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

Efficacy of Stereotactic Radiosurgery as Single or Combined Therapy for Brain Metastasis: A Systematic Review and Meta-Analysis

To determine the efficacy of stereotactic radiosurgery (SRS) in treating patients with brain metastases (BMs), a network meta-analysis (NMA) of randomized controlled trials (RCTs) and a direct comparison of cohort studies were performed. Relevant literature regarding the effectiveness of SRS alone and in combination with whole-brain radiotherapy (WBRT) and surgery was retrieved using systematic database searches up to April 2019. The patterns of overall survival (OS), one-year OS, progression-free survival (PFS), one-year local brain control (LBC), one-year distant brain control (DBC), neurological death (ND), and complication rate were analyzed. A total of 18 RCTs and 37 cohorts were included in the meta-analysis. Our data revealed that SRS carried a better OS than SRS+WBRT (p= 0.048) and WBRT (p= 0.041). Also, SRS+WBRT demonstrated a significantly improved PFS, LBC, and DBC compared to WBRT alone and SRS alone. Finally, SRS achieved the same LBC as high as surgery, but intracranial relapse occurred considerably more frequently in the absence of WBRT. However, there were not any significant differences in ND and toxicities between SRS and other groups. Therefore, SRS alone may be a better alternative since increased patient survival may outweigh the increased risk of brain tumor recurrence associated with it.

Long‑term survival in a patient with extensive‑stage small cell lung cancer treated with multiple courses of salvage stereotactic radiation after whole brain radiotherapy: A case report

Intracranial recurrence following initial cranial irradiation for extensive-stage small cell lung cancer (ES-SCLC) can often be a treatment dilemma given the aggressive nature of the disease, the overall poor prognosis and concerns regarding re-treatment toxicity. The present report describes the case of a 62-year-old man diagnosed with ES-SCLC and synchronous brain metastases who initially underwent whole brain radiotherapy, chemotherapy and consolidative thoracic radiotherapy. The patient was found to have a solitary intracranial recurrence at both 3.5 and 6 years after his diagnosis. On both occasions, the patient received salvage stereotactic radiation, 30 Gy in 5 fractions, and continues to remain functionally independent. Overall, the present case demonstrates that with the appropriate patient selection, aggressive local salvage of recurrent intracranial ES-SCLC with stereotactic radiation can yield excellent and durable clinical outcomes.

Enhancement of Radiosurgical Treatment Outcome Prediction Using MRI Radiomics in Patients with Non-Small Cell Lung Cancer Brain Metastases

Simple Summary

Non-small cell lung cancer (NSCLC) is the most common cause of brain metastasis (BM). Approximately 50% of patients with metastatic NSCLC harbor BMs. Within the past decade, Gamma Knife radiosurgery (GKRS) has become one of the first-line treatments for BMs. Ability to predict treatment response after GKRS can therefore guide treatment strategy. This study aimed to determine whether pre-radiosurgical neuroimaging radiomics can predict survival and local tumor control after GKRS. Based on the collected magnetic resonance images and clinical characteristics of the 237 NSCLC BM patients with BMs (for survival prediction) and 256 NSCLC patients with 976 BMs (for prediction of local tumor control), we concluded that the identified radiomic features could provide valuable additional information to enhance the prediction of BM responses after GKRS. The proposed approach provided physicians with an intuitive way to predict the patient outcome based on pre-radiosurgical magnetic resonance images.

Abstract

The diagnosis of brain metastasis (BM) is commonly observed in non-small cell lung cancer (NSCLC) with poor outcomes. Accordingly, developing an approach to early predict BM response to Gamma Knife radiosurgery (GKRS) may benefit the patient treatment and monitoring. A total of 237 NSCLC patients with BMs (for survival prediction) and 256 patients with 976 BMs (for prediction of local tumor control) treated with GKRS were retrospectively analyzed. All the survival data were recorded without censoring, and the status of local tumor control was determined by comparing the last MRI follow-up in patients’ lives with the pre-GKRS MRI. Overall 1763 radiomic features were extracted from pre-radiosurgical magnetic resonance images. Three prediction models were constructed, using (1) clinical data, (2) radiomic features, and (3) clinical and radiomic features. Support vector machines with a 30% hold-out validation approach were constructed. For treatment outcome predictions, the models derived from both the clinical and radiomics data achieved the best results. For local tumor control, the combined model achieved an area under the curve (AUC) of 0.95, an accuracy of 90%, a sensitivity of 91%, and a specificity of 89%. For patient survival, the combined model achieved an AUC of 0.81, an accuracy of 77%, a sensitivity of 78%, and a specificity of 80%. The pre-radiosurgical radiomics data enhanced the performance of local tumor control and survival prediction models in NSCLC patients with BMs treated with GRKS. An outcome prediction model based on radiomics combined with clinical features may guide therapy in these patients.

Role of Gamma Knife Radiosurgery in Small Cell Lung Cancer: A Multi-Institutional Retrospective Study of the International Radiosurgery Research Foundation (IRRF)

BACKGROUND

Despite a high incidence of brain metastases in patients with small-cell lung cancer (SCLC), limited data exist on the use of stereotactic radiosurgery (SRS), specifically Gamma Knife™ radiosurgery (Elekta AB), for SCLC brain metastases.

OBJECTIVE

To provide a detailed analysis of SCLC patients treated with SRS, focusing on local failure, distant brain failure, and overall survival (OS).

METHODS

A multi-institutional retrospective review was performed on 293 patients undergoing SRS for SCLC brain metastases at 10 medical centers from 1991 to 2017. Data collection was performed according to individual institutional review boards, and analyses were performed using binary logistic regression, Cox-proportional hazard models, Kaplan-Meier survival analysis, and competing risks analysis.

RESULTS

Two hundred thirty-two (79%) patients received SRS as salvage following prior whole-brain irradiation (WBRT) or prophylactic cranial irradiation, with a median marginal dose of 18 Gy. At median follow-up after SRS of 6.4 and 18.0 mo for surviving patients, the 1-yr local failure, distant brain failure, and OS were 31%, 49%, and 28%. The interval between WBRT and SRS was predictive of improved OS for patients receiving SRS more than 1 yr after initial treatment (21%, <1 yr vs 36%, >1 yr, P = .01). On multivariate analysis, older age was the only significant predictor for OS (hazard ratio 1.63, 95% CI 1.16-2.29, P = .005).

CONCLUSION

SRS plays an important role in the management of brain metastases from SCLC, especially in salvage therapy following WBRT. Ongoing prospective trials will better assess the value of radiosurgery in the primary management of SCLC brain metastases and potentially challenge the standard application of WBRT in SCLC patients.

Central Nervous System Cancers, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Central Nervous System (CNS) Cancers focus on management of adult CNS cancers ranging from noninvasive and surgically curable pilocytic astrocytomas to metastatic brain disease. The involvement of an interdisciplinary team, including neurosurgeons, radiation therapists, oncologists, neurologists, and neuroradiologists, is a key factor in the appropriate management of CNS cancers. Integrated histopathologic and molecular characterization of brain tumors such as gliomas should be standard practice. This article describes NCCN Guidelines recommendations for WHO grade I, II, III, and IV gliomas. Treatment of brain metastases, the most common intracranial tumors in adults, is also described.

Current Management and Progress in Radiotherapy for Small Cell Lung Cancer

Radiotherapy (RT) and chemotherapy continue to be widely utilized in small cell lung cancer (SCLC) management. In most limited stage (LS)-SCLC cases, the standard initial therapy remains concurrent chemoradiotherapy (CRT), typically with an etoposide and platinum-based regimen. Hyperfractionated twice daily (BID) RT remains the standard of care, though conventional daily (QD) RT is now a viable alternative supported by randomized evidence. In LS-SCLC patients who experienced good response to CRT, prophylactic cranial irradiation (PCI) remains the standard of care. Brain imaging, ideally with MRI, should be performed prior to PCI to screen for clinically apparent brain metastases that may require a higher dose of cranial irradiation. Platinum doublet chemotherapy alone is the historic standard initial therapy in extensive stage (ES)-SCLC. Addition of immunotherapy such as atezolizumab and durvalumab to chemotherapy is now recommended after their benefits were demonstrated in recent trials. In patients with response to chemotherapy, consolidation thoracic RT and PCI could be considered, though with caveats. Emergence of hippocampal avoidance cranial irradiation and SRS in SCLC patients may supplant whole cranial irradiation as future standards of care. Incorporation of novel systemic therapies such as immunotherapies has changed the treatment paradigm and overall outlook of patients with SCLC. This narrative review summarizes the current state, ongoing trials, and future directions of radiotherapy in management of SCLC.

Should Stereotactic Radiosurgery Be Considered for Salvage of Intracranial Recurrence after Prophylactic Cranial Irradiation or Whole Brain Radiotherapy in Small Cell Lung Cancer? A Population-Based Analysis and Literature Review

BACKGROUND

Prophylactic cranial irradiation (PCI) improves survival and prevents intracranial recurrence (IR) in limited stage (LS) and extensive stage (ES) small cell lung cancer (SCLC). However, despite PCI, IR affects 12%-45%, and limited data exist regarding salvage brain reirradiation (ReRT). We performed a population-based review of IR in SCLC.

METHODS

Demographic, treatment, and outcome data of consecutive patients (N = 371) with SCLC assessed at a tertiary cancer centre (01/2013-12/2015) were abstracted, and summary statistics calculated. Kaplan-Meier estimates and univariate and multivariate analysis (MVA) via the Cox proportional hazard model were performed.

RESULTS

Median age was 66.1 years, and 59.8% were Eastern Cooperative Oncology Group (ECOG) performance status 0-2. Median survival was 24 months (95% CI 18.3-29.7 months) for LS (N = 103) and 7 months (95% CI 6.1-7.9 months) for ES (N = 268). 72 of 103 patients with LS and 97 of 214 of those with ES received PCI. 54 of 268 ES presented with brain metastases (BM) of whom 46 of 54 received whole brain RT (WBRT). 18.9% (32/169) recurred post-PCI (13 LS; 19 ES) and 30.4% (14/46) recurred after WBRT. Of those who recurred/progressed after cranial RT, 56.5% (26/46) had <5 BM, 39.1% had no extracranial disease, and 50% were ECOG 0-2. In retrospect, 17 of 46 would have been candidates for salvage stereotactic radiosurgery: 13 post-PCI and 4 post-WBRT.

CONCLUSIONS

This cohort challenges commonly held beliefs that IR is always diffuse, associated with clinical deterioration, and synchronous with systemic failure. Approximately 1 in 3 SCLC patients with IR after PCI or WBRT appear clinically appropriate for salvage stereotactic radiosurgery.

Outcomes of re-irradiation for brain recurrence after prophylactic or therapeutic whole-brain irradiation for small cell lung Cancer: a retrospective analysis

Background

Small cell lung cancer (SCLC) can recur in the brain after whole-brain irradiation (WBI). We documented outcomes after treatment of such recurrences and sought predictors of local control and overall survival (OS).

Materials and methods

Eighty-five patients with SCLC and brain recurrence after prophylactic or therapeutic WBI in 1998–2015 were identified and data were extracted from the medical records. Survival was estimated with the Kaplan-Meier method, and univariate and multivariate Cox proportional hazards modeling was used to identify factors associated with OS or further brain progression.

Results

Brain recurrence was treated by stereotactic radiosurgery (SRS) in 33 patients (39%), repeat WBI in 14 (16%), chemotherapy-only in 16 (19%), and observation in 22 (26%). Median OS time after brain recurrence (OSrec) was 4.3 months for all patients; 6-month OSrec rates were 58% after SRS, 21% after repeat WBI, 50% after chemotherapy-only, and 5% after observation (P < 0.001). Inferior OSrec was associated with poor performance status (ECOG score ≥ 3) and uncontrolled extracranial disease. Superior OSrec was associated with receipt of ≥4 chemotherapy cycles before brain recurrence and receipt of chemotherapy, SRS, or repeat WBI afterward. Receipt of chemotherapy after brain recurrence correlated with brain progression.

Conclusions

Some patients with brain recurrence after WBI for SCLC can survive for extended periods with appropriate intervention, especially those with adequate performance status or controlled extracranial disease.

ACR Appropriateness Criteria® follow-up and retreatment of brain metastases

Multiple options for retreatment are available, which include whole-brain radiation therapy, stereotactic radiosurgery, surgery, chemotherapy, and supportive care. Size, number, timing, location, histology, performance status, and extracranial disease status all need to be carefully considered when choosing a treatment modality. There are no randomized trials examining the retreatment of brain metastases. Repeat whole-brain radiation has been examined in a single-institution experience, showing the potential for clinical responses in selected patients. Local control rates as high as 91% using stereotactic radiosurgery for relapses after whole-brain radiation are reported. Surgery can be indicated in progressive and/or hemorrhagic lesions causing mass effect. The role of chemotherapy in the recurrent setting is limited but some agents may have activity on the basis of experiences on a smaller scale. Supportive care continues to be an important option, especially in those with a poor prognosis. Follow-up for brain metastases patients is discussed, examining the modality, frequency of imaging, and imaging options in differentiating treatment effect from recurrence. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of the current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

1st ESMO Consensus Conference in lung cancer; Lugano 2010: small-cell lung cancer

The 1st ESMO Consensus Conference on lung cancer was held in Lugano, Switzerland on 21st and 22nd May 2010 with the participation of a multidisciplinary panel of leading professionals in pathology and molecular diagnostics and medical, surgical and radiation oncology. Before the conference, the expert panel prepared clinically relevant questions concerning five areas as follows: early and locally advanced non-small-cell lung cancer (NSCLC), first-line metastatic NSCLC, second-/third-line NSCLC, NSCLC pathology and molecular testing, and small-cell lung cancer (SCLC) to be addressed through discussion at the Consensus Conference. All relevant scientific literature for each question was reviewed in advance. During the Consensus Conference, the panel developed recommendations for each specific question. The consensus agreement in SCLC is reported in this article. The recommendations detailed here are based on an expert consensus after careful review of published data. All participants have approved this final update.

Clinical and pathological characteristics of brain metastasis resected after failed radiosurgery

OBJECTIVE

This study evaluates the tumor histopathology and clinical characteristics of patients who underwent resection of their brain metastasis after failed gamma knife radiosurgery.

METHODS

This study was a retrospective review from a prospective database. A total of 1200 brain metastases in 912 patients were treated by gamma knife radiosurgery during a 7-year period. Fifteen patients (1.6% of patients, 1.2% of all brain metastases) underwent resective surgery for either presumed tumor progression (6 patients) or worsening neurological symptoms associated with increased mass effect (9 patients). Radiographic imaging, radiosurgical and surgical treatment parameters, histopathological findings, and long-term outcomes were reviewed for all patients.

RESULTS

The mean age at the time of radiosurgery was 57 years (age range, 32-65 years). Initial pathological diagnoses included metastatic non-small cell lung carcinoma in 8 patients (53%), melanoma in 4 patients (27%), renal cell carcinoma in 2 patients (13%), and squamous cell carcinoma of the tongue in 1 patient (7%). The mean time interval between radiosurgery and surgical extirpation was 8.5 months (range, 3 weeks to 34 months). The mean treatment volume for the resected lesion at the time of radiosurgery was 4.4 cm(3) (range, 0.6-8.4 cm(3)). The mean dose to the tumor margin was 21Gy (range, 18-24 Gy). In addition to the 15 tumors that were eventually resected, a total of 32 other metastases were treated synchronously, with a 78% control rate. The mean volume immediately before surgery for the 15 resected lesions was 7.5 cm(3) (range, 3.8-10.2 cm(3)). Histological findings after radiosurgery varied from case to case and included viable tumor, necrotic tumor, vascular hyalinization, hemosiderin-laden macrophages, reactive gliosis in surrounding brain tissue, and an elevated MIB-1 proliferation index in cases with viable tumor. The mean survival for patients in whom viable tumor was identified (9.4 months) was significantly lower than that of patients in whom only necrosis was seen (15.1 months; Fisher's exact test, P < 0.05).

CONCLUSION

Radiation necrosis and tumor radioresistance are the most common causes precipitating a need for surgical resection after radiosurgery in patients with brain metastasis.

The role of retreatment in the management of recurrent/progressive brain metastases: a systematic review and evidence-based clinical practice guideline

QUESTION

What evidence is available regarding the use of whole brain radiation therapy (WBRT), stereotactic radiosurgery (SRS), surgical resection or chemotherapy for the treatment of recurrent/progressive brain metastases?

TARGET POPULATION

This recommendation applies to adults with recurrent/progressive brain metastases who have previously been treated with WBRT, surgical resection and/or radiosurgery. Recurrent/progressive brain metastases are defined as metastases that recur/progress anywhere in the brain (original and/or non-original sites) after initial therapy.

RECOMMENDATION

Level 3 Since there is insufficient evidence to make definitive treatment recommendations in patients with recurrent/progressive brain metastases, treatment should be individualized based on a patient's functional status, extent of disease, volume/number of metastases, recurrence or progression at original versus non-original site, previous treatment and type of primary cancer, and enrollment in clinical trials is encouraged. In this context, the following can be recommended depending on a patient's specific condition: no further treatment (supportive care), re-irradiation (either WBRT and/or SRS), surgical excision or, to a lesser extent, chemotherapy. Question If WBRT is used in the setting of recurrent/progressive brain metastases, what impact does tumor histopathology have on treatment outcomes? No studies were identified that met the eligibility criteria for this question.

Early brain tumor metastasis reduction following Gamma Knife surgery

OBJECT

Unlike whole-brain radiation therapy, Gamma Knife surgery (GKS) is delivered in a single session for the treatment of brain metastases. The extent to which GKS can facilitate early tumor control was the focus of this study.

METHODS

The authors reviewed 134 metastatic lesions in 82 patients treated with GKS at the University of Virginia who underwent follow-up MR imaging within 30 days or less of GKS. For accurate volumetry only tumors measuring 0.5 cm3 or greater in volume were included. Radiological review as well as tumor volumetry was performed to assess the tumor's response to GKS. Tumors were characterized as either enlarged (> 15% volume increase), stable (follow-up volume +/- 15% of the initial volume), or decreased (> 15% volume decrease). A multivariate analysis was performed to determine factors related to each volume outcome group.

RESULTS

Within the first month following GKS, a decrease was observed in 47.8% of the tumors. Tumor reduction varied according to carcinoma histopathological subtype, with 46.4% of non-small cell lung carcinomas, 70% of breast carcinomas, and 22.6% of melanomas showing volume reduction within 30 days after GKS. The mean volume decrease was 41.7%. For the remaining tumors, 41% were stable and 11.2% increased in volume. The overall analysis showed that there was a significant difference in percentage tumor change according to histopathological type (p < 0.001). There was a trend toward increased tumor reduction in those carcinoma types that are traditionally viewed as radiation sensitive (breast and non-small cell lung carcinomas).

CONCLUSIONS

Gamma Knife surgery can offer patients early substantial volume reduction in many brain metastases. In instances in which early volume reduction of limited intracranial disease is desired, GKS may be used alone or before whole brain radiation therapy.

[Small cell lung cancer]

With about 20% of all lung cancers small cell lung cancer (SCLC) represents a major subset of this entity. Although therapeutic improvements did not receive as much attention as in non small cell lung cancer (NSCLC), many small steps of clinical progress have been achieved within the last 20 years. An optimal treatment should be based on an interdisciplinary treatment plan. The standard treatment in localized stages represents combined radiation and chemotherapy. Cisplatin and etoposide are in this concern considered as a gold standard. 3D-planned conformal radiotherapy should start as early as possible and should be applied concomitantly to chemotherapy and in certain cases even in a hyperfractionated treatment protocol. In very early stages surgical resection could be an option in selected cases. In advanced stages a platinum-based doublet offers high response rates. As already established in limited disease prophylactic cranial irradiation is now also indicated in extensive disease in case of any tumor remission. In the second line treatment and in patients with reduced performance status topotecan is recommended. Similar as in NSCLC pemetrexed might become an alternative treatment option in the second line setting. In the field of new targeted therapies bevacizumab achieved the most promising results. The present review highlights historical milestones and up-to-date trends in radiotherapy, chemotherapy and surgery. Furthermore, the role of experimental strategies and the management of certain special clinical situations are discussed.

Treatment of central nervous system metastases: parenchymal, epidural, and leptomeningeal

PURPOSE OF REVIEW

With prolonged survival from systemic therapies in the adjuvant and salvage setting, and because these agents cannot cross the intact blood-brain barrier, central nervous system metastases are becoming a therapeutic challenge in oncology.

RECENT FINDINGS

Recent therapeutic achievements include an extended use of surgery and radiosurgery. Although each of these treatment modalities has its own indications, in patients eligible for both treatments the upfront comparison of these two techniques has not been performed yet. Systemic chemotherapies and biotherapies may be effective in the management of central nervous system metastases as they may act on both neurologic and extra-central nervous system lesions. In the treatment of epidural metastases, a surgical procedure providing immediate direct circumferential decompression of the spinal cord followed by local irradiation has been demonstrated in a prospective randomized trial. The management of leptomeningeal metastases remains controversial and of limited efficacy especially in chemoresistant tumours and still relies on the combination of chemotherapy (intrathecal and intravenous) and focal radiotherapy.

SUMMARY

Aggressive treatments in patients with early diagnosis and in whom central nervous system metastases are the life-threatening location may provide a substantial increase in survival and favourably affect quality of life.

Indications for resection and radiosurgery for brain metastases

PURPOSE OF REVIEW

This review is focused on indications for resection, stereotactic radiosurgery, and fractionated radiotherapy for patients with single or multiple brain metastases. Our purpose is to summarize the indications and effect of these management approaches.

RECENT FINDINGS

Brain metastases are a frequent challenge in patients with extracranial solid cancers. More than 40% of patients with cancer will develop metastases to the brain. While some patients present with large lesions and symptoms related to mass effect, many are diagnosed when asymptomatic tumors are found on screening studies. The main options for patients with brain metastases are whole brain radiation therapy, surgical resection, and stereotactic radiosurgery. Much information regarding outcomes, survival, management morbidity, and quality of life is available. Randomized, class III clinical trials demonstrate that multimodal therapy is important for both life quality and extended survival. A better understanding of the current therapeutic options should result in improvements in patient care.

SUMMARY

This is a review of the literature from May 2004 to June 2005 with special attention on publications related to effect on quality of life with different procedures and therapies.