Metastatic Neoplasm Volume Kinetics Following Two-Staged Stereotactic Radiosurgery

Multi-institutional study of 'Sandwich treatment' for motor area large brain metastases (LBM) with diameter over 3 cm

BACKGROUND

The objective of the present study was to explore the effectiveness and safety of 'Sandwich treatment' strategy for large brain metastases (LBM) with diameter over 3 cm (minimum volume >= 15 cm3) located in motor area.

PATIENTS AND METHODS

Patients from four gamma knife center that received 'Sandwich treatment' were retrospectively studied from January 2016 to March 2023. The strategy was one-week treatment course including 2 stages of stereotactic radiosurgery (SRS) and using bevacizumab once during SRS gap. The tumor volume and peri-tumor edema changes were analyzed before and after 'Sandwich treatment'. Manual muscle testing (MMT) score and Barthel Index (BI) score were used to evaluate the changes of patients' movement and physical strength rehabilitation. The patients' overall survival (OS) and tumor local control (TLC) rate was calculated. Cox regression model was used to analyze the risk factors that related to TLC.

RESULTS

61 patients with 72 lesions received the 'Sandwich treatment'. The median prescription dose was 13.0 Gy and 12.5 Gy at the first- and second-stage SRS. The mean tumor volume at the time of 'Sandwich treatment' and 3 months later was 20.1 cm3 and 12.3, respectively (P < 0.01). The mean peri-tumor edema volume at the first- and second-stage SRS was 12.6 cm3 and 5.2 cm3, respectively (P < 0.01). Patients' median MMT score improved from 6 at the beginning to 8 at the end of 'Sandwich treatment' (P < 0.01), BI score was also greatly improved from 45 at the time of 'Sandwich treatment' to 95 after 3 months (P < 0.01). Patients' median OS was 14.0 months, and the 3, 6, 12 months OS rate was 92.0%, 86.0% and 66.0%, respectively. The TLC rate at 3, 6, 12 months was 98.4%, 93.4%, and 85.3%, respectively. Patients with lung cancer had lower risk of tumor relapse. The cumulative incidence of patient's hemorrhage and radiation necrosis was 4.92% (3/61) and 13.11% (8/61) after 'Sandwich treatment'.

CONCLUSIONS

'Sandwich treatment' strategy is safe and effective for LBM located in motor area. The strategy could rapidly improve the patients' movement and enhance their physical strength rehabilitation.

Efficacy and safety of a "sandwich therapy" based on staged stereotactic radiosurgery and bevacizumab for large brainstem metastases

OBJECTIVE

Gamma Knife stereotactic radiosurgery (SRS) is an effective therapeutic option for unresectable brainstem metastases. Currently, staged stereotactic radiosurgery (SSRS) has become available for large brainstem metastases（≥ 1 cm3） despite the limitation of peritumoral edema. The authors developed the so-called "sandwich therapy" which integrated 2-stage stereotactic radiosurgery (2-SSRS) with bevacizumab for peritumoral edema reduction and local control of large brainstem metastases.

METHODS

42 patients with large brainstem metastases ≥1 cm3 who received 2-SSRS simultaneously with bevacizumab were screened from 2019 to 2021 retrospectively. The first SRS margin doses were 13 Gy (range 11-15) and the second SRS margin doses were 12 Gy (range 11-13), one-time vascular endothelial growth factor (VEGF) inhibitor (bevacizumab) of 3.5-5 mg/kg was administrated intravenously the next day after the first SRS. The median interval between the two sessions of SRS was 6 days. Baseline demographics, clinical and radiology imaging follow-ups were recorded to determine symptomatic improvement, peritumoral edema reduction, local control, and disease progression. Median survival was calculated using Kaplan-Meier analysis. Multivariate analysis was performed to identify prognostic factors.

RESULTS

The "sandwich therapy" was applied to 42 lesions. Significant reductions of tumor volume (p < 0.05) and peritumoral edema volume (p < 0.01) were achieved at the second SRS in comparison to those at the first SRS. The proportion of favorable Karnofsky performance scale (KPS) (≥80 %) increased significantly at early follow-up time points and reached the highest value of 85.7 %. The median survival time was 9.7 months, the median local control duration was 11.3 months. 8 acute adverse events of CTCAE grade 2 and 3 were observed in 6 patients and resolved with palliative treatment. Tyrosine kinase inhibitor (TKI) treatment was identified as a predictive factor for longer survival.

CONCLUSION

The "sandwich therapy" which integrates 2-SSRS with bevacizumab is a safe and effective option for large brainstem metastases.

'Sandwich treatment' for posterior fossa brain metastases with volume larger than 4cm3: a multicentric retrospective study

Single stereotactic radiosurgery (SRS) for posterior fossa brain metastases (BM) larger than 4cm3 is dangerous. 'Sandwich treatment' strategy was developed for these BMs. The strategy was one week treatment course which includes 2-stage SRS and using Bevacizumab once during SRS gap. Patients from four gamma knife center were retrospectively analyzed. The changes of tumor and peri-tumor edema volume were studied. The Dizziness Handicap Inventory (DHI) Vomiting Score (VS) and Glasgow Coma Scale (GCS) were used to evaluate patients' clinical symptom changes. Karnofsky performance scale (KPS) and Barthel Index (BI) were used to evaluate patients' overall fitness status and physical activity rehabilitation. Tumor local control (TLC) and patients' overall survival (OS) rate were also calculated. Forty patients with 45 LBMs received 'Sandwich treatment'. The mean edema volume reduced remarkably at the course of therapy and 3 months later (P < 0.01). The mean tumor volume greatly decreased 3 months later (P < 0.01). Patients' clinical symptoms that reflected by median score of DHI, VS, GCS were improved dramatically at the course of therapy and 3 months later (P < 0.01). Similar changes happened in median score of KPS and BI that reflected patients' overall fitness status and physical activity rehabilitation (P < 0.01). Patients' median OS was 14.3 months, with 95.4%, 76.2%, and 26.3% survival rate at 6, 12, 24 months. The TLC rate at 6, 12, 24 months was 97.5%, 86.0% and 62.2%.The 'Sandwich treatment' is safe and effective for patients with LBM over 4cm3 in the posterior fossa. The strategy could quickly improve patients' symptoms, well control tumor growth, prolong patient's OS, and has controllable side effects.

Modern Stereotactic Radiotherapy for Brain Metastases from Lung Cancer: Current Trends and Future Perspectives Based on Integrated Translational Approaches

Brain metastases (BMs) represent the most frequent metastatic event in the course of lung cancer patients, occurring in approximately 50% of patients with non-small-cell lung cancer (NSCLC) and in up to 70% in patients with small-cell lung cancer (SCLC). Thus far, many advances have been made in the diagnostic and therapeutic procedures, allowing improvements in the prognosis of these patients. The modern approach relies on the integration of several factors, such as accurate histological and molecular profiling, comprehensive assessment of clinical parameters and precise definition of the extent of intracranial and extracranial disease involvement. The combination of these factors is pivotal to guide the multidisciplinary discussion and to offer the most appropriate treatment to these patients based on a personalized approach. Focal radiotherapy (RT), in all its modalities (radiosurgery (SRS), fractionated stereotactic radiotherapy (SRT), adjuvant stereotactic radiotherapy (aSRT)), is the cornerstone of BM management, either alone or in combination with surgery and systemic therapies. We review the modern therapeutic strategies available to treat lung cancer patients with brain involvement. This includes an accurate review of the different technical solutions which can be exploited to provide a "state-of-art" focal RT and also a detailed description of the systemic agents available as effective alternatives to SRS/SRT when a targetable molecular driver is present. In addition to the validated treatment options, we also discuss the future perspective for focal RT, based on emerging clinical reports (e.g., SRS for patients with many BMs from NSCLC or SRS for BMs from SCLC), together with a presentation of innovative and promising findings in translational research and the combination of novel targeted agents with SRS/SRT.