Stereotactic radiosurgical treatment of brain metastases

The role of adjuvant radiation and multiple resection within the surgical management of brain metastases

Cerebral metastases occur in 25% to 35% of all cancer patients. The advances in systemic and topical treatment as well as the rising incidence of lung cancer and melanomas are associated with an increasing incidence of cerebral metastases. More than 20,000 patients die every year in the Federal Republic of Germany of this disease. This retrospective analysis covers 145 patients who underwent surgery. Survival analysis of different subgroups was performed. The patients were grouped according to their clinical status and the different therapeutical procedures which were performed. Group A, consisting of all those patients where a gross total resection could be performed and where no systemic disease was apparent at the time of craniotomy showed the best results, having the highest portion of long term survivors. Group B, consisting of those patients who underwent a subtotal resection and who had no systemic disease at the time of craniotomy, had a worse outcome. Group C patients (gross total resection and systemic disease) as well as Group D (subtotal resection and systemic disease) presented the poorest results with respect to survival. A benefit was mediated by adjuvant radiation as well as multiple resections. Surgery is the method of choice for the treatment of a single metastasis. Advances in microsurgery nowadays sometimes justify even the removal of multiple metastases, depending on their location, on the general condition of the patient and on prognosis.

Brain tumors

This synthesis of the literature on radiotherapy for brain tumors, ie, cancer originating in the central nervous system (CNS), is based on 81 scientific articles, including 25 randomized studies, 13 prospective studies, and 25 retrospective studies. These studies involve 11,081 patients. A more comprehensive chapter on brain tumors may be ordered from SBU. Curative treatment is not available for patients with highly malignant glioma (grades III and IV). Postoperative radiotherapy for highly malignant glioma extends patients' survival, with good quality of life, by several weeks to several months. Virtually all patients die from this disease. Although the clinical benefits from radiotherapy, measured as survival, appear to be modest, it is more effective than any chemotherapy tested thus far. The clinical effects of radiotherapy for highly malignant glioma are improved only marginally by altering factors such as absorbed dose, fractionation, irradiated tissue volume, radiation quality, or by adding radiosensitizing substances. Radiotherapy alone usually provides a clear but temporary improvement in patients with highly malignant glioma, hence it clearly has a palliative benefit. Postoperative radiotherapy for low-grade malignant gliomas (grades I and II) may extend survival. It also reduces tumor volume. No evidence shows that radiotherapy alone or postoperatively can lead to cure. In patients who have undergone subtotal meningioma resection, postoperative radiotherapy substantially reduces the risk for recurrence and extends life, and is thereby indicated. Radiotherapy is not indicated following macroscopic radical meningioma surgery. Patients with brain metastases experience rapid neurological improvement following radiotherapy to the whole brain, and this palliative effect often remains throughout the remainder of the patient's life. Palliative radiotherapy, often to large volumes of the CNS, is therefore motivated in a large proportion of the patient groups. In a smaller group of patients with solitary metastases, radiotherapy may be given postoperatively following radical neurosurgery. Life may be extended in this group, otherwise radiotherapy does not influence survival. Stereotactic radiotherapy of solitary, mainly spherical metastases in the brain is often superior to other known methods with respect to palliation and survival. The number of patients is, however, relatively small.

Survival after surgical treatment of brain metastases from lung cancer: a follow-up study of 231 patients treated between 1976 and 1991

The authors reviewed the records of 231 patients who underwent resection of brain metastases from nonsmall-cell lung cancer between 1976 and 1991. Data regarding the primary disease and the characteristics of brain metastasis were retrospectively collected. Median survival in the group from the time of first craniotomy was 11 months; post-operative mortality was 3%. Survival rates of 1, 2, 3, and 5 years were 46.3%, 24.2%, 14.7%, and 12.5%, respectively. One hundred twelve women survived significantly longer than 119 men (13.8 vs. 9.5 months, p < 0.02). Patients with single metastatic lesions (200 patients) survived longer than those (31 patients) with multiple metastases (11.1 vs. 8.5 months, p < 0.02). Patients with supratentorial tumors survived longer than patients with cerebellar lesions. A high Karnofsky performance scale score before surgery also indicated increased survival. In multivariate analyses, incomplete resection or no resection of primary lung tumor, male gender, infratentorial location, presence of systemic metastases, and age older than 60 years were significantly correlated with shorter survival. Approximately one-third of the patients died of neurological causes, one-third of systemic disease, and one-third of a combination of both. The results of this series confirm that the overall prognosis for patients with even a single resectable brain metastasis is poor, but that aggressive therapy can prolong life with quality of life preserved and can occasionally permit long-term survival.

The cost effectiveness of stereotactic radiosurgery versus surgical resection in the treatment of solitary metastatic brain tumors

Solitary metastatic brain tumors are the most common intracranial neoplasms encountered by neurosurgeons. Surgical resection of brain metastasis with whole brain radiotherapy (WBR) significantly increases survival in comparison with WBR alone. Stereotactic radiosurgery (SR) seems to provide results that are similar to those of surgical resection. To analyze the economic efficiency of these different treatments, we compared the results of surgical resection and SR as reported in the medical literature between 1974 and 1994. We included studies in which: 1) at least 75% of patients received WBR; 2) study dates were in the computed tomography era (after 1975); 3) operative morbidity, mortality, and median survival were reported; 4) study dates were not included in a more recent update or review; 5) tumor histologies were reported; and 6) the cobalt-60 gamma unit was used for SR. Three surgical resection studies and one SR study met all entry requirements. The WBR baseline was developed from two prospective, randomized trials and used for incremental cost effectiveness analysis. We developed a model of typical resource usage for uncomplicated procedures, reported complications, and subsequent craniotomies (for recurrent tumor or radiation necrosis) for both treatment options. Costs were estimated from the societal viewpoint using the 1992 Medicare Provider Analysis and Review database with average cost:charge ratios for surgery and WBR. A survey of capital and operating costs from five sites was used for radiosurgery. Our analysis revealed that radiosurgery had a lower uncomplicated procedure cost ($20,209 versus $27,587), a lower average complication cost per case ($2,534 versus $2,874), and a lower total cost per procedure ($22,743 versus $30,461), was more cost effective ($24,811 versus $32,149 per life year), and had a better incremental cost effectiveness ($40,648 versus $52,384 per life year) than surgical resection. A sensitivity analysis revealed that large changes in key assumptions would be required to change the analysis outcome. Equalization of the incremental cost effectiveness of the two treatments would require one of the following: 1) a 38.7% reduction in SR annual case volume, 2) a 34.7% increase in SR procedure cost, 3) a 18.8% reduction in surgical resection procedure cost, 4) a 240.5% increase in SR morbidity cost, 5) a 12.7% reduction in SR median survival, 6) a 16.8% increase in surgical resection median survival. Elimination of all surgical resection morbidity cost would still result in superior incremental cost effectiveness for SR.(ABSTRACT TRUNCATED AT 400 WORDS)

Metástase cerebral: tratamento paliativo com radiocirurgia

O artigo faz avaliação de 52 pacientes com metástase cerebral tratados com radiocirurgia estereotática na Universidade McGill, em Montreal. A radiocirurgia foi realizada com a técnica dinâmica em que, ao mesmo tempo, giram a mesa e a cabeça do acelerador linear de 10 MV. Todos os pacientes (56 tratamentos ao todo) foram tratados com um único isocentro e uma dose única mediana de 1800 cGy na periferia da metástase. Em 88% dos casos a radiocirurgia foi usada após falha de tratamento radioterápico fracionado em todo cérebro. Todos os 52 casos tiveram avaliação com CT pós radiocirurgia. O seguimento mediano foi de 6 meses (variou entre 1 e 37 meses) e a taxa de resposta, parcial ou completa, foi de 64%. Apenas 4 pacientes (7%) tiveram algum tipo de complicação tardia relacionada ao tratamento. Estes achados vão de encontro com dados da literatura. A radiocirurgia é tratamento pouco agressivo, bem tolerado e com alta taxa de resposta para lesões locais e pode ser útil para pacientes selecionados. O seu valor definitivo, como tratamento único ou combinado com radioterapia em todo cérebro, está sendo avaliado de forma prospectiva e randomizada.

The treatment of patients with recurrent brain metastases. A retrospective analysis of 109 patients with nonsmall cell lung cancer

BACKGROUND

Brain metastases represent a major source of morbidity in patients with cancer.

METHODS

Treatment outcomes were analyzed retrospectively in 214 patients with brain metastases from nonsmall cell lung cancer (NSCLC) who underwent resection at Memorial Hospital (New York, NY) between January, 1976, and December, 1990.

RESULTS

The study group included 109 patients (51%) with symptomatic recurrent brain tumors (median, 5.0 months after complete resection). Recurrence in the brain was at the original site in 62% of patients and at other sites in 38%. The median survival (MS) was 11.3 months in the recurrence group compared with 9.5 months (P < 0.5) in the nonrecurrence group (N = 105). Thirty-two patients had further surgery after recurrence; their median relapse time was 5.2 months. In these patients, survival (MS, 15.0 months) calculated from the time of their first operation, was significantly different (P < 0.001) from that of patients who did not undergo a second procedure (N = 77) (MS, 10.0 months). In the 32 patients who underwent reoperation, MS from the time of the second operation was 10 months, whereas the median interval from the first operation was 5 months (average, 5.7 months). Eight of these 32 patients had a third operation, after a median relapse time of 4 months; their MS was 42 months. There was a significant difference (P < 0.02) between the MS of 39 patients synchronously diagnosed with lung cancer and brain metastasis (MS, 9.0 months) and 70 metachronously diagnosed patients (MS, 14.6 months). Women (N = 55) survived longer than men (N = 54) (14.4 months vs. 9.7 months, P < 0.01). Univariate analysis showed that histology, disease stage, and completeness of resection of the primary tumor also affected survival (P < 0.02, P < 0.014, and P < 0.001, respectively). Although no significant difference was found between survival of patients with recurrence in the supratentorial space and patients with recurrence in the posterior fossa (MS, 11.4 months vs. 11.2 months, P < 0.13), no one from the latter subgroup survived 3 years.

CONCLUSIONS

If technically feasible, further surgery is effective in prolonging the survival of patients with NSCLC who have recurring brain metastases.

Treatment selection factors for stereotactic radiosurgery of intracranial metastases

PURPOSE

To define treatment selection criteria for patients with intracranial metastases treated with stereotactic radiosurgery.

METHODS AND MATERIALS

Between August 1989 and July 1993, 25 patients with intracranial metastases (28 lesions) were treated with stereotactic radiosurgery at the University of Florida. Thirteen patients were treated for progressive intracranial disease after external-beam radiotherapy, and 12 were treated with radiosurgery as an adjunct to initial treatment. Minimum eligibility criteria included histologic verification of primary disease, Karnofsky performance status 50% or greater, three or fewer intracranial metastases, radiographically distinct lesion(s) 4 cm or less in diameter, and reasonably well-controlled primary disease. Univariate and multivariate analyses tested the prognostic significance of Karnofsky performance status, lesion volume, number of lesions, treatment dose (both external beam and stereotactic), histology, site of primary disease, and time interval (less than or greater than 1 year) from primary diagnosis to development of intracranial metastasis or from treatment of intracranial disease to recurrence.

RESULTS

Local control was achieved in 84% of 28 lesions treated. The only significant prognostic indicator among the tested variables was the interval to development or recurrence of intracranial metastasis.

CONCLUSION

Although stereotactic radiosurgery improves local control rates and is likely to offer improved palliation for a select cohort of patients, the selection criteria for such patients remain poorly defined. Our data suggest that an interval of greater than 1 year from primary disease diagnosis to development of intracranial metastasis, or from treatment of intracranial metastasis to its recurrence, defines a patient cohort that is more likely to benefit from this treatment technique.

Gamma knife radiosurgery for metastatic brain tumors

Sixty-three patients with metastatic brain tumors have had stereotactic radiosurgery 90 times with the Leksell Gamma Knife over a 29-month period. Initially, a single treatment of 35 to 45 Gy was delivered to the enhanced CT margin. This dose was found to be inadequate for tumor control. We then raised the marginal dose to 50 to 55 Gy, but even this radiosurgical dose did not appear to control tumor growth. However, we have found that metastatic brain tumors can be controlled successfully using enhanced MR scans and a peripheral dose of 60 Gy or even 65 Gy adjacent to the enhanced margins of the metastatic brain tumors, especially melanomas.

Stereotactic high dose fraction radiation therapy of extracranial tumors using an accelerator. Clinical experience of the first thirty-one patients

A stereotactic body frame with a fixation device has been developed for stereotactic radiation therapy of extracranial targets, a precision localization and positioning system in analogy with the stereotactic head frames used for intracranial targets. Results of the first 42 treated tumors in 31 patients are presented. Most of the patients had solitary tumors in liver, lung or retroperitoneal space. Clinical target volumes ranged from 2 to 622 cm3 (mean 78 cm3) and minimum doses to the planning target volumes (PTV) of 7.7-30 Gy/fraction (mean 14.2 Gy) were given on 1-4 occasions to a total minimum dose to the PTVs of 7.7-45 Gy (mean 30.2 Gy) to the periphery of the PTV and total mean doses to the PTVs of 8-66 Gy (mean 41 Gy). The central part of the tumor was usually given about 50% higher dose compared to that of the periphery of the PTV by a planned inhomogeneous dose distribution. Some of the patients received stereotactic radiation therapy concomitantly to more than one target, in others new metastases were also treated which appeared during the follow-up period. We observed a local rate of no progressive disease of 80% during a follow-up period of 1.5-38 months. Fifty percent of the tumors decreased in size or disappeared.

Brain metastatic lesions

OBJECTIVE

To describe current concepts in the diagnosis and treatment of brain metastases.

RESULTS

More than 25% of all autopsy-proven brain metastases have a pulmonary source. Most brain metastases manifest with a combination of focal and generalized symptoms and signs. Typically, patients have subacute, progressive symptoms. In most situations, a computed tomographic scan of the head provides sufficient neuroimaging and allows one to monitor the effects of therapy. Magnetic resonance imaging has become increasingly useful in the diagnosis and management of brain metastases. It can detect computed tomographic occult metastases, identify associated leptomeningeal disease, and reveal early therapeutic complications.

CONCLUSION

Treatment options for patients with brain metastases include corticosteroids, whole-brain radiation therapy (WBRT), surgical intervention, stereotactic radiosurgical techniques, and chemotherapy. Corticosteroids produce prompt improvement in most patients; however, prolonged use is associated with considerable risks. For most patients, WBRT is the preferred treatment. Nonetheless, it has associated nonneurologic and neurologic complications, some of which are serious. In patients with a single metastasis, surgical removal should be considered. Recent studies have suggested that resection of a single metastatic lesion followed by radiation therapy offers better survival than does radiation therapy alone. The subsequent administration of WBRT after radiosurgical treatment has become standard practice. The role of chemotherapy is uncertain.

Registration of images from sequential MR studies of the brain

For sequential studies of patients with brain tumors, the authors have designed an automated registration procedure for intra- and interexamination alignment of magnetic resonance images. This was evaluated with artificially misregistered data and data from repeat studies of six healthy volunteers and six brain tumor patients. In a subset of cases, a manual procedure based on matching of neuroanatomic landmarks was also applied for comparison. The results showed that the technique is robust and reproducible, giving an accuracy in the range of 1-2 mm, which corresponded to the spatial resolution of the images. Subject motion between imaging sequences within the same study was negligible, although adjustments (one to two section thicknesses) were required in the z direction to correlate multisection and volume images and to allow accurate image segmentation. For alignment between sequential volunteer and patient examinations, translations of up to 22 mm and rotations in the x, y, and z axes of up to 9 degrees were required. This alignment procedure may be valuable in numerous aspects of treatment planning and patient follow-up.

Radiosurgery with the first Austrian cobalt-60 Gamma-unit. A one year experience

During the period of one year, from the 21. 4. 1992 to 21. 4. 1993, a total of 201 radiosurgical sessions on 181 patients were performed with the first Austrian Gamma-unit in Graz. 42% of radiosurgical sessions were undertaken for malignomas, 20% for meningiomas, 11.5% for vascular malformations, 9% for neurinomas, 8.5% for low grade astrocytomas and glomus jugulare tumours, 5% for sellar and suprasellar lesions, and 4% for functional disorders. Dose plan data for all the lesions treated are shown. Clinical and imaging data of the first year which are available for 120 patients (66%) are presented and discussed.

Stereotactic radiosurgery for recurrent gliomas

BACKGROUND

The treatment of recurrent gliomas is palliative; however, the local pattern of tumor recurrence permits retreatment with single fraction, high dose stereotactic radiotherapy or radiosurgery (RS).

METHODS

Twenty patients (median Karnofsky performance status, 80), aged 8-62 years with recurrent gliomas, were treated with RS after failing adjuvant therapy. Tumor histologies included glioblastoma multiforme (5), anaplastic astrocytoma (10), fibrillary astrocytoma (4), and primitive neuroectodermal tumor (1). Tumor volumes ranged from 3-53.5 cc, with a median of 17 cc.

RESULTS

Seven early and one late radiation complication were seen. All seven early radiation complications were due to raised intracranial pressure and resolved in all but one patient who died. Median follow-up in 19 evaluable patients was 8 months (range, 2-29 months). Fourteen patients died from progressive tumor (median survival, 7 months). Five patients, four with recurrent tumor, were alive (median follow-up, 19 months) with a median time-to-tumor progression of 9 months.

CONCLUSIONS

Radiosurgery demonstrates modest efficacy with acceptable toxicity in selected patients with recurrent gliomas and warrants further investigation.

Role of stereotactic biopsy in multifocal brain lesions: considerations on 100 consecutive cases

One hundred patients affected by multifocal brain lesions were investigated by serial stereotactic biopsy. Systemic diseases and primary neoplasms elsewhere were previously ruled out. The histological diagnosis obtained in this series comprises malignant gliomas in 37% of patients; primary non-Hodgkin's brain lymphoma in 15%; metastatic brain tumours in 15% (no evidence of the primary tumour at the time of stereotactic surgery); low grade gliomas in 12%; infective diseases in 10% (including brain abscesses and multifocal viral encephalitis); and ischaemic lesions in 6%. In addition, two patients with germinomas, two with primitive neuroepithelial tumours, two with multiple telangiectases, and one with a teratoma were also included in this series. Histological findings obtained by stereotactic procedures guided the choice of treatment, avoiding the risks of blind treatments. Indications and future perspectives for stereotactic surgery in multifocal brain lesions are discussed with emphasis on advances in diagnostic and therapeutic tools.

Cost and survival analysis of metastatic cerebral tumors treated by resection and radiation

The surgical treatment of metastatic brain tumors remains controversial, primarily because of the limited prognosis of patients with metastatic cancer. The cost effectiveness of even standard therapies is of increasing concern to third-party payers. We reviewed the records of patients who had a single metastatic brain tumor resected at the Medical Center Hospital of Vermont (a referral center in a rural state) since cost data recording began. The 32 patients ranged in age from 35 to 77 years, with a 2.2:1 female-to-male ratio. Thirty-four percent of tumors originated in the lung, 15.6% were renal, 12.5% were breast, 12.5% were gynecological, 9.4% were gastrointestinal, and 9.4% were ultimately of unknown origin. Thirty-one tumors were completely resected; 30 patients were irradiated, most after surgery (mean dose, 3,908 +/- 1,250 cGy). Karnofsky scores improved from 80 +/- 11 to 88 +/- 16 postoperatively (P = 0.0038, one-tailed paired t-test). Patients were hospitalized an average of 8.22 +/- 6.26 days postoperatively, with total operative and postoperative charges of $19,190 +/- 5,684, noninclusive of radiotherapy. The expected median survival of all patients was 26 months (Kaplan-Meier estimate). The presence of disseminated disease was not significantly correlated with survival (P = 0.237). The number of postoperative days was more for patients with disseminated disease (P = 0.0274), but not for patients with infratentorial tumors (P = 0.6991). Age higher than the median was not correlated with an increased number of postoperative days (P = 0.1366) nor was a preoperative Karnofsky score of 70 or less (P = 0.1382).(ABSTRACT TRUNCATED AT 250 WORDS)

Radiosurgical treatment of a hemangioblastoma: case report

A hemangioblastoma of the fourth ventricle was treated with radiosurgery after attempts at surgical resection failed. No change in the size of the lesion has been seen in 2 years of follow-up, and the patient's neurological status remains normal. A brief review of the rationale for conventional radiation therapy and radiosurgery in the management of persistent/recurrent hemangioblastomas is presented.

Management of brain metastases

Brain metastases usually develop in patients with disseminated systemic disease. Effective palliation is available for the vast majority of patients with brain metastases, but many will die within 6 months, usually from progressive systemic tumor. However, in a substantial proportion of patients, a vigorous therapeutic approach using surgery, radiotherapy, and possibly chemotherapy leads to years of productive life. Recurrent brain metastases can often be retreated using newer techniques of brachytherapy and stereotactic radiosurgery as well as conventional treatments. Brain metastases do not necessarily mean imminent death for every patient, and physicians can now offer patients a growing range of therapeutic options. Furthermore, attention to symptomatic therapies can improve the quality of life for all patients, even those whose survival will be relatively short.

Linac radiosurgery in brain metastases

Brain metastases are usually well-circumscribed and more or less spherical lesions. These conditions meet the criteria for radiosurgery (RS). A pilot study initiated by our group in 1983, demonstrated the effectiveness of Linac-RS in the treatment of solitary brain metastases with low radiosensitivity. A second trial including patients with 1-3 metastases started in 1990. By April 1993, 46 patients had been treated in this series. The radiation doses delivered to the tumour margin ranged from 10 to 25 Gy, and were chosen with respect to size, number and location of the tumours or previous whole brain radiotherapy (WBRT), decreasing mainly with increasing tumour volumes. 34/46 patients had a follow-up of more than 12 weeks. In 7/46 patients the disease progressed rapidly during the first weeks after RS and follow-up examinations were not performed. 5/46 patients had a follow-up of less than 6 weeks and follow-up CT/MR-examinations were not available. 14/46 patients received WBRT before RS. The regularly performed follow-up examinations (clinical status, CT-/MR-examinations in 6 or 12 weekly intervals) revealed tumour progression in 5/34 patients. Permanent cessation of the growth (11/34), tumour shrinkage (18/34) and decrease of surrounding oedema together with clinical amelioration have been observed a few weeks after radiosurgery. The median follow-up was 50 weeks. 14/46 patients died due to generalized progression of their disease.(ABSTRACT TRUNCATED AT 250 WORDS)

A phase I/II study of salvage radiosurgery in the treatment of recurrent brain metastases

Radiosurgery has been advocated as a salvage treatment for relapsed patients with brain metastases. This report describes a phase I/II study of salvage radiosurgery for patients previously treated with whole brain irradiation. The study was opened in March 1989 and the last patient was treated in July 1992. All patients have been followed to recurrence at the radiosurgically treated site or to death. Twenty progressing metastases in 12 patients were treated using 14 radiosurgical procedures. The radiation dose was always 25 Gy with the 90% isodose volume encompassing all enhancing tumour. Nineteen metastases were evaluable at +4 weeks. There were no instances of progressive disease; there were three complete responses, six partial responses, and 10 metastases remained unchanged. Median survival from the date of radiosurgery was 6 months. Nine of 12 patients eventually failed at the radiosurgically treated site (two remain alive). Radiosurgery at the time of relapse provides temporary control of recurrent brain metastases with acceptable toxicity.

Gamma knife radiosurgery of a series of only minimally selected metastatic brain tumours

From December 1991 to October 1992, 77 lesions in 25 consecutive patients were treated with Gamma Knife radiosurgery. Thirteen patients (52%) had multiple metastases up to sixteen lesions and twelve patients had a single metastasis. The volume of the largest tumour treated was 12.5 cm3. Karnofsky performance status (KPS) of the patients was 20-90% (mean 70). Marginal tumour dose given was 18 to 35 Gy (mean 26.1 Gy) in 30 to 90% isodose line according to the tumour volume and site. All but two patients were followed by MRI or CT scan repeatedly for a minimum of 6 month or to death. All but one of the tumours were locally controlled. Seventeen patients died during follow up and in four death was due to remote CNS metastases. The median survival for this minimally selected group of patients was 8.5 months, and the median survival for the patients with a single metastasis was 10.5 months. In patients with multiple metastases the median survival reached only 2.5 months but in 11 patients out of 13 patients neurological symptoms and signs improved or stabilized shortly after radiosurgery.

Radiosurgery/stereotactic external beam radiotherapy for malignant brain tumours: the Royal Marsden Hospital experience

SRT is a high-precision technique of radiotherapy which delivers focused irradiation to small target volumes. In the context of external beam radiotherapy it can be described as stereotactically guided conformal radiotherapy. As the technique originated from neurosurgical technology, it has initially been limited to single fraction treatment. However, with the use of relocatable fixation devices the way ahead particularly in its application in the treatment of brain tumours is in fractionated SRT. Currently, single fraction SRT/radiosurgery is of proven value only in the treatment of small inoperable arteriovenous malformations. It is being exploited in the management of brain tumours but so far remains as experimental treatment. We have demonstrated that fractionated SRT in patients with gliomas is a non-invasive equivalent to brachytherapy and in patients with solitary metastases a non-invasive alternative to surgical excision. However, the treatment is not without side effects, and the long-term effectiveness and toxicity of SRT, particularly with the use of unconventional fractionation, is not defined. The future use of SRT in the treatment of brain tumours should not be guided simply by the technical possibilities but by a rational appraisal of all treatment options to achieve the best disease control, survival and toxicity. Although there is potential for benefit in a number of small tumours, SRT cannot at present be recommended as the primary treatment in any tumour. In addition, its use should be discouraged in the treatment of unbiopsied brain lesions and as the major form of treatment of pineal germinomas. The technology of stereotactic radiotherapy is evolving, and it is likely that SRT will be integrated into conventional radiotherapy practice to become simply a high-precision technique of radiotherapy delivery in everyday use.

Stereotactic radiosurgery for cerebral metastatic melanoma

To determine local tumor control rates and survival of patients with melanoma metastases to the brain, the authors reviewed the results of 23 consecutive patients with a total of 32 tumors (19 patients had a solitary tumor and four had multiple tumors) who underwent adjuvant stereotactic radiosurgery. Tumor locations included the cerebral hemisphere (24 cases), brain stem (four cases), basal ganglia (two cases), and cerebellum (two cases). Fifteen patients had associated cranial symptomatology and eight had incidental metastases. All patients had tumors of 3 cm or less in diameter (mean tumor volume 2.5 cu cm), and all received fractionated whole-brain radiation therapy (30 Gy) in addition to radiosurgery (mean tumor margin dose 16 Gy). Nineteen patients were managed with both modalities at the time of diagnosis; four underwent radiosurgery 3 to 12 months after fractionated whole-brain radiotherapy. The mean patient follow-up period was 12 months (range 3 to 38 months). After radiosurgery, eight patients improved, 13 remained stable, and two deteriorated. One patient subsequently required craniotomy because of intratumoral hemorrhage; this patient and three others are living 13 to 38 months after radiosurgery. Nineteen patients died, 18 from progression of their systemic disease and one from another hemorrhage into a new brain metastasis. The local tumor control rate was 97%. Only two patients subsequently developed new intracranial metastases. The median survival period after diagnosis was 9 months (range 3 to 38 months). The authors believe that stereotactic radiosurgery coupled with fractionated whole-brain irradiation is an effective management strategy for cerebral metastases from a melanoma. Multi-institutional trials are warranted to confirm that stereotactic radiosurgery results equal or surpass the outcome achieved with craniotomy and tumor resection.

Surgical treatment of multiple brain metastases

The authors conducted a retrospective review of the charts of 56 patients who underwent resection for multiple brain metastases. Of these, 30 had one or more lesions left unresected (Group A) and 26 underwent resection of all lesions (Group B). Twenty-six other patients with a single metastasis who underwent resection (Group C) were selected to match Group B by type of primary tumor, time from first diagnosis of cancer to diagnosis of brain metastases, and presence or absence of systemic cancer at the time of surgery. Statistical analysis indicated that Groups A and B were also homogeneous for these prognostic indicators. Median survival duration was 6 months for Group A, 14 months for Group B, and 14 months for Group C. There was a statistically significant difference in survival time between Groups A and B (p = 0.003) and Groups A and C (p = 0.012) but not between Groups B and C (p > 0.5). Brain metastasis recurred in 31% of patients in Group B and in 35% of those in Group C; this difference was not significant (p > 0.5). Symptoms improved after surgery in 65% of patients in Group A, 83% in Group B, and 84% in Group C. Symptoms worsened in 13% of patients in Group A, 6% in Group B, and 0% in Group C. Groups A, B, and C had complication rates per craniotomy of 8%, 9%, and 8%, and 30-day mortality rates of 3%, 4%, and 0%, respectively. Guidelines for management of patients with multiple brain metastases are discussed. The authors conclude that surgical removal of all lesions in selected patients with multiple brain metastases results in significantly increased survival time and gives a prognosis similar to that of patients undergoing surgery for a single metastasis.

Endometrial cancer metastasis to brain: report of two cases and a review of the literature

Two cases of brain metastases from endometrial adenocarcinoma are reported. A 70-year-old female presented with lung metastases 14 months after hysterectomy and adjuvant treatment. At 6 months later, a cerebellar metastasis was resected and followed by radiation therapy. The patient died 5.5 months later. In the second case, a 60-year-old patient developed a lung endometrial metastasis 6 years after initial treatment. At 1 year later she was diagnosed with bilateral hydrocephalus caused by a left temporal and posterior fossa tumor. A ventriculoperitoneal shunt was inserted and she received brain radiation. Two weeks later she gradually became comatose, with right hemiparesis. A metastatic, hemorrhagic temporal tumor was resected but the patient never regained consciousness and died after 7 weeks. The existing literature on brain metastases from endometrial adenocarcinoma is reviewed.

Multiple intracranial melanoma metastases treated with surgery and radiosurgery with long term control. A case report

A case of malignant melanoma with multiplex brain metastases is described, where both surgical and radiosurgical treatment was applied. Due to CNS manifestations the patient was operated on in two sessions. First the symptomatic large tumor was removed, and the other, small lesion which could not be reached from the same approach was operated later. The primary skin lesion was discovered and removed between the two operations. A CT scan three months after the second operation revealed recurrence at the site of the first operation, and the appearance of two new tumors. The intracranial neoplasms were treated in one session by stereotactic radiosurgery using a linear accelerator. Six months after this treatment a new skin lesion was removed and the patient received DTIC therapy. Successive CT scans after the irradiation showed a steady regression of the radiosurgically treated tumors, and more than one year after the irradiation no tumor could be detected on the CT scans.

The radiobiology of radiosurgery: rationale for different treatment regimes for AVMs and malignancies

Based on basic radiobiological principles, we suggest that the radiosurgery technique of delivering a radiation dose in a single fraction, whilst appropriate for benign brain lesions such as arteriovenous malformations (AVM), is not optimal for treating malignant tumors. Radiosurgery was originally developed to treat benign lesions in the brain, such as AVMs, and has been successfully used for this purpose for over four decades. Recently, the technique has been adopted for treating small primary malignant brain tumors or single metastases. We argue, and derive radio-biological data to support the view that, treating malignant tumors with a single fraction will result in a suboptimal therapeutic ratio between tumor control and late effects, even for small tumors; and that improved therapeutic ratios would be expected if the treatment were fractionated into a small number of fractions. On the other hand, no therapeutic gain is to be expected from fractionating treatment of AVMs. A new generation of noninvasive relocatable stereotactic head frames makes feasible the use of fractionated stereotactic external-beam radiotherapy, and may allow significant benefits over single, radiosurgical, treatments for malignant brain tumors. As stereotactic fractionation/protraction regimes become more widespread, a uniform approach for determining equivalent fractionation schemes becomes important for intercomparing clinical results, and such calculations can be reliably carried out using the linear-quadratic formalism.

Fractionated stereotactic external beam radiotherapy in the management of brain metastases

24 patients with 28 brain metastases were treated with fractionated stereotactic radiotherapy (SRT). Doses ranged from 10 Gy in two fractions to 20 Gy in two fractions. 13 patients received SRT boost after whole brain radiotherapy (WBRT), 5 were treated with SRT alone and 6 were treated at the time of recurrence following WBRT. The median progression-free survival at the treated site was 18 months and the median survival was 18 months. All patients were treated without admission to hospital. Toxicity of fractionated SRT was minimal and patients treated without WBRT did not suffer significant alopecia. Fractionated SRT offers a non-toxic non-invasive alternative to excision surgery in patients with solitary brain metastases. The optimum fractionation schedule and the role of whole brain irradiation remain to be determined.

Comparison between radiosurgery and stereotactic fractionated radiation for the treatment of brain metastases

This study evaluates the treatment of intracerebral brain metastases with single dose stereotactic radiosurgery in comparison to stereotactic fractionated radiotherapy (SFR). Twenty six patients with 41 lesions were evaluated. Thirty four lesions in 19 patients were treated with radiosurgery, and 7 lesions in 7 patients were treated with SFR. The radiosurgery group was treated with an average number of isocenters of 1.4, and an average of 9 arcs. The average dose was 2140 cGy delivered to the 70% isodose line. The average volume of the lesions was 5.22 cc. The SFR group lesions received a mean dose to the indicated area delivered by 4 to 6 coplanar fields. The dose was 600 cGy per fraction, 2 to 3 fractions were given. The average volume of the treated lesions was 21.2 cc. Follow-up extended from 2-18 months. Twenty five lesions of the radiosurgery group had image follow-up. The overall local control was seen in 92% of the patients. Six lesions of the SFR group had image follow-up, the local control was 83%. The small number in each group, the non-randomized nature of the study, and the relatively short follow-up preclude a definitive conclusion. SFR may be the method of choice for large lesions surrounded by significant edema. The delivery of the dose in large fractions may obviate the transient acute reactions seen when radiosurgical dose is delivered to large lesions surrounded by edema. However, both forms of therapy have proven to be effective in the control of brain metastases.