Update on the Management of Brain Metastasis

Predictors and surgical outcome of hemorrhagic metastatic brain malignancies

PURPOSE

Intracerebral metastases present a substantial risk of tumor-associated intracerebral hemorrhage (ICH). This study aimed to investigate the risk of hemorrhagic events in brain metastases (BM) from various primary tumor sites and evaluate the safety and outcomes of surgical tumor removal.

METHODS

A retrospective, single-center review of medical records was conducted for patients who underwent BM removal between January 2016 and December 2017. Patients with hemorrhagic BM were compared to those with non-hemorrhagic BM. Data on preoperative predictors, perioperative management, and postoperative outcomes were collected and analyzed.

RESULTS

A total of 229 patients met the inclusion criteria. Melanoma metastases were significantly associated with preoperative hemorrhage, even after adjusting for confounding factors (p = 0.001). Poor clinical status (p = 0.001), larger tumor volume (p = 0.020), and unfavorable prognosis (p = 0.001) independently predicted spontaneous hemorrhage. Importantly, preoperative use of anticoagulant medications was not linked to increased hemorrhagic risk (p = 0.592). Surgical removal of hemorrhagic BM, following cessation of blood-thinning medication, did not significantly affect intraoperative blood loss, surgical duration, or postoperative rebleeding risk (p > 0.096). However, intra-tumoral hemorrhage was associated with reduced overall survival (p = 0.001).

CONCLUSION

This study emphasizes the safety of anticoagulation in patients with BM and highlights the safety of neurosurgical treatment in patients with hemorrhagic BM when blood-thinning medication is temporarily paused. The presence of intra-tumoral hemorrhage negatively impacts survival, highlighting its prognostic significance in BM patients. Further research with larger cohorts is warranted to validate these findings and elucidate underlying mechanisms.

Double Trouble: A Case Report on the Surgical Management of Dual Intracranial Metastases

Intracranial metastasis disease (IMD) has proven to be a frequent secondary occurrence, usually for primary cancers such as lung, breast, and melanoma, which have a high possibility of metastasizing to the brain. Due to the reasons listed above, treatment and early diagnosis are incredibly challenging. In the past decade, medicine has developed much better imaging solutions and radiological and surgical approaches, increasing the postoperative survival prognosis and achieving more time-efficient results. It is still exceptionally difficult to be able to prevent what type of metastasis a patient might develop other than by using the tumor type or subtype. We present a case of a 51-year-old female patient entering the Neurosurgical Clinic at the University Hospital "St. Ivan Rilski" for operative treatment of a second metastatic lesion located on the left parietal lobe in January 2024. She had previously had an operative resection of an initial lesion located on the left temporal lobe in December 2023. Her medical history began in 2015 when her first diagnosis was a breast carcinoma, followed by operative treatment and radio-, chemo-, and targeted therapy. In 2020, due to metastases located in the bones, she had to undergo another treatment with chemotherapy as well as have a total hysterectomy done as a result of another metastasis. The patient did not provide any family history, nor did she confirm any past or current allergies to foods, drugs, etc. Under general inhalation anesthesia, the patient was placed in a park bench position to the right and had a Mayfield head holder applied. Through a left parietal craniotomy and neuronavigation, a tumor formation was revealed with the characteristic of a secondary lesion. A gross total resection was achieved through a microsurgical technique. Postoperatively, there were no further complications observed in the patient, and she was discharged on day five from the hospital with relief of her symptoms.

Targeted therapeutic options in early and metastatic NSCLC-overview

The complex therapeutic strategy of non-small cell lung cancer (NSCLC) has changed significantly in recent years. Disease-free survival increased significantly with immunotherapy and chemotherapy registered in perioperative treatments, as well as adjuvant registered immunotherapy and targeted therapy (osimertinib) in case of EGFR mutation. In oncogenic-addictive metastatic NSCLC, primarily in adenocarcinoma, the range of targeted therapies is expanding, with which the expected overall survival increases significantly, measured in years. By 2021, the FDA and EMA have approved targeted agents to inhibit EGFR activating mutations, T790 M resistance mutation, BRAF V600E mutation, ALK, ROS1, NTRK and RET fusion. In 2022, the range of authorized target therapies was expanded. With therapies that inhibit KRASG12C, EGFR exon 20, HER2 and MET. Until now, there was no registered targeted therapy for the KRAS mutations, which affect 30% of adenocarcinomas. Thus, the greatest expectation surrounded the inhibition of the KRAS G12C mutation, which occurs in ∼15% of NSCLC, mainly in smokers and is characterized by a poor prognosis. Sotorasib and adagrasib are approved as second-line agents after at least one prior course of chemotherapy and/or immunotherapy. Adagrasib in first-line combination with pembrolizumab immunotherapy proved more beneficial, especially in patients with high expression of PD-L1. In EGFR exon 20 insertion mutation of lung adenocarcinoma, amivantanab was registered for progression after platinum-based chemotherapy. Lung adenocarcinoma carries an EGFR exon 20, HER2 insertion mutation in 2%, for which the first targeted therapy is trastuzumab deruxtecan, in patients already treated with platinum-based chemotherapy. Two orally administered selective c-MET inhibitors, capmatinib and tepotinib, were also approved after chemotherapy in adenocarcinoma carrying MET exon 14 skipping mutations of about 3%. Incorporating reflex testing with next-generation sequencing (NGS) expands personalized therapies by identifying guideline-recommended molecular alterations.

Navigating Post-Operative Outcomes: A Comprehensive Reframing of an Original Graded Prognostic Assessment in Patients with Brain Metastases

BACKGROUND

Graded Prognostic Assessment (GPA) has been proposed for various brain metastases (BMs) tailored to the primary histology and molecular profiles. However, it does not consider whether patients have been operated on or not and does not include surgical outcomes as prognostic factors. The residual tumor burden (RTB) is a strong predictor of overall survival. We validated the GPA score and introduced "volumetric GPA" in the largest cohort of operated patients and further explored the role of RTB as an additional prognostic factor.

METHODS

A total of 630 patients with BMs between 2007 and 2020 were included. The four GPA components were analyzed. The validity of the original score was assessed using Cox regression, and a modified index incorporating RTB was developed by comparing the accuracy, sensitivity, specificity, F1-score, and AUC parameters.

RESULTS

GPA categories showed an association with survival: age (p < 0.001, hazard ratio (HR) 2.9, 95% confidence interval (CI) 2.5-3.3), Karnofsky performance status (KPS) (p < 0.001, HR 1.3, 95% CI 1.2-1.5), number of BMs (p = 0.019, HR 1.4, 95% CI 1.1-1.8), and the presence of extracranial manifestation (p < 0.001, HR 3, 95% CI 1.6-2.5). The median survival for GPA 0-1 was 4 months; for GPA 1.5-2, it was 12 months; for GPA 2.5-3, it was 21 months; and for GPA 3.5-4, it was 38 months (p < 0.001). RTB was identified as an independent prognostic factor. A cut-off of 2 cm3 was used for further analysis, which showed a median survival of 6 months (95% CI 4-8) vs. 13 months (95% CI 11-14, p < 0.001) for patients with RTB > 2 cm3 and <2 cm3, respectively. RTB was added as an additional component for a modified volumetric GPA score. The survival rates with the modified GPA score were: GPA 0-1: 4 months, GPA 1.5-2: 7 months, GPA 2.5-3: 18 months, and GPA 3.5-4: 34 months. Both scores showed good stratification, with the new score showed a trend towards better discrimination in patients with more favorable prognoses.

CONCLUSION

The prognostic value of the original GPA was confirmed in our cohort of patients who underwent surgery for BM. The RTB was identified as a parameter of high prognostic significance and was incorporated into an updated "volumetric GPA". This score provides a novel tool for prognosis and clinical decision making in patients undergoing surgery. This method may be useful for stratification and patient selection for further treatment and in future clinical trials.

Combination of radiosurgery and immunotherapy in brain metastases: balance between efficacy and toxicities

PURPOSE OF REVIEW

The incidence of brain metastasis is high and still increasing. Among local therapies, stereotactic radiosurgery (SRS) is an effective treatment option, optimally sparing normal brain, even for multiple brain metastases. Immune checkpoint inhibitors (ICIs) become the new standard of care in an increasing number of cancers, and the combination SRS and ICI is often proposed to patients, but few data have been published on the efficacy and the toxicity of this association.

RECENT FINDINGS

Explaining this lack of consensus: retrospective studies with different primary cancers, various treatment lines and unknown levels of steroid exposure. Concerning the toxicity, the independent association of radionecrosis with brain-PTV volume was confirmed, and a decreased dose of SRS is now tested in a randomized study. Finally, a 'concurrent' delivery of SRS and ICI (within a 4 weeks' interval) seems the optimal schedule; fractionated radiosurgery for large brain metastasis should be favored. Radio-sensitizing nanoparticles and devices aiming to increase the permeability of the blood brain barrier should be considered in future combinations.

SUMMARY

The efficacy/toxicity balance of SRS-ICI combination should be regularly re-evaluated, anticipating continued progress in ICI and SRS delivery, with more long-survivors potentially exposed to long-term toxicities. Patients should be included in clinical trials and clearly informed to participate more closely in the final choice.

Dose-effect relationship of linear accelerator based stereotactic radiotherapy for brain metastases

OBJECTIVE

The purpose of this study is to reveal the dose-effect relationship of linear accelerator (LINAC)-based stereotactic radiotherapy (SRT) in patients with brain metastases (BM).

MATERIALS AND METHODS

The PubMed, Cochrane, and Web of Science databases were used to identify studies that reported local tumour control after LINAC-based SRT in patients with BMs. Studies of other approaches that could affect local tumour control, such as whole brain radiotherapy, targeted therapy, and immunotherapy, were excluded from the dose-effect relationship analysis. Data extracted included patient and treatment characteristics and tumour local control. Probit model in XLSTAT 2016 was used for regression analysis, and P < 0.05 was set as the statistically significant level.

RESULTS

After literature screening, 19 eligible studies involving 1523 patients were included in the probit model regression analysis. There was no significant dose-effect relationship between nominal BED10 and peripheral BED10 versus 12-month local control probability. There were significant dose effect relationships between the centre BED10 and the average BED10 versus the 12-month local control probability, with P values of 0.015 and 0.011, respectively. According to the model, the central BED10 and the average BED10 corresponding to probabilities of 90% 12-month local control were 109.2 GyBED10 (95% confidence interval (CI): 88.7-245.9 GyBED10) and 87.8 GyBED10 (95% CI: 74.3-161.5 GyBED10), respectively. A 12-month local control rate of 86.9% (95% CI: 81.7-89.7%) and 85.5% (95% CI: 81.2-89.2%) can be expected at a centre BED10 of 80 Gy and an average BED10 of 60 Gy, respectively.

CONCLUSION

For patients with BM treated with LINAC-based SRT, more attention should be given to the central and average doses of PTV. A clear definition of the dose prescription should be established to ensure the effectiveness and comparability of treatment.

Identification of FKBP10 prognostic value in lung adenocarcinoma patients with surgical resection of brain metastases: A retrospective single-institution cohort study

OBJECTIVE

To explore the expression levels and clinical value of FKBP10 in lung adenocarcinoma brain metastases.

DESIGN

A retrospective single-institution cohort study.

PATIENTS

The perioperative records of 71 patients with lung adenocarcinoma brain metastases who underwent surgical resection at the authors' institution between November 2012 and June 2019 were retrospectively analyzed.

METHODS

The authors evaluated FKBP10 expression levels using immunohistochemistry in tissue arrays of these patients. Kaplan-Meier survival curves were constructed, and a Cox proportional hazards regression model was used to identify independent prognostic biomarkers. A public database was used to detect FKBP10 expression and its clinical value in primary lung adenocarcinoma.

RESULTS

The authors found that the FKBP10 protein was selectively expressed in lung adenocarcinoma brain metastases. Survival analysis showed that FKBP10 expression (p = 0.02, HR = 2.472, 95% CI [1.156, 5.289]), target therapy (p < 0.01, HR = 0.186, 95% CI [0.073, 0.477]), and radiotherapy (p = 0.006, HR = 0.330, 95% CI [0.149, 0.731]) were independent prognostic factors for survival in lung adenocarcinoma patients with brain metastases. The authors also detected FKBP10 expression in primary lung adenocarcinoma using a public database, found that FKBP10 is also selectively expressed in primary lung adenocarcinoma, and affects the overall survival and disease-free survival of patients.

LIMITATIONS

The number of enrolled patients was relatively small and patients' treatment options varied.

CONCLUSIONS

A combination of surgical resection, adjuvant radiotherapy, and precise target therapy may benefit the survival of selected patients with lung adenocarcinoma brain metastases. FKBP10 is a novel biomarker for lung adenocarcinoma brain metastases, which is closely associated with survival time and may serve as a potential therapeutic target.

Ten-Fraction Stereotactic Radiosurgery With Different Gross Tumor Doses and Inhomogeneities for Brain Metastasis of >10 cc: Treatment Responses Suggesting Suitable Biological Effective Dose Formula for Single and 10 Fractions

Stereotactic radiosurgery (SRS) with >5 fractions (fr) has been increasingly adopted to improve local control and safety for brain metastases (BM) of >10 cm³, given the limited brain tolerance of SRS with ≤5 fr. However, the optimal indication and treatment design, including the prescribed dose and distribution for 10 fr SRS, remains uncertain. A single fr of 24 Gy provides approximately 95% of the one-year local tumor control probability. The potential SRS doses in 10 fr that is clinically equivalent to a single fr of 24 Gy regarding anti-tumor effect range from 48.4 to 81.6 Gy as biological effective doses (BED) as a function of the BED model formulas along with the alpha/beta ratios. The most appropriate BED formula in conjunction with an alpha/beta ratio to estimate similar anti-BM effects for single and 10 fr remains controversial. Herein, we describe four cases of symptomatic radiation-naïve BM >10 cm³ (range, 11 to 26 cm³), treated with 10 fr SRS with a standard prescribed dose of 42 Gy, for which modified dynamic conformal arcs were used with forward planning to improve dose conformity. In the first two cases with gross tumor volumes (GTV) of 15.3 and 10.9 cm³, 42 Gy was prescribed to 70%-80% isodose, normalized to 100% at the isocenter, which encompasses the boundary of the planning target volume: GTV + isotropic 1 mm margin. The tumor responses were initially marked regression followed by regrowth within three months in case 1 and no shrinkage with subsequent progression within three months in case 2. In the remaining two cases with larger GTVs of 19.1 and 26.2 cm³, the GTV boundary and 2-3 mm margin-added object volume was covered by 80% and 56% isodoses with 53 Gy and 37 Gy, respectively, to further increase the marginal and internal doses of GTV and to ensure moderate dose spillage outside the GTV, while >1-1.5 mm outside the GTV was covered by 42 Gy with 63% isodose. According to the BED based on the linear-quadratic (LQ) model with an alpha/beta ratio of 10 (BED₁₀), 53 Gy corresponds to approximately 81 Gy in BED₁₀ and 24 Gy in a single fr. Excellent initial maximum tumor response and subsequently sustained tumor regression (STR) were achieved in both cases. Subsequently, enlarging nodules that could not exclude the possibility of tumor regrowth were disclosed within two years, while late adverse radiation effects remained moderate. These dose-effect relationships suggest that a GTV marginal dose of ≥53 Gy with ≤80% isodose would be preferred to effect ≥1-year STR and that further dose escalation of both marginal and internal GTV may be necessary to achieve ≥2-year STR, while GTV of >25 cm³ may be unsuitable for 10 fr SRS in terms of long-term brain tolerance. Among LQ, LQ-cubic, and LQ-linear model formulas and alpha/beta ratios of 10-20, BED₁₀ may be clinically most suitable to estimate a 10 fr SRS dose that provides anti-BM efficacy similar to that for a single fr.