Gamma Knife radiosurgery to the surgical cavity following resection of brain metastases

Brachytherapy in Brain Metastasis Treatment: A Scoping Review of Advances in Techniques and Clinical Outcomes

Brain metastases pose a significant therapeutic challenge in the field of oncology, necessitating treatments that effectively control disease progression while preserving neurological and cognitive functions. Among various interventions, brachytherapy, which involves the direct placement of radioactive sources into or near tumors or into the resected cavity, can play an important role in treatment. Current literature describes brachytherapy's capacity to deliver targeted, high-dose radiation while minimizing damage to adjacent healthy tissues-a crucial consideration in the choice of treatment modality. Furthermore, advancements in implantation techniques as well as in the development of different isotopes have expanded its efficacy and safety profile. This review delineates the contemporary applications of brachytherapy in managing brain metastases, examining its advantages, constraints, and associated clinical outcomes, and provides a comprehensive understanding of advances in the use of brachytherapy for brain metastasis treatment, with implications for improved patient outcomes and enhanced quality of life.

Is there an optimal time to administer postoperative stereotactic radiosurgery in patients with brain metastases? A systematic review of the literature and meta-analysis

Postoperative stereotactic radiosurgery improves local tumor control in patients with metastatic brain cancer. However, the influence of timing on its therapeutic efficacy is unclear. In this study, we performed a meta-analysis and systematic literature review examining publications that reported the timing of postoperative stereotactic radiosurgery (SRS) for patients with intracranial metastases. Our primary outcomes included median overall survival and rates of local and regional failure, while secondary outcomes examined the incidence of treatment-related adverse events. Correlations between median SRS timing and these variables were assessed using linear regression and publication bias was appraised via Egger's test. Our study resulted in 22 articles comprising 1338 patients. The median timing of adjuvant SRS spanned 14.5 to 41 days. There was a significant negative study-level correlation of median time to SRS with regional failure (p = 0.043, R2 = 0.32) but not with overall survival (p = 0.54, R2 = 0.03) or local failure (p = 0.16, R2 = 0.14). Additionally, there was significant heterogeneity within the reports (p<0.0001). In conclusion, our analysis demonstrated that postoperative SRS timing did not influence local failure rates which may in part be due to significant variability between individual study designs and patient demographics. Further research is warranted to elucidate the role of timing for postoperative SRS on oncologic outcomes.

Metastatic Lesions of the Brain and Spine

Brain and spinal metastases are common in cancer patients and are associated with significant morbidity and mortality. Continued advancement in the systemic care of cancer has increased the life expectancy of patients, and consequently, the incidence of brain and spine metastasis has increased. There has been an increase in the understanding of oncogenic mutations, and research has also demonstrated spatial and temporal mutations in patients that may drive overall treatment resistance and failure. Combinatory treatments with radiation, surgery, and newer systemic therapies have continued to increase the life expectancy of patients with brain and spine metastases. Given the overall complexity of brain and spine metastases, this chapter aims to give a comprehensive overview and cover important topics concerning brain and spine metastases. This will include the molecular, genetic, radiographic, surgical, and non-surgical treatments of brain and spinal metastases.

Integrated Multidisciplinary Brain Metastasis Care Reduces Patient Visits and Shortens Time to Adjuvant Irradiation

PURPOSE

Timely surgical cavity stereotactic radiosurgery (SRS) is an important adjuvant to brain metastasis resection, with earlier treatment associated with less frequent recurrence. The logistical complexity of treatment organization, however, has resulted in suboptimal start times postsurgically. We implemented a process improvement approach to reduce the time from surgery to adjuvant irradiation of resected brain metastases.

METHODS

A multidisciplinary working group used process mapping to identify opportunities to reduce visits and shorten treatment times. The care delivery process was modified to streamline perioperative SRS preparation with (1) early patient identification, (2) preoperative intrateam communication, and (3) consolidation of required steps. Plan-Do-Study-Act cycles were used for process improvement. The surgery-to-SRS initiation time interval was the primary outcome. Secondary outcomes included the number of associated patient encounters.

RESULTS

After implementation, the median (interquartile range) interval from surgery to SRS was reduced 48% from 27 (21-34) to 14 days (13-17; P < .001). The rate of surgical cavity SRS within 30 days increased from 64% (n = 63 of 98) to 97% (n = 60 of 62; P < .001). The median (interquartile range) number of CNS-associated encounters between resection and SRS decreased from 5 (4-6) to 4 (3-5; P < .001). The proportion of patients who had > 1 magnetic resonance imaging/computed tomography between surgery and SRS decreased from 45% (44 of 98) to 13% (8 of 62; P < .001). The time from surgery to systemic therapy resumption/initiation among patients treated within 90 days postoperatively decreased from 35 (24-48) to 32 days (23-40; P = .074). There were no wound complications in either group.

CONCLUSION

Adjuvant SRS latency and treatment-associated encounters were significantly reduced after care-coordination implementation. This approach reduces patient and health care system burden and can be applied to other scenarios where early postoperative SRS administration is critical.

Salvage brachytherapy for multiply recurrent metastatic brain tumors: a matched-case analysis

Background

Patients with recurrent brain metastases who have exhausted external radiation options pose a treatment challenge in the setting of advances in systemic disease control which have improved quality of life and survival. Brachytherapy holds promise as salvage therapy given its ability to enforce surgical cytoreduction and minimize regional toxicity. This study investigates the role of salvage brachytherapy in maintaining local control for recurrent metastatic lesions.

Methods

We retrospectively reviewed our institution’s experience with brachytherapy in patients with multiply recurrent cerebral metastases who have exhausted external radiation treatment options (14 cases). The primary outcome of the study was freedom from local recurrence (FFLR). To capture the nuances of tumor biology, we compared FFLR achieved by brachytherapy to the preceding treatment for each patient. We further compared the response to brachytherapy in patients with lung cancer (8 cases) against a matched cohort of maximally radiated lung brain metastases (10 cases).

Results

Brachytherapy treatment conferred significantly longer FFLR compared to prior treatments (median 7.39 vs 5.51 months, P = .011) for multiply recurrent brain metastases. Compared to an independent matched cohort, brachytherapy demonstrated superior FFLR (median 8.49 vs 1.61 months, P = .004) and longer median overall survival (11.07 vs 5.93 months, P = .055), with comparable side effects.

Conclusion

Brachytherapy used as salvage treatment for select patients with a multiply recurrent oligometastatic brain metastasis in the setting of well-controlled systemic disease holds promise for improving local control in this challenging patient population.

Clinical Evaluation of the Inverse Planning System Utilized in Gamma Knife Lightning

Objectives

The purpose of this study is to independently compare the performance of the inverse planning algorithm utilized in Gamma Knife (GK) Lightning Treatment Planning System (TPS) to manual forward planning, between experienced and inexperienced users, for different types of targets.

Materials and Methods

Forty patients treated with GK stereotactic radiosurgery (SRS) for pituitary adenoma (PA), vestibular schwannoma (VS), post-operative brain metastases (pBM), and intact brain metastases (iBM) were randomly selected, ten for each site. Three inversely optimized plans were generated for each case by two experienced planners (OptExp1 and OptExp2) and a novice planner (OptNov) using GK Lightning TPS. For each treatment site, the Gradient Index (GI), the Paddick Conformity Index (PCI), the prescription percentage, the scaled beam-on time (sBOT), the number of shots used, and dosimetric metrics to OARs were compared first between the inversely optimized plans and the manually generated clinical plans, and then among the inversely optimized plans. Statistical analyses were performed using the Student’s t-test and the ANOVA followed by the post-hoc Tukey tests.

Results

The GI for the inversely optimized plans significantly outperformed the clinical plans for all sites. PCIs were similar between the inversely optimized and clinical plans for PA and VS, but were significantly improved in the inversely optimized plans for iBM and pBM. There were no significant differences in the sBOT between the inversely optimized and clinical plans, except for the PA cases. No significant differences were observed in dosimetric metrics, except for lower brain V_12Gy and PTV D_98% in the inversely optimized plans for iBM. There were no noticeable differences in plan qualities among the inversely optimized plans created by the novice and experienced planners.

Conclusion

Inverse planning in GK Lightning TPS produces GK SRS plans at least equivalent in plan quality and similar in sBOT compared to manual forward planning in this independent validation study. The automatic workflow of inversed planning ensures a consistent plan quality regardless of a planner’s experience.

GammaTile for Gliomas: A Single-Center Case Series

GammaTile® (GT Medical Technologies, Tempe, Arizona) is a surgically targeted radiation source, approved by FDA for brachytherapy in primary and secondary brain neoplasms. Each GammaTile is composed of a collagen sponge with four seeds of cesium 131 and is particularly useful in recurrent tumors. We report our early experience in seven patients with recurrent gliomas to assess this type of brachytherapy with particular attention to ease of use, complication, and surgical planning. This study represents a retrospective chart review of surgical use and early clinical outcomes of GammaTile in recurrent gliomas. The number of tiles was planned using pre-operative imaging and dosimetry was planned based on post-operative imaging. Patients were followed during their hospital stay and were followed up after discharge. Parameters such as case length, resection extent, complication, ICU length of stay (LOS), hospital LOS, pre-operative Glasgow Coma Scale (GCS), immediate post-operative GCS, post-operative imaging findings, recurrence at follow-up, length of follow-up, and dosimetry were collected in a retrospective manner. Seven patients were identified that met the inclusion criteria. Two patients were diagnosed with recurrent glioblastoma multiforme (GBM), one lower-grade glioma that recurred as a GBM, one GBM that recurred as a gliosarcoma, and two recurrent oligodendrogliomas. We found that operation time, ICU LOS, hospital LOS, pre- and post-operative GCS, and post-operative complications were within the expected ranges for tumor resection patients. Further, dosimetry data suggests that six out of seven patients received adequate radiation coverage, with the seventh having implantation limitations due to nearby organs at risk. We report no postoperative complications that can be attributed to the GammaTiles themselves. In our cohort, we report seven cases where GammaTiles were implanted in recurrent gliomas. No implant-related post-operative complications were identified. This early data suggests that GammaTile can be a safe form of brachytherapy in recurrent gliomas.

Resecting the dominant lesion: Patient outcomes after surgery and radiosurgery vs stand-alone radiosurgery in the setting of multiple brain metastases

BACKGROUND

Brain metastases are the most common central nervous system (CNS) tumors, occurring in 300,000 people per year in the US. While there are immediate local benefits to surgical resection for dominant lesions, including reduction of tumor burden and edema, the survival benefits of surgical resection, over radiosurgery, remains unclear.

METHODS

The University of Pennsylvania Health System database was retrospectively reviewed for patients presenting with multiple brain metastases from 1/1/16-8/31/18 with one dominant lesion > 2 cm in diameter, who underwent initial treatment with either resection of the dominant lesion or Gamma Knife radiosurgery (GKS). Inclusion criteria were age > 18, > 1 brain metastasis, and presence of a dominant lesion (>2 cm). We analyzed factors associated with mortality.

RESULTS

129 patients were identified (surgery=84, GKS=45). The median number of intracranial metastases was 3 (IQR: 2-5). The median diameter of the largest lesion was 31 mm (IQR: 25-38) in the surgery group vs 21 mm (IQR: 20-24) in the GKS group (p < 0.001). Mortality did not differ between surgery and GKS patients (69.1% vs 77.8%, p = 0.292). In a multivariate survival analysis, there was no difference in mortality between the surgery and GKS cohorts (aHR: 1.35, 95% CI: 0.74-2.45 p = 0.32). Pre-operative KPS (aHR: 0.97, 95% CI: 0.95-0.99, p = 0.004), CNS radiotherapy (aHR: 0.33, 95% CI: 0.19-0.56 p < 0.001), chemotherapy (aHR: 0.27, 95% CI: 0.15-0.47, p < 0.001), and immunotherapy (aHR: 0.41, 95% CI: 0.25-0.68, p = 0.001) were associated with decreased mortality.

CONCLUSION

In our institution, patients with multiple brain metastases and one symptomatic dominant lesion demonstrated similar survival after GKS when compared with up-front surgical resection of the dominant lesion.

Retrospective analysis of portal dosimetry pre-treatment quality assurance of intracranial SRS/SRT VMAT treatment plans

Background:

The complexity associated with the treatment planning and delivery of stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) volumetric modulated arc therapy (VMAT) plans which employs continuous dynamic modulation of dose rate, field aperture and gantry speed necessitates diligent pre-treatment patient-specific quality assurance (QA). Numerous techniques for pre-treatment VMAT treatment plans QA are currently available with the aid of several different devices including the electronic portal imager (EPID). Although several studies have provided recommendations for gamma criteria for VMAT pre-treatment QA, there are no specifics for SRS/SRT VMAT QA. Thus, we conducted a study to evaluate intracranial SRS/SRT VMAT QA to determine clinical action levels for gamma criteria based on the institutional estimated means and standard deviations.

Materials and methods:

We conducted a retrospective analysis of 118 EPID patient-specific pre-treatment QA dosimetric measurements of 47 brain SRS/SRT VMAT treatment plans using the integrated Varian solution (RapidArcTM planning, EPID and Portal dosimetry system) for planning, delivery and EPID QA analysis. We evaluated the maximum gamma (γmax), average gamma (γave) and percentage gamma passing rate (%GP) for different distance-to-agreement/dose difference (DTA/DD) criteria and low-dose thresholds.

Results:

The gamma index analysis shows that for patient-specific SRS/SRT VMAT QA with the portal dosimetry, the mean %GP is ≥98% for 2–3 mm/1–3% and Field+0%, +5% and +10% low-dose thresholds. When applying stricter spatial criteria of 1 mm, the mean %GP is >90% for DD of 2–3% and ≥88% for DD of 1%. The mean γmax ranges: 1·32 ± 1·33–2·63 ± 2·35 for 3 mm/1–3%, 1·57 ± 1·36–2·87 ± 2·29 for 2 mm/1–3% and 2·36 ± 1·83–3·58 ± 2·23 for 1 mm/1–3%. Similarly the mean γave ranges: 0·16 ± 0·06–0·19 ± 0·07 for 3 mm/1–3%, 0·21 ± 0·08–0·27 ± 0·10 for 2 mm/1–3% and 0·34 ± 0·14–0·49 ± 0·17 for 1 mm/1–3%. The mean γmax and mean γave increase with increased DTA and increased DD for all low-dose thresholds.

Conclusions:

The establishment of gamma criteria local action levels for SRS/SRT VMAT pre-treatment QA based on institutional resources is imperative as a useful tool for standardising the evaluation of EPID-based patient-specific SRS/SRT VMAT QA. Our data suggest that for intracranial SRS/SRT VMAT QA measured with the EPID, a stricter gamma criterion of 1 mm/2% or 1 mm/3% with ≥90% %GP could be used while still maintaining an in-control QA process with no extra burden on resources and time constraints.

A matched-pair analysis of clinical outcomes after intracavitary cesium-131 brachytherapy versus stereotactic radiosurgery for resected brain metastases

OBJECTIVE

Adjuvant radiation therapy (RT), such as cesium-131 (Cs-131) brachytherapy or stereotactic radiosurgery (SRS), reduces local recurrence (LR) of brain metastases (BM). However, SRS is less efficacious for large cavities, and the delay between surgery and SRS may permit tumor repopulation. Cs-131 has demonstrated improved local control, with reduced radiation necrosis (RN) compared to SRS. This study represents the first comparison of outcomes between Cs-131 brachytherapy and SRS for resected BM.

METHODS

Patients with BM treated with Cs-131 and SRS following gross-total resection were retrospectively identified. Thirty patients who underwent Cs-131 brachytherapy were compared to 60 controls who received SRS. Controls were selected from a larger cohort to match the patients treated with Cs-131 in a 2:1 ratio according to tumor size, histology, performance status, and recursive partitioning analysis class. Overall survival (OS), LR, regional recurrence, distant recurrence (DR), and RN were compared.

RESULTS

With a median follow-up of 17.5 months for Cs-131-treated and 13.0 months for SRS-treated patients, the LR rate was significantly lower with brachytherapy; 10% for the Cs-131 cohort compared to 28.3% for SRS patients (OR 0.281, 95% CI 0.082-0.949; p = 0.049). Rates of regional recurrence, DR, and OS did not differ significantly between the two cohorts. Kaplan-Meier analysis with log-rank testing showed a significantly higher likelihood of freedom from LR (p = 0.027) as well as DR (p = 0.018) after Cs-131 compared to SRS treatment (p = 0.027), but no difference in likelihood of OS (p = 0.093). Six (10.0%) patients who underwent SRS experienced RN compared to 1 (3.3%) patient who received Cs-131 (p = 0.417).

CONCLUSIONS

Postresection patients with BM treated with Cs-131 brachytherapy were more likely to achieve local control compared to SRS-treated patients. This study provides preliminary evidence of the potential of Cs-131 to reduce LR following gross-total resection of single BM, with minimal toxicity, and suggests the need for a prospective study to address this question.

Stereotactic Radiosurgery to Prevent Local Recurrence of Brain Metastasis After Surgery: Neoadjuvant Versus Adjuvant

Over the past 15-20 years, stereotactic radiosurgery (SRS) has become the dominant method for treating patients with brain metastases (BM). The role of surgery for management of large tumors also remains important. Combining these two treatment modalities may well achieve the best local control, safety, and symptomatic relief in cases of neoplasms for which resection is desirable. After 10 years of retrospective studies that suggested patients might do better if surgery were followed by early adjuvant SRS, a prospective, randomized, controlled trial was conducted to compare such treatment with postoperative observation after tumor removal, and it showed significantly better local control in the former cohort, especially in smaller lesions, but no difference in overall survival. On the other hand, in the past 5 years, some groups have argued that neoadjuvant SRS before resection of BM might be superior to adjuvant SRS, while no clinical trial has yet been concluded that compares these two treatment strategies. For now, adjuvant and neoadjuvant SRS show evidence of utility in achieving better local control after surgical removal of BM in comparison with surgery alone, but no specific guidelines exist favoring one method over the other, and both should be considered beneficial in clinical care.

Image-Guided, Linac-Based, Surgical Cavity-Hypofractionated Stereotactic Radiotherapy in 5 Daily Fractions for Brain Metastases

BACKGROUND

Cavity stereotactic radiotherapy has emerged as a standard option following resection of brain metastases. However, the optimal approach with either single-fraction or hypofractionated stereotactic radiotherapy (HSRT) remains a significant question.

OBJECTIVE

To report outcomes for 5-fraction HSRT to the surgical cavity, based on contouring according to a recently reported international consensus guideline.

METHODS

Patients treated with cavity HSRT were identified from a prospective institutional database. Local brain control (LC), distant brain failure (DBF), leptomeningeal disease (LMD), and overall survival rates were determined. Univariate and multivariable analyses were performed on potential predictive factors.

RESULTS

One hundred thirty-seven cavities in 122 patients were treated at a median total dose of 30 Gy (range, 25-35 Gy). The median follow-up was 16 mo (range, 1-60 mo). Nonsmall cell lung cancer was the most common histology (44%), followed by breast cancer (21%). In 57% of surgical cavities, the preoperative tumor diameter was >3 cm. One-year LC, DBF, LMD, and overall survival rates were 84%, 45%, 22%, and 62%, respectively. Multivariable analyses identified colorectal (hazard ratio [HR] 4.1, P = .0066) and melanoma (HR 2.4, P = .012) metastases as predictors of local recurrence; preoperative tumor diameter >2 cm (HR 8.9, P = .012) and absence of targeted therapy (HR 4.4, P = .03) as predictors of DBF; and breast cancer histology (HR 2.1, P = .05) and subtotal resection (HR 2.6, P = .009) as predictors of LMD. Symptomatic radiation necrosis was observed in 7 patients (6%).

CONCLUSION

High rates of LC were observed following this 5-fraction HSRT regimen. Superiority as compared to single-fraction SRS requires a randomized trial.

The role of brachytherapy in the management of brain metastases: a systematic review

Purpose

Brain metastases have a highly variable prognosis depending on the primary tumor and associated prognostic factors. Standard of care for patients with these tumors includes craniotomy, stereotactic radiosurgery (SRS), or whole brain radiotherapy (WBRT) for patients with brain metastases. Brachytherapy shows great promise as a therapy for brain metastases, but its role has not been sufficiently explored in the current literature.

Material and methods

The PubMed, Cochrane, and Scopus databases were searched using a combination of search terms and synonyms for brachytherapy, brain neoplasms, and brain metastases, for articles published between January 1^st, 1990 and January 1^st, 2018. Of the 596 articles initially identified, 37 met the inclusion criteria, of which 14 were review articles, while the remaining 23 papers with detailing individual studies were fully analyzed.

Results

Most data focused on ¹²⁵I and suggested that it offers rates of local control and overall survival comparable to standard of care modalities such as SRS. However, radiation necrosis and regional recurrence were often high with this isotope. Studies using photon radiosurgery modality of brachytherapy have also been completed, resulting superior regional control as compared to SRS, but worse local control and higher rates of radiation necrosis than ¹²⁵I. More recently, studies using the ¹³¹Cs for brachytherapy offered similar local control and survival benefits to ¹²⁵I, with low rates of radiation necrosis.

Conclusions

For a variety of reasons including absence of physician expertise in brachytherapy, lack of published data on treatment outcomes, and rates of radiation necrosis, brachytherapy is not presently a part of standard paradigm for brain metastases. However, our review indicates brachytherapy as a modality that offers excellent local control and quality of life, and suggested that its use should be further studied.

Brain metastasis of Merkel cell carcinoma - A rare case report

Background:

Merkel cell carcinoma (MCC) is a rare neuroendocrine skin tumor. In our knowledge, only 30 cases of brain metastasis were reported in literature. The authors report a case of 57-year-old male with elevated intracranial pressure signs, which a frontal mass with pathological diagnosis of MCC.

Case Description:

A 57-year-old male was admitted with a 3-month history of progressive headache, associated with nausea and dizziness. The magnetic resonance imaging showed a left frontal lobe, parasagittal, and nodular lesion with perilesional edema. The patient underwent complete surgical resection with success. The adjuvant treatment was radiotherapy and chemotherapy.

Conclusion:

In our knowledge, there is a little number of cases of MCC reported in literature. Surgical management is considered in cases with intracranial hypertension or focal signs. The adjuvant treatment options are immunotherapy and radiotherapy.

The Relationship Between Tumor Volume and Timing of Post-resection Stereotactic Radiosurgery to Maximize Local Control: A Critical Review

After maximally safe neurosurgical resection of brain metastases, stereotactic radiosurgery (SRS) is now recommended as an alternative to whole-brain radiation therapy (WBRT), which has been associated with cognitive decline. One complicating factor associated with SRS is that postoperative cavity dynamics can change dramatically, creating significant variability in the recommended timing of SRS. While SRS has been shown to improve local control (LC) in smaller tumor cavities, achieving excellent LC rates still remains a challenge in larger ones. Furthermore, factors predicting the optimal timing of SRS in relation to the cavity size need to be defined and implemented. Variables such as the delay between postoperative MRI and treatment are critical but poorly understood. One potential treatment option that may improve outcomes is brachytherapy, but the widespread implementation of this technique has been slow. This critical review analyzes the relationship between preoperative tumor volume, resection cavity size, and timing of SRS and explores how these variables must be understood in order to achieve the highest LC possible.

Three-stage Gamma Knife treatment for metastatic brain tumors larger than 10 cm3: a 2-institute study including re-analyses of earlier results using competing risk analysis

OBJECTIVEThe results of 3-stage Gamma Knife treatment (3-st-GK-Tx) for relatively large brain metastases have previously been reported for a series of patients in Chiba, Japan (referred to in this study as the C-series). In the current study, the authors reappraised, using a competing risk analysis, the efficacy and safety of 3-st-GK-Tx by comparing their experience with that of the C-series.METHODSThis was a retrospective cohort study. Among 1767 patients undergoing GK radiosurgery for brain metastases at Mito Gamma House during the 2005-2015 period, 78 (34 female, 44 male; mean age 65 years, range 35-86 years) whose largest tumor was > 10 cm3, treated with 3-st-GK-Tx, were studied (referred to in this study as the M-series). The target volumes were covered with a 50% isodose gradient and irradiated with a peripheral dose of 10 Gy at each procedure. The interval between procedures was 2 weeks. Because competing risk analysis had not been employed in the published C-series, the authors reanalyzed the previously published data using this method.RESULTSThe overall median survival time after 3-st-GK-Tx was 8.3 months (95% CI 5.6-12.0 months) in the M-series and 8.6 months (95% CI 5.5-10.6 months) in the C-series (p = 0.41). Actuarial survival rates at the 6th and 12th post-3-st-GK-Tx months were, respectively, 55.1% and 35.2% in the M-series and 62.5% and 26.4% in the C-series (HR 1.175, 95% CI 0.790-1.728, p = 0.42). Cumulative incidences at the 12th post-3-st-GK-Tx, determined by competing risk analyses, of neurological deterioration (14.2% in C-series vs 12.8% in M-series), neurological death (7.2% vs 7.7%), local recurrence (4.8% vs 6.2%), repeat SRS (25.9% vs 18.0%), and SRS-related complications (2.3% vs 5.1%) did not differ significantly between the 2 series.CONCLUSIONSThere were no significant differences in post-3-st-GK-Tx results between the 2 series in terms of overall survival times, neurological death, maintained neurological status, local control, repeat SRS, and SRS-related complications. The previously published results (C-series) are considered to be validated by the M-series results.

Efficacy of pre-operative stereotactic radiosurgery followed by surgical resection and correlative radiobiological analysis for patients with 1-4 brain metastases: study protocol for a phase II trial

BACKGROUND

Stereotactic radiosurgery (SRS) has emerged as a common adjuvant modality used with surgery for resectable brain metastases (BMs). However, the optimal sequence of the multi-modality therapy has not been established. The goal of the study is to evaluate 6-month local control utilizing pre-operative SRS followed by surgical resection for patients with 1-4 brain metastases.

METHODS

This prospective, single arm, phase II trial will recruit patients with up to 4 brain metastases and at least one resectable lesion. All lesions will be treated with SRS and symptomatic lesions will be resected within 1-4 days after SRS. Patients will be monitored for 6-month local control, in-brain progression free survival, distant in-brain failure, rate of leptomeningeal spread, radiation necrosis and overall survival. Additionally, we will also perform correlative radiobiological molecular studies to assess the effect of radiation dosing on the tumor tissue and clinical outcomes. We expect that pre-operative SRS to the gross tumor prior to surgical resection will improve local control and decrease leptomeningeal failure.

DISCUSSION

Our study is the second prospective trial to investigate the efficacy of pre-operative SRS in the treatment of multiple BMs. In addition, the correlative molecular studies will be the first to investigate early response of BMs at a cellular and genetic level in response to radiation doses and potentially provide molecular prognostic markers for local control and overall survival.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT03398694 (registration date: January 12, 2018).

Postoperative Cavity Stereotactic Radiosurgery for Brain Metastases

During the past decade, tumor bed stereotactic radiosurgery (SRS) after surgical resection has been increasingly utilized in the management of brain metastases. SRS has risen as an alternative to adjuvant whole brain radiation therapy (WBRT), which has been shown in several studies to be associated with increased neurotoxicity. Multiple recent articles have shown favorable local control rates compared to those of WBRT. Specifically, improvements in local control can be achieved by adding a 2 mm margin around the resection cavity. Risk factors that have been established as increasing the risk of local recurrence after resection include: subtotal resection, larger treatment volume, lower margin dose, and a long delay between surgery and SRS (>3 weeks). Moreover, consensus among experts in the field have established the importance of (a) fusion of the pre-operative magnetic resonance imaging scan to aid in volume delineation (b) contouring the entire surgical tract and (c) expanding the target to include possible microscopic disease that may extend to meningeal or venous sinus territory. These strategies can minimize the risks of symptomatic radiation-induced injury and leptomeningeal dissemination after postoperative SRS. Emerging data has arisen suggesting that multifraction postoperative SRS, or alternatively, preoperative SRS could provide decreased rates of radiation necrosis and leptomeningeal disease. Future prospective randomized clinical trials comparing outcomes between these techniques are necessary in order to improve outcomes in these patients.

Predictors of survival in neurometastatic Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy of neuroendocrine origin, with about 30 cases of brain metastasis (BM) reported in the literature. Historically, the treatment of neurometastatic MCC has largely included chemotherapy and radiotherapy. The aim was to investigate predictors of overall survival (OS) in neurometastatic MCC.

METHODS

In this retrospective study, we surveyed institutional databases and conducted a systematic review of the literature to identify cases reporting on management of distant MCC BM. A pooled survival analysis was performed on the institutional and literature cases to assess predictors of OS.

RESULTS

Forty cases were included for analysis, describing operative [14] and non-operative [26] management. Median time to central nervous system involvement was 17.0-mos (interquartile range 10.5-26.5), and most patients had a single BM (62.5%). Management of intracranial disease included radiotherapy (82.5%), systemic therapy (59.5%) and surgical resection (35%). Operative management was associated with a lower intracranial burden of disease (BoD), but similar systemic BoD. Both neurosurgery (hazard ratio [HR] 0.18, 95% confidence interval [CI]: 0.06-0.54, p = 0.002), having RT (HR 0.37, 95% CI: 0.14:0.93, p = 0.04) and having a single BM (extensive intracranial BoD: HR 2.51, 95% CI: 1.12-5.6, p = 0.03) conferred an OS benefit on risk-unadjusted analysis. Only, neurosurgical resection was an independent predictor of OS (HR 0.12, 95% CI: 0.03-0.49, p = 0.003), controlling for age, BoD and radiotherapy.

CONCLUSIONS

Resection of MCC BM may confer a survival benefit given appropriate patient selection. Prospective investigation of multimodal management of neurometastatic MCC is warranted, especially given the promise of new immunotherapy agents in treating MCC.

Stereotactic radiosurgery to surgical cavity post resection of brain metastases: Local recurrence and overall survival rates. A single-centre experience

INTRODUCTION

We reviewed local control (LC) and overall survival (OS) post intracranial SRS to cavity post resection of brain metastases at one institution, and factors affecting LC.

METHODS

A retrospective review was conducted of adjuvant SRS at one institution from 2013 to 2016. Patient records, treatment plans and diagnostic images were reviewed. Local failure was MRI defined. Categorical variables were analysed using chi-square and Fisher's exact tests. Continuous variables were analysed using Mann-Whitney tests. The Kaplan-Meier method was used to estimate survival times and the log-rank test was used to compare differences in survival.

RESULTS

Forty-seven patients with 48 cavities were treated with SRS post operatively. LC rate was 69%, and the distant intracranial failure rate was 47% for entirety of the follow-up period. The 12-month freedom from local recurrence (FFLR) was 77% (63-91%). Median OS (95% CI) was 22.7 (14.6-30.8) months. Patients with a single metastasis had longer FFLR (30.1 vs 14.4 months; P = 0.014). Median interval from surgery to SRS was 6.3 weeks. Patients with interval >7 weeks had increased local recurrence (LR) (62%) than <7 weeks (37%), P = 0.025. Patients with a margin < 2 mm were more likely to experience LR (48%) than those with margin equal to 2 mm (20%); this approached statistical significance (P = 0.063). The median follow-up for all patients was 15.4 months (2-41).

CONCLUSIONS

We determined LC and OS post adjuvant SRS at our institution. Based on the findings of this retrospective review SRS should be given promptly post operatively with a 2 mm PTV margin.

Modern management for brain metastasis patients using stereotactic radiosurgery: literature review and the authors' gamma knife treatment experiences

Historically, whole brain radiotherapy was administered to most patients with brain metastases. However, over the past three decades, stereotactic radiosurgery (SRS), targeted at individual cranial lesions, has been accepted widely. In this study, based on the authors' experiences along with published data, recent trends in SRS for brain metastases are discussed. This article focuses on the following issues: 1) How many tumors can or should be treated with SRS? 2) Two-/three-staged SRS for relatively large tumors, 3) post- or preoperative SRS, and 4) repeat SRS.

Local control and possibility of tailored salvage after hypofractionated stereotactic radiotherapy of the cavity after brain metastases resection

In patients undergoing surgical resection of brain metastases, the risk of local recurrence remains high. Adjuvant whole brain radiation therapy (WBRT) can reduce the risk of local relapse but fails to improve overall survival. At two tertiary care centers in Germany, a retrospective study was performed to evaluate the role of hypofractionated stereotactic radiotherapy (HFSRT) in patients with brain metastases after surgical resection. In particular, need for salvage treatment, for example, WBRT, surgery, or stereotactic radiosurgery (SRS), was evaluated. Both intracranial local (LF) and locoregional (LRF) failures were analyzed. A total of 181 patients were treated with HFSRT of the surgical cavity. In addition to the assessment of local control and distant intracranial control, we analyzed treatment modalities for tumor recurrence including surgical strategies and reirradiation. Imaging follow-up for the evaluation of LF and LRF was available in 159 of 181 (88%) patients. A total of 100 of 159 (63%) patients showed intracranial progression after HFSRT. A total of 81 of 100 (81%) patients received salvage therapy. Fourteen of 81 patients underwent repeat surgery, and 78 of 81 patients received radiotherapy as a salvage treatment (53% WBRT). Patients with single or few metastases distant from the initial site or with WBRT in the past were retreated by HFSRT (14%) or SRS, 33%. Some patients developed up to four metachronous recurrences, which could be salvaged successfully. Eight (4%) patients experienced radionecrosis. No other severe side effects (CTCAE≥3) were observed. Postoperative HFSRT to the resection cavity resulted in a crude rate for local control of 80.5%. Salvage therapy for intracranial progression was commonly needed, typically at distant sites. Salvage therapy was performed with WBRT, SRS, and surgery or repeated HFSRT of the resection cavity depending on the tumor spread and underlying histology. Prospective studies are warranted to clarify whether or not the sequence of these therapies is important in terms of quality of life, risk of radiation necrosis, and likelihood of neurological cause of death.

Local recurrence patterns after postoperative stereotactic radiation surgery to resected brain metastases: A quantitative analysis to guide target delineation

PURPOSE

In the treatment of resected metastatic brain disease, a recent phase 3 trial by the North Central Cancer Treatment Group (N107C/CEC.3) surprisingly found that the local control rate for whole-brain radiation therapy was better than that of stereotactic radiation surgery (SRS). To optimize target delineation, we performed a quantitative analysis of local failure patterns after postoperative SRS.

METHODS AND MATERIALS

Patients with brain metastases who were treated with surgery and SRS to the cavity were evaluated. Local failure was defined by pathologic confirmation or magnetic resonance imaging evidence of progression leading to further overlapping radiation therapy. T1 postgadolinium magnetic resonance imaging scans that were taken preoperatively and at recurrence were co-registered to the simulation computed tomography. Three volumes were compared: (1) Preoperative tumors, (2) resection cavities that were originally contoured as clinical target volumes for SRS, and (3) recurrent tumors. Overlap volume histograms quantified the proximity of the three volumes to the meninges.

RESULTS

In the cohort of 173 patients, 18 patients experienced local failure in 19 resection cavities. The original SRS target volume overlapped with a median of 69.6% of the recurrent tumor. When the entire preoperative tumor was included, the overlap with the recurrent tumor increased to a median of 76.8%. Recurrent tumors were closer to the meninges than corresponding preoperative tumors (P = .03) but a median 8.2 mm expansion of the target volume from the meninges was needed to increase overlap with the recurrent tumor to 90%. Increases in overlap with the recurrent tumor were achieved most efficiently by uniformly expanding the contoured cavity and a median 2.8 mm expansion covered 90% of the recurrent tumor.

CONCLUSIONS

Our quantitative analysis of recurrence patterns suggests that a larger 3 mm uniform expansion of the SRS target volume substantially increases coverage of the volume that is later occupied by the recurrent tumor and may provide improved local control. The extent of the preoperative tumor in the target volume or expanding the target volume from the meninges provides little benefit.

Stereotactic radiosurgery (SRS) in the modern management of patients with brain metastases

Stereotactic radiosurgery (SRS) is an established non-invasive ablative therapy for brain metastases. Early clinical trials with SRS proved that tumor control rates are superior to whole brain radiotherapy (WBRT) alone. As a result, WBRT plus SRS was widely adopted for patients with a limited number of brain metastases (“limited number” customarily means 1-4). Subsequent trials focused on answering whether WBRT upfront was necessary at all. Based on current randomized controlled trials (RCTs) and meta-analyses comparing SRS alone to SRS plus WBRT, adjuvant WBRT results in better intracranial control; however, at the expense of neurocognitive functioning and quality of life. These adverse effects of WBRT may also negatively impact on survival in younger patients. Based on the results of these studies, treatment has shifted to SRS alone in patients with a limited number of metastases. Additionally, RCTs are evaluating the role of SRS alone in patients with >4 brain metastases. New developments in SRS include fractionated SRS for large tumors and the integration of SRS with targeted systemic therapies that cross the blood brain barrier and/or stimulate an immune response. We present in this review the current high level evidence and rationale supporting SRS as the standard of care for patients with limited brain metastases, and emerging applications of SRS.

[Delineation of the surgical bed of operated brain metastases treated with adjuvant stereotactic irradiation: A review]

Stereotactic radiotherapy of the surgical bed of brain metastases is a technique that comes supplant indications of adjuvant whole brain radiotherapy after surgery. After a growing number of retrospective studies, a phase III trial has been presented and validated this indication. However, several criteria such as the dose, the fractionation, the use of a margin and definition of volumes remain to be defined. Our study consisted in making a literature review in order to provide a guideline of delineation of surgical beds of brain metastases, as well as the different modalities of their implementation process.

Local control and overall survival for adjuvant stereotactic radiosurgery in patients with residual or recurrent disease

Prior studies of post-operative stereotactic radiosurgery (SRS) have not distinguished between Adjuvant SRS (ARS) versus Adjuvant SRS to residual/recurrent disease (ARD). In this study, we defined ARS and ARD and investigated local control (LC), overall survival (OS), distant development of brain metastases (DBF), and leptomeningeal disease (LMD). We retrospectively identified BM patients who received surgical resection and SRS for BM from an IRB approved database between Jan 2009-Aug 2015. Patients were stratified into two groups: ARS and ARD. LC was determined by follow-up MRI studies and OS was measured from the date of surgery. LC and OS were assessed using the Kaplan-Meier method. 70 cavities underwent surgical resection of BM and received SRS to the post-operative bed. 41 cavities were classified as ARS and 29 as ARD. There was no significant difference in 12-month LC between the ARS and ARD group (71.4 vs. 80.8%, respectively; p = 0.135) from the time point of SRS. The overall 1-year survival for ARS and ARD was 79.9 and 86.1%, respectively (p = 0.339). Mean time to progression was 6.45 and 8.0 months and median follow-up was 10 and 15 months for ARS and ARD, respectively. 11.8% of ARS patients and 15.4% of ARD patients developed LMD, p = 0.72. 29.4% of ARS and 48.0% of ARD patients developed DBF, p = 0.145. Our findings suggest that observation after surgical resection, with subsequent treatment with SRS after the development of local failure, may not compromise treatment efficacy. If validated, this would spare patients who do not recur post-surgically from additional treatment.

Resection and Observation for Brain Metastasis without Prompt Postoperative Radiation Therapy

Objective

Total resection without consecutive postoperative whole brain radiation therapy is indicated for patients with a single or two sites of brain metastasis, with close follow-up by serial magnetic resonance imaging (MRI). In this study, we explored the effectiveness, usefulness, and safety of this follow-up regimen.

Methods

From January 2006 to December 2015, a total of 109 patients (76 males, 33 females) underwent tumor resection as the first treatment for brain metastases (97 patients with single metastases, 12 with two metastases). The mean age was 59.8 years (range 27-80). The location of the 121 tumors in the 109 patients was supratentorial (n=98) and in the cerebellum (n=23). The origin of the primary cancers was lung (n=45), breast (n=17), gastrointestinal tract (n=18), hepatobiliary system (n=8), kidney (n=7), others (n=11), and unknown origin (n=3). The 121 tumors were totally resected. Follow-up involved regular clinical and MRI assessments. Recurrence-free survival (RFS) and overall survival (OS) after tumor resection were analyzed by Kaplan-Meier methods based on clinical prognostic factors.

Results

During the follow-up, MRI scans were done for 85 patients (78%) with 97 tumors. Fifty-six of the 97 tumors showed no recurrence without adjuvant local treatment, representing a numerical tumor recurrence-free rate of 57.7%. Mean and median RFS was 13.6 and 5.3 months, respectively. Kaplan-Meier analysis revealed the cerebellar location of the tumor as the only statistically significant prognostic factor related to RFS (p=0.020). Mean and median OS was 15.2 and 8.1 months, respectively. There were no significant prognostic factors related to OS. The survival rate at one year was 8.2% (9 of 109).

Conclusion

With close and regular clinical and image follow-up, initial postoperative observation without prompt postoperative radiation therapy can be applied in patients of brain metastasi(e)s when both the tumor(s) are completely resected.

Retrospective study of 229 surgically treated patients with brain metastases: Prognostic factors, outcome and comparison of recursive partitioning analysis and diagnosis-specific graded prognostic assessment

Background:

Metastases are the most frequent tumors in the brain. Most often used scoring systems to predict the outcome are the RPA (Recursive Partitioning Analysis) classification and the DS-GPA (Diagnosis-Specific Graded Prognostic Assessment) score. The goal of our study was to determine prognostic factors which influence outcome in patients who undergo surgery for brain metastases and to compare different outcome scores.

Methods:

Two hundred and twenty-nine patients who underwent surgery for brain metastases in our institution between January 2005 and December 2014 were included in the study. Patient data were evaluated retrospectively.

Results:

The mean survival time was 19.2 months (median survival time, MST: 8 months), for patients with a single metastasis (n = 149) 17.6 months (MST: 8 months), and for patients with multiple metastases (n = 80) 17.9 months (MST: 6 months). Significant influence on MST had age <65 years (9 vs. 5 months, P = 0.002), female sex (10 vs. 6 months, P < 0.001), RPA Class I and II (11 vs. 4 months, P < 0.001), Karnofsky score >70% (11 vs. 4 months, P < 0.001), and postoperative radiotherapy (8 vs. 5 months, P < 0.002). To evaluate the diagnostic power of DS-GPA and RPA score in respect of survival, two Cox regressions were modeled, where the RPA classification showed a better predictive power.

Conclusion:

Favorable factors for prolonged survival were KPS >70%, RPA Class I and II, age <65 years, female sex, a DS-GPA Score of 2.5–3 and 3.5–4, and adjuvant radiotherapy. The RPA Classification was more accurate in predicting the outcome than the DS-GPA score.

Neurosurgical management of brain metastases

Brain metastases present a significant public health issue, affecting more than 100,000 patients per year in the U.S. and result in significant morbidity. Brain metastases can occur in a variety of clinical situations ranging from multiple brain metastases with uncontrolled systemic disease to a solitary metastasis in the setting of controlled systemic disease. Additionally, advances in genomics have broadened the opportunities for targeted treatment options and potentially more durable systemic responses. As such, the treatment of brain metastases is now more tailored and multimodal, involving systemic, radiation, and surgical therapies, often in combination. This review discusses the historical and current role of neurosurgical techniques in the treatment of brain metastases.

Impact of 2-staged stereotactic radiosurgery for treatment of brain metastases ≥ 2 cm

OBJECTIVE Stereotactic radiosurgery (SRS) is the primary modality for treating brain metastases. However, effective radiosurgical control of brain metastases ≥ 2 cm in maximum diameter remains challenging and is associated with suboptimal local control (LC) rates of 37%-62% and an increased risk of treatment-related toxicity. To enhance LC while limiting adverse effects (AEs) of radiation in these patients, a dose-dense treatment regimen using 2-staged SRS (2-SSRS) was used. The objective of this study was to evaluate the efficacy and toxicity of this treatment strategy. METHODS Fifty-four patients (with 63 brain metastases ≥ 2 cm) treated with 2-SSRS were evaluated as part of an institutional review board-approved retrospective review. Volumetric measurements at first-stage stereotactic radiosurgery (first SSRS) and second-stage SRS (second SSRS) treatments and on follow-up imaging studies were determined. In addition to patient demographic data and tumor characteristics, the study evaluated 3 primary outcomes: 1) response at first follow-up MRI, 2) time to local progression (TTP), and 3) overall survival (OS) with 2-SSRS. Response was analyzed using methods for binary data, TTP was analyzed using competing-risks methods to account for patients who died without disease progression, and OS was analyzed using conventional time-to-event methods. When needed, analyses accounted for multiple lesions in the same patient. RESULTS Among 54 patients, 46 (85%) had 1 brain metastasis treated with 2-SSRS, 7 patients (13%) had 2 brain metastases concurrently treated with 2-SSRS, and 1 patient underwent 2-SSRS for 3 concurrent brain metastases ≥ 2 cm. The median age was 63 years (range 23-83 years), 23 patients (43%) had non-small cell lung cancer, and 14 patients (26%) had radioresistant tumors (renal or melanoma). The median doses at first and second SSRS were 15 Gy (range 12-18 Gy) and 15 Gy (range 12-15 Gy), respectively. The median duration between stages was 34 days, and median tumor volumes at the first and second SSRS were 10.5 cm³ (range 2.4-31.3 cm³) and 7.0 cm³ (range 1.0-29.7 cm³). Three-month follow-up imaging results were available for 43 lesions; the median volume was 4.0 cm³ (range 0.1-23.1 cm³). The median change in volume compared with baseline was a decrease of 54.9% (range -98.2% to 66.1%; p < 0.001). Overall, 9 lesions (14.3%) demonstrated local progression, with a median of 5.2 months (range 1.3-7.4 months), and 7 (11.1%) demonstrated AEs (6.4% Grade 1 and 2 toxicity; 4.8% Grade 3). The estimated cumulative incidence of local progression at 6 months was 12% ± 4%, corresponding to an LC rate of 88%. Shorter TTP was associated with greater tumor volume at baseline (p = 0.01) and smaller absolute (p = 0.006) and relative (p = 0.05) decreases in tumor volume from baseline to second SSRS. Estimated OS rates at 6 and 12 months were 65% ± 7% and 49% ± 8%, respectively. CONCLUSIONS 2-SSRS is an effective treatment modality that resulted in significant reduction of brain metastases ≥ 2 cm, with excellent 3-month (95%) and 6-month (88%) LC rates and an overall AE rate of 11%. Prospective studies with larger cohorts and longer follow-up are necessary to assess the durability and toxicities of 2-SSRS.

Postoperative Fractionated Stereotactic Radiosurgery to the Tumor Bed for Surgically Resected Brain Metastases

Introduction

Stereotactic radiosurgery (SRS) is increasingly used as an alternative to whole brain radiotherapy (WBRT) following surgical resection of brain metastases. We analyzed the outcomes of postoperative frameless fractionated stereotactic radiosurgery (fSRS) cases for surgically resected brain metastases at our institution.

Materials and Methods

We performed a retrospective review of 85 patients who underwent fSRS to 87 resection beds from 2006 - 2014 with a median follow-up of 6.4 months. Clinically relevant outcomes were assessed with analysis to determine predictors of these outcomes.

Results

The median target volume was 9.8 cm­³ (1.1 - 43.1 cm­³). The most frequently used fractionation scheme was 3,000 cGy in five fractions. The rates of local control (LC), distant brain failure (DBF), and overall survival (OS) at one-year were 87%, 52%, and 52%, respectively. Five patients (5.9%) experienced Grade >2 toxicity related to fSRS, including seizures (two), symptomatic radionecrosis (two), and potential treatment-related death (one). A multivariable analysis revealed that tumor volume (p < 0.001) and number of fractions (p < 0.001) were associated with LC, while recursive partitioning analysis (RPA) class (p < .0001), tumor volume (p = .0181), and the number of fractions (p = .0181) were associated with OS.

Conclusions

Postoperative fSRS for surgically resected brain metastases is well-tolerated and achieves durable LC. Further studies are needed to determine the optimal dose and fractionation for fSRS as well as to compare outcomes with WBRT.

Outcome appraisal of patients with limited brain metastases (BMs) from non small cell lung cancer (NSCLC) treated with different local therapeutic strategies: a single institute evaluation

OBJECTIVE

To evaluate the outcome of patients with non-small-cell lung cancer (NSCLC) with limited brain metastases (BMs) treated with local approaches omitting whole-brain radiation therapy (WBRT).

METHODS

Surgery was performed in case of a single, large BM, controlled extracranial disease and Karnofsky Performance Status (KPS) 90-100; stereotactic radiosurgery (SRS) or hypofractionated stereotactic radiosurgery (HSRS) was performed in all other cases. The prescribed dose was 24 Gy/1 fraction for lesions <2.5 cm, and a median of 30 Gy (24-40 Gy) in 3-5 fractions for lesions >2.5 cm.

RESULTS

156 patients treated for 228 BMs were retrospectively evaluated. The median age was 62 years. The majority of patients had a KPS 90-100, recursive partitioning analysis Class II, diagnosis-specific graded prognostic assessment score 2.5-3 and 1-2 BMs. Surgical resection was performed in 18 cases, and SRS/HSRS was performed in 210 cases. The 1-2-year local control was 87.2 ± 3.0% and 72.8 ± 5.0%; the 1.2-year brain distant failure was 30.8 ± 4.0% and 58.1 ± 6.0%; the 1-2-year overall survival was 60.9 ± 3.9% and 31.4 ± 4.0%. On univariate and multivariate analysis, the following factors influenced survival: age (p = 0.01), the presence of lymph node involvement (p = 0.03), KPS (p << 0.01), the presence of extracranial metastases at the time of BM treatment (p < 0.01), the number of BMs (p = 0.02) and the treatment performed (p < 0.01).

CONCLUSION

The choice of an adequate local treatment can impact on survival in patients with limited BMs from NSCLC. A careful evaluation of prognostic and predictive factors is a pivotal additional aid. Advances in knowledge: Radiosurgery or surgery followed by radiosurgery on the tumour bed in place of WBRT proved to be an effective treatment influencing outcome. Surgical resection followed by SRS on the tumour bed has to be considered for lesions ≥15 mm, in patients with good KPS, age ≤70 years, adenocarcinoma histology and oligometastatic disease.

Radiosurgery to the Postoperative Tumor Bed for Metastatic Carcinoma Versus Whole Brain Radiation After Surgery

Background

The treatment paradigm from postoperative whole brain radiation therapy (WBRT) to post-operative stereotactic radiosurgery (SRS) to the tumor bed has shifted with little data to evaluate whether each treatment modality confers equivalent tumor control and survival outcomes.

Methods

Patients with surgical resection of single brain metastases from January 2010 to December 2014 were treated postoperatively with either WBRT or SRS. Retrospective patient data was compared for local control, distant brain recurrence, overall survival, and radiation complications.

Results

Forty-six received WBRT, and 37 received tumor bed SRS. Twelve of 35 (34%) SRS patients experienced local recurrence compared to 17 of 31 (55%) WBRT patients (p = 0.09). The median survival was 440 days (14.7 months) for SRS and 202 days (6.7 months) for WBRT (p = 0.062, log-rank). SRS demonstrated improved survival benefit in the first six months (p = 0.0034; Wilcoxon). Radiation-related adverse changes after SRS (22%) were not statistically different from WBRT (8.7%) (p = 0.152). Age (p = 0.08), systemic cancer status (p = 0.30), Graded Prognostic Assessment (p = 0.28), number of brain metastases at diagnosis (p = 0.65), tumor volume at diagnosis (p = 0.13), new brain lesions (p = 0.74) and neurologic versus systemic cause of death (p = 0.11) did not differ between the groups.

Conclusions

Following surgical resection, tumor bed SRS can be used effectively in lieu of WBRT to treat brain metastases with comparable local control and distant control and without significantly more adverse events.

Hypofractionated Stereotactic Radiosurgery and Radiotherapy to Large Resection Cavity of Metastatic Brain Tumors

OBJECTIVE

To evaluate the efficacy of postoperative fractionated stereotactic radiosurgery (FSRS) and hypofractionated stereotactic radiotherapy (SRT) to large surgical cavities after gross total resection of brain metastases.

METHODS

A retrospective analysis of 41 patients who had received tumor-bed FSRS (5 fractions) or SRT (10 fractions) after resection of brain metastasis between 2005 and 2015 was performed. All resection cavities were treated with a frameless linear accelerator-based system. Patients who underwent subtotal resection, single-dose SRS to the resection cavity, or were treated with a fractionation schedule other than 5 or 10 fractions, were excluded.

RESULTS

Twenty-six patients were treated with 5 fractions and 15 patients with 10 fractions. The median planning target volume was 19.78 cm³ (12.3-28 cm³) to the 5-fraction group and 29.79 cm³ (26.3-47.6 cm³) to the 10-fraction group (P = 0.020). The 1-year and 2-year local control rates for all patients were 89.4% and 77.1%, respectively, and 89.6% and 78.6% were free from distant intracranial progression, respectively. No difference was observed in local control or freedom from distant intracranial progression between the 5-fraction or 10-fraction groups. The median overall survival was 28.27 months (95% confidence interval, 19.42-37.12) for all patients. No patient developed necrosis at the resection cavity.

CONCLUSIONS

Fractionation offers the potential to exploit the different biological responses between neoplastic and normal tissues to ionizing radiation. The use of 5 daily doses of 5-6 Gy or 10 daily doses of 3 Gy is a good strategy to have a reasonable local control and avoid neurotoxicity.

Updates in the management of brain metastases

The clinical management/understanding of brain metastases (BM) has changed substantially in the last 5 years, with key advances and clinical trials highlighted in this review. Several of these changes stem from improvements in systemic therapy, which have led to better systemic control and longer overall patient survival, associated with increased time at risk for developing BM. Development of systemic therapies capable of preventing BM and controlling both intracranial and extracranial disease once BM are diagnosed is paramount. The increase in use of stereotactic radiosurgery alone for many patients with multiple BM is an outgrowth of the desire to employ treatments focused on local control while minimizing cognitive effects associated with whole brain radiotherapy. Complications from BM and their treatment must be considered in comprehensive patient management, especially with greater awareness that the majority of patients do not die from their BM. Being aware of significant heterogeneity in prognosis and therapeutic options for patients with BM is crucial for appropriate management, with greater attention to developing individual patient treatment plans based on predicted outcomes; in this context, recent prognostic models of survival have been extensively revised to incorporate molecular markers unique to different primary cancers.

Outcome Evaluation of Oligometastatic Patients Treated with Surgical Resection Followed by Hypofractionated Stereotactic Radiosurgery (HSRS) on the Tumor Bed, for Single, Large Brain Metastases

Purpose

The aim of this study was to evaluate the benefit of a combined treatment, surgery followed by adjuvant hypofractionated stereotactic radiosurgery (HSRS) on the tumor bed, in oligometastatic patients with single, large brain metastasis (BM).

Methods and Materials

Fom January 2011 to March 2015, 69 patients underwent complete surgical resection followed by HSRS with a total dose of 30Gy in 3 daily fractions. Clinical outcome was evaluated by neurological examination and MRI 2 months after radiotherapy and then every 3 months. Local progression was defined as radiographic increase of the enhancing abnormality in the irradiated volume, and brain distant progression as the presence of new brain metastases or leptomeningeal enhancement outside the irradiated volume. Surgical morbidity and radiation-therapy toxicity, local control (LC), brain distant progression (BDP), and overall survival (OS) were evaluated.

Results

The median preoperative volume and maximum diameter of BM was 18.5cm³ (range 4.1–64.2cm³) and 3.6cm (range 2.1-5-4cm); the median CTV was 29.0cm³ (range 4.1–203.1cm³) and median PTV was 55.2cm³ (range 17.2–282.9cm³). The median follow-up time was 24 months (range 4–33 months). The 1-and 2-year LC in site of treatment was 100%; the median, 1-and 2-year BDP was 11.9 months, 19.6% and 33.0%; the median, 1-and 2-year OS was 24 months (range 4–33 months), 91.3% and 73.0%. No severe postoperative morbidity or radiation therapy toxicity occurred in our series.

Conclusions

Multimodal approach, surgery followed by HSRS, can be an effective treatment option for selected patients with single, large brain metastases from different solid tumors.

Cesium-131 brachytherapy for recurrent brain metastases: durable salvage treatment for previously irradiated metastatic disease

OBJECTIVE Managing patients whose intraparenchymal brain metastases recur after radiotherapy remains a challenge. Intraoperative cesium-131 (Cs-131) brachytherapy performed at the time of neurosurgical resection may represent an excellent salvage treatment option. The authors evaluated the outcomes of this novel treatment with permanent intraoperative Cs-131 brachytherapy. METHODS Thirteen patients with 15 metastases to the brain that recurred after stereotactic radiosurgery and/or whole brain radiotherapy were treated between 2010 and 2015. Stranded Cs-131 seeds were placed as a permanent volume implant. Prescription dose was 80 Gy at 5-mm depth from the resection cavity surface. The primary end point was resection cavity freedom from progression (FFP). Resection cavity freedom from progression (FFP), regional FFP, distant FFP, median survival, overall survival (OS), and toxicity were assessed. RESULTS The median duration of follow-up after salvage treatment was 5 months (range 0.5-18 months). The patients' median age was 64 years (range 51-74 years). The median resected tumor diameter was 2.9 cm (range 1.0-5.6 cm). The median number of seeds implanted was 19 (range 10-40), with a median activity per seed of 2.25 U (range 1.98-3.01 U) and median total activity of 39.6 U (range 20.0-95.2 U). The 1-year actuarial local FFP was 83.3%. The median OS was 7 months, and 1-year OS was 24.7%. Complications included infection (3), pseudomeningocele (1), seizure (1), and asymptomatic radionecrosis (RN) (1). CONCLUSIONS After failure of prior irradiation of brain metastases, re-irradiation with intraoperative Cs-131 brachytherapy implants provides durable local control and limits the risk of RN. The authors' initial experience demonstrates that this treatment approach is well tolerated and safe for patients with previously irradiated tumors after failure of more than 1 radiotherapy regimen and that it results in excellent response rates and minimal toxicity.

The Current and Future Treatment of Brain Metastases

Brain metastases are the most common intracranial malignancy, accounting for significant morbidity and mortality in oncology patients. The current treatment paradigm for brain metastasis depends on the patient’s overall health status, the primary tumor pathology, and the number and location of brain lesions. Herein, we review the modern management options for these tumors, including surgical resection, radiotherapy, and chemotherapy. Recent operative advances, such as fluorescence, confocal microscopy, and brachytherapy, are highlighted. With an increased understanding of the pathophysiology of brain metastasis come increased future therapeutic options. Therapy targeted to specific tumor molecular pathways, such as those involved in blood–brain barrier transgression, cell–cell adhesion, and angiogenesis, are also reviewed. A personalized plan for each patient, based on molecular characterizations of the tumor that are used to better target radiotherapy and chemotherapy, is undoubtedly the future of brain metastasis treatment.

Surgical Cavity Constriction and Local Progression Between Resection and Adjuvant Radiosurgery for Brain Metastases

Stereotactic radiosurgery (SRS) to a surgical cavity after brain metastasis resection is a promising treatment for improving local control. The optimal timing of adjuvant SRS, however, has yet to be determined. Changes in resection cavity volume and local progression in the interval between surgery and SRS are likely important factors in deciding when to proceed with adjuvant SRS. We conducted a retrospective review of patients with a brain metastasis treated with surgical resection followed by SRS to the resection cavity. Post-operative and pre-radiosurgery magnetic resonance imaging (MRI) was reviewed for evidence of cavity volume changes, amount of edema, and local tumor progression. Resection cavity volume and edema volume were measured using volumetric analysis. We identified 21 consecutive patients with a brain metastasis treated with surgical resection and radiosurgery to the resection cavity. Mean age was 57 yrs. The most common site of metastasis was the frontal lobe (38%), and the most common primary neoplasms were lung adenocarcinoma and melanoma (24% each). The mean postoperative resection cavity volume was 7.8 cm(3) and shrank to a mean of 4.5 cm(3) at the time of repeat imaging for radiosurgical planning (median 41 days after initial post-operative MRI), resulting in a mean reduction in cavity volume of 43%. Patients who underwent pre-SRS imaging within 1 month of their initial post-operative MRI had a mean volume reduction of 13% compared to 61% in those whose pre-SRS imaging was ≥1 month (p=0.0003). Post-resection edema volume was not related to volume reduction (p=0.59). During the interval between MRIs, 52% of patients showed evidence of tumor progression within the resection cavity wall. There was no significant difference in local recurrence if the interval between resection and radiosurgery was <1 month (n=8) versus ≥1 month (n=13, p=0.46). These data suggest that the surgical cavity after brain metastasis resection constricts over time with greater constriction seen in patients whose pre-SRS imaging is ≥1 month after initial post-operative imaging. Given that there was no difference in local recurrence rate, the data suggest there is benefit in waiting in order to treat a smaller resection cavity.

HFSRT of the resection cavity in patients with brain metastases

PURPOSE

Aim of this single center, retrospective study was to assess the efficacy and safety of linear accelerator-based hypofractionated stereotactic radiotherapy (HFSRT) to the resection cavity of brain metastases after surgical resection. Local control (LC), locoregional control (LRC = new brain metastases outside of the treatment volume), overall survival (OS) as well as acute and late toxicity were evaluated.

PATIENTS AND METHODS

46 patients with large (> 3 cm) or symptomatic brain metastases were treated with HFSRT. Median resection cavity volume was 14.16 cm(3) (range 1.44-38.68 cm(3)) and median planning target volume (PTV) was 26.19 cm(3) (range 3.45-63.97 cm(3)). Patients were treated with 35 Gy in 7 fractions prescribed to the 95-100 % isodose line in a stereotactic treatment setup. LC and LRC were assessed by follow-up magnetic resonance imaging.

RESULTS

The 1-year LC rate was 88 % and LRC was 48 %; 57% of all patients showed cranial progression after HFSRT (4% local, 44% locoregional, 9% local and locoregional). The median follow-up was 19 months; median OS for the whole cohort was 25 months. Tumor histology and recursive partitioning analysis score were significant predictors for OS. HFSRT was tolerated well without any severe acute side effects > grade 2 according to CTCAE criteria.

CONCLUSION

HFSRT after surgical resection of brain metastases was tolerated well without any severe acute side effects and led to excellent LC and a favorable OS. Since more than half of the patients showed cranial progression after local irradiation of the resection cavity, close patient follow-up is warranted. A prospective evaluation in clinical trials is currently being performed.

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.

Dose painting with Gamma Knife: Two techniques for delivering different doses to areas of recurrent or residual tumor after resection of brain metastases

PURPOSE

We investigated the feasibility of using Gamma Knife (GK) radiosurgery for "dose painting" to deliver higher doses to residual or recurrent nodules and surgical cavity after resection of brain metastases.

METHODS AND MATERIALS

Two integrated boost techniques were developed with GK. The single-target technique delineated both the surgical cavity (cavity) and gross disease (nodule) as a single target. Dose was prescribed to the target with the goal of covering the nodule with a higher dose. The 2-target technique delineated the cavity and nodule as separate target volumes, each prescribed to its own dose and planned separately. Two cases were used to illustrate each technique. The single-target technique was used to deliver 16 Gy to a smaller cavity (7 cm(3)) and a 20-Gy integrated boost to 2 nodules (case 1). The 2-target technique was used to deliver 12 Gy to a larger cavity (21.5 cm(3)) and 20 Gy to a single nodule (case 2).

RESULTS

For both cases, the cavity coverage with the prescribed dose was 100% with the standard plan and integrated boost techniques. For case 1, compared with a standard plan, the single-target technique improved the 20-Gy nodule coverage from 89.7% (nodule 1) and 97.9% (nodule 2) to 100% (both) and increased the minimum dose from 16.6 Gy to 20.8 Gy (nodule 1) and from 19.4 Gy to 20.8 Gy (nodule 2). For case 2, compared with a standard plan, the 2-target technique improved the 20-Gy nodule coverage from 4% to 100% and the minimum dose from 13.8 Gy to 21 Gy.

CONCLUSIONS

Both GK integrated boost approaches allowed for effective delivery of higher doses to residual or recurrent nodules in a surgical cavity. In our experience, the single-target technique works well for small cavities, whereas the 2-target technique is well suited for larger cavities.

Tumor progression in patients receiving adjuvant whole-brain radiotherapy vs localized radiotherapy after surgical resection of brain metastases

BACKGROUND

Surgery followed by adjuvant radiotherapy is a well-established treatment paradigm for brain metastases.

OBJECTIVE

To examine the effect of postsurgical whole-brain radiotherapy (WBRT) or localized radiotherapy (LRT), including stereotactic radiosurgery and intraoperative radiotherapy, on the rate of recurrence both local and distal to the resection site in the treatment of brain metastases.

METHODS

We retrospectively identified patients who underwent surgery for brain metastasis at the Cleveland Clinic between 2004 and 2012. Institutional review board-approved chart review was conducted, and patients who had radiation before surgery, who had nonmetastatic lesions, or who lacked postadjuvant imaging were excluded.

RESULTS

The final analysis included 212 patients. One hundred fifty-six patients received WBRT, 37 received stereotactic radiosurgery only, and 19 received intraoperative radiotherapy. One hundred forty-six patients were deceased, of whom 60 (41%) died with no evidence of recurrence. Competing risks methodology was used to test the association between adjuvant modality and progression. Multivariable analysis revealed no significant difference in the rate of recurrence at the resection site (hazard ratio [HR] 1.46, P = .26) or of unresected, radiotherapy-treated lesions (HR 1.70, P = .41) for LRT vs WBRT. Patients treated with LRT had an increased hazard of the development of new lesions (HR 2.41, P < .001) and leptomeningeal disease (HR 2.45, P = .04). Median survival was 16.5 months and was not significantly different between groups.

CONCLUSION

LRT as adjuvant treatment to surgical resection of brain metastases is associated with an increased rate of development of new distant metastases and leptomeningeal disease compared with WBRT, but not with recurrence at the resection site or of unresected lesions treated with radiation.

Comparative Effectiveness Analysis of Treatment Options for Single Brain Metastasis

BACKGROUND

Brain metastases (BMs) occur in up to 30% of patients with cancer. Treatments include surgery, whole-brain radiotherapy (WBRT), and stereotactic radiosurgery (SRS), alone or in combination. Although guidelines exist, data to inform individualized approaches to therapy remain sparse. We sought to compare semiquantitatively the effectiveness of various modalities in the treatment of single brain metastasis.

METHODS

We performed a comparative effectiveness analysis (CEA) that integrated efficacy, cost, and quality of life (QoL) data for alternate BM treatments. Efficacy data were obtained from a comprehensive review of current literature. Cost estimates were based on publicly available data. QoL data included the Karnofsky Performance Status (KPS) and other questionnaires. Six treatment strategies using combinations of surgery, WBRT, and SRS were compared with decision tree software.

RESULTS

The clinical efficacy, cost, and QoL effects of each strategy were scored semiquantitatively. We constructed a model to integrate individual preferences regarding the relative importance of efficacy, QoL, and cost to provide personalized rankings of the effectiveness of each strategy.

CONCLUSION

The choice of strategy must be individualized for patients with a single BM. Our CEA and decision model combines empirical data with patient priorities to produce a ranking of alternate management strategies.