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

Mathematical modeling of brain metastases growth and response to therapies: A review

Brain metastases (BMs) are the most common intracranial tumor type and a significant health concern, affecting approximately 10% to 30% of all oncological patients. Although significant progress is being made, many aspects of the metastatic process to the brain and the growth of the resulting lesions are still not well understood. There is a need for an improved understanding of the growth dynamics and the response to treatment of these tumors. Mathematical models have been proven valuable for drawing inferences and making predictions in different fields of cancer research, but few mathematical works have considered BMs. This comprehensive review aims to establish a unified platform and contribute to fostering emerging efforts dedicated to enhancing our mathematical understanding of this intricate and challenging disease. We focus on the progress made in the initial stages of mathematical modeling research regarding BMs and the significant insights gained from such studies. We also explore the vital role of mathematical modeling in predicting treatment outcomes and enhancing the quality of clinical decision-making for patients facing BMs.

Cytoreduction of Residual Tumor Burden Is Decisive for Prolonged Survival in Patients with Recurrent Brain Metastases-Retrospective Analysis of 219 Patients

BACKGROUND

Despite advances in treatment for brain metastases (BMs), the prognosis for recurrent BMs remains poor and requires further research to advance clinical management and improve patient outcomes. In particular, data addressing the impact of tumor volume and surgical resection with regard to survival remain scarce.

METHODS

Adult patients with recurrent BMs between December 2007 and December 2022 were analyzed. A distinction was made between operated and non-operated patients, and the residual tumor burden (RTB) was determined by using (postoperative) MRI. Survival analysis was performed and RTB cutoff values were calculated using maximally selected log-rank statistics. In addition, further analyses on systemic tumor progression and (postoperative) tumor therapy were conducted.

RESULTS

In total, 219 patients were included in the analysis. Median age was 60 years (IQR 52-69). Median preoperative tumor burden was 2.4 cm3 (IQR 0.8-8.3), and postoperative tumor burden was 0.5 cm3 (IQR 0.0-2.9). A total of 95 patients (43.4%) underwent surgery, and complete cytoreduction was achieved in 55 (25.1%) patients. Median overall survival was 6 months (IQR 2-10). Cutoff RTB in all patients was 0.12 cm3, showing a significant difference (p = 0.00029) in overall survival (OS). Multivariate analysis showed preoperative KPSS (HR 0.983, 95% CI, 0.967-0.997, p = 0.015), postoperative tumor burden (HR 1.03, 95% CI 1.008-1.053, p = 0.007), and complete vs. incomplete resection (HR 0.629, 95% CI 0.420-0.941, p = 0.024) as significant. Longer survival was significantly associated with surgery for recurrent BMs (p = 0.00097), and additional analysis demonstrated the significant effect of complete resection on survival (p = 0.0027). In the subgroup of patients with systemic progression, a cutoff RTB of 0.97 cm3 (p = 0.00068) was found; patients who had received surgery also showed prolonged OS (p = 0.036). Single systemic therapy (p = 0.048) and the combination of radiotherapy and systemic therapy had a significant influence on survival (p = 0.036).

CONCLUSIONS

RTB is a strong prognostic factor for survival in patients with recurrent BMs. Operated patients with recurrent BMs showed longer survival independent of systemic progression. Maximal cytoreduction should be targeted to achieve better long-term outcomes.

Repeated Stereotactic Radiotherapy for Local Brain Metastases Failure or Distant Brain Recurrent: A Retrospective Study of 184 Patients

BACKGROUND

The main advantages of stereotactic radiotherapy (SRT) are to delay whole-brain radiotherapy (WBRT) and to deliver ablative doses. Despite this efficacy, the risk of distant brain metastases (BM) one year after SRT ranges from 26% to 77% and 20 to 40% of patients required salvage treatment. The role and consequences of reirradiation remain unclear, particularly in terms of survival. The objective was to study overall survival (OS) and neurological death-free survival (NDFS) and to specify the prognostic factors of long-term survival.

METHODS

we retrospectively reviewed the data of patients treated between 2010 and 2020 with at least two courses of SRT without previous WBRT.

RESULTS

In total, 184 patients were treated for 915 BMs with two-to-six SRT sessions. Additional SRT sessions were provided for local (5.6%) or distant (94.4%) BM recurrence. The median number of BMs treated per SRT was one with a median of four BMs in total. The mean time between the two SRT sessions was 8.9 months (95%CI 7.7-10.1) and there was no significant difference in the delay between the two sessions. The 6-, 12- and 24-month NDFS rates were 97%, 82% and 52%, respectively. The 6-, 12- and 24-month OS rates were 91%, 70% and 38%, respectively. OS was statistically related to the number of SRT sessions (HR = 0.48; p < 0.01), recursive partitioning analysis (HR = 1.84; p = 0.01), salvage WBRT (HR = 0.48; p = 0.01) and brain metastasis velocity (high: HR = 13.83; p < 0.01; intermediate: HR = 4.93; p < 0.01).

CONCLUSIONS

Lung cancer and melanoma were associated with a lower NDFS compared to breast cancer. A low KPS, a low number of SRT sessions, synchronous extracerebral metastases, synchronous BMs, extracerebral progression at SRT1, a high BMV grade, no WBRT and local recurrence were also associated with a lower NDFS. A high KPS at SRT1 and low BMV grade are prognostic factors for better OS, regardless of the number of BM recurrence events.

Re-Irradiation by Stereotactic Radiotherapy of Brain Metastases in the Case of Local Recurrence

PURPOSE

To evaluate the efficacy and safety of a second course of stereotactic radiotherapy (SRT2) treatment for a local recurrence of brain metastases previously treated with SRT (SRT1), using the Hypofractionated Treatment Effects in the Clinic (HyTEC) reporting standards and the European Society for Radiotherapy and Oncology guidelines.

METHODS

From December 2014 to May 2021, 32 patients with 34 brain metastases received salvage SRT2 after failed SRT1. A total dose of 21 to 27 Gy in 3 fractions or 30 Gy in 5 fractions was prescribed to the periphery of the PTV (99% of the prescribed dose covering 99% of the PTV). After SRT2, multiparametric MRI, sometimes combined with 18F-DOPA PET-CT, was performed every 3 months to determine local control (LC) and radionecrosis (RN).

RESULTS

After a median follow-up of 12 months (range: 1-37 months), the crude LC and RN rates were 68% and 12%, respectively, and the median overall survival was 25 months. In a multivariate analysis, the performance of surgery was predictive of a significantly better LC (p = 0.002) and survival benefit (p = 0.04). The volume of a normal brain receiving 5 Gy during SRT2 (p = 0.04), a dose delivered to the PTV in SRT1 (p = 0.003), and concomitant systemic therapy (p = 0.04) were associated with an increased risk of RN.

CONCLUSION

SRT2 is an effective approach for the local recurrence of BM after initial SRT treatment and is a potential salvage therapy option for well-selected people with a good performance status. Surgery was associated with a higher LC.

Changes in the characteristics of patients treated for brain metastases with repeat stereotactic radiotherapy (SRT): a retrospective study of 184 patients

PURPOSE

Brain metastases (BMs) are the leading cause of intracranial malignant neoplasms in adults. WHO, Karnofsky performance status (KPS), age, number of BMs, extracerebral progression (ECP), recursive partitioning analysis (RPA), diagnosis-specific graded prognostic assessment (Ds-GPA) are validated prognostic tools to help clinicians decide on treatment. No consensus exists for repeat stereotactic radiotherapy (SRT) for BMs. The aim of this study was to review the changes in patient characteristics treated with repeated SRTs.

METHODS AND MATERIALS

The data of patients treated between 2010 and 2020 with at least two courses of SRT without previous whole brain radiotherapy (WBRT) were reviewed. Age, WHO, KPS, ECP, type of systemic treatment, number of BMs were recorded. RPA, Ds-GPA and brain metastasis velocity (BMV) were calculated.

RESULTS

184 patients were treated for 915 BMs and received two to six SRTs for local or distant brain recurrence. The median number of BMs treated per SRT was 1 (range: 1-6), for a median of 4 BMs treated during all sessions (range: 2-19). WHO, Ds-GPA and RPA were stable between each session of SRT, whereas KPS was significantly better in SRT1 than in the following SRT. The number of BMs was not significantly different between each SRT, but there was a tendency for more BM at SRT1 (p = 0.06). At SRT1, patients had largest BM and undergo more surgery than during the following SRT (p < 0.001). 6.5%, 37.5% and 56% of patients were classified as high, intermediate, and low BMV, respectively, at the last SRT session. There was almost perfect concordance between the BMV-grade calculated at the last SRT session and at SRT2 (r = 0.89; p < 0.001).

CONCLUSION

Repeated SRT doesn't lead to a marked alteration in the general condition, KPS was maintained at over 70% for more than 95% of patients during all SRTs. Long survival can be expected, especially in low-grade BMV patients. WBRT shouldn't be aborted, especially for patients developing more than twelve BMs annually.

Tumor Control Probability following Radiosurgery of Brain Metastases with and without Retreatment

PURPOSE

To develop and compare tumor-control-probability (TCP) models for single-fraction stereotactic radiosurgery (SRS) for brain metastasis (BMs) with and without retreatment.

METHODS

We developed three different schemas to model TCP of BMs treated with LINAC-based SRS. Dose to 99% of each planning-target-volume (PTV D₉₉) and six-month local-control was fit using linear-quadratic-linear (LQ-L) models based on equivalent-dose conversions in 2Gy (EQD2). The M1 schema had separate LQ-L TCP models for initial dose (M1-initial) and retreatment dose (M1-retreat), and the M2 schema had an LQ-L model using the sum of 50% of the initial SRS dose plus the retreatment SRS dose. The M1-initial and M1-retreat schema modeled local control following 1^st SRS to 48 lesions (patients=22) and 2^nd SRS to 46 lesions (patients=21). The M0 schema included a whole dataset of 349 lesions (patients=136) receiving first SRS (no retreatment and M1-initial).

RESULTS

LQ-L models fitted the data well (Chi-2=0.059-0.525 and p=0.999-1.000). For M0 and M1-retreat, the fitted models EQD2₅₀ and γ₅₀ parameters, were similar. The LQ-L fitted EQD2₅₀ was ∼8.0Gy for M0 and M1-retreat, ∼24Gy for M1-initial, and ∼19Gy for M2. The model fitted γ₅₀ was 0.1Gy for M0, M1-retreat, and M2 and 0.5 for M1-initial. For the PTV D₉₉ of 10Gy and 20Gy, the steepest to shallowest dose-response or largest change in TCP, i.e., TCP_20Gy - TCP_10Gy was observed in M1-initial (0.49) and M2 (0.17). M0 and M1-retreat showed a similar change in TCP of 0.21.

CONCLUSION

The model fitted parameters predict the recurrent BMs required a higher threshold dose and had a steeper dose-response for 1^st SRS vs. 2^nd SRS and M0. Alternatively, the recurrent BMs required ∼2Gy higher predicted PTV D₉₉ dose for 1^st SRS to achieve the same TCP of 0.75 when compared to 2^nd SRS and M0. Further investigations on larger patient cohorts are needed for validating our findings in predictive modeling of recurrent brain metastases.

Clinical outcomes of patients with multiple courses of radiosurgery for brain metastases from non-small cell lung cancer

We investigated the long-term clinical outcomes of patients who underwent multiple courses (≥ 5) of gamma knife radiosurgery (GKRS) due to recurrent brain metastases (BM) from non-small cell lung cancer (NSCLC). Between December 2001 and July 2019, consecutive 2571 patients underwent GKRS for BM from NSCLC. Clinical and radiological outcomes were investigated in 76 patients who underwent GKRS ≥ 5 times. The median follow-up period after the diagnosis of NSCLC was 54.6 months (range 14.5–159.1 months). The median number of GKRS procedures per patient was six (range 5–15). Actuarial post-GKRS survival rates at 1, 2, 3, 4, and 5 years following initial GKRS were 88.1%, 79.5%, 65.3%, 51.4%, and 37.3%, respectively. No significant difference in overall survival was observed between patients (n = 22) with whole-brain radiotherapy (WBRT) and patients (n = 54) without WBRT (p = 0.076). The incidence of radiation-induced leukoencephalopathy was 64% and 18% in patients with and without WBRT, respectively (p < 0.0001). Multiple courses of SRS are a tolerable and effective treatment option for recurrent BM from NSCLC. Repeat SRS may be an alternative treatment option to avoid or delay WBRT.

Recurrent brain metastases: the role of resection of in a comprehensive multidisciplinary treatment setting

Background

Treatment decision for recurrent symptomatic brain metastases (BM) is challenging with scarce data regarding surgical resection. We therefore evaluated the efficacy of surgery for pretreated, recurrent BM in a comprehensive multidisciplinary treatment setting.

Methods

In a retrospective single center study, patients were analyzed, who underwent surgical resection of recurrent BM between 2007 and 2019. Intracranial event-free survival (EFS) and overall survival (OS) were evaluated by Kaplan-Maier and Cox regression analysis.

Results

We included 107 patients with different primary tumor entities and individual previous treatment for BM. Primary tumors comprised non-small cell lung cancer (NSCLC) (37.4%), breast cancer (19.6%), melanoma (13.1%), gastro-intestinal cancer (10.3%) and other, rare entities (19.6%). The number of previous treatments of BM ranged from one to four; the adjuvant treatment modalities comprised: none, focal or whole brain radiotherapy, brachytherapy and radiosurgery. The median pre-operative Karnofsky Performance Score (KPS) was 70% (range 40–100) and improved to 80% (range 0-100) after surgery. The complication rate was 26.2% and two patients died during the perioperative period. Sixty-seven (62.6%) patients received postoperative local radio-oncologic and/or systemic therapy. Median postoperative EFS and OS were 7.1 (95%CI 5.8–8.2) and 11.1 (95%CI 8.4–13.6) months, respectively. The clinical status (postoperative KPS ≥ 70 (HR 0.27 95%CI 0.16–0.46; p < 0.001) remained the only independent factor for survival in multivariate analysis.

Conclusions

Surgical resection of recurrent BM may improve the clinical status and thus OS but is associated with a high complication rate; therefore a very careful patient selection is crucial.

Factors associated with the use of salvage whole brain radiation therapy versus salvage stereotactic radiosurgery after initial stereotactic radiosurgery for brain metastases

Objectives

Patients undergoing stereotactic radiosurgery (SRS) for brain metastases require additional radiation for relapse. Our objective is to determine the factors associated with salvage SRS versus whole brain radiation therapy (WBRT) for salvage of first intracranial failure (ICF) after upfront SRS.

Method

We identified a cohort of 110 patients with brain metastases treated with SRS in the definitive or postoperative setting followed by subsequent salvage WBRT or SRS at least one month after initial SRS. Clinical and demographic characteristics were retrospectively recorded.

Results

78 Patients received SRS and 32 patients received WBRT at the time of first ICF. On multivariate analysis (MVA) factors associated with decreased use of salvage SRS were male gender (p=0.044) and local progression (p<0.001).

Conclusions

Local progression and male gender were the strongest factors associated with selection of salvage WBRT. Possible etiologies of this difference could be provider or patient driven, but warrant further exploration.

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.

Multimodality durable salvage of recurrent brain metastases refractory to LITT, SRS and immunotherapy with resection and cesium-131 brachytherapy: case report and literature review

Brain metastases (BrM) are treated with multimodality therapy, however the optimal combination and timing of modalities in the setting of recurrent tumours that have failed prior treatments remain poorly defined. We present a case of a patient with biopsy-confirmed renal cell carcinoma BrM with good performance status initially treated with laser interstitial thermal ablation therapy (LITT) followed by stereotactic radiosurgery and dual checkpoint inhibitor immunotherapy. He subsequently developed rapid in-field recurrence which was treated with salvage surgical resection and implantation of intracavitary cesium-131 brachytherapy. The patient's disease remained stable through 18 months postoperatively. This case illustrates the range of options available and provides a combination salvage therapy strategy in a select group of locally recurrent patients who have exhausted conventional treatment options.

Reirradiation of Whole Brain for Recurrent Brain Metastases: A Case Report of Lung Cancer With 12-Year Survival

Whole brain radiotherapy (WBRT) for brain metastases (BMs) was considered to be dose limited. Reirradiation of WBRT for recurrent BM has always been challenged. Here, we report a patient with multiple BMs of non-small-cell lung cancer (NSCLC), who received two courses of WBRT at the interval of 5 years with the cumulative administration dose for whole brain as 70 Gy and a boost for the local site as 30 Gy. Furthermore, after experiencing relapse in the brain, he underwent extra gamma knife (GK) radiotherapy for local brain metastasis for the third time after 5 years. The overall survival was 12 years since he was initially diagnosed with NSCLC with multiple brain metastases. Meanwhile, each time of radiotherapy brought a good tumor response to brain metastasis. Outstandingly, during the whole survival, he had a good quality of life (QoL) with Karnofsky Performance Score (KPS) above 80. Even after the last GK was executed, he had just a mild neurocognitive defect. In conclusion, with the cautious evaluation of a patient, we suggest that reirradiation of WBRT could be a choice, and the cumulative radiation dose of the brain may be individually modified.

Efficacy and Safety of a Second Course of Stereotactic Radiation Therapy for Locally Recurrent Brain Metastases: A Systematic Review

Simple Summary

Approximately 30% of patients diagnosed with cancer will ultimately develop brain metastases. Many improvements have been made in systemic and local cancer treatments, which have increased overall survival but also, as a consequence, the number of patients who present with local recurrence following intracranial stereotactic radiotherapy. The management of these recurrences remains controversial. The aim of our review is to evaluate the efficacy and tolerance of a second course of stereotactic radiotherapy.

Abstract

Recent advances in cancer treatments have increased overall survival and consequently, local failures (LFs) after stereotactic radiotherapy/radiosurgery (SRS/SRT) have become more frequent. LF following SRS or SRT may be treated with a second course of SRS (SRS2) or SRT (SRT2). However, there is no consensus on whenever to consider reirradiation. A literature search was conducted according to PRISMA guidelines. Analysis included 13 studies: 329 patients (388 metastases) with a SRS2 and 135 patients (161 metastases) with a SRT2. The 1-year local control rate ranged from 46.5% to 88.3%. Factors leading to poorer LC were histology (melanoma) and lack of prior whole-brain radiation therapy, large tumor size and lower dose at SRS2/SRT2, poorer response at first SRS/SRT, poorer performance status, and no controlled extracranial disease. The rate of radionecrosis (RN) ranged from 2% to 36%. Patients who had a large tumor volume, higher dose and higher value of prescription isodose line at SRS2/SRT2, and large overlap between brain volume irradiated at SRS1/SRT1 and SRS2/SRT2 at doses of 18 and 12 Gy had a higher risk of developing RN. Prospective studies involving a larger number of patients are still needed to determine the best management of patients with local recurrence of brain metastases

Neurosurgical resection for locally recurrent brain metastasis

BACKGROUND

In patients with locally recurrent brain metastases (LRBMs), the role of (repeat) craniotomy is controversial. This study aimed to analyze long-term oncological outcomes in this heterogeneous population.

METHODS

Craniotomies for LRBM were identified from a tertiary neuro-oncological institution. First, we assessed overall survival (OS) and intracranial control (ICC) stratified by molecular profile, prognostic indices, and multimodality treatment. Second, we compared LRBMs to propensity score-matched patients who underwent craniotomy for newly diagnosed brain metastases (NDBM).

RESULTS

Across 180 patients, median survival after LRBM resection was 13.8 months and varied by molecular profile, with >24 months survival in ALK/EGFR+ lung adenocarcinoma and HER2+ breast cancer. Furthermore, 102 patients (56.7%) experienced intracranial recurrence; median time to recurrence was 5.6 months. Compared to NDBMs (n = 898), LRBM patients were younger, more likely to harbor a targetable mutation and less likely to receive adjuvant radiation (p < 0.05). After 1:3 propensity matching stratified by molecular profile, LRBM patients generally experienced shorter OS (hazard ratio 1.67 and 1.36 for patients with or without a mutation, p < 0.05) but similar ICC (hazard ratio 1.11 in both groups, p > 0.20) compared to NDBM patients with similar baseline. Results across specific molecular subgroups suggested comparable effect directions of varying sizes.

CONCLUSIONS

In our data, patients with LRBMs undergoing craniotomy comprised a subgroup of brain metastasis patients with relatively favorable clinical characteristics and good survival outcomes. Recurrent status predicted shorter OS but did not impact ICC. Craniotomy could be considered in selected, prognostically favorable patients.

The Management of Brain Metastases-Systematic Review of Neurosurgical Aspects

Simple Summary

In this comprehensive review, we focused on the neurosurgical treatment as an integrative part of the challenging multidisciplinary management of cerebral metastases, a neuro-oncologic entity, which has been observed to have an increased incidence over the last years. In selected cases, the surgical removal of the space-occupying mass reduces the intracranial pressure, normalizes the metabolic environment, reduces the symptom burden, and allows for the intensification of local and systemic adjuvant treatment. In detail, we discuss the incidence of brain metastases, the role of surgical resection, as well as the evolution of current neurosurgical techniques, the surgical morbidity and mortality of single and multiple lesions, and we enlighten the role of surgery for recurrent tumors.

Abstract

The multidisciplinary management of patients with brain metastases (BM) consists of surgical resection, different radiation treatment modalities, cytotoxic chemotherapy, and targeted molecular treatment. This review presents the current state of neurosurgical technology applied to achieve maximal resection with minimal morbidity as a treatment paradigm in patients with BM. In addition, we discuss the contribution of neurosurgical resection on functional outcome, advanced systemic treatment strategies, and enhanced understanding of the tumor biology.

Resection and Surgically Targeted Radiation Therapy for the Treatment of Larger Recurrent or Newly Diagnosed Brain Metastasis: Results From a Prospective Trial

Introduction Achieving durable local control (LC) for larger (e.g., >2-3 cm) brain metastasis whether newly diagnosed or recurrent remains problematic. Resection (R) alone is typically insufficient and adding radiation therapy (RT) still results in a 12-month recurrence rate of 20% or more in many series. Hypothesizing that R plus immediate radiation utilizing brachytherapy may improve outcomes for this cohort of patients, we designed and prospectively evaluated a permanently implanted surgically targeted radiation therapy (STaRT) device consisting of cesium-131 (Cs-131) seeds positioned within a collagen carrier (GammaTile, GT Medical Technologies, Tempe, AZ). The device was designed to prevent direct source-to-brain contact and maintain inter-source spacing after closure. Methods This was a subgroup analysis of a cohort of patients with either recurrent or previously untreated brain metastases enrolled in a prospective, multi-histology single-arm trial (ClinicalTrials.gov, NCT#03088579), conducted between February 2013 and February 2018, of resection and tumor bed brachytherapy with Cs-131 containing permanently implanted collagen tiles to deliver 60 Gray (Gy) at .5 cm depth. No additional local therapy was given without progression. Results A total of 16 metastases in 11 patients were treated; 12 tumors were recurrent and four were previously untreated. The median preoperative maximum diameter was 3.2 cm (range: 1.9-5.1 cm). Histology was seven breasts, six lungs, and three sarcomas. The median age was 60 years (range: 41-80 years); the Karnofsky Performance Status (KPS) was 70 (range: 70-90). The cohort consisted of seven females and four males. The mean time for implantation completion was five minutes. The median overall survival (OS) was 9.3 months. At a median radiographic follow-up of 9.5 months' treatment, site progression was found in 1/16 (6%) at 10.9 months, and the median treatment site time-to-progression (TTP) has not been reached [95% confidence interval (CI): >10.9 months]. At 12 months, the Kaplan-Meier (K-M) estimates for LC after R+STaRT for all tumors was 83%; for previously untreated tumors, LC at 12 months was 100% and for recurrent tumors, it was 80%. Two tumor beds (12.5%) experienced radiation brain changes: one had grade two and the other grade three. No surgical adverse events occurred. Conclusion In this single-arm precommercial study, R+STaRT demonstrated excellent safety and LC in this cohort. The device has recently received FDA clearance for use in newly diagnosed and recurrent brain metastasis, and randomized clinical trials vs. standard of care treatments in both settings are scheduled to open in 2020.

Brain Metastasis Recurrence Versus Radiation Necrosis: Evaluation and Treatment

Radiation necrosis (RN) occurs in 5% to 25% of patients with brain metastases treated with stereotactic radiosurgery. RN must be distinguished from recurrent tumor to determine appropriate treatment. Stereotactic biopsy remains the gold standard for identifying RN. Initial treatment of RN often involves management of edema using corticosteroids, antiangiogenic therapies, and hyperbaric oxygen therapy. For refractory symptoms, surgical resection can be considered. Minimally invasive stereotactic laser ablation has the benefit of providing tissue diagnosis and treating RN or recurrent tumor with similar efficacy. Laser ablation should be considered for lesions in need of intervention where the diagnosis requires tissue confirmation.

[What is the place of surgery in the management of brain metastases in 2020?]

Brain metastases are the most common intracranial tumors and are associated with a dismal prognosis. The management of patients with brain metastases has become more important because of the increased incidence of these tumours, the better treatment of the systemic disease and the improvement of surgical techniques. The treatment requires multidisciplinary approaches and become complex because of new emerging systemic therapy and advancements in neurosurgery and radiation oncology. The surgical treatment has an indispensable role to obtain a tissue diagnosis, in relieving intracranial effect mass and improving neurological status by improving induced encephalopathy. An understanding of the role and indications of the surgery in patients with metastatic brain lesions is essential for the effective management of this growing population.

Stereotactic reirradiation with temozolomide in patients with recurrent aggressive pituitary tumors and pituitary carcinomas

OBJECTIVES

To evaluate the efficacy of a second course of fractionated stereotactic radiotherapy (re-SRT) and temozolomide (TMZ) as salvage treatment option in patients with aggressive pituitary tumors (APTs) and pituitary carcinomas (PCs).

PATIENTS AND METHODS

Twenty-one patients with recurrent or progressive APTs (n = 17) and PCs (n = 4) who received combined TMZ and re-SRT, 36 Gy/18fractions or 37.5 Gy/15fractions, were retrospectively evaluated. TMZ was given at a dose of 75 mg/m² given concurrently to re-SRT, and then 150-200 mg/m²/day for 5 days every 4 weeks or 50 mg/m² daily for 12 months. Local control (LC) and overall survival (OS) were calculated from the time of re-SRT by Kaplan-Meier method.

RESULTS

With a median follow-up of 27 months (range 12-58 months), 2-year and 4-year LC rates were 73% and 65%, respectively; 2-year and 4-year survival rates were 82% and 66%, respectively. A complete response was achieved in 2 and partial response in 11 patients. Six patients recurred with a median time to progression of 14 months. O(6)-Methylguanine-DNA methyltransferase (MGMT) status and tumor volume emerged as prognostic factors. Grade 3 radiation-related toxicities occurred in 3 (14%) patients. Grade 2 or 3 hematologic toxicities during chemotherapy occurred in 8 (38%) patients.

CONCLUSION

Re-SRT and TMZ is a safe treatment offering high LC in patients with progressive APTs and PCs. The potential advantages of combined chemoradiation as up-front or salvage treatment need to be explored in prospective trials.

Stereotactic reirradiation for local failure of brain metastases following previous radiosurgery: Systematic review and meta-analysis

INTRODUCTION

Local failure (LF) following stereotactic radiosurgery (SRS) of brain metastases (BM) may be treated with a second course of SRS (SRS2), though this procedure may increase the risk of symptomatic radionecrosis (RN).

METHODS

A literature search was conducted according to PRISMA to identify studies reporting LF, overall survival (OS) and RN rates following SRS2. Meta-analysis was performed to identify predictors of RN.

RESULTS

Analysis included 11 studies (335 patients,389 metastases). Pooled 1-year LF was 24 %(CI95 % 19-30 %): heterogeneity was acceptable (I2 = 21.4 %). Median pooled OS was 14 months (Confidence Interval 95 %, CI95 % 8.8-22.0 months). Cumulative crude RN rate was 13 % (95 %CI 8 %-19 %), with acceptable heterogeneity (I2 = 40.3 %). Subgroup analysis showed higher RN incidence in studies with median patient age ≥59 years (13 % [95 %CI 8 %-19 %] vs 7 %[95 %CI 3 %-12 %], p = 0.004) and lower incidence following prior Whole Brain Radiotherapy (WBRT, 19 %[95 %CI 13 %-25 %] vs 7%[95 %CI 3 %-13 %], p = 0.004).

CONCLUSIONS

SRS2 is an effective strategy for in-site recurrence of BM previously treated with SRS.

Repeated stereotactic radiosurgery for recurrent brain metastases: An effective strategy to control intracranial oligometastatic disease

Due to improvements in systemic therapies and longer survivals, cancer patients frequently present with recurrent brain metastases (BM). The optimal therapeutic strategies for limited brain relapse remain undefined. We analyzed tumor control and survival in patients treated with salvage focal radiotherapy in our center. Thirty-three patients with 112 BM received salvage stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) for local or regional recurrences. Local progression was observed in 11 BM (9.8 %). After 1 year, 72 % of patients were free of distant brain failure, and the 2-year overall survival (OS) was 37.7 %. No increase in toxicity or neurologically related deaths were observed. The 2- and 3-year whole brain radiation therapy free survival (WFS) rates were 92.9 % and 77.4 %, respectively. Hence, focal radiotherapy is a feasible salvage of recurrent BM in selected group of patients with limited brain disease, achieving a maintained intracranial control and less neurological toxicity.

Retrospective analysis of salvage surgery for local progression of brain metastasis previously treated with stereotactic irradiation: diagnostic contribution, functional outcome, and prognostic factors

Background

Stereotactic irradiation (STI) is a primary treatment for patients with newly diagnosed brain metastases. Some of these patients experience local progression, which is difficult to differentiate from radiation necrosis, and difficult to treat. So far, just a few studies have clarified the prognosis and effectiveness of salvage surgery after STI. We evaluated the diagnostic value and improvement of functional outcomes after salvage surgery. Based on these results, we reconsidered surgical indication for patients with local progression after STI.

Methods

We evaluated patients with brain metastases treated with salvage surgery for local progression from October 2002 to July 2019. These patients had undergone salvage surgery based on magnetic resonance imaging findings and/or clinical evidence of post-STI local progression and stable systemic disease. We employed two prospective strategies according to the eloquency of the lesions. Lesions in non-eloquent areas had been resected completely with a safety margin, utilizing a fence-post method; while lesions in eloquent areas had been treated with minimal resection and postoperative STI. Kaplan-Meier curves were used for the assessment of overall survival. Prognostic factors for survival were analyzed.

Results

Fifty-four salvage surgeries had been performed on 48 patients. The median age of patients was 63.5 years (range 36–79). The median interval from STI to surgery was 12 months. The median overall survival was 20.2 months from salvage surgery and 37.5 months from initial STI. Primary cancers were lung 31, breast 9, and others 8. Local recurrence developed in 13 of 54 lesions (24%). Leptomeningeal dissemination occurred after surgery in 3 patients (5.6%). Primary breast cancer (breast vs. lung: HR: 0.17), (breast vs. others: HR: 0.08) and RPA class 1–2 (RPA 1 vs. 3, HR:0.13), (RPA 2 vs 3, HR:0.4) were identified as good prognostic factors for overall survival (OS) in multivariate analyses. The peripheral neutrophil-to-lymphocyte ratio (NLR) of ≤3.65 predicted significantly longer OS (median 25.5 months) than an NLR > 3.65 (median 8 months).

Conclusion

We insist that salvage surgery leads to rapid improvement of neurological function and clarity of histological diagnosis. Salvage surgery is recommended for large lesions especially with surrounding edema either in eloquent or non-eloquent areas.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for the Treatment of Adults With Metastatic Brain Tumors: Executive Summary

BACKGROUND

The Congress of Neurological Surgeons systematic review and evidence-based clinical practice parameter guidelines for the treatment of adults with metastatic brain tumors was first published in 2010. Because of the time elapsed since that publication, an update of this set of guidelines based on literature published since is now indicated.

OBJECTIVE

To establish the best evidence-based management of metastatic brain tumors over all commonly used diagnostic and treatment modalities in regularly encountered clinical situations.

METHODS

Literature searches regarding management of metastatic brain tumors with whole brain radiation therapy, surgery, stereotactic radiosurgery, chemotherapy, prophylactic anticonvulsants, steroids, instances of multiple brain metastases, and emerging and investigational therapies were carried out to answer questions designed by consensus of a multidisciplinary writing group.

RESULTS

Recommendations were created and their strength linked to the quality of the literature data available thus creating an evidence-based guideline. Importantly, shortcomings and biases to the literature data are brought out so as to provide guidance for future investigation and improvements in the management of patients with metastatic brain tumors.

CONCLUSION

This series of guidelines was constructed to assess the most current and clinically relevant evidence for management of metastatic brain tumors. They set a benchmark regarding the current evidence base for this management while also highlighting important key areas for future basic and clinical research, particularly on those topics for which no recommendations could be formulated.The full guideline can be found at: https://www.cns.org/guidelines-treatment-adults-metastatic-brain-tumors/chapter_1.

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.

Operative and peri-operative considerations in the management of brain metastasis

The number of patients who develop metastatic brain lesions is increasing as the diagnosis and treatment of systemic cancers continues to improve, resulting in longer patient survival. The role of surgery in the management of brain metastasis (BM), particularly multiple and recurrent metastases, remains controversial and continues to evolve. However, with appropriate patient selection, outcomes after surgery are typically favorable. In addition, surgery is the only means to obtain a tissue diagnosis and is the only effective treatment modality to quickly relieve neurological complications or life‐threatening symptoms related to significant mass effect, CSF obstruction, and peritumoral edema. As such, a thorough understanding of the role of surgery in patients with metastatic brain lesions, as well as the factors associated with surgical outcomes, is essential for the effective management of this unique and growing patient population.

Reirradiation of Recurrent Brain Metastases: Where Do We Stand?

Brain metastases occur in a large portion of patients with cancer. Although advances in radiotherapy have helped to improve survival, they have also raised questions regarding the best modality for retreatment in the context of recurrent disease. The spectrum of treatment options for recurrent intracranial metastatic disease after previous radiotherapy includes salvage stereotactic radiosurgery, whole brain radiotherapy, and brachytherapy. We have comprehensively reviewed the existing data on the efficacy and toxicity of the various reirradiation treatment modalities. We examined the key clinical considerations that guide patient selection, such as dose, tumor size, interval to retreatment, and local control and survival rates.

Brain volume reduction after whole-brain radiotherapy: quantification and prognostic relevance

Background

Recent studies have questioned the value of adding whole-brain radiotherapy (WBRT) to stereotactic radiosurgery (SRS) for brain metastasis treatment. Neurotoxicity, including radiation-induced brain volume reduction, could be one reason why not all patients benefit from the addition of WBRT. In this study, we quantified brain volume reduction after WBRT and assessed its prognostic significance.

Methods

Brain volumes of 91 patients with cerebral metastases were measured during a 150-day period after commencing WBRT and were compared with their pretreatment volumes. The average daily relative change in brain volume of each patient, referred to as the "brain volume reduction rate," was calculated. Univariate and multivariate Cox regression analyses were performed to assess the prognostic significance of the brain volume reduction rate, as well as of 3 treatment-related and 9 pretreatment factors. A one-way analysis of variance was used to compare the brain volume reduction rate across recursive partitioning analysis (RPA) classes.

Results

On multivariate Cox regression analysis, the brain volume reduction rate was a significant predictor of overall survival after WBRT (P < 0.001), as well as the number of brain metastases (P = 0.002) and age (P = 0.008). Patients with a relatively favorable prognosis (RPA classes 1 and 2) experienced significantly less brain volume decrease after WBRT than patients with a poor prognosis (RPA class 3) (P = 0.001). There was no significant correlation between delivered radiation dose and brain volume reduction rate (P = 0.147).

Conclusion

In this retrospective study, a smaller decrease in brain volume after WBRT was an independent predictor of longer overall survival.

A Practical Radiotherapy Treatment Planning Technique for Second-Incidence Cancers That Incorporates Complete Organ-At-Risk Dose History

INTRODUCTION

Patients requiring treatment for second cancer incidences present unique radiotherapy plan development challenges. Historical dose delivered to organs at risk must be accounted for to properly estimate lifetime toxicity risks, but historical dose delivered to the region now occupied by tumours does not contribute to the prescription dose. Treatment planning systems permit inclusion of a base plan but do not provide the ability to manipulate it. We present a technique, dose cropping, which incorporates organ-at-risk dose history into the base plan while selectively excising dose history to diseased tissues now occupied by tumours. A retrospective plan comparison is performed to assess the effectiveness of dose cropping.

METHODS AND MATERIALS

Nine patients who received a second course of radiotherapy for cancers of the head-and-neck were replanned using the proposed technique. Clinical second courses and replans were compared on the basis of conformity index, heterogeneity index, maximum point dose, tissue control probability (TCP), normal tissue complication probability (NTCP), and whether the planning guidelines could be met by the treatment planning system. Replan constraints and guidelines followed the clinical treatment. In addition, a tissue recovery model was incorporated, applied to both clinical and replan courses, and compared to estimate the relevance of the dose cropping technique in such regimes.

RESULTS AND DISCUSSION

Replans had reduced organ-at-risk maximum point doses (5 Gy for spinal cord, 4 Gy for brainstem), NTCP (2.9% median reduction), and were able to more consistently achieve the V_95% > 98% coverage target regardless of the tissue recovery model. At the same time, replans using the dose cropping technique were statistically indistinguishable from clinical second courses on the basis of plan conformity, heterogeneity, or TCP (P > .31 in all cases).

CONCLUSIONS

Dosimetric history cropping is a valuable and widely applicable technique for second cancer radiotherapy planning. It also provides a natural means to incorporate tissue recovery models, biologically effective dose conversion, and NTCP and TCP model evaluation.

CyberKnife Radiosurgery in Recurrent Brain Metastases: Do the Benefits Outweigh the Risks?

Introduction

Local treatment concepts are in high demand in the salvage treatment of recurrent brain metastases. Still, their risks and benefits are scarcely characterized. In this study, we analyzed the outcome and risk-/benefit-ratio of salvage CyberKnife (Accuray Incorporated, Sunnyvale, California, US) radiosurgery in the treatment of recurrent brain metastases after whole brain radiotherapy (WBRT).

Materials and methods

Seventy-six patients with 166 recurrent brain metastases and a multimodal pretreatment were retrospectively investigated. All patients underwent salvage CyberKnife radiosurgery (single fraction, reference dose: 17-22 Gy). Study endpoints were post-recurrence survival (PRS) after salvage treatment as well as local and distant tumor control rates. Central nervous system (CNS) toxicity was assessed according to the toxicity criteria of the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer (RTOG/EORTC)).

Results

The population was homogenous regarding its demographic parameters. All patients had a history of WBRT prior to salvage CyberKnife radiosurgery. PRS was 13.3 months (10.4 - 16.2 months), one-year local and distant tumor control rates were 87% (95% CI: 75-99) and 38% (95% CI: 23-52), respectively. Eighteen patients suffered from RTOG/EORTC grade I/II toxicity. No toxicity-related risk factors were identified.

Discussion

This study found indicative survival and tumor control rates as well as a favorable risk/benefit ratio regarding radiotoxicity in salvage CyberKnife radiosurgery. These results point to a proactive therapeutic strategy based on appropriate patient selection instead of therapeutic nihilism.

The Role of Navigated Transcranial Magnetic Stimulation Motor Mapping in Adjuvant Radiotherapy Planning in Patients With Supratentorial Brain Metastases

Purpose: In radiotherapy (RT) of brain tumors, the primary motor cortex is not regularly considered in target volume delineation, although decline in motor function is possible due to radiation. Non-invasive identification of motor-eloquent brain areas is currently mostly restricted to functional magnetic resonance imaging (fMRI), which has shown to lack precision for this purpose. Navigated transcranial magnetic stimulation (nTMS) is a novel tool to identify motor-eloquent brain areas. This study aims to integrate nTMS motor maps in RT planning and evaluates the influence on dosage modulations in patients harboring brain metastases.

Materials and Methods: Preoperative nTMS motor maps of 30 patients diagnosed with motor-eloquent brain metastases were fused with conventional planning imaging and transferred to the RT planning software. RT plans of eleven patients were optimized by contouring nTMS motor maps as organs at risk (OARs). Dose modulation analyses were performed using dose-volume histogram (DVH) parameters.

Results: By constraining the dose applied to the nTMS motor maps outside the planning target volume (PTV) to 15 Gy, the mean dose (Dmean) to the nTMS motor maps was significantly reduced by 18.1% from 23.0 Gy (16.9–30.4 Gy) to 18.9 Gy (13.5–28.8 Gy, p < 0.05). The Dmean of the PTV increased by 0.6 ± 0.3 Gy (1.7%).

Conclusion: Implementing nTMS motor maps in standard RT planning is feasible in patients suffering from intracranial metastases. A significant reduction of the dose applied to the nTMS motor maps can be achieved without impairing treatment doses to the PTV. Thus, nTMS might provide a valuable tool for safer application of RT in patients harboring motor-eloquent brain metastases.

Repeat Stereotactic Radiosurgery for Recurred Metastatic Brain Tumors

OBJECTIVE

We investigated the outcomes of repeat stereotactic radiosurgery (SRS) for metastatic brain tumors that locally recurred despite previous SRS, focusing on the tumor control.

METHODS

A total of 114 patients with 176 locally recurring metastatic brain tumors underwent repeat SRS after previous SRS. The mean age was 59.4 years (range, 33 to 85), and there were 68 male and 46 female patients. The primary cancer types were non-small cell lung cancer (n=67), small cell lung cancer (n=12), gastrointestinal tract cancer (n=15), breast cancer (n=10), and others (n=10). The number of patients with a single recurring metastasis was 95 (79.8%), and another 19 had multiple recurrences. At the time of the repeat SRS, the mean volume of the locally recurring tumors was 5.94 mL (range, 0.42 to 29.94). We prescribed a mean margin dose of 17.04 Gy (range, 12 to 24) to the isodose line at the tumor border primarily using a 50% isodose line.

RESULTS

After the repeat SRS, we obtained clinical and magnetic resonance imaging follow-up data for 84 patients (73.7%) with a total of 108 tumors. The tumor control rate was 53.5% (58 of the 108), and the median and mean progression-free survival (PFS) periods were 246 and 383 days, respectively. The prognostic factors that were significantly related to better tumor control were prescription radiation dose of 16 Gy (p=0.000) and tumor volume less than both 4 mL (p=0.001) and 10 mL at the repeat SRS (p=0.008). The overall survival (OS) periods for all 114 patients after repeat SRS varied from 1 to 56 months, and median and mean OS periods were 229 and 404 days after the repeat SRS, respectively. The main cause of death was systemic problems including pulmonary dysfunction (n=58, 51%), and the identified direct or suspected brain-related death rate was around 20%.

CONCLUSION

The tumor control following repeat SRS for locally recurring metastatic brain tumors after a previous SRS is relatively lower than that for primary SRS. However, both low tumor volume and high prescription radiation dose were significantly related to the tumor control following repeat SRS for these tumors after previous SRS, which is a general understanding of primary SRS for metastatic brain tumors.

Repeated in-field radiosurgery for locally recurrent brain metastases: Feasibility, results and survival in a heavily treated patient cohort

Purpose

Stereotactic radiosurgery (SRS) is an established primary treatment for newly diagnosed brain metastases with high local control rates. However, data about local re-irradiation in case of local failure after SRS (re-SRS) are rare. We evaluated the feasibility, efficacy and patient selection characteristics in treating locally recurrent metastases with a second course of SRS.

Methods

We retrospectively evaluated patients with brain metastases treated with re-SRS for local tumor progression between 2011 and 2017. Patient and treatment characteristics as well as rates of tumor control, survival and toxicity were analyzed.

Results

Overall, 32 locally recurrent brain metastases in 31 patients were irradiated with re-SRS. Median age at re-SRS was 64.9 years. The primary histology was breast cancer and non-small-cellular lung cancer (NSCLC) in respectively 10 cases (31.3%), in 5 cases malignant melanoma (15.6%). In the first SRS-course 19 metastases (59.4%) and in the re-SRS-course 29 metastases (90.6%) were treated with CyberKnife^® and the others with Gamma Knife. Median planning target volume (PTV) for re-SRS was 2.5 cm³ (range, 0.1–37.5 cm³) and median dose prescribed to the PTV was 19 Gy (range, 12–28 Gy) in 1–5 fractions to the median 69% isodose (range, 53–80%). The 1-year overall survival rate was 61.7% and the 1-year local control rate was 79.5%. The overall rate of radiological radio-necrosis was 16.1% and four patients (12.9%) experienced grade ≥ 3 toxicities.

Conclusions

A second course of SRS for locally recurrent brain metastases after prior local SRS appears to be feasible with acceptable toxicity and can be considered as salvage treatment option for selected patients with high performance status. Furthermore, this is the first study utilizing robotic radiosurgery for this indication, as an additional option for frameless fractionated treatment.

Second course of stereotactic radiosurgery for locally recurrent brain metastases: Safety and efficacy

In the present study, we have evaluated the efficacy and toxicity of repeated brain metastases (BM) stereotactic radiosurgery (SRS2) following local failure of a prior radiosurgical procedure (SRS1). Between December 1996 and August 2015, 30 patients with 36 BM underwent SRS2 with a median dose of 18Gy. All BM were located outside critical structures. Following SRS2, local control at 6 months and one year were respectively 82.9% (IC 95%: 67.6–91.9) and 67.8% (IC 95%: 51–81). On multivariate analysis, planning target volume (PTV) < 3cc (HR: 0.19 (0.1–0.52)) and whole brain radiotherapy (WBRT) prior to SRS2 (HR: 0.25 (0.1–0.64)) were significantly associated with a better local control. One- and two-year overall survival rates after SRS2 were respectively 65.5% (IC 95%: 47.3–80%) and 27.6% (IC 95%: 14.7–45.7). Median overall survival following SRS2 was 14.2 months (range 1–106). Nineteen (63%) patients died from progressive systemic disease. Three (10%) patients died from out-field progressive brain disease and 8 (27%) in-field. Concerning toxicities, edema, radionecrosis, and hemorrhages were identified in 5 (12.8%), 4 (10.2%), and 5 (12.8%) patients respectively. No toxicity resulted in a neurological deficit. On univariate analysis, toxicities were significantly associated with PTV > 7cc (p = 0.02) and all patients had a WBRT before SRS2. A second course of SRS for locally recurrent brain metastases showed encouraging rates of local control. This treatment led to acceptable toxicities, especially for brain metastases smaller than 7cc, in our selected cohort of patients with BM located outside critical structures. Further studies are needed.

Response of brain metastasis from lung cancer patients to an oral nutraceutical product containing silibinin

Despite multimodal treatment approaches, the prognosis of brain metastases (BM) from non-small cell lung cancer (NSCLC) remains poor. Untreated patients with BM have a median survival of about 1 month, with almost all patients dying from neurological causes. We herein present the first report describing the response of BM from NSCLC patients to an oral nutraceutical product containing silibinin, a flavonoid extracted from the seeds of the milk thistle. We present evidence of how the use of the silibinin-based nutraceutical Legasil^® resulted in significant clinical and radiological improvement of BM from NSCLC patients with poor performance status that progressed after whole brain radiotherapy and chemotherapy. The suppressive effects of silibinin on progressive BM, which involved a marked reduction of the peritumoral brain edema, occurred without affecting the primary lung tumor outgrowth in NSCLC patients. Because BM patients have an impaired survival prognosis and are in need for an immediate tumor control, the combination of brain radiotherapy with silibinin-based nutraceuticals might not only alleviate BM edema but also prove local control and time for either classical chemotherapeutics with immunostimulatory effects or new immunotherapeutic agents such as checkpoint blockers to reveal their full therapeutic potential in NSCLC BM patients. New studies aimed to illuminate the mechanistic aspects underlying the regulatory effects of silibinin on the cellular and molecular pathobiology of BM might expedite the entry of new formulations of silibinin into clinical testing for progressive BM from lung cancer patients.

Outcome and prognostic factors in single brain metastases from small-cell lung cancer

PURPOSE

Whole brain radiation therapy (WBRT) is historically the standard of care for patients with brain metastases (BM) from small-cell lung cancer (SCLC), although locally ablative treatments are the standard of care for patients with 1-4 BM from other solid tumors. The objective of this analysis was to find prognostic factors influencing overall survival (OS) and intracranial progression-free survival (iPFS) in SCLC patients with single BM (SBM) treated with WBRT.

METHODS

A total of 52 patients were identified in the authors' cancer center database with histologically confirmed SCLC and contrast-enhanced magnet resonance imaging (MRI) or computed tomography (CT), which confirmed SBM between 2006 and 2015 and were therefore treated with WBRT. A Kaplan-Meier survival analysis was performed for OS analyses. The log-rank (Mantel-Cox) test was used to compare survival curves. Univariate Cox proportional-hazards ratios (HRs) were used to assess the influence of cofactors on OS and iPFS.

RESULTS

The median OS after WBRT was 5 months and the median iPFS after WBRT 16 months. Patients that received surgery prior to WBRT had a significantly longer median OS of 19 months compared to 5 months in the group receiving only WBRT (p = 0.03; HR 2.24; 95% confidence interval [CI] 1.06-4.73). Patients with synchronous disease had a significantly longer OS compared to patients with metachronous BM (6 months vs. 3 months, p = 0.005; HR 0.27; 95% CI 0.11-0.68). Univariate analysis for OS revealed a statistically significant effect for metachronous disease (HR 2.25; 95% CI 1.14-4.46; p = 0.019), initial response to first-line chemotherapy (HR 0.58; 95% CI 0.35-0.97; p = 0.04), and surgical resection (HR 0.36; 95% CI 0.15-0.88; p = 0.026). OS was significantly affected by metachronous disease in multivariate analysis (HR 2.20; 95% CI 1.09-4.45; p = 0.028).

CONCLUSIONS

Univariate analysis revealed that surgery followed by WBRT can improve OS in patients with SBM in SCLC. Furthermore, synchronous disease and response to initial chemotherapy appeared to be major prognostic factors. Multivariate analysis revealed metachronous disease as a significantly negative prognostic factor on OS. The value of WBRT, stereotactic radiosurgery (SRS), or surgery alone or in combination for patients with a limited number of BM in SCLC should be evaluated in further prospective clinical trials.

Lesion Optimization for Laser Ablation: Fluid Evacuation Prior to Laser-Induced Thermal Therapy

BACKGROUND

Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is a minimally invasive surgical procedure for ablating intracranial lesions. The presence of a fluid body can sequester thermal energy generated by the laser catheter, which compromises the performance of MRgLITT, resulting in suboptimal ablation of cystic lesions. We report our use of stereotactic fluid evacuation followed by MRgLITT in 2 patients with cystic brain tumors. This is the first report on lesion optimization by fluid aspiration before MRgLITT.

METHODS

Two cystic tumors in 2 patients were treated. In 1 patient, an external ventricular drain was placed stereotactically to allow drainage of cystic fluid 1 day before laser ablation. In the second patient, a stereotactic biopsy needle was used to aspirate the cystic fluid immediately before laser ablation. The remaining solid portions of the both tumors were ablated using the Visualase system. Both patients were followed clinically and radiologically after the procedures.

RESULTS

Stereotactic placement of an external ventricular drain and a biopsy needle both successfully resulted in fluid evacuation. MRgLITT was performed without any complications in both patients after fluid evacuation. Both patients demonstrated clinical and radiologic improvement after the procedure.

CONCLUSIONS

Cystic fluid evacuation is a promising strategy for optimizing intracranial cystic lesions for MRgLITT. This novel approach may broaden the utility of MRgLITT in the management of various technically demanding lesions.

Preserving the legacy of reirradiation: A narrative review of historical publications

PURPOSE

The purpose of this study is to illustrate the historical development of reirradiation during several decades of the 20th century, in particular between 1920 and 1960.

METHODS AND MATERIALS

We chose the format of a narrative review because the historical articles are heterogeneous. No systematic extraction of baseline data, treatment details, or follow-up care was possible in many cases.

RESULTS

Both hematological malignancies and solid tumors were treated with a second course of radiation therapy, and indications included local relapse, regional nodal recurrence, and second primary tumors developing in a previously treated region. The literature consists of retrospective single-institution analyses describing treatment approaches that included external beam radiation therapy, brachytherapy, or combinations thereof. Data on toxicities and survival were often provided. Breast cancer and gynecological, head and neck, brain, and skin tumors are among the entities included in this review.

CONCLUSIONS

The leading pioneers in the field are fully aware of many of the challenges we continue to debate today. These include the process of late tissue changes and development of personalized treatment approaches and better ways to select patients who are likely to benefit from a second course of radiation therapy.

Brain metastasis reirradiation in patients with advanced breast cancer

The outcome of recurrent brain metastasis is dismal. This study aims to assess the clinical outcomes and toxicity of reirradiation as a salvage treatment for progressive brain metastasis in patients with advanced breast cancer. Between July 2005 and September 2014, the medical records of 56 patients with brain metastasis from breast cancer were retrospectively reviewed. Of these patients, 39 received whole-brain radiotherapy (WBRT) followed by stereotactic radiosurgery (SRS) reirradiation (Group 1), and 17 received SRS followed by WBRT reirradiation (Group 2). Overall survival (OS) and brain progression-free survival rates/times were calculated using the Kaplan-Meier method. Prognostic factors were evaluated using the Cox proportional hazards model. Change in neurologic function was also assessed. The median OS was 10.8 months (range, 1.3-56.8 months). In Group 1, the median PFS time (PFS-1) was 6.5 months and the OS time was 11.4 months. Multivariate analysis revealed that longer OS was significantly associated with a high Karnofsky performance score (KPS) (P = 0.004), controlled extracranial metastasis (P = 0.001) and a good response to reirradiation (P = 0.034). In Group 2, the median PFS time (PFS-2) after reirradiation was 8.5 months and the OS time was 10.8 months. Multivariate analysis revealed that longer OS was significantly associated with a high KPS (P = 0.018). The majority of the patients had improved or stable neurological function. Reirradiation is an effective and a safe treatment for patients with brain metastases from breast cancer. It might delay the progression of intracranial disease and improve neurological function. A suitable patient selection for reirradiation was suggested.

Methods and results of locoregional treatment of brain metastases in patients with non-small cell lung cancer

This article presents methods and results of surgery and radiotherapy of brain metastases from non-small cell lung cancer (BMF-NSCLC). Patients with single BMF-NSCLC, with Karnofsky score ≥ 70 and controlled extracranial disease are the best candidates for surgery. Stereotactic radiosurgery (SRS) is recommended in patients with 1-3 BMF-NSCLC below 3-3.5 cm, with minor neurological symptoms, located in parts of the brain not accessible to surgery, with controlled extracranial disease. Whole brain radiotherapy (WBRT) following SRS reduces the risk of local relapse; in selected patients median survival reaches more than 10 months. Whole brain radiotherapy alone is a treatment in patients with multiple metastases, poor performance status, uncontrolled extracranial disease, disqualified from surgery or SRS with median survival 3 to 6 months. There is no doubt that there are patients with BMF-NSCLC who should receive only the best supportive care. There is a debate in the literature on how to select these patients.

The Role of MRgLITT in Overcoming the Challenges in Managing Infield Recurrence After Radiation for Brain Metastasis

Radiation necrosis and tumor recurrence are common sequelae after radiation therapy for brain metastasis. The differentiation of radiation necrosis and recurrent brain metastases continues to remain a difficult task despite a number of diagnostic methods. Techniques including magnetic resonance imaging, diffusion-weighted imaging, nuclear studies, and the gold standard of biopsy have all been studied for their effectiveness in accurately diagnosing the postradiation condition. Various specific treatment options of the distinct pathologies are available with the general theory that recurrences require more immediate treatment whereas radiation necrosis can be observed until symptomatic before intervention. This further emphasizes the necessity to accurately diagnose the condition to start appropriate and effective treatment. Despite both pathologies being pathophysiologically distinct, controversies exist as to whether there should be a distinction made at all or if the two can be perceived as a single condition if treatment and presentation are similar enough. Furthermore, a single treatment option such as magnetic resonance–guided, laser-induced thermal therapy (MRgLITT) can be used, potentially eliminating the need to differentiate the 2 entities because it successfully treats both conditions while being minimally invasive.

Management approach for recurrent brain metastases following upfront radiosurgery may affect risk of subsequent radiation necrosis

Purpose

Many patients treated with stereotactic radiosurgery (SRS) alone as initial treatment require 1 or more subsequent salvage therapies. This study aimed to determine if commonly used salvage strategies are associated with differing risks of radiation necrosis (RN).

Methods and materials

All patients treated with upfront SRS alone for brain metastases at our institution were retrospectively analyzed. Salvage treatment details were obtained for brain failures. Patients who underwent repeat SRS to the same lesion were excluded. RN was determined based on pathological confirmation or advanced brain imaging consistent with RN in a symptomatic patient. Patients were grouped according to salvage treatment and rates of RN were compared via Fisher's exact tests.

Results

Of 284 patients treated with upfront SRS alone, 132 received salvage therapy and 44 received multiple salvage treatments. This included 31 repeat SRS alone, 58 whole brain radiation therapy (WBRT) alone, 28 SRS and WBRT, 7 surgery alone, and 8 surgery with adjuvant radiation. With a median follow-up of 10 months, the rate of RN among all patients was 3.17% (9/284), salvaged patients 4.55% (6/132), and never salvaged patients 1.97% (3/152). Receiving salvage therapy did not significantly increase RN risk (P = .31). Of the patients requiring salvage treatments, the highest RN rate was among patients that had both salvage SRS and WBRT (delivered as separate salvage therapies) (6/28, 21.42%). RN rate in this group was significantly higher than in those treated with repeat SRS alone (0/31), WBRT alone (0/58), surgery alone (0/7), and surgery with adjuvant radiation (0/8). Comparing salvage WBRT doses <30 Gy versus ≥30 Gy revealed no effect of dose on RN rate. Additionally, among patients who received multiple SRS treatments, number of treated lesions was not predictive of RN incidence.

Conclusion

Our results suggest that initial management approach for recurrent brain metastasis after upfront SRS does not affect the rate of RN. However, the risk of RN significantly increases when patients are treated with both repeat SRS and salvage WBRT. Methods to improve prediction of toxicity and optimize patient selection for salvage treatments are needed.