Gamma Knife surgery for metastatic brain tumors without prophylactic whole-brain radiotherapy: results in 1000 consecutive cases

Overall survival following stereotactic radiosurgery for ten or more brain metastases: a systematic review and meta-analysis

BACKGROUND

Brain metastases are the most common intracranial tumours. Variation exists in the use of stereotactic radiosurgery for patients with 10 or more brain metastases. Concerns include an increasing number of brain metastases being associated with poor survival, the lack of prospective, randomised data and an increased risk of toxicity.

METHODS

We performed a systematic review and meta-analysis to assess overall survival of patients with ten or more brain metastases treated with stereotactic radiosurgery as primary therapy. The search strings were applied to MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL). Log hazard ratios and standard errors were estimated from each included study. A random-effects meta-analysis using the DerSimonian and Laird method was applied using the derived log hazard ratios and standard errors on studies which included a control group.

RESULTS

15 studies were included for systematic review. 12 studies were used for pooled analysis for overall survival at set time points, with a predicted 12 month survival of 20-40%. The random-effects meta-analysis in five studies of overall survival comparing ten or greater metastases against control showed statistically worse overall survival in the 10 + metastases group (1.10, 95% confidence interval 1.03-1.18, p-value = < 0.01, I2 = 6%). A funnel plot showed no evidence of bias. There was insufficient information for a meta-analysis of toxicity.

DISCUSSION

Overall survival outcomes of patients with ten or more brain metastases treated with SRS is acceptable and should not be a deterrent for its use. There is a lack of prospective data and insufficient real-world data to draw conclusions on toxicity.

PROSPERO ID

CRD42021246115.

Review of the diagnosis and treatment of brain metastases

Brain metastases (BM) occur in at least 10% of cancer patients, and are one of the main causes of cancer-related deaths and significant deterioration in the quality of life of cancer patients due to the neurological deterioration caused by brain compression and tumor invasion. Whole-brain irradiation has been emphasized as the standard treatment for BM. However, recent clinical trials including the JLGK0901 and JCOG0504 trials conducted in Japan have established therapeutic evidence for the use of stereotactic radiosurgery with regular follow-up with magnetic resonance imaging for BM. In addition to surgery and stereotactic radiotherapy, advances in drug therapy for BM, such as tyrosine kinase inhibitors and immune checkpoint inhibitors, are expected. This review describes the history and the recent evidence of the diagnosis and treatment of BM.

Local tumor progression treated with Gamma Knife radiosurgery: differences between patients with 2-4 versus 5-10 brain metastases based on an update of a multi-institutional prospective observational study (JLGK0901)

OBJECTIVE

The Japanese Leksell Gamma Knife (JLGK)0901 study proved the efficacy of Gamma Knife radiosurgery (GKRS) in patients with 5-10 brain metastases (BMs) as compared to those with 2-4, showing noninferiority in overall survival and other secondary endpoints. However, the difference in local tumor progression between patients with 2-4 and those with 5-10 BMs has not been sufficiently examined for this data set. Thus, the authors reappraised this issue, employing the updated JLGK0901 data set with detailed observation via enhanced MRI. They applied sophisticated statistical methods to analyze the data.

METHODS

This was a prospective observational study of 1194 patients harboring 1-10 BMs treated with GKRS alone. Patients were categorized into groups A (single BM, 455 cases), B (2-4 BMs, 531 cases), and C (5-10 BMs, 208 cases). Local tumor progression was defined as a 20% increase in the maximum diameter of the enhanced lesion as compared to its smallest documented maximum diameter on enhanced MRI. The authors compared cumulative incidence differences determined by competing risk analysis and also conducted propensity score matching.

RESULTS

Local tumor progression was observed in 212 patients (17.8% overall, groups A/B/C: 93/89/30 patients). Cumulative incidences of local tumor progression in groups A, B, and C were 15.2%, 10.6%, and 8.7% at 1 year after GKRS; 20.1%, 16.9%, and 13.5% at 3 years; and 21.4%, 17.4%, and not available at 5 years, respectively. There were no significant differences in local tumor progression between groups B and C. Local tumor progression was classified as tumor recurrence in 139 patients (groups A/B/C: 68/53/18 patients), radiation necrosis in 67 (24/31/12), and mixed/undetermined lesions in 6 (1/5/0). There were no significant differences in tumor recurrence or radiation necrosis between groups B and C. Multivariate analysis using the Fine-Gray proportional hazards model revealed age < 65 years, neurological symptoms, tumor volume ≥ 1 cm3, and prescription dose < 22 Gy to be significant poor prognostic factors for local tumor progression. In the subset of 558 case-matched patients (186 in each group), there were no significant differences between groups B and C in local tumor progression, nor in tumor recurrence or radiation necrosis.

CONCLUSIONS

Local tumor progression incidences did not differ between groups B and C. This study proved that tumor progression after GKRS without whole-brain radiation therapy for patients with 5-10 BMs was satisfactorily treated with the doses prescribed according to the JLGK0901 study protocol and that results were not inferior to those in patients with a single or 2-4 BMs.Clinical trial registration no.: UMIN000001812 (umin.ac.jp).

Salvage gamma knife radiosurgery for active brain metastases from small-cell lung cancer after whole-brain radiation therapy: a retrospective multi-institutional study (JLGK1701)

PURPOSE

To evaluate the efficacy of gamma knife radiosurgery (GKS) for brain metastases (BMs) from small-cell lung cancer after whole-brain radiotherapy (WBRT).

METHODS

We retrospectively analyzed the usefulness and safety of GKS in 163 patients from 15 institutions with 1-10 active BMs after WBRT. The usefulness and safety of GKS were evaluated using statistical methods.

RESULTS

The median age was 66 years, and 79.1% of patients were men. The median number and largest diameter of BM were 2.0 and 1.4 cm, respectively. WBRT was administered prophylactically in 46.6% of patients. The median overall survival (OS) was 9.3 months, and the neurologic mortality was 20.0%. Crude incidences of local control failure and new lesion appearance were 36.6% and 64.9%, respectively. A BM diameter ≥ 1.0 cm was a significant risk factor for local progression (hazard ratio [HR] 2.556, P = 0.039) and neurologic death (HR 4.940, P = 0.031). Leukoencephalopathy at the final follow-up was more prevalent in the therapeutic WBRT group than in the prophylactic group (P = 0.019). The symptom improvement rate was 61.3%, and neurological function was preserved for a median of 7.6 months. Therapeutic WBRT was not a significant risk factor for OS, neurological death, local control, or functional deterioration (P = 0.273, 0.490, 0.779, and 0.560, respectively). Symptomatic radiation-related adverse effects occurred in 7.4% of patients.

CONCLUSIONS

GKS can safely preserve neurological function and prevent neurologic death in patients with 1-10 small, active BMs after prophylactic and therapeutic WBRT.

Comparison of treatment results between 3- and 2-stage Gamma Knife radiosurgery for large brain metastases: a retrospective multi-institutional study

OBJECTIVE

In order to obtain better local tumor control for large (i.e., > 3 cm in diameter or > 10 cm3 in volume) brain metastases (BMs), 3-stage and 2-stage Gamma Knife surgery (GKS) procedures, rather than a palliative dose of stereotactic radiosurgery, have been proposed. Here, authors conducted a retrospective multi-institutional study to compare treatment results between 3-stage and 2-stage GKS for large BMs.

METHODS

This retrospective multi-institutional study involved 335 patients from 19 Gamma Knife facilities in Japan. Major inclusion criteria were 1) newly diagnosed BMs, 2) largest tumor volume of 10.0-33.5 cm3, 3) cumulative intracranial tumor volume ≤ 50 cm3, 4) no leptomeningeal dissemination, 5) no more than 10 tumors, and 6) Karnofsky Performance Status 70% or better. Prescription doses were restricted to between 9.0 and 11.0 Gy in 3-stage GKS and between 11.8 and 14.2 Gy in 2-stage GKS. The total treatment interval had to be within 6 weeks, with at least 12 days between procedures. There were 114 cases in the 3-stage group and 221 in the 2-stage group. Because of the disproportion in patient numbers and the pre-GKS clinical factors between these two GKS groups, a case-matched study was performed using the propensity score matching method. Ultimately, 212 patients (106 from each group) were selected for the case-matched study. Overall survival, tumor progression, neurological death, and radiation-related adverse events were analyzed.

RESULTS

In the case-matched cohort, post-GKS median survival time tended to be longer in the 3-stage group (15.9 months) than in the 2-stage group (11.7 months), but the difference was not statistically significant (p = 0.65). The cumulative incidences of tumor progression (21.6% vs 16.7% at 1 year, p = 0.31), neurological death (5.1% vs 6.0% at 1 year, p = 0.58), or serious radiation-related adverse events (3.0% vs 4.0% at 1 year, p = 0.49) did not differ significantly.

CONCLUSIONS

This retrospective multi-institutional study showed no differences between 3-stage and 2-stage GKS in terms of overall survival, tumor progression, neurological death, and radiation-related adverse events. Both 3-stage and 2-stage GKS performed according to the aforementioned protocols are good treatment options in selected patients with large BMs.

Clinical outcomes of hypofractionated image-guided multifocal irradiation using volumetric-modulated arc therapy for brain metastases

Volumetric-modulated arc therapy (VMAT) can be used to design hypofractionated radiotherapy treatment plans for multiple brain metastases. The purpose of this study was to evaluate treatment outcomes of hypofractionated image-guided multifocal irradiation using VMAT (HFIGMI-VMAT) for brain metastases. From July 2012 to December 2016, 67 consecutive patients with 601 brain metastases were treated with HFIGMI-VMAT at our institution. The prescribed dose was 50 Gy to a 95% volume of the planning target volume in 10 fractions. Fifty-five of the 67 patients had non-small-cell lung cancer, and the remaining 12 had other types of cancer. The median number of brain metastases was five, and the median maximum diameter was 1.2 cm. The median duration of follow-up was 12.0 months (range, 1.9-44.8 months), and the median survival time 18.7 months. Four patients with six lesions had local recurrences. The local control rate in the 64 assessed patients was 98.4% and 95.3% at 6 and 12 months, respectively (three died before assessment). The local control rate for the 572 assessed lesions was 99.8% and 99.3% at 6 and 12 months, respectively. Thirty-nine patients developed distant brain metastases, the distant brain control rate being 59.7% and 40.5% at 6 and 12 months, respectively. Acute toxicities were generally mild (Grade 1-2). Three patients (4.5%) developed radiation necrosis requiring corticosteroid therapy. The HFIGMI-VMAT technique with flat dose delivery was well tolerated and achieved excellent local control. This technique is a promising treatment option for patients with multiple and large brain metastases.

Evaluation of new lesions and symptoms after gamma knife radiosurgery for brain metastases: a retrospective cohort study

BACKGROUND

Symptomatic new lesions that appear after gamma knife radiosurgery (GKRS) for brain metastases have not been thoroughly described.

METHODS

Among 238 patients who underwent a single session of GKRS without whole-brain radiotherapy or surgery for brain metastases between 2009 and 2014, a total of 165 (69.3%) patients underwent follow-up magnetic resonance imaging (MRI). Their electrical health records were reviewed retrospectively. The median age was 68 years, and 62.4% patients were men. The median number of brain metastases was 2. The most frequent primary organ site was the lung (71.5%). Then, we evaluated predictors for the symptoms of new lesions.

RESULTS

New lesions and leptomeningeal dissemination were observed in 101 (61.2%) and 23 (14.2%) patients, respectively. The median number of new lesions was 2; moreover, 20 of 101 patients (19.8%) with new lesions had tumours with the largest diameters of > 1 cm. Among 101 patients with new lesions, 13 were symptomatic (12.9%). Patients with larger new lesions (> 1 cm of the largest diameter) experienced symptoms more frequently (odds ratio 7.6, P < 0.01). Symptoms resolved after salvage GKRS in seven of 11 patients who abided by the recommended follow-up MRI schedule. No significant risk factors were found for symptoms of new lesions.

CONCLUSIONS

The incidence of symptomatic new lesions that appeared after GKRS was low, and more than half of the patients showed improvements in their symptoms after salvage GKRS. However, careful MRI-based assessments and salvage GKRS are critical for the quality of life.

Robustness of the neurological prognostic score in brain metastasis patients treated with Gamma Knife radiosurgery

OBJECTIVE

The neurological prognostic score (NPS) was recently proposed as a means for predicting neurological outcomes, such as the preservation of neurological function and the prevention of neurological death, in brain metastasis patients treated with Gamma Knife radiosurgery (GKRS). NPS consists of 2 groups: Group A patients were expected to have better neurological outcomes, and Group B patients were expected to have poorer outcomes. NPS robustness was tested in various situations.

METHODS

In total, 3040 patients with brain metastases that were treated with GKRS were analyzed. The cumulative incidence of the loss of neurological function independence (i.e., neurological deterioration) was estimated using competing risk analysis, and NPS was compared between Groups A and B by employing Gray's model. NPS was tested to determine if it can be applied to 5 cancer categories—non–small cell lung cancer, small cell lung cancer, gastrointestinal tract cancer, breast cancer, and other cancers—as well as if it can be incorporated into the 5 major grading systems: recursive partitioning analysis (RPA), score index for stereotactic radiosurgery (SIR), basic score for brain metastases (BSBM), graded prognostic assessment (GPA), and modified-RPA (M-RPA).

RESULTS

There were 2263 patients in NPS Group A and 777 patients in Group B. Neurological deterioration was observed in 586 patients (19.2%). The cumulative incidences of neurological deterioration were 9.5% versus 21.0%, 14.1% versus 25.4%, and 17.6% versus 27.8% in NPS Groups A and B at 1, 2, and 5 years, respectively. Significant differences were detected between the NPS groups in all cancer categories. There were significant differences between NPS Groups A and B for all classes in terms of the BSBM, GPA, and M-RPA systems, but the differences failed to reach statistical significance in terms of RPA Class I and SIR Class 0 to 3.

CONCLUSIONS

The NPS was verified as being highly applicable to all cancer categories and almost all classes for the 5 grading systems in terms of neurological function independence. This NPS system appears to be quite robust in various situations for brain metastasis patients treated with GKRS.

Intracranial control after Cyberknife radiosurgery to the resection bed for large brain metastases

Background

Stereotactic radiosurgery (SRS) is an alternative to post-operative whole brain radiation therapy (WBRT) following resection of brain metastases. At our institution, CyberKnife (CK) is considered for local treatment of large cavities ≥2 cm. In this study, we aimed to evaluate patterns of failure and characterize patients best suited to treatment with this approach.

Methods

We retrospectively reviewed 30 patients treated with CK to 33 resection cavities ≥2 cm between 2011 and 2014. Patterns of intracranial failure were analyzed in 26 patients with post-treatment imaging. Survival was estimated by the Kaplan-Meier method and prognostic factors examined with log-rank test and Cox proportional hazards model.

Results

The most frequent histologies were lung (43 %) and breast (20 %). Median treatment volume was 25.1 cm³ (range 4.7–90.9 cm³) and median maximal postoperative cavity diameter was 3.8 cm (range 2.8–6.7). The most common treatment was 30 Gy in 5 fractions prescribed to the 75 % isodose line. Median follow up for the entire cohort was 9.5 months (range 1.0–34.3). Local failure developed in 7 treated cavities (24 %). Neither cavity volume nor CK treatment volume was associated with local failure. Distant brain failure occurred in 20 cases (62 %) at a median of 4.2 months. There were increased rates of distant failure in patients who initially presented with synchronous metastases (p = 0.02). Leptomeningeal carcinomatosis (LMC) developed in 9 cases, (34 %). Salvage WBRT was performed in 5 cases (17 %) at a median of 5.2 months from CK. Median overall survival was 10.1 months from treatment.

Conclusions

This study suggests that adjuvant CK is a reasonable strategy to achieve local control in large resection cavities. Patients with synchronous metastases at the time of CK may be at higher risk for distant brain failure. The majority of cases were spared or delayed WBRT with the use of local CK therapy.

A minimally invasive treatment option for large metastatic brain tumors: long-term results of two-session Gamma Knife stereotactic radiosurgery

Background

Large brain metastases (BM) remain a significant cause of morbidity and death for cancer patients despite current advances in multimodality therapies. The goal of the present study was to evaluate the efficacy and limitations of 2-session Gamma Knife stereotactic radiosurgery (SRS) for patients with large BM.

Methods

This is a prospective, open-label and single arm study analyzing 58 consecutive patients who received 2-session SRS for large BM (≥ 10 mL). The median age was 66 years, and the median Karnofsky performance status (KPS) score was 70. SRS was the initial treatment in 51 large tumors (84%) and was used as salvage after failed prior treatments for 10 tumors (16%). The fraction protocol was 20-30 Gy given in 2 fractions with 3–4 weeks between fractions. Overall survival (OS) and neurological death (ND), local tumor control and KPS were analyzed.

Results

The median follow-up time was 9.0 months. One- and 2-year OS rates were 47% and 20%, respectively. The median OS time was 11.8 months (95% CI: 5.5-15.6). The causes of death were intracranial local progression in 5 cases, meningeal carcinomatosis in 3 and progression of the primary lesion in 39. One- and 2-year ND-free survival rates were 91% and 84%, respectively. In 52 of 61 large BM (85%) with sufficient radiological follow-up data, 6- and 12-month local tumor control rates were 85% and 64%, respectively. The mean KPS improved from 70 at the 1st SRS to 82 at the 2nd; the first follow-up mean KPS was 87 (P < 0.001). Symptomatic radiation injury developed and required conservative treatment in 3 patients (5%).

Conclusions

Long-term follow-up showed that two-session Gamma Knife SRS achieved durable tumor control rates as well as acceptable treatment-related morbidity. This treatment method may potentially merit being offered to patients with large BM who are in poor condition or are otherwise ineligible for standard care.

Gamma Knife radiosurgery to four or more brain metastases in patients without prior intracranial radiation or surgery

Data on stereotactic radiosurgery (SRS) for four or more metastases are limited. Existing studies are confounded by significant proportions of patients receiving prior whole-brain radiation therapy (WBRT) or concurrent WBRT with SRS. Furthermore, published results disagree about the impact of tumor volume on overall survival. A retrospective review identified 38 patients without prior intracranial radiation or surgery who received Gamma Knife (GK) as sole treatment to ≥4 brain metastases in a single session. Twenty-eight cases with follow-up imaging were analyzed for intracranial progression. Prognostic factors were examined by univariate (log-rank test) and multivariate (Cox proportional hazards model) analyses. Common primary tumors were non-small cell lung (45%), melanoma (37%), and breast (8%). Cases were recursive partitioning analysis class II (94%) or III (6%). Patients harbored a median five tumors (range 4–12) with median total tumor volume of 1.2 cc. A median dose of 21 Gy was prescribed to the 50% isodose line. Patients survived a median 6.7 months from GK. Local treatment failure occurred in one case (4%) and distant failure in 22 (79%). On multivariate analysis, total tumor volume ≥3 cc was significantly associated with distant failure and worsened overall survival (P = 0.042 and 0.040). Fourteen patients (37%) underwent salvage WBRT at a median 10.3 months from GK and seven patients received repeat GK. GK as sole initial treatment for four or more simultaneous metastases spares some patients WBRT and delays it for others. Increased total tumor volume (≥3 cc) is significantly associated with worsened overall survival.

Efficacy and limitations of salvage gamma knife radiosurgery for brain metastases of small-cell lung cancer after whole-brain radiotherapy

BACKGROUND

The efficacy and limitations of salvage gamma knife surgery (GKS) have not been thoroughly described. This study evaluated the efficacy of GKS for treating brain metastases associated with small-cell lung cancer (SCLC) after whole-brain radiotherapy (WBRT) as the first-line radiation therapy.

METHODS

Forty-four patients with recurrent or new SCLC-associated brain metastases underwent GKS after receiving WBRT (median age, 62 years; median duration between WBRT and first GKS, 8.8 months). The median Karnofsky performance status (KPS) score was 100 (range, 40-100), and the median number of brain metastases at the first GKS was five. Ten patients who partially or completely responded to chemotherapy received prophylactic cranial irradiation (PCI) for limited disease.

RESULTS

The median prescribed dose and number of lesions treated with the initial GKS were 20.0 Gy and 3.5, respectively, and the tumor control rate was 95.8 % (median follow-up period, 4.0 months). The 6-month new lesion-free survival, functional preservation rates, and overall survival were 50.0 %, 94.7 %, and 5.8 months, respectively. Neurological death occurred in 17.9 % of cases. The poor prognostic factors for new lesion-free survival time and functional preservation were >5 brain metastases and carcinomatous meningitis, respectively. Poor prognostic factors for survival time were KPS <70, >10 brain metastases, diameter of the largest tumor >20 mm, and carcinomatous meningitis. Median overall survival time from brain metastasis diagnosis was 16.9 months.

CONCLUSIONS

GKS may be an effective option for controlling SCLC-associated brain metastases after WBRT and for preventing neurological death in patients without carcinomatous meningitis.

A prospective pilot study of two-session Gamma Knife surgery for large metastatic brain tumors

The purpose of this prospective study is to evaluate the efficacy and limitations of two-session Gamma Knife radiosurgery (GKS) alone for large metastatic brain tumors. Inclusion criteria were as follows: (i) patients with large metastatic brain tumors (volume >15 cm(3) in the supratentorial region or >10 cm(3) in the infratentorial region), and (ii) tumors not causing clinical signs of impending cerebral herniation. Twenty-eight lesions in 27 consecutive patients (18 men and 9 women, age range 32 to 88 years, median age 65 years) were included in this study. The radiosurgical protocol was as follows: 20-30 Gy given in two fractions 3-4 weeks apart. The local tumor control rate and the overall survival rate were calculated by using the Kaplan-Meier method. Median tumor volumes were 17.8 cm(3) at first GKS and 9.7 cm(3) at second GKS. Median follow-up time was 8.9 months. The local control rate was 85 % at 6 months and 61 % at 12 months. The overall survival rate after GKS was 63 % at 6 months and 45 % at 12 months. The 1-year rate of prevention of neurological death was maintained at 78 %. Mean Karnofsky performance status (KPS) improved from 61 [95 % confidence interval (CI), 57-71] at first GKS to 80 (95 % CI, 74-85) at second GKS; the best follow-up mean KPS was 85 (95 % CI, 78-91) (p < 0.001). Local tumor recurrence necessitated craniotomy in two patients and repeat GKS in three patients. Seventeen patients died, and the causes of death were as follows: 3 from local progression, 2 from meningeal carcinomatosis, and 12 from progression of the primary tumor. Delayed symptomatic perilesional edema developed in one patient and eventually resolved with conservative treatment. Two-session GKS for large brain metastases appears to be an effective treatment in terms of both local tumor control and neurological palliation with minimal treatment-related morbidity. These data suggest that two-session GKS could be used as an alternative to surgical resection of large tumors in patients with significant comorbidity and/or at an advanced age. The optimum regimen for dose and fraction schedule remains to be established.

Stereotactic radiosurgery as primary and salvage treatment for brain metastases from breast cancer

Object

To evaluate the role of stereotactic radiosurgery (SRS) in the management of brain metastases from breast cancer, the authors assessed clinical outcomes and prognostic factors for survival.

Methods

The records from 350 consecutive female patients who underwent SRS for 1535 brain metastases from breast cancer were reviewed. The median patient age was 54 years (range 19–84 years), and the median number of tumors per patient was 2 (range 1–18 lesions). One hundred seventeen patients (33%) had a single metastasis to the brain, and 233 patients (67%) had multiple brain metastases. The median tumor volume was 0.7 cm3 (range 0.01–48.9 cm3), and the median total tumor volume for each patient was 4.9 cm3 (range 0.09–74.1 cm3).

Results

Overall survival after SRS was 69%, 49%, and 26% at 6, 12, and 24 months, respectively, with a median survival of 11.2 months. Factors associated with a longer survival included controlled extracranial disease, a lower recursive partitioning analysis (RPA) class, a higher Karnofsky Performance Scale score, a smaller number of brain metastases, a smaller total tumor volume per patient, the presence of deep cerebral or brainstem metastases, and HER2/neu overexpression. Sustained local tumor control was achieved in 90% of the patients. Factors associated with longer progression-free survival included a better RPA class, fewer brain metastases, a smaller total tumor volume per patient, and a higher tumor margin dose. Symptomatic adverse radiation effects occurred in 6% of patients. Overall, the condition of 82% of patients improved or remained neurologically stable.

Conclusions

Stereotactic radiosurgery was safe and effective in patients with brain metastases from breast cancer and should be considered for initial treatment.

Radiation treatment strategies for acromegaly

The high morbidity and mortality associated with acromegaly can be addressed with multiple treatment modalities, including surgery, medicines, and radiation therapy. Radiation was initially delivered through conventional fractionated radiotherapy, which targets a wide area over many treatment sessions and has been shown to induce remission in 50%&#x2013;60% of patients with acromegaly. However, conventional fractionated radiotherapy takes several years to achieve remission in patients with acromegaly and carries a risk of hypopituitarism that may limit its use. Stereotactic radiosurgery, of which there are several forms, including Gamma Knife surgery, CyberKnife therapy, and proton beam therapy, offers slightly attenuated efficacy but achieves remission in less time and provides more precise targeting of the adenoma with better control of the dose of radiation received by adjacent structures such as the pituitary stalk, pituitary gland, optic chiasm, and cranial nerves in the cavernous sinus. Of the forms of stereotactic radiosurgery, Gamma Knife surgery is the most widely used and, because of its long-term follow-up in clinical studies, is the most likely to compete with medical therapy for first-line adjuvant use after resection. In this review, the authors outline the major modes of radiation therapies in clinical use today, and they critically assess the feasibility of these modalities for acromegaly treatment. Acromegaly is a multisystem disorder that demands highly specialized treatment protocols including neurosurgical and endocrinological intervention. As more efficient forms of pituitary radiation develop, acromegaly treatment options may continue to change with radiation therapies playing a more prominent role.

Gamma Knife surgery for brain metastases from colorectal cancer. Clinical article

OBJECT

The outcomes after Gamma Knife surgery (GKS) were retrospectively analyzed in patients with brain metastases from radioresistant primary colorectal cancer to evaluate the efficacy of GKS and the prognostic factors for local tumor control and overall survival.

METHODS

The authors reviewed the medical records of 152 patients with 616 tumors. The group included 102 men and 50 women aged 35-85 years (mean age 64.4 years), who underwent GKS for metastatic brain tumors from colorectal cancer between April 1992 and September 2008 at Yokohama Rosai Hospital.

RESULTS

The mean prescription dose to the tumor margin was 18.5 Gy (range 8-30 Gy). The mean tumor volume at GKS was 2.0 cm(3) (range 0.004-10.0 cm(3)). The primary tumors were located in the colon in 88 patients and the rectum in 64. The median interval between the diagnosis of primary lesions and the diagnosis of brain metastases was 27 months (range 0-180 months). The median neuroradiological follow-up period after GKS was 3 months (mean 6.4 months, range 1-93 months). The local tumor growth control rate, based on MR imaging, was 91.2%. The significant factors for unfavorable local tumor growth control, based on multivariate analysis, were larger tumor volume (p = 0.001) and lower margin dose (p = 0.016). The median overall survival time was 6 months. Lower Karnofsky Performance Scale (KPS) score (p = 0.026) and the presence of extracranial metastases (p = 0.004) at first GKS were significantly correlated with poor overall survival period in multivariate analysis. The cause of death was systemic disease in 112 patients and neurological disease in 13 patients. Leptomeningeal carcinomatosis was significantly correlated with a shorter duration of neurological survival in multivariate analysis (p < 0.0001).

CONCLUSIONS

Gamma Knife surgery is effective for suppression of local tumor growth in patients with brain metastases from radioresistant colorectal primary cancer. Therefore, clinical and radiological screening of intracranial metastases for patients with lower KPS scores and/or the presence of extracranial metastases as well as follow-up examinations after GKS for brain metastases should be performed periodically in patients with colorectal cancer, because the neurological prognosis is improved by initial and repeat GKS for newly diagnosed or recurrent tumors leading to a prolonged high-quality survival period.

Synergistic action of oncolytic herpes simplex virus and radiotherapy in pancreatic cancer cell lines

BACKGROUND

Despite much research in chemotherapy and radiotherapy, pancreatic adenocarcinoma remains a fatal disease, highly resistant to all treatment modalities. Recent developments in the field of herpes simplex virus (HSV) engineering have allowed the generation of a number of promising virus vectors for treatment of many cancers, including pancreatic tumours. This study examined the use of one such virus, NV1023, in combination with radiation therapy in pancreatic cancer cell lines.

METHODS

HSV therapy in combination with radiotherapy was investigated in pancreatic cancer cell lines Hs766T, Panc-1 and MIA PaCa-2. Multiple therapy effect analysis was performed by computerized simulation. Mechanisms underlying synergy, such as virus replication and apoptosis, were investigated.

RESULTS

The combination of NV1023 and radiation yielded a synergistic oncolytic effect in all tested pancreatic cancer cell lines, with the greatest effect achieved in MIA PaCa-2. This effect was not mediated by an increase in rapid viral replication, but by a substantial increase in apoptosis.

CONCLUSION

The synergistic oncolytic actions of HSV and radiotherapy observed in pancreatic cancer cell lines encourage further testing of this multimodality treatment.

Leptomeningeal carcinomatosis from renal cell cancer: treatment attempt with radiation and sunitinib (case report)

A case of leptomeningeal carcinomatosis in a patient with known brain and lung metastases from renal cell cancer without previous systemic therapy is presented. Neoplastic meningitis (NM) developed 31 months after first diagnosis of simultaneous extra- and intracranial recurrence of kidney cancer and surgical resection of a cerebellar metastasis. In spite of local radiotherapy to the macroscopic NM lesions in the cervical and lumbar spine followed by initiation of sunitinib, the patient succumbed to his disease 4 months after the diagnosis of NM. The untreated lung metastases progressed very slowly during almost 3 years of observation. This case illustrates important issues around both biological behaviour and treatment approaches in metastatic renal cell cancer.

Gamma knife surgery for 1-10 brain metastases without prophylactic whole-brain radiation therapy: analysis of cases meeting the Japanese prospective multi-institute study (JLGK0901) inclusion criteria

We evaluated the results of stereotactic radiosurgery (SRS) alone using gamma knife (GK) for selected patients with 1-10 brain metastases without prophylactic whole-brain radiation therapy (WBRT) among JLGK0901-eligible cases. Seven hundred seventy-eight consecutive cases meeting the following JLGK0901 study inclusion criteria were analyzed: (1) newly diagnosed brain metastases, (2) 1-10 brain lesions, (3) less than 10 cm(3) volume of the largest tumor, (4) less than 15 cm(3) total tumor volume, (5) no magnetic resonance (MR) findings of cerebrospinal fluid (CSF) dissemination, and (6) no impaired activity of daily living [<70 Karnofsky Performance Score (KPS)] due to extracranial disease. At initial treatment, all lesions were irradiated with SRS without upfront WBRT. Thereafter, enhanced magnetic resonance imaging (MRI) was applied every 2-3 months, and new distant lesions were appropriately retreated with SRS or WBRT. We divided patients according to tumor number: single lesion for group A (280 cases), 2 for group B (135), 3-4 for group C (148), 5-6 for group D (93), and 7-10 for group E (122). Differences among groups were compared in terms of overall, neurological, qualitative, and new-lesion-free survival (NLFS). Median age was 65 years (range 26-92 years). There were 505 men and 273 women. The primary organ was lung in 579 patients, gastrointestinal tract in 79, breast in 48, urinary tract in 34, and others/unknown in 38. Mean survival time was 0.72 years (0.83 years for 1, 0.69 years for 2, 0.69 years for 3-4, 0.59 years for 5-6, and 0.62 years for 7-10 metastases). On multivariate analysis, significant poor prognostic factors for overall survival (OS) were active systemic disease, poor (<70) initial KPS, and male gender. Neurological survival and qualitative survival at 1 year were 92.7% and 88.2%, respectively. NLFS at 6 months and 1 year were 69.8% and 43.8%, respectively. There were statistically significant differences in new lesion emergence between groups A and B and between groups B and C. SRS using GK provides excellent results in selected patients with 1-10 brain lesions, without prophylactic WBRT. This study revealed that brain lesion number has no effect on any of the four types of survivals, which is anticipated to be confirmed by the JLGK0901 study.

Treatment of brain metastases from renal cell cancer

OBJECTIVE

To evaluate disease pattern, patient characteristics, and survival in patients treated for brain metastases from renal cell carcinoma.

METHODS

Retrospective analysis of all patients with brain metastases from renal cell carcinoma treated between 1983 and 2009 in northern Norway.

RESULTS

The time interval between first cancer diagnosis and brain metastases was dependent on initial TNM stage (median 42 months in stage II vs. 10 months in both stage III and stage IV). Only few patients did not harbor extracranial metastases. Systemic therapy after diagnosis of brain metastases has been used in only three patients. Surgical resection and/or radiosurgery have been administered in 34% of patients, but whole-brain radiotherapy (WBRT) alone remained the cornerstone. Median survival was 4.1 months (3.7 months in the WBRT alone group, 10.1 months in the surgery and/or radiosurgery group). Two factors were significantly associated with better survival: solitary brain metastasis and age ≤64 years. The prognostic impact of the recursive partitioning analysis classes was not confirmed, while the new graded prognostic assessment index performed better.

CONCLUSIONS

Surgical resection and/or radiosurgery contribute to prolonged survival. As most patients harbor extracranial metastases that threaten their lives, systemic treatment theoretically might play a role in the management of these patients, but more data need to be collected to confirm the clinical impact of immunotherapy, angiogenesis inhibition, and other signal transduction inhibitor approaches.

Gamma Knife surgery for metastatic brain tumors

Object

The authors compared results of Gamma Knife surgery (GKS) for brain metastases obtained at 2 institutions in Japan.

Methods

They analyzed a consecutive series of 2390 patients with brain metastases who underwent GKS from 1998 through 2005 in 2 institutes (1181 patients in Chiba; 1209 in Mito). In the 2 facilities, 1 neurosurgeon each was responsible for diagnosis, patient selection, GKS procedures, and follow-up (T.S. in Chiba, M.Y. in Mito). Even if tumor numbers exceeded 4, all visible lesions were irradiated with a total skull integral dose (TSID) of ≤ 10–12 J. No prophylactic whole-brain radiotherapy (WBRT) was applied. If new distant lesions were detected, salvage GKS was appropriately performed.

Results

The distributions of patient and treatment factors did not differ between institutes. The most common primary tumors were lung cancer (1572 patients), followed by gastrointestinal tract (316), breast (211), kidney (113), and other cancers (159). The median survival periods were 7.7 months in Chiba and 7.0 months in Mito (p = 0.0635). The significant poor prognostic factors for overall survival were active extracranial disease status, male sex, and low initial Karnofsky Performance Scale score on multivariate analysis (all p < 0.0001). The neurological survival rates at 1 year were 86.6% in Chiba and 84.2% in Mito (p = 0.3310).

Conclusions

This 2-institute study demonstrated no significant institutional differences in any of the treatment result items. Gamma Knife surgery for brain metastases without prophylactic WBRT prevents neurological death and allows a patient to maintain good brain condition. However, there is 1 important patient selection criterion: regardless of how many tumors there are, all lesions can be irradiated with a TSID of ≤12 J.

Incidence of brain atrophy and decline in mini-mental state examination score after whole-brain radiotherapy in patients with brain metastases: a prospective study

PURPOSE

To determine the incidence of brain atrophy and dementia after whole-brain radiotherapy (WBRT) in patients with brain metastases not undergoing surgery.

METHODS AND MATERIALS

Eligible patients underwent WBRT to 40 Gy in 20 fractions with or without a 10-Gy boost. Brain magnetic resonance imaging or computed tomography and Mini-Mental State Examination (MMSE) were performed before and soon after radiotherapy, every 3 months for 18 months, and every 6 months thereafter. Brain atrophy was evaluated by change in cerebrospinal fluid-cranial ratio (CCR), and the atrophy index was defined as postradiation CCR divided by preradiation CCR.

RESULTS

Of 101 patients (median age, 62 years) entering the study, 92 completed WBRT, and 45, 25, and 10 patients were assessable at 6, 12, and 18 months, respectively. Mean atrophy index was 1.24 +/- 0.39 (SD) at 6 months and 1.32 +/- 0.40 at 12 months, and 18% and 28% of the patients had an increase in the atrophy index by 30% or greater, respectively. No apparent decrease in mean MMSE score was observed after WBRT. Individually, MMSE scores decreased by four or more points in 11% at 6 months, 12% at 12 months, and 0% at 18 months. However, about half the decrease in MMSE scores was associated with a decrease in performance status caused by systemic disease progression.

CONCLUSIONS

Brain atrophy developed in up to 30% of patients, but it was not necessarily accompanied by MMSE score decrease. Dementia after WBRT unaccompanied by tumor recurrence was infrequent.

Boost radiosurgery for treatment of brain metastases after surgical resections

BACKGROUND

We evaluated results of resection surgery followed by boost radiosurgery for the treatment of brain metastases.

METHODS

We treated 21 patients (13 male, 8 female) with surgical resection (subtotal or total) followed by boost radiosurgery. The mean patient age was 61 years (range, 41-80 years); supratentorial lesions were treated in 12 patients, and posterior fossa lesions were treated in 9 patients. The most common primary cancers were lung (24%) and colon (24%). Fifty-three percent of patients had brain metastases only, whereas 47% had extracranial metastases. The radiosurgery dose plan was designed to radiate the operative cavity; the mean treatment volume (50% isodose) was 10.7 mL (range, 3.4-23.3 mL), and the mean marginal dose was 17 Gy (range, 13-20 Gy).

RESULTS

Local control was achieved in 16 (76%) patients. However, new intracranial lesions developed in 10 patients, and meningeal carcinomatosis occurred in 5 patients. Local tumor recurrence occurred more often for patients treated with lower radiotherapy doses (<18 vs > or =18 Gy, P = .03), and meningeal carcinomatosis occurred more often in patients with posterior fossa lesions (P = 0.05). Gamma knife radiosurgery was performed in 13 patients, and whole-brain radiation was performed in 2 patients. No patients experienced symptomatic radiation injury, and the median survival time was 20 months.

CONCLUSIONS

Although boost radiosurgery is less invasive and reduces morbidity, the radiosurgical dose must be higher than 18 Gy for the treatment to be most effective. Treatment of lesions of the posterior fossa must be considered carefully because of the higher frequency of meningeal carcinomatosis. Also, we recommend that the surgeons who operate on the metastatic tumors must try to decrease the resected cavity volume and to prevent cerebrospinal fluid dissemination at the operation for posterior fossa lesions.