cGy) and form the core of this report. Sixty five percentage had been previously unsuccessfully treated by whole-brain radiation or had recurrence after craniotomy. Survival was calculated by the Kaplan-Meier method. The median age at diagnosis of brain metastases was 52 years, with median interval of 49 months following the diagnosis of tumor primary. Median survival from brain diagnosis reached 13.6 months. Overall median survival from radiosurgery treatment was 7.5 months. Fifteen patients with one or two brain lesions survived a median of 11.5 months. For the fractionated cohort of patients 1- and 2-year actuarial survival was 28.2% and 12.8%, respectively. Three patients are alive at 32, 34 and 64 months, respectively. We conclude that fractionated radiosurgery improves survival of patients with brain metastases from breast cancer, especially those with small lesions, good functional status and no other metastatic disease. These patients should be encouraged to consider radiosurgery, possibly before WBRT. Considering our 7.5 months overall survival including patients with multiple metastases, and patients with progressive brain metastases despite extensive standard therapy and often systemic disease, these results suggest that radiosurgery could benefit breast cancer patients with brain metastases and extend life.

Gamma knife radiosurgery for brain metastases: prognostic factors for survival and local control

Object. The authors conducted an analysis of prognostic factors for patient survival and local control of brain metastases after gamma knife radiosurgery.

Methods. In the survival analysis, 53 consecutive patients with 121 lesions treated in the last 2 years were examined. Common primary sites were lung (26 patients), kidney (seven), breast (three), and colon (three). Patient age ranged from 28 to 75 years (median 58 years) and the female/male ratio was 1:0.9. The median tumor volume was 2.1 cm3 (range 0.02–45.5cm3) and the average prescription dose was 15.4 Gy to the 50% isodose. The median follow up was 12 months (range 1–23 months) and the median survival was 46 weeks.

Six-month and 1-year survival rates were 63% and 39%, respectively. Karnofsky Performance Scale score, tumor volume, and presence of extracranial disease were statistically significant prognostic factors (p < 0.05) for survival in multivariate analysis. Number of lesions, patient age, and adjuvant whole-brain radiation therapy were not statistically significant. Ninety-one of 121 lesions with follow-up images were included in the local control analysis. The 1-year actuarial local control rate was 48%. In multivariate analysis smaller volume was associated with better control (p = 0.0043), and, control period of renal cell carcinoma was shorter than that of the other tumor types (p = 0.0070).

Conclusions. Karnofsky Performance Scale score, tumor volume, controlled primary cancer, and absence of extracranial metastases were associated with longer survival in the present study. For local control, tumor volume was a statistically significant factor.

Brain metastases

Brain metastases are an increasingly common complication in patients with systemic cancer. The optimal treatment for each patient depends on careful evaluation of several factors: the location, size, and number of brain metastases; the patient's age, general condition, and neurologic status; and the extent of systemic cancer to name a few. For patients with a single brain metastasis and limited systemic disease, the standard treatment is surgical resection followed by whole brain radiation therapy. In patients with a small, single metastasis, stereotactic radiosurgery is probably comparable to surgery. Patients with several metastases (up to three) and controlled systemic disease can be treated with whole-brain radiation and stereotactic radiosurgery. Patients with multiple metastases (more than three) are generally treated with whole-brain radiation alone. Radiosurgery is effective in treating patients with a limited number of recurrent brain metastases and stable systemic diseases. Surgery may have a role in patients with a large symptomatic recurrent lesion producing mass effect. Reirradiation and chemotherapy may have a limited role in patients with multiple recurrent metastases.

Practice parameters for the management of single brain metastasis

Object

In January 1998 the Guidelines and Outcomes Committee of the American Association of Neurological Surgeons (AANS) issued a charge for the development of evidence-based practice parameters focusing on the treatment of patients with single metastasis to the brain. The charge was imposed in response to the significant controversy surrounding questions relating to the optimal management strategies for patients with single brain metastasis.

Methods

A team consisting of physicians from the AANS, the American Academy of Neurology, and the American Association of Therapeutic Radiation Oncology convened and the literature was reviewed. Methodically drawing from the best of Class I, II, and III levels of available evidence, authors sought to determine how the literature addressed and disposed of the question of the optimal management for an adult with a known history of cancer and a single meta-static brain lesion. Framing the question in this specific manner allowed researchers to focus directly on treatment issues, without having to consider diagnostic issues.

Conclusions

The results of the evidence-based analysis demonstrated that there was insufficient information to establish standards of care. Data from the literature does, however, support a guideline stating that surgical resection accompanied by whole brain radiation therapy is associated with the best survival rate. Additional lower-quality evidence supports an option for management with radiosurgery.

Dose-response relationships for radiotherapy of brain metastases: role of intermediate-dose stereotactic radiosurgery plus whole-brain radiotherapy

The effects of intermediate-dose radiotherapy consisting of whole-brain radiotherapy (WBRT, 10 fractions of 3 Gy) plus stereotactic radiosurgery (SRS) were studied prospectively. Twenty-five adult patients with 31 brain metastases received WBRT plus linear accelerator (LINAC)-based single dose SRS with fixed treatment parameters (10 Gy at the isocenter, target volume enclosed by the 90% isodose). Median age was 63 years, median Karnofsky performance status 80%, and median diameter of brain metastases 2.4 cm. Fifteen patients had non-small-cell lung cancer. Because of some early deaths, only 26 lesions could be evaluated for response. We observed 1 complete and 15 partial remissions. Median time to progression inside or outside the SRS volume was 4.5 months. Actuarial local control of SRS-treated lesions was 61% at 1 year. At that time, only 37% of patients were free from new lesions outside the SRS volume. Median survival and cause-specific survival were 2.3 and 4.5 months, respectively (1-year survival rate 8% and 21%). Ten patients died of progressive brain metastases, 13 from extracranial disease progression (unknown cause of death in 2 cases). Comparable to SRS studies with higher doses, the majority of brain failures occurred outside the SRS volume and more patients died of extracranial progression than of uncontrolled brain metastases. Failure to improve survival can be explained by the high percentage of patients with extracranial metastases (52%). However, the present results appear less favorable than those of previous studies of SRS with 15 Gy to 16 Gy (1-year actuarial local control rates of 66-89%). Therefore, we recommend SRS with 15 Gy to 16 Gy for patients whose favorable prognostic factors justify a boost after WBRT.

Fractionated stereotactic radiotherapy of brain metastases from renal cell carcinoma

PURPOSE

To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for brain metastases from renal cell carcinoma (RCC).

METHODS AND MATERIALS

From May 1983 to September 1998, 35 patients with brain metastases from RCC underwent radiotherapy at the National Cancer Center Hospital, Tokyo; 10 patients treated initially with FSRT (FSRT group); 11 with surgery followed by conventional radiotherapy (S/CR group); and 14 with conventional radiotherapy (CR group). Survival and local control rates were determined for patients who had an ECOG performance status of 0-2.

RESULTS

Overall median survival rate was 18 months, and actuarial 1- and 2-year survival rates were 57.6% and 31.0%, respectively. Median survival rates were 25.6 months for the FSRT group, 18.7 months for the S/CR group, and 4.3 months for the CR group. Significant prognostic factors associated with survival were age less than 60 years and good performance status. In patients treated with FSRT, imaging studies revealed that 21 of 24 tumors (88%) were locally controlled during a median follow-up time of 5.2 months (range 0.5-68). Actuarial 1- and 2-year local control rates were 89.6% and 55.2%, respectively. No patient suffered from acute or late complications during and following FSRT.

CONCLUSIONS

FSRT offers better tumor control and prolonged survival over the S/CR or CR groups, and should be considered as primary treatment for brain metastases from RCC. Patients under 60-years-old and those with a good performance status at the beginning of radiotherapy had a better prognosis.

Gamma knife radiosurgery for simultaneous multiple metastatic brain tumors

Object. The authors assessed the efficacy of gamma knife radiosurgery (GKS) in the treatment of patients with 10 or more simultaneous metastatic brain tumors.

Methods. Gamma knife radiosurgery was performed for the treatment of 10 or more simultaneous metastatic brain tumors in 24 patients. The performance status before and after GKS was expressed using the Karnofsky Performance Scale (KPS). The cumulative survival rate was analyzed using the Kaplan—Meier method. The level of satisfaction with the procedure was assessed by telephone interview.

No patient has died due to brain metastasis—related symptoms, and all patients and/or their families were satisfied with the GKS. In 12 patients who had brain metastasis—related symptoms, five improved, six were unchanged, and one deteriorated, as reflected by the KPS scores. The cumulative survival rate calculated by the Kaplan—Meier method was 70.4%, 49.3%, and 12.3% at 12 weeks, 24 weeks, and 36 weeks, respectively. The median survival time was 11 weeks.

Conclusions. Single-fraction GKS can achieve acceptable tumor control, low morbidity, and good quality of life in the treatment of multiple metastatic brain tumors even in cases with 10 or more simultaneous metastases.

Gamma knife treatment for multiple metastatic brain tumors compared with whole-brain radiation therapy

Object. The purpose of this retrospective study was to compare the effectiveness of gamma knife radiosurgery (GKS) for multiple cerebral metastases with that of whole-brain radiation therapy (WBRT).

Methods. Ninety-six consecutive patients with cerebral metastases from nonsmall cell lung cancer were treated between 1990 and 1999. The entry criteria were the presence of between one and 10 multiple brain lesions at initial diagnosis, no surgically inaccessible tumors with more than a 30-mm diameter, no carcinomatous meningitis, and more than 2 months of life expectancy. The patients were divided into two groups: the GKS group (62 patients) and the WBRT group (34 patients).

In the GKS group, large lesions (> 30 mm) were removed surgically and all other small lesions (≤ 30 mm) were treated by GKS. New distant lesions were treated by repeated GKS without prophylactic WBRT. In the WBRT group, the patients were treated by the traditional combined therapy of WBRT and surgery. In both groups, chemotherapy was administered according to the primary physician's protocol. The two groups did not differ in terms of age, sex, initial Karnofsky Performance Scale (KPS) score, type, lesion number, and size of lesion, systemic control, and chemotherapy.

Neurological survival and qualitative survival of the GKS group were longer than those of the WBRT group. In multivariate analysis, significant poor prognostic factors were systemically uncontrolled patients, WBRT group, and poor initial KPS score.

Conclusions. Gamma knife radiosurgery without prophylactic WBRT could be a primary choice of treatment for patients with as many as 10 cerebral metastases from nonsmall cell cancer.

Solitary brain metastases treated with the Leksell gamma knife: prognostic factors for patients

PURPOSE

To analyze treatment results, complications, prognostic factors and their statistical significance in surviving patients treated with the Leksell gamma knife (LGK) for solitary brain metastases.

MATERIALS AND METHODS

Between 1992-1998, 237 patients were treated with solitary brain metastasis (SBM). The histological subtypes were as follows: 101 patients (42.6%) non small-cell lung cancer, 42 (17.7%) renal cell carcinoma, 36 (15.2%) breast carcinoma, 30 (12.7%) colorectal carcinomas and 28 (11.8%) melanoma.

RESULTS

A complete or partial regression was observed in 193 (81.4%) patients, cessation of growth activity in 32 (13.5%) and local progression in 12 (5.1%). Local recurrence was observed in nine (4.7%) of 193 patients with complete or partial regression. Acute toxicity appeared in 24 (10%) patients (score 3.4), late complications (score 3.4) were observed in 13 patients (5.5%). Out of 237 patients, 182 patients died with a median survival of 6 months and 55 patients are still alive with a median survival 12 months and with a minimal follow up period of 10 months. The significant prognostic factors for longer survival in these series of patients were: Karnofsky performance status (70% or more), the extent of extra-cerebral disease (no extra-cerebral disease), pretreatment neurological symptoms neurological functional class (NFC 1), histology (renal cell and breast carcinomas) and the dose to the planning target volume (20 Gy and higher).

CONCLUSIONS

Radiosurgery provides an effective local control for 90% of treated patients with low morbidity. Several significant prognostic factors were detected for patients' survival. These factors can help to predict better patients' survival after the LGK treatment.

Brain metastases in patients with no known primary tumor

BACKGROUND

The care of patients with a brain metastasis from unknown primary site is controversial. The authors reviewed the results of stereotactic radiosurgery in this group of patients to better define clinical expectations.

METHODS

During an 11-year interval, radiosurgery was performed in 421 patients with brain metastases at the University of Pittsburgh. Fifteen patients had solitary or multiple (< or = 5) brain metastases without a detectable primary site at the time of initial presentation. In five patients, a histologic diagnosis of cancer was obtained from extracranial metastatic sites. In 10 patients, a diagnosis was obtained from the brain. A total of 31 tumors with a mean volume of 4.3 mL (range, 0. 05-18.6 mL) underwent radiosurgery with a mean marginal dose of 16.2 Gray (Gy) (range, 12-20 Gy). Fourteen patients (93.3%) also received whole brain fractionated radiation therapy.

RESULTS

The median survival was 15 months after radiosurgery (range, 1-48 months) and 27 months after their initial diagnosis of cancer. In 4 patients (26. 7%), the primary tumor was discovered later (lung in 3 patients and liver in 1). Three of these four patients died due to progression of their primary tumor. Of the remaining 11 patients, 4 died of progression of extracranial metastases, 2 died of other systemic diseases, and 3 patients died because of progression of brain metastasis. Three patients (20%) were still living between 21-48 months after radiosurgery. The presence of active systemic disease and brain stem location both were associated with a poor outcome (P = 0.004 and 0.04). The actuarial imaging-defined local tumor control rate was 91.3 +/- 5.9% at 4 years.

CONCLUSIONS

Radiosurgery was an effective strategy for patients with brain metastases from an unknown primary site. Disease progression outside of the brain was the usual cause for patient death.

Megavoltage CT-assisted stereotactic radiosurgery for thoracic tumors: original research in the treatment of thoracic neoplasms

PURPOSE

The aim of the study was to evaluate the efficacy of stereotactic radiosurgery (SRS) for thoracic tumors with megavoltage computed tomography (MVCT) from the point of view of symptom palliation as well as local control.

METHODS AND MATERIALS

MVCT-assisted positioning verification and real-time monitoring for a multileaf collimator (MLC) were used to enhance the accuracy of the thoracic SRS. Twenty-two thoracic tumors in 15 patients underwent the present treatment. All but 1 tumor were metastases from various primary malignancies. Eleven patients were symptomatic. The treatment site was the chest wall/pleura in 10 tumors, and the lung in 12 tumors. The median volume of the clinical target was 4.5 cc and the median peripheral dose was 20 Gy, for the lung tumors. For the chest wall/pleura tumors, the median volume of the clinical target was 40 cc and the median peripheral dose was 20 Gy. Conventional fractionated conformal radiation therapy (CRT) followed SRS in 10 tumors.

RESULTS

Of 21 tumors eligible for evaluation, there were 13 with complete responses, 6 with partial responses, and 2 without response. Duration of local control ranged from 0.6 to 82 months with a median of 8 months, with only one local recurrence seen. Immediate palliation was obtained in most symptomatic patients. Interstitial changes in the lung were limited. Autopsy performed for a patient revealed remarkable histologic effects with minimal injuries to the lung.

CONCLUSION

The geometric accuracy of MVCT-assisted SRS appeared to enhance the clinical efficacy and safety of treatment to thoracic malignancies.

Stereotactic radiosurgery in patients with multiple brain metastases

Object

Patients with multiple brain metastases are often treated primarily with fractionated whole-brain radiation therapy (WBRT). In previous reports the authors have shown that patients with four or fewer brain metastases can benefit from stereotactic radiosurgery in addition to fractionated WBRT. In this paper the authors review their experience using linear accelerator stereotactic radiosurgery to treat patients with multiple brain metastases.

Methods

Fifty-three patients with 149 brain metastases underwent stereotactic radiosurgery. The mean age of patients was 53.1 years (range 20–78 years). There were 23 men and 30 women. The primary tumor location was lung (27 patients), melanoma (10), breast (six), ovary (six), and other (four). All patients harbored at least two metastatic tumors treated with radiosurgery; 27 patients (51%) harbored two lesions, 17 (32%) three lesions, eight (15%) four lesions, and one patient (2%) harbored five lesions. The mean radiation dose administered was 19.6 Gy (range 14–30 Gy), and the mean secondary collimator size was 15.7 mm (range 7.5–40 mm). One hundred thirty-two (89%) of the 149 treated tumors were available for review on magnetic resonance (MR) imaging at 3 months posttreatment. Fifty-two percent were smaller in size, 31% were stable, 9% had increased in size, and 8% had disappeared. New metastatic tumors appeared in 12 (23%) of the 53 patients on MR imaging within 6 months posttreatment. Radiation-induced necrosis occurred at the site of eight (5.4%) of the 149 tumors at 6 months. Seven tumors (4.7%) subsequently required surgical resection for either tumor progression (four cases) or worsening edema from radiation-induced necrosis (three cases). Median actuarial survival was 9.6 months.

Conclusions

Stereotactic radiosurgery can be used to treat patients with up to four brain metastases with a 91% rate of either decrease or stabilization in tumor size and a low rate of radiation-induced necrosis. In the authors' study only a small number of patients subsequently required surgical resection of a treated lesion.

Current treatment of patients with multiple brain metastases

The management of patients with multiple brain metastases remains a difficult challenge for neurosurgeons. This patient population has a poor prognosis when compared with those harboring a solitary brain metastasis, and historically treatment has generally consisted of administering whole-brain radiotherapy once the diagnosis of multiple brain metastases is made. Resection can be useful in a subset of patients with multiple metastases in whom one or two of the lesions are symptomatic, as this may provide rapid reduction of mass effect and edema. Furthermore, the authors of recent studies have shown that stereotactic radiosurgery can be used in certain patients with multiple brain metastases as part of the treatment regimen. In this review the authors outline the treatment options and indications as well as a management strategy for the treatment of patients with multiple brain metastases.

Stereotactic radiosurgery in the treatment of metastatic disease to the brain

OBJECTIVE

In recent years, stereotactic radiosurgery has been growing in popularity as a treatment modality for metastatic disease to the brain. The technique has advantages of reduced cost and low morbidity compared with open surgical treatment. Furthermore, it avoids the potential cognitive side effects of fractionated whole-brain radiotherapy. We undertook this study to determine the usefulness of adjuvant radiation therapy and to determine prognostic factors in patients treated with stereotactic radiosurgery.

METHODS

We reviewed our series of patients with metastatic tumors treated using gamma knife stereotactic radiosurgery from August 1994 to February 1999. Nonparametric methods were used to compare treatment subgroups by demographic features including age, Karnofsky Performance Scale score, diagnosis, and systemic disease status. Univariate and multivariate analyses of survival and freedom from progression were performed using Kaplan-Meier and Cox proportional hazards regression techniques.

RESULTS

This study included 190 patients harboring 431 lesions who were treated in 263 treatment sessions. The median follow-up after radiosurgery was 36 weeks for all patients. The median actuarial survival from the time of radiosurgery in all patients was 34 weeks. When patients were stratified according to tumor histology, those without melanoma had a median survival of 39 weeks, and those with melanoma had a median survival of 28 weeks. The cause of death could be determined in 122 (92%) of the patients known to have died during the data capture period. For patients harboring melanoma, death was attributable to systemic disease in 31 (47%), to central nervous system-related processes in 29 (44%), and to unknown causes in 6 (9%). For non-melanoma patients, death was attributable to systemic disease in 45 (68%), to central nervous system-related processes in 17 (26%), and to unknown causes in 4 (6%). Significantly improved survival (P = 0.002) was observed in patients with controlled systemic disease. No significant difference in survival could be ascertained for patients presenting with up to four lesions, although patients with a total tumor volume greater than 9 cc had shortened survival. No survival benefit could be demonstrated for whole-brain radiotherapy administered either concomitantly or after radiosurgery.

CONCLUSION

Factors correlated with significantly improved survival included controlled systemic disease and non-melanoma histology. We found no significant survival benefit that could be discerned from adjuvant whole-brain radiotherapy in this patient group.

The role of radiosurgery for multiple brain metastases

Object

The authors evaluated the role of stereotactic radiosurgery (SRS) in patients with multiple brain metastases by analyzing prognostic factors that predict survival.

Methods

Between March 1991 and January 1999, 83 patients with multiple brain metastases underwent SRS in which they used a 6 mV linear accelerator. The median radiation dose of 15 Gy (range 6–50 Gy) was delivered to the 40 to 90% (median 87%) isodose line encompassing the target. Actuarial overall survival was calculated from the date of SRS by using the Kaplan–Meier method. Univariate comparisons of survival between different groups were performed using a log-rank test. All 83 patients were included in the calculation of overall survival. Actuarial overall survival was 22% at 1 year and 13% at 2 years, and a median survival of 5.4 months (range, 0.3–28.8 months) was demonstrated. Variables that predicted survival were Karnofsky Performance Scale (KPS) score, extracranial disease status, and the number of intracranial metastases. Median survival in patients with a KPS score greater than as compared with less than 70 was 9.1 and 2.7 months, respectively (p = 0.002). Median survival when comparing absence and presence of extracranial disease was 9.9 and 4.1 months, respectively (p = 0.02). Median survival in patients harboring two, three, or four or more lesions was 6.6 months, 5.4 months, and 2.7 months, respectively (p = 0.02). In patients with a KPS score greater than or equal to 70 and with three or fewer lesions, median survival was 7 months or longer. In patients with four or more lesions median survival was 7.4 months for those with no extracranial disease and 2.4 months for those with extracranial disease. Other variables tested (sex, histological tumor type, previous resection, location of metastases, treatment modality, and tumor status) did not influence outcome.

Conclusions

The absence of extracranial disease, a KPS score greater than or equal to 70, and fewer number of metastases were shown to be significant predictors of longer survival. Stereotactic radiosurgery appears to be a reasonable therapeutic option in patients with up to three lesions when their KPS score is greater than or equal to 70, regardless of extracranial disease status. In those with four or more metastases, however, SRS should be limited to those with no extracranial disease.

Decision making for patients with multiple brain metastases: radiosurgery, radiotherapy, or resection?

Object

Multiple brain metastases are a common health problem, frequently found in patients with cancer. The prognosis, even after treatment with whole-brain radiation therapy (WBRT), is poor, with an average expected survival time of less than 6 months. Investigators at numerous centers have evaluated the role of stereotactic radiosurgery in retrospective case series of patients harboring solitary or multiple tumors. Tumor resection is used mainly for patients with large tumors that cause acute neurological syndromes. The authors conducted a randomized trial in which they compared radiosurgery combined with WBRT with WBRT alone.

Methods

Twenty-seven patients were randomized (14 to recieve WBRT alone and 13 to receive WBRT combined with radiosurgery). The rate of local failure at 1 year was 100% after WBRT alone but only 8% in patients in whom boost radiosurgery was performed. 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 and radiosurgery (p = 0.0005). The median time to the development of any brain failure was improved in the combined modality group (p = 0.002). Survival was shown to be related to the extent of extracranial disease (p = 0.02).

Conclusions

Combined WBRT and radiosurgery for the treatment of patients with two to four brain metastases significantly improves control of brain disease. Whole-brain radiation therapy alone does not provide lasting and effective care when treating most patients. Surgical resection remains important for patients with large symptomatic tumors and in whom limited extracranial disease has been demonstrated.

Analysis of dose distribution in gamma knife radiosurgery for multiple targets

PURPOSE

The aim of this study is to evaluate the actual effect of irradiation for other targets in dose planning for the treatment of multiple metastases with Gamma Knife.

METHODS AND MATERIALS

We analyzed dose distributions for 51 targets in 10 patients with metastatic brain tumors who underwent radiosurgery with Gamma Knife for the treatment of more than one target in one session. We made dose plans with every attempt to include as many targets as possible and calculate dose distributions separately for each dose matrix. We also calculated the composite dose distribution by including the effect of all shots used. We compared these noncomposite and composite dose distributions.

RESULTS

The differences in the mean target dose between the noncomposite dose distribution and the composite one ranged from 0.0 to 4.5 Gy with a mean of 1.5 Gy and was more than 2 Gy in 12 (24%) targets. The difference tended to be larger when targets were small in volume and/or the number of targets was large.

CONCLUSIONS

The effect of irradiation from the shots for other targets was not negligible in some cases. This difference of dose distribution should be considered in the analysis of clinical outcomes of cases with multiple targets treated in one session.

Application of recursive partitioning analysis and evaluation of the use of whole brain radiation among patients treated with stereotactic radiosurgery for newly diagnosed brain metastases

PURPOSE

To evaluate the usefulness of whole brain radiotherapy (WBRT) and of the Radiation Therapy Oncology Group recursive partitioning analysis (RPA) for brain metastases among patients receiving stereotactic radiosurgery (SRS).

METHODS AND MATERIALS

A retrospective analysis was performed on 135 patients who underwent linear accelerator (Linac) (n = 73) or Gamma Knife (n = 62) SRS for newly diagnosed brain metastases at the Cleveland Clinic Foundation between 8/89 and 12/98. Univariate and multivariate analyses were performed to evaluate the effects of age, primary site, control of the primary, interval to development of brain metastases (disease-free interval [DFI]), number of brain metastases, presence of extracranial metastases, Karnofsky performance status (KPS), treatment of brain metastases, and RPA class on overall survival.

RESULTS

Application of the RPA classification revealed 29 patients fit the criteria for class I, 96 for class II, and 10 for class III. All of the patients underwent SRS. Fifty-seven patients also received WBRT at the time of initial presentation (SRS and immediate WBRT), and 78 patients received WBRT only if CNS relapse occurred (SRS alone). The median survival for all patients was 7.9 months (range: 1.1-90.1), and was 11.2 months for RPA class I compared to 6. 9 months for RPA classes II-III (p = 0.016). Median survival was 10. 5 months following SRS alone compared to 6.4 months following SRS and WBRT (p = 0.07). On univariate analysis, KPS >/= 80% (p = 0.002) and absence of systemic disease (p = 0.013) were also associated with longer survival, whereas control of the primary, DFI, and number of brain metastases did not have an impact. Multivariate analysis revealed only RPA class (p = 0.023) to be an independent predictor for overall survival, whereas treatment group (p = 0.079) was only marginally significant. At 2 years, immediate WBRT improved control at the original site of metastases (80% vs. 52%, p = 0.03) and prevention of new metastatic sites within the brain, 74% vs. 48% (p = 0.06). The 2-year intracranial disease-free survival was 60% following SRS and WBRT compared to only 34% following SRS alone (p = 0.03).

CONCLUSIONS

Despite the inherent biases to select more favorable patients for SRS, the RPA class retains its prognostic value. Omission of WBRT from the initial management was not detrimental in terms of overall survival; however, progressive disease occurred in over 50% of patients treated in this manner. Further studies are required to determine which, if any, patients should be considered for SRS with WBRT held in reserve.

The role of whole brain radiotherapy and stereotactic radiosurgery on brain metastases from renal cell carcinoma

PURPOSE

We reviewed our experience with patients who have undergone stereotactic radiosurgery (SRS) for brain metastases secondary to renal cell carcinoma (RCC). Analysis was performed to determine the survival, local control, distant brain failure (DBF), and then to define which tumors may not require upfront whole-brain radiotherapy (WBRT).

METHODS AND MATERIALS

Twenty-nine patients with 66 tumors underwent SRS from 1991 to 1998. Median follow-up from time of brain metastases diagnoses relative to each tumor was 12.5 months and 6.8 months from the time of SRS. Median SRS dose was 1,800 cGy to the 60% isodose line. Three patients had undergone SRS for previously treated tumors.

RESULTS

Median survival time from diagnosis was 10.0 months. Overall survival was not affected by age, addition of WBRT, number of lesions, tumor volume, or the presence of systemic disease. Of the 23 patients with follow-up neuroimaging, 4 of 47 (9%) tumors recurred. The addition of WBRT did not improve local control. Of the 13 patients who presented with a single lesion, 3 went on to develop DBF (23%), while 6 of the 10 patients who presented with multiple metastases developed DBF (60%).

CONCLUSION

Patients with brain metastases secondary to RCC treated by SRS alone have excellent local control. The decision of whether or not to add WBRT to SRS should depend on whether the patient has a high likelihood of developing DBF. Our study suggests that patients who present with multiple brain lesions may be more likely to benefit from the addition of WBRT because they appear to be more than twice as likely to develop DBF as compared to patients with a single lesion.