Radiosurgery for solitary brain metastases using the cobalt-60 gamma unit: methods and results in 24 patients

Impact of Clinical Examination and Gamma Knife Surgery in Stage IV Breast Cancer With Brain Metastasis

Metastatic breast cancer often presents with significant diagnostic and treatment challenges. This case report highlights the crucial role of thorough clinical examination and history-taking in diagnosing and managing a patient with metastatic breast cancer, mainly focusing on the successful integration of Gamma Knife radiosurgery (GKRS). We present a case of a 68-year-old postmenopausal woman with metastatic breast cancer, initially presenting with a primary tumour in the left breast and later developing a solitary brain metastasis (BM) in the left temporal lobe. Following neoadjuvant chemotherapy and left mastectomy, the patient experienced involuntary movements in the right arm, leading to the discovery of the brain lesion. Critical to this diagnosis was a detailed clinical examination emphasising the importance of vigilant monitoring in cancer management. The patient underwent GKRS, offering a focused and less invasive treatment approach with favourable outcomes. This case underscores the value of clinical vigilance in managing complex breast cancer cases. The integration of GKRS as a targeted treatment modality for BM represents a pivotal aspect of modern oncological care, especially for patients with multiple treatment modalities. This report emphasizes the importance of clinical examination in the early detection of complications such as BM in breast cancer patients. Furthermore, it demonstrates the effectiveness of GKRS in managing such metastases, reinforcing its role as a valuable tool in the multidisciplinary treatment approach for advanced breast cancer.

Comparison of dosimetric parameters and robustness for rotational errors in fractionated stereotactic irradiation using automated noncoplanar volumetric modulated arc therapy for patients with brain metastases: single- versus multi-isocentric technique

To compare the dosimetric parameters of automated noncoplanar volumetric modulated arc therapy plans using single-isocentric (SIC) and multi-isocentric (MIC) techniques for patients with two brain metastases (BMs) in stereotactic irradiation and to evaluate the robustness of rotational errors. The SIC and MIC plans were retrospectively generated (35 Gy/five fractions) for 58 patients. Subsequently, a receiver operating characteristic curve analysis between the tumor surface distance (TSD) and V_25Gy was performed to determine the thresholds for the brain tissue. The SIC and MIC plans were recalculated based on the rotational images to evaluate the dosimetric impact of rotational error. The MIC plans showed better brain tissue sparing for TSD > 6.6 cm. The SIC plans provided a significantly better conformity index for TSD ≤ 6.6 cm, while significantly lower gradient index was obtained (3.22 ± 0.56vs. 3.30 ± 0.57, p < 0.05) in the MIC plans with TSD > 6.6 cm. For organs at risk (OARs) (brainstem, chiasm, lens, optic nerves, and retinas), D_0.1 cc was significantly lower (p < 0.05) in the MIC plans than in the SIC plans. The prescription dose could be delivered (D_99%) to the gross tumor volume (GTV) for patients with TSD ≤ 6.6 cm when the rotational error was < 1°, whereas 31% of the D_99% of GTV fell below the prescription dose with TSD > 6.6 cm. MIC plans can be an optimal approach for reducing doses to OARs and providing robustness against rotational errors in BMs with TSD > 6.6 cm.

Does Stereotactic Radiosurgery Have a Role in the Management of Patients Presenting With 4 or More Brain Metastases?

Stereotactic radiosurgery (SRS) and whole brain radiation therapy (WBRT) are effective treatments for management of brain metastases. Prospective trials comparing the 2 modalities in patients with fewer than 4 brain metastases demonstrate that overall survival (OS) is similar. Intracranial failure is more common after SRS, while WBRT is associated with neurocognitive decline. As technology has advanced, fewer technical obstacles remain for treating patients with 4 or more brain metastases with SRS, but level I data supporting its use are lacking.  Observational prospective studies and retrospective series indicate that in patients with 4 or more brain metastases, performance status, total volume of intracranial disease, histology, and rate of development of new brain metastases predict outcomes more accurately than the number of brain metastases. It may be reasonable to initially offer SRS to some patients with 4 or more brain metastases. Initiating therapy with SRS avoids the acute and late sequelae of WBRT. Multiple phase III trials of SRS vs WBRT, both currently open or under development, are directly comparing quality of life and OS for patients with 4 or more brain metastases to help answer the question of SRS appropriateness for these patients.

Triple-negative breast cancer with brain metastasis in a pregnant woman

A woman aged 35 years was diagnosed with triple-negative breast cancer in October 2012. During the investigation, it was discovered that she was pregnant, the patient decided to have an abortion. She was submitted to a radical modified mastectomy and adjuvant chemotherapy followed by adjuvant breast radiotherapy of the left breast. 2 months after the adjuvant treatment, she began to have headaches and dizziness. The cranial MRI (head MRI) showed brain metastasis. She was then treated with whole brain radiotherapy, stereotactic radiosurgery and concomitant temozolomide which resulted in complete response. 1.5 year later, she was able to get pregnant and gave birth to a baby without complications. The previous imaging reassessment performed in September 2016 shows no evidence of recurrent breast cancer.

Do Recent Advances in MR Technologies Contribute to Better Gamma Knife Radiosurgery Treatment Results for Brain Metastases?

The detection of intracerebral lesions has improved greatly with advancements in MR imaging, especially the greater sensitivity of the 1.5 Tesla unit versus the older 1.0 Tesla unit. We aimed to determine whether improvements in MR imaging have actually improved diagnostic capabilities and treatment outcomes in gamma knife radiosurgery (GKRS) for brain metastases (METs). Ours was a retrospective study of a consecutive series of 1179 patients (441 females, 738 males, mean age: 63 years, range: 19–92 years) with brain METs who underwent GKRS from 1998 to 2004. Our treatment policy was to irradiate all lesions visible on MR images during a single GKRS session. Mean and median tumor numbers were seven and three (range; 1–74). The 1179 patients were divided into two groups: a 1.0 T-group of 660 patients examined using a 1.0 Tesla MR unit before August, 2002, and a 1.5 T-group of 519 examined using a 1.5 Tesla MR unit after September 2002. In the 1.5 T-group, lesion volumes as small as 0.004 cc were detected with a 5 mm slice thickness. The corresponding lesion size was 0.013 cc in the 1.0 T-group. One or more lesions invisible on a 5 mm slice study were additionally detected on a 2 mm slice study in 47.8% of patients in the 1.0 T-group and 25.2% in the 1.5 T-group (p<.0001). The median survival time (MST) in the 1.5 T-group was significantly longer than that in the 1.0 T-group (8.4 vs. 6.3 months, p=.0004). Due to biases in patient numbers between the two groups, we analyzed subgroups with KPS of 80% or better, no neurological deficits, stable primary tumors, lung cancer, tumor numbers of four or less and tumor volumes of 10.0 cc or smaller. In every subgroup analysis, the MSTs of the 1.5-Tesla group were significantly longer than those of the 1.0-Tesla group. The prognosis of a cancer patient is undoubtedly influenced by multiple factors. Nevertheless, we conclude that application of the 1.5 Tesla MR unit has had a favorable impact on diagnosis and GKRS treatment results in patients with brain METs.

Stereotactic radiosurgery (SRS) for brain metastases: a systematic review

In many patients with brain metastases, the primary therapeutic aim is symptom palliation and maintenance of neurologic function, but in a subgroup, long-term survival is possible. Local control in the brain, and absent or controlled extracranial sites of disease are prerequisites for favorable survival. Stereotactic radiosurgery (SRS) is a focal, highly precise treatment option with a long track record. Its clinical development and implementation by several pioneering institutions eventually rendered possible cooperative group randomized trials. A systematic review of those studies and other landmark studies was undertaken. Most clinicians are aware of the potential benefits of SRS such as a short treatment time, a high probability of treated-lesion control and, when adhering to typical dose/volume recommendations, a low normal tissue complication probability. However, SRS as sole first-line treatment carries a risk of failure in non-treated brain regions, which has resulted in controversy around when to add whole-brain radiotherapy (WBRT). SRS might also be prescribed as salvage treatment in patients relapsing despite previous SRS and/or WBRT. An optimal balance between intracranial control and side effects requires continued research efforts.

Brain metastases research 1990-2010: pattern of citation and systematic review of highly cited articles

BACKGROUND

High and continuously increasing research activity related to different aspects of prevention, prediction, diagnosis and treatment of brain metastases has been performed between 1990 and 2010. One of the major databases contains 2695 scientific articles that were published during this time period. Different measures of impact, visibility, and quality of published research are available, each with its own pros and cons. For this overview, article citation rate was chosen.

RESULTS

Among the 10 most cited articles, 7 reported on randomized clinical trials. Nine covered surgical or radiosurgical approaches and the remaining one a widely adopted prognostic score. Overall, 30 randomized clinical trials were published between 1990 and 2010, including those with phase II design and excluding duplicate publications, for example, after longer followup or with focus on secondary endpoints. Twenty of these randomized clinical trials were published before 2008. Their median number of citations was 110, range 13-1013, compared to 5-6 citations for all types of publications. Annual citation rate appeared to gradually increase during the first 2-3 years after publication before reaching high levels.

CONCLUSIONS

A large variety of preclinical and clinical topics achieved high numbers of citations. However, areas such as quality of life, side effects, and end-of-life care were underrepresented. Efforts to increase their visibility might be warranted.

Surgery for distant melanoma metastasis

Traditionally, distant metastatic melanoma has a poor prognosis owing to lack of efficacious, U.S. Food and Drug Administration-approved systemic therapy and the limited use of surgical resection as a therapeutic option. More recently, new biological therapies such as vemurafenib (Zelboraf) and ipilimumab (Yervoy) have shown strong promise and dramatically improved the landscape of stage IV melanoma therapy. Although there are numerous single-institution studies advocating the role for therapeutic surgical intervention, many remain skeptical of nonpalliative surgery for metastatic melanoma. Surgical resection of advanced melanoma has been proven to be effective as long as all disease is removed (R0). Patient selection is paramount. The combination of newer systemic therapies and surgical resection is currently under investigation. Understanding the tumor biology of melanoma and its mechanism of metastatic spread is essential to developing the most efficacious treatment strategy.

Management of single brain metastasis: a practice guideline

QUESTIONS

Should patients with confirmed single brain metastasis undergo surgical resection? Should patients with single brain metastasis undergoing surgical resection receive adjuvant whole-brain radiation therapy (wbrt)? What is the role of stereotactic radiosurgery (srs) in the management of patients with single brain metastasis?

PERSPECTIVES

Approximately 15%-30% of patients with cancer will develop cerebral metastases over the course of their disease. Patients identified as having single brain metastasis generally undergo more aggressive treatment than do those with multiple metastases; however, in the province of Ontario, management of patients with single brain metastasis varies. Given that conflicting evidence has been reported, the Neuro-oncology Disease Site Group (dsg) of the Cancer Care Ontario Program in Evidence-based Care felt that a systematic review of the evidence and a practice guideline were warranted.

OUTCOMES

Outcomes of interest were survival, local control of disease, quality of life, and adverse effects.

METHODOLOGY

The medline, cancerlit, embase, and Cochrane Library databases and abstracts published in the proceedings of the annual meetings of the American Society of Clinical Oncology (1997-2005) and American Society for Therapeutic Radiology and Oncology (1998-2004) were systematically searched for relevant evidence. The review included fully published reports or abstracts of randomized controlled trials (rcts), nonrandomized prospective studies, and retrospective studies. The present systematic review and practice guideline has been reviewed and approved by the Neuro-oncology dsg, which comprises medical and radiation oncologists, surgeons, neurologists, a nurse, and a patient representative. External review by Ontario practitioners was obtained through an electronic survey. Final approval of the guideline report was obtained from the Report Approval Panel and the Neuro-oncology dsg.

RESULTS

QUALITY OF EVIDENCE

The literature search found three rcts that compared surgical resection plus wbrt with wbrt alone. In addition, a Cochrane review, including a meta-analysis of published data from those three rcts, was obtained. One rct compared surgical resection plus wbrt with surgical resection alone. One rct compared wbrt plus srs with wbrt alone. Evidence comparing srs with surgical resection or examining srs with or without wbrt was limited to prospective case series and retrospective studies.

BENEFITS

Two of three rcts reported a significant survival benefit for patients who underwent surgical resection as compared with those who received wbrt alone. Pooled results of the three rcts indicated no significant difference in survival or likelihood of dying from neurologic causes; however, significant heterogeneity was detected between the trials. The rct that compared surgical resection plus wbrt with surgical resection alone reported no significant difference in overall survival or length of functional independence; however, tumour recurrence at the site of the metastasis and anywhere in the brain was less frequent in patients who received wbrt as compared with patients in the observation group. In addition, patients who received wbrt were less likely to die from neurologic causes. Results of the rct that compared wbrt plus srs with wbrt alone indicated a significant improvement in median survival in patients who received srs. No quality evidence compares the efficacy of srs with surgical resection or examines the question of whether patients who receive srs should also receive wbrt.

HARMS

Pooled results of the three rcts that examined surgical resection indicated no significant difference in adverse effects between groups. Postoperative complications included respiratory problems, intracerebral hemorrhage, and infection. One rct reported no significant difference in adverse effects between patients who received wbrt plus srs and those who received wbrt alone.

PRACTICE GUIDELINE

TARGET POPULATION

The recommendations that follow apply to adults with confirmed cancer and a single brain metastasis. This practice guideline does not apply to patients with metastatic lymphoma, small-cell lung cancer, germ-cell tumour, leukemia, or sarcoma.

RECOMMENDATIONS

Surgical excision should be considered for patients with good performance status, minimal or no evidence of extracranial disease, and a surgically accessible single brain metastasis amenable to complete excision. Because treatment in cases of single brain metastasis is considered palliative, invasive local treatments must be individualized. Patients with lesions requiring emergency decompression because of intracranial hypertension were excluded from the rcts, but should be considered candidates for surgery. To reduce the risk of tumour recurrence for patients who have undergone resection of a single brain metastasis, postoperative wbrt should be considered. The optimal dose and fractionation schedule for wbrt is 3000 cGy in 10 fractions or 2000 cGy in 5 fractions. As an alternative to surgical resection, wbrt followed by srs boost should be considered for patients with single brain metastasis. The evidence is insufficient to recommend srs alone as a single-modality therapy.

QUALIFYING STATEMENTS

No high-quality data are available regarding the choice of surgery versus radiosurgery for single brain metastasis. In general, the size and location of the metastasis determine the optimal approach. The standard wbrt regimen for management of patients with single brain metastasis in the United States is 3000 cGy in 10 fractions, and this treatment is usually the standard arm in randomized studies of radiation in patients with brain metastases. Based solely on evidence, the understanding that no reason exists to choose 3000 cGy in 10 fractions over 2000 cGy in 5 fractions is correct; however, fraction size is believed to be important, and therefore 300 cGy daily (3000/10) is believed to be associated with fewer long-term neurocognitive effects than 400 cGy daily (2000/5) in the occasional long-term survivor. For that reason, many radiation oncologists in Ontario prefer 3000 cGy in 10 fractions. No data exist to either support or refute that preference; therefore, finding a resolution to this issue is not currently possible. The Neuro-oncology dsg will update the recommendations as new evidence becomes available.

Gamma knife radiosurgery for metastatic brain tumors from thyroid cancer

OBJECTIVE

We report our experience using gamma knife radiosurgery (GKR) for brain metastasis from thyroid cancer, which is extremely rare.

METHODS

Between 1995 and 2007, 9 patients with 26 metastatic brain tumor(s) from thyroid cancer underwent GKR. The mean patient age was 58 years (range: 10-78). Seven patients had metastases from papillary thyroid cancer, and two from medullary thyroid cancer. Five patients had solitary tumors, and four patients had multiple metastases. Three patients who had multiple metastases also underwent whole brain radiation therapy (WBRT). The mean tumor volume was 2.4 cc (range: 0.03-14.0). A median margin dose of 18.0 Gy (range: 12-20) was delivered to the tumor margin.

RESULTS

Tumor control was obtained in 25 out of 26 tumors (96%). The median progression-free period after GKR was 12 months (range: 4-53). The overall median survival after GKR was 33 months (range: 5-54). There were no procedure-related complications and six patients are still living 5-54 months after GKR.

CONCLUSIONS

Radiosurgery is an effective and minimally invasive strategy for management of brain metastases form thyroid cancer.

New frontiers in radiosurgery for the brain and body

Radiosurgery is defined as the use of highly focused beams of radiation to ablate a pathologic target, thus achieving a surgical objective by noninvasive means. Recent advances have allowed a wide variety of intracranial lesions to be effectively treated with radiosurgery, and radiosurgical treatment has been accepted as a standard part of the neurosurgical armamentarium. The advent of frameless radiosurgery now permits radiosurgical treatment to all parts of the body and is being actively explored by many centers. This article reviews some of the modern tools for radiosurgical treatment and discusses the current clinical practice of radiosurgery.

Radiosurgery for patients with recurrent small cell lung carcinoma metastatic to the brain: outcomes and prognostic factors

Object.Lung carcinoma is the leading cause of death from cancer. More than 50% of those with small cell lung cancer develop a brain metastasis. Corticosteroid agents, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, median survival for patients with small cell lung carcinoma metastasis is approximately 4 to 5 months after cranial irradiation. In this study the authors examine the efficacy of gamma knife surgery for treating recurrent small cell lung carcinoma metastases to the brain following tumor growth in patients who have previously undergone radiation therapy, and they evaluate factors affecting survival.

Methods.A retrospective review of 27 patients (47 recurrent small cell lung cancer brain metastases) undergoing radiosurgery was performed. Clinical and radiographic data obtained during a 14-year treatment period were collected. Multivariate analysis was utilized to determine significant prognostic factors influencing survival.

The overall median survival was 18 months after the diagnosis of brain metastases. In multivariate analysis, factors significantly affecting survival included: 1) tumor volume (p = 0.0042); 2) preoperative Karnofsky Performance Scale score (p = 0.0035); and 3) time between initial lung cancer diagnosis and development of brain metastasis (p = 0.0127). Postradiosurgical imaging of the brain metastases revealed that 62% decreased, 19% remained stable, and 19% eventually increased in size. One patient later underwent a craniotomy and tumor resection for a tumor refractory to radiosurgery and radiation therapy. In three patients new brain metastases were demonstrating on follow-up imaging.

Conclusions.Stereotactic radiosurgery for recurrent small cell lung carcinoma metastases provided effective local tumor control in the majority of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can extend survival.

Radiosurgery for patients with recurrent small cell lung carcinoma metastatic to the brain: outcomes and prognostic factors

Object. Lung carcinoma is the leading cause of death from cancer. More than 50% of those with small cell lung cancer develop a brain metastasis. Corticosteroid agents, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, median survival for patients with small cell lung carcinoma metastasis is approximately 4 to 5 months after cranial irradiation. In this study the authors examine the efficacy of gamma knife surgery for treating recurrent small cell lung carcinoma metastases to the brain following tumor growth in patients who have previously undergone radiation therapy, and they evaluate factors affecting survival.

Methods. A retrospective review of 27 patients (47 recurrent small cell lung cancer brain metastases) undergoing radiosurgery was performed. Clinical and radiographic data obtained during a 14-year treatment period were collected. Multivariate analysis was utilized to determine significant prognostic factors influencing survival.

The overall median survival was 18 months after the diagnosis of brain metastases. In multivariate analysis, factors significantly affecting survival included: 1) tumor volume (p = 0.0042); 2) preoperative Karnofsky Performance Scale score (p = 0.0035); and 3) time between initial lung cancer diagnosis and development of brain metastasis (p = 0.0127). Postradiosurgical imaging of the brain metastases revealed that 62% decreased, 19% remained stable, and 19% eventually increased in size. One patient later underwent a craniotomy and tumor resection for a tumor refractory to radiosurgery and radiation therapy. In three patients new brain metastases were demonstrating on follow-up imaging.

Conclusions. Stereotactic radiosurgery for recurrent small cell lung carcinoma metastases provided effective local tumor control in the majority of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can extend survival.

Linear Accelerator Radiosurgery in the Treatment of Brain Metastases

OBJECTIVE:

To review a 12-year experience treating metastatic brain disease with linear accelerator-based stereotactic radiosurgery (SRS).

METHODS:

We performed a retrospective analysis of all patients treated between 1989 and 2001 with linear accelerator radiosurgery for brain metastases. Patients were followed up both clinically and with imaging studies to document local control, regional control, and survival. Demographic data, dosing parameters, number of lesions, histology, history of whole-brain radiation therapy, and other factors were obtained prospectively. Cox proportional-hazards regression with multivariate and univariate analysis was performed with Stata 8.0 software.

RESULTS:

A total of 383 patients received SRS for brain metastases during the study interval. Median survival was 9 months. Patients with tumor-type melanoma or multiple metastatic lesions had decreased survival. Actuarial 1-year local control was 75%. Differences in regional control rates were not statistically significant between patients treated with SRS and whole-brain radiation therapy versus SRS alone.

CONCLUSION:

Radiosurgery is an effective and safe method for treating selected patients with brain metastases.

The expanding role of neurosurgeons in the management of brain metastases

BACKGROUND

Brain metastases are the most common type of intracranial tumor. Until recently, whole brain fractionated radiation therapy (WBRT) was the mainstay of treatment, thereby confining the role of neurosurgeons to resection of an occasional solitary, accessible, and symptomatic brain metastasis. Median survival after surgery and radiation typically ranged from 5 to 11 months.

METHODS

We analyzed various demographic incidence reports and our series of brain metastasis patients treated with radiosurgery. During a 15-year interval (1987-2002), radiosurgery was performed on 5,032 patients of whom 1,088 (21.6%) had metastatic brain tumors.

RESULTS

In the United States, 266,820 to 533,640 new cases of brain metastases will be diagnosed in the year 2003. Evidence to date demonstrates that radiosurgery provides effective local tumor control for brain metastases. Important prognostic factors affecting patient survival include the absence of active systemic disease, the patient's preoperative performance status, age, and the number of metastases. Survival and local tumor control rates attained with radiosurgery are superior to those of either conventional surgery or WBRT. The morbidity associated with radiosurgery of brain metastasis is very low, and the mortality rate approaches zero.

CONCLUSIONS

Compelling evidence indicates that radiosurgery is an effective neurosurgical management strategy for intracranial brain metastases. Quite often, favorable tumor control and survival can be achieved without WBRT. With radiosurgery as a therapeutic option, neurosurgeons now have a vastly expanded armamentarium for treatment of patients with brain metastases. The large number of patients with brain metastases who require care by a neurosurgeon for optimal treatment has significant implications for both the patterns of neurosurgical training and practice in the United States.

LINAC radiosurgery for brain metastasis of renal cell carcinoma

The purpose of the study was to evaluate the efficacy and toxicity of stereotactic radiotherapy in the treatment of the brain metastasis of renal cell carcinoma. From 1994 to 2001, 28 patients presenting with 65 metastases of renal cell cancer were treated by radiosurgery. Median age was 55 years (35-75), and median Karnofski performance status ranges between 50 and 100. Seven patients had received whole brain radiotherapy (WBRT) before radiosurgery. Twelve patients were treated by radiosurgery for 1 metastasis, 5 patients for two metastases and 6 for three, and 5 for more than three metastases. One procedure was performed in 22 patients and, 2 or 3 procedures for 6 patients. Median metastasis diameter was 19 mm (5-55 mm). Median metastasis volume was 1.28 cc (0.02-28 cc). Irradiation was delivered by linear accelerator. Median minimal dose (on the 70% isodose) was 14.7 Gy (10.8 Gy, 19.5 Gy), median maximal dose (at the isocenter) 20.5 Gy (14.3 Gy, 39.6 Gy). Median follow-up was 14 months (1-33). Two metastases progressed (3%), 2 and 12 months after radiosurgery. Overall, crude local control rate was 97% and 3-, 6- and 12-month local control rates were 98% +/- 2%, 98% +/- 2%, and 93% +/- 5%, respectively. In univariate analysis, no prognostic factor of local control was retrieved. Median brain disease-free survival was 25 months after RS. the 3-, 6- and 12-month distant brain control rates were 91% +/- 4%, 91% +/- 4%, and 70% +/- 12%, respectively. Median survival duration was 11 months. The 3-, 6-, 12- and 24-month overall survival rates were 82% +/- 7%, 67% +/- 9%, 48% +/- 10%, and 33% +/- 10%, respectively. According to univariate analysis, only site of metastasis was overall survival prognostic factor. Radiosurgery for brain metastasis of renal cell carcinoma is an effective and accurate treatment. The use of radiosurgery alone is an appropriate management strategy for many patients with brain metastasis of renal cell carcinoma. Radiosurgery is efficient even after development of new metastasis appearing after WBRT.

Safety of multiple stereotactic radiosurgery treatments for multiple brain lesions

BACKGROUND

Stereotactic radiosurgery (SRS) is a widely used therapy for multiple brain lesions, and studies have clearly established the safety and efficacy of single-dose SRS. However, as patient survival has increased, the recurrence of tumors and the development of metastases to new sites within the brain have made it desirable to repeat treatments over time. The cumulative toxicity of multi-isocenter, multiple treatments has not been well defined. We have retrospectively studied 10 patients who received multiple SRS treatments for multiple brain lesions to assess the cumulative toxicity of these treatments.

METHODS

In a retrospective review of all patients treated with SRS using the X-knife (Radionics, Burlington, MA) at Westchester Medical Center/New York Medical College between December 1995 and December 2000, 10 patients were identified who received at least two treatments to at least 3 isocenters and had a minimum follow-up period of 6 months. Image fusion technique was used to determine cumulative doses to targeted lesions, whole brain and critical brain structures. Toxicities and complications were identified by chart and radiological review.

RESULTS

The average of the maximum doses (cGy) to a point within the whole brain was 2402 (range 1617-3953); to the brainstem, 1059 (range 48-4126); to the right optic nerve, 223 (range 14-1012); to the left optic nerve, 159 (range 17-475); and to the optic chiasm, 219 (range 15-909). There were no focal neurological toxicities, including visual disturbances, cranial nerve palsies, or ataxia in any of the 10 patients. There were also no global toxicities, including cognitive decline or secondary tumors. Only one patient developed seizures that were difficult to control in association with radiation necrosis.

CONCLUSIONS

Multiple SRS treatments at the cumulative doses used in our study are a safe therapy for patients with multiple brain lesions.

Malignant melanoma

In the European Community cutaneous melanoma accounts for 1 and 1.8% of cancers occurring in men and women, respectively. The incidence rate is increasing faster than that of any other tumour. Sun exposure, patient's phenotype, family history, and history of a previous melanoma are the major risk factors. The change over a period of months is the main sign of a skin lesion turned into a melanoma. The ABCDE scheme for early detection of melanoma is commonly accepted. A new staging classification will be published in the next AJCC/UICC Cancer Staging System Manual in 2002. The clinical course of melanoma is determined by its dissemination and depends on thickness, ulceration, localisation, gender and histology of the primary tumour. Tumour stage at diagnosis remains the major prognostic factor. Surgery is the standard treatment option for operable local-regional disease. Sentinel node biopsy represents a promising experimental approach in the clinical detection and early treatment of occult lymph node involvement. For metastatic inoperable patients systemic chemotherapy can be attempted, while radiation therapy has to be considered as palliative treatment. No studies concerning frequency of follow-up are currently available, but common procedures may be performed.

Radiosurgery in patients with renal cell carcinoma metastasis to the brain: long-term outcomes and prognostic factors influencing survival and local tumor control

OBJECT

Renal cell carcinoma is a leading cause of death from cancer and its incidence is increasing. In many patients with renal cell cancer, metastasis to the brain develops at some time during the course of the disease. Corticosteroid therapy, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, the median survival in patients with renal cell carcinoma metastasis is approximately 3 to 6 months. In this study the authors examined the efficacy of gamma knife surgery in treating renal cell carcinoma metastases to the brain and evaluated factors affecting long-term survival.

METHODS

The authors conducted a retrospective review of 69 patients undergoing stereotactic radiosurgery for a total of 146 renal cell cancer metastases. Clinical and radiographic data encompassing a 14-year treatment interval were collected. Multivariate analyses were used to determine significant prognostic factors influencing survival. The overall median length of survival was 15 months (range 1-65 months) from the diagnosis of brain metastasis. After radiosurgery, the median survival was 13 months in patients without and 5 months in those with active extracranial disease. In a multivariate analysis, factors significantly affecting the rate of survival included the following: 1) younger patient age (p = 0.0076); 2) preoperative Karnofsky Performance Scale score (p = 0.0012); 3) time from initial cancer diagnosis to brain metastasis diagnosis (p = 0.0017); 4) treatment dose to the tumor margin (p = 0.0252); 5) maximal treatment dose (p = 0.0127); and 6) treatment isodose (p = 0.0354). Prior tumor resection, chemotherapy, immunotherapy, or whole-brain radiation therapy did not correlate with extended survival. Postradiosurgical imaging of the brain demonstrated that 63% of the metastases had decreased, 33% remained stable, and 4% eventually increased in size. Two patients (2.9%) later underwent a craniotomy and resection for a tumor refractory to radiosurgery or a new symptomatic metastasis. Eighty-three percent of patients died of progression of extracranial disease.

CONCLUSIONS

Stereotactic radiosurgery for treatment of renal cell carcinoma metastases to the brain provides effective local tumor control in approximately 96% of patients and a median length of survival of 15 months. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can offer patients an extended survival.

Surgical treatment of malignant melanoma

The surgical management of melanoma has evolved over the last 100 years. when early concepts of lymphatic permeation of the tumors and metastases led surgeons to perform radical operative procedures. Wide excision of primary melanoma is now performed with 1- to 2-cm radial margins, significantly reducing the need for complex plastic closures, skin grafts. and hospital admissions. Although elective lymph node dissection remains controversial as a therapeutic procedure, the development of SL has improved the staging of the regional lymph nodes and diminished the morbidity of lymph node dissection. The role of SL for routine care of melanoma patients remains unknown. Metastasectomy, which is the surgical resection of distant metastases with tumor-free surgical margins, has not been popular for AJCC stage IV patients with multiple metastases, because surgery is considered a local therapy and therefore of little value for management of disseminated disease. Nevertheless, the many reports of long-term survival after resection of distant melanoma metastases to diverse soft tissue and organ sites clearly indicate that this form of cytoreductive surgery can be extremely successful in carefully selected patients. Unlike chemotherapy, complete surgical metastasectomy can rapidly render a patient disease-free with only a short period of postoperative morbidity. Most patients fully recover from the surgical procedure within 6 weeks, returning to most or all activities. The ability to select patients for surgery is based on the development of more sophisticated imaging techniques, which allow better preoperative differentiation of patients with single versus multiple metastases and improve the surgeon's ability to identify and resect multiple metastatic sites. The overall data suggest that patients whose metastases can be completely resected will experience improved overall survival and occasional long-term cure regardless of the metastatic organ site and number of metastases. We believe that increased understanding of the biology of the primary and metastases, dramatic improvement in the accuracy of staging metastatic disease, and better techniques of surgical resection provide the best chance for long-term palliation or cure of melanoma. Cytoreductive surgery should be considered a form of immunotherapy. The long-term clinical benefit of this therapy depends on the patient's immune response to, the surgical reduction in tumor burden: an immune response that controls subclinical micrometastases should optimize postoperative survival.

Gamma knife radiosurgery for metastatic brain tumors from lung cancer: a comparison between small cell and non—small cell carcinoma

Object. The purpose of this retrospective study was to evaluate the effectiveness of gamma knife radiosurgery (GKS) for the treatment of metastatic brain tumors from lung cancer, with particular reference to small cell lung carcinoma (SCLC) compared with non-SCLC (NSCLC).

Methods. Two hundred forty-five consecutive patients meeting the following five criteria were evaluated in this study: 1) no prior brain tumor treatment; 2) 25 or fewer lesions; 3) a maximum of three tumors with a diameter of 20 mm or larger; 4) no surgically inaccessible tumor 30 mm or greater in diameter; and 5) more than 3 months of life expectancy. According to the same treatment protocol, large tumors (≥ 30 mm) were surgically removed and the other small lesions (< 30 mm) were treated with GKS. New lesions were treated with repeated GKS. Chemotherapy was administered, according to the primary physician's protocol, as aggressively as possible. Progression-free, overall, neurological, qualitative, and new lesion—free survival were calculated with the Kaplan—Meier method and were compared in the SCLC and NSCLC groups by using the log-rank test. The poor prognostic factors for each type of survival were also analyzed with the Cox proportional hazard model.

Conclusions. Tumor control rate at 1 year was 94.5% in the SCLC group and 98% in the NSCLC group. The median survival time was 9.1 months in the SCLC group and 8.6 months in the NSCLC group. The 1-year survival rates in the SCLC group were 86.5% for neurological survival and 68.9% for qualitative survival; those in the NSCLC group were 87.9% for neurological and 78.9% for qualitative survival. The estimated median interval to emergence of a new lesion was 6.9 months in the SCLC group and 9.8 months in the NSCLC group. There was no significant difference between the two groups for any type of survival; this finding was verified by multivariate analysis. The results of this study suggest that GKS appears to be as effective in treating brain metastases from SCLC as for those from NSCLC.

Radiosurgery for non-small cell lung carcinoma metastatic to the brain: long-term outcomes and prognostic factors influencing patient survival time and local tumor control

OBJECT

Lung carcinoma is the leading cause of death from cancer. More than 25% of those patients with lung cancer develop a brain metastasis at some time during the course of their disease. Corticosteroid therapy, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, the median survival for patients with lung carcinoma metastasis is approximately 3 to 6 months. The authors examine the efficacy of gamma knife radiosurgery (GKS) for treating non-small cell lung carcinoma (NSCLC) metastases to the brain and evaluate factors affecting long-term patient survival.

METHODS

A retrospective review of 273 patients who had undergone GKS to treat a total of 627 NSCLC metastases was performed. Clinical and neuroimaging data encompassing a 14-year treatment interval were collected. Univariate and multivariate analyses were performed to determine significant prognostic factors influencing patient survival. The overall median patient survival time was 15 months (range 1-116 months) from the diagnosis of brain metastases. The median survival was 10 months from GKS treatment in those patients with adenocarcinoma and 7 months for those with other histological tumor types. In patients with no active extracranial disease at the time of GKS, the median survival time was 16 months. In multivariate analyses, factors significantly affecting survival included: 1) female sex (p = 0.014); 2) preoperative Karnofsky Performance Scale score (p < 0.0001); 3) adenocarcinoma histological subtype (p = 0.0028); 4) active systemic disease (p = 0.0001); and 5) time from lung cancer diagnosis to the development of brain metastasis (p = 0.0074). Prior tumor resection or whole-brain radiation therapy did not correlate with extended patient survival time. Postradiosurgical imaging of brain metastases revealed that 60% decreased, 24% remained stable, and 16% eventually increased in size. Factors affecting local tumor control included tumor volume (p = 0.042) and treatment isodose (p = 0.015). Fourteen patients (5.1%) later underwent craniotomy and tumor resection for tumor refractory to GKS or a new symptomatic metastasis.

CONCLUSIONS

Gamma knife surgery for NSCLC metastases affords effective local tumor control in approximately 84% of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including GKS can afford patients an extended survival time.

Results of recent therapy for non-small-cell lung cancer with brain metastasis as the initial relapse

The results of radiosurgery for treatment of patients with non-small-cell lung cancer with brain metastasis as the initial relapse were evaluated. Twenty-three patients were included in the study. The dominant pathologic type was adenocarcinoma (56.5%). In the mean interval of 13.7 months (range, 3-52 months) between the lung operation and treatment of brain metastasis, a solitary lesion developed in 9 patients and multiple lesions developed in 14 patients. The modalities used for brain metastasis were gamma-knife radiation therapy (GKS) in nine patients, GKS plus operation in six, GKS plus whole brain radiation therapy (WBR) in two, operation plus WBR in two, operation only in one, WBR only in two, and no treatment in one. The 1- and 3-year survival rates after treatment of brain were 47.3% and 7.4%, respectively. The prognostic impact of stage and number of brain metastases was not clear. Primary tumor size and adjuvant chemotherapy after the lung operation significantly affected survival after the management of brain metastasis. The low invasive radiosurgery is beneficial in terms of improving the quality of life of patients.

Evaluation of prognostic factors and treatment modalities in ovarian cancer patients with brain metastases

OBJECTIVE

The objective of this study is to evaluate the impact of different clinical variables and treatment modalities on survival in patients with brain metastases from ovarian carcinoma.

METHODS

Methods included: (1) retrospective chart review of all patients with ovarian cancer and brain metastases from 1986 to 2000 at Roswell Park Cancer Institute and (2) Medline search was performed to extract data from all published reports with three or more cases of ovarian cancer with brain metastases. Cox regression analysis, Kaplan-Meier test, and log rank test were used to calculate survival and compare the impacts of clinical variables and treatment modalities.

RESULTS

Fifteen patients with brain metastases out of 1042 women with ovarian carcinoma were identified from our institution, an incidence of 1.4%. The median time from initial diagnosis to detection of brain metastases was 22 months. Patients who were not treated after brain metastasis had a median survival of 0.5 month versus 6 months with therapy. In the subgroup of patients treated with a combination of radiation, surgery, and chemotherapy, the median survival was 22 months. Literature analysis combined with our data generated 124 patients. The only clinically significant variable impacting survival was the presence or absence of additional distant recurrence with median survivals of 3 and 8 months, respectively (P = 0.005). Among patients who received treatment, the combination of radiation and surgery with or without chemotherapy appears to be beneficial, with a median survival of 20 months (P < 0.001).

CONCLUSION

Patients with brain metastases from ovarian cancer without any evidence of disease in other sites appear to benefit from aggressive combined treatment with external radiation and surgery with or without chemotherapy with a median survival of 20 months.

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.

Effects of stereotactic radiosurgery on metastatic brain tumors of various histopathologies

Although reports have been published describing clinical results in a large series of patients with metastatic brain tumors treated by stereotactic radiosurgery (SRS), clinical neuropathological correlation has rarely been available. The present paper describes three autopsy cases and one surgical case treated with linear accelerator based radiosurgery. The cases comprised a lung cancer, a rectal cancer, an osteosarcoma, and a malignant melanoma. Histological sections of each tumor were analyzed by light microscopy based on the Ohosi and Shimosato's histopathological classification of the effects of radiation therapy. In three cases (pulmonary squamous cell carcinoma, rectal adenocarcinoma and osteosarcoma), a large area of the tumors consisted of coagulation necrosis and non-viable tumor cells, while coagulation necrosis and non-viable tumor cells comprised a very small part of the malignant melanoma. Histopathological type of the metastatic brain tumor may be one of the factors influencing outcome after SRS.

What is the optimal therapy of brain metastases?

The conclusions of a symposium held in London in October 1999 and devoted to the optimal management of brain metastatic disease were: 1. Prognostic factors are: size and number of metastases (and the presence of mass effect); the status of the systemic cancer outside the central nervous system; performance/neurological status; the age of the patient; and the type of cancer. 2. Surgical management of the single, superficially located brain metastasis with symptomatic mass effect is recommended in good performance status patients. Many would follow this routinely by whole brain radiotherapy. 3. Whole brain radiotherapy is often not followed by durable control of the disease and carries morbidity; better management plans are required. In poor prognosis patients the delivery of radiotherapy may not always be indicated. 4. The current literature demonstrates that stereotactic radiosurgery can enhance the likelihood of sterilizing individual brain metastases compared with whole brain radiotherapy alone. 5. The results of questionnaire showed that the histological diagnosis and latency to onset made little difference to the opinion of neuroscience clinicians, who generally favoured stereotactic radiation therapy over whole brain radiotherapy (with or without a conventionally delivered boost) for all patients with less than four metastases. The opinions of oncologists differed. For bronchial and breast cancer patients, whole brain radiotherapy, with or without a boost, was favoured by the majority, particularly in oat cell cancer. However, with a long latency to 'isolated' brain metastasis, oncologists favoured focal radiation therapy. There was a strong preference amongst oncology experts to reserve stereotactic radiation therapy for apparently isolated brain metastasis; this opinion applied to bronchus and breast cancer, and also to melanoma. 6. Whole brain radiotherapy followed by positron emission tomography scanning to determine what viable metastatic disease remained (and potentially treatable by stereotactic/focal technology) was favoured by most of delegates who answered this question.

Radiation necrosis following gamma knife surgery: a case-controlled comparison of treatment parameters and long-term clinical follow up

OBJECT

Radiation necrosis is the only significant complication of gamma knife surgery (GKS). The authors studied treatment plan parameters in patients who had radiation necrosis to determine if risk factors for necrosis could be identified.

METHODS

Between September 1994 and December 1998, 286 patients were treated with GKS by the senior author. Of the 243 patients who were suitable for analysis, 17 developed radiation necrosis and were prospectively followed. Concurrently, 17 patients without necrosis were randomly selected as case controls on the basis of histological findings in their lesions. Integral dose-volume histograms (DVHs) were calculated and dose-volume treatment parameters were determined. A comparison was made with both the established Kjellberg and Flickinger isonecrosis risk lines. Clinical outcome was assessed according to time to resolution of symptoms and return to normal radiographic appearance.

CONCLUSIONS

Treatment plan variables associated with the risk of necrosis were increased tumor volume (TV) integral dose, increased TV, and increased 10-Gy volume. Other risk factors included repeated radiosurgery to the same lesion and glioma histological findings. The Kjellberg 1% risk line predicted a 5% risk of radiation necrosis and the Flickinger 3% risk line predicted a 3% risk. The median time to development of necrosis was 4 months, and symptomatic and radiographic recovery times were 7.5 and 10.5 months, respectively. The median survival time in patients with necrosis was 30 months. The authors recommend prospective TV determination and DVH calculation for all radiosurgical treatments and the avoidance of repeated radiosurgical treatments to the same lesion when possible.

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.

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 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.

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 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.

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.

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.

[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.

Application of proton chemical shift imaging in monitoring of gamma knife radiosurgery on brain tumors

Our objective was to assess proton chemical shift imaging for potential clinical application in monitoring response to gamma knife radiosurgery. Twenty-five proton chemical shift imaging studies and conventional magnetic resonance images were performed on six patients with intracranial tumors. The peak areas of N-acetylaspartate, choline-containing compounds (Cho), creatine, and lipids were calculated and normalized to N-acetylaspartate in the contralateral hemisphere. The spectra from the lesion before treatment showed a relatively high Cho peak, reported as a characteristic spectrum of tumors. Tumor size and Cho level after radiosurgery did not increase except in two cases. In these cases, radiation necrosis was observed with elevated Cho and a mobile lipid peak. Stable or decreased Cho seems to suggest a loss of tumor viability, and changes in Cho indicate the effectiveness of radiosurgery. Increasing Cho and the appearance of the mobile lipid peak may distinguish radiation necrosis from recurrent tumors, which cannot be distinguished by magnetic resonance imaging.

Stereotactic radiosurgery for brain metastases: comparison of lung carcinoma vs. non-lung tumors

In the medical literature, stereotactic radiosurgery (SRS) for brain metastases results in rates of local control of 65 to 85 %. To define patient selection criteria, we measured the survival in a population with a high proportion of non-small cell lung carcinoma (NCS lung) metastases that occurred soon after primary diagnosis. Between 9/89 and 10/93 30 adults (21 M, 9 F) had SRS for metastatic NSC lung carcinoma (14 patients) vs. non-lung carcinomas (16 patients having breast (3), renal (3), melanoma (3), GI (2, thyroid (1) or carcinoma of unknown origin (4)). The metastases were solitary for 22 patients and multiple for 8 patients. Average ages (y) (+/-SD) were 58.6+/-10.4 for NSC lung patients and 53.4+/-12.5 (p = 0.32) for non-lung patients. The average interval (months) from diagnosis of the primary to metastasis was 23.8+/-41.4 for all patients. This interval was shorter for NSC lung patients: 3.1+/-6.0 vs. 48.0+/-51.7 (p < 0.001) for non-lung patients. Twenty seven patients had conventional radiotherapy (XRT) before (24 patients) or after (3 patients) SRS. Doses (cGy) were 3303+/-841 for 13 NSC lung patients and 4256+/-992 for 14 non-lung patients (p = 0.034). The median time from primary diagnosis to SRS was shorter for the NSC lung patients (11 mo) compared to the non-lung patients (35 mo). SRS was given for recurrence of metastases after XRT for 11/14 NSC lung patients and 13/16 non-lung patients. The doses (cGy) of SRS were 1579+/-484 vs. 1682+/-476 (p=0.45) for the NSC lung and non-lung groups, respectively. After SRS a decrease in metastasis diameter was observed in 10 of 14 NSC lung patients vs. 12 of 16 non-lung patients (p=0.85 Chi-square). Twenty-seven of the 30 patients have died. For all patients, the median survival after diagnosis of the primary and after radiosurgery was 31.3 and 8.4 months, respectively. The median survival (95% CI) from primary diagnosis was 24.3 months (13.2-27.3) for NSC lung patients and 46.5 months (39.2-65.5) for non-lung patients (p=0.005 logrank test). The median survival (95% CI) after SRS was 7.9 months (3.0-14.3) for the NSC lung patients and 8.4 (2.9-11.9) months for the non-lung patients (p=0.98 logrank test). Within the two groups, no difference in survival was observed for patients who had SRS sooner (< 1 yr for NSC lung; < 3 yr for non-lung) after primary diagnosis: 9.3 vs. 6.5 mo for NSC lung (p=0.21) and 10.5 vs. 7.2 mo for non-lung (p=0.87). In this series, the shortened intervals from primary diagnosis to SRS for NSC lung metastases was associated with post-SRS survivorship that was equivalent to the more favorable non-lung group.