Stereotactic body radiation therapy for the treatment of lymph node metastases: a retrospective mono-institutional study in a large cohort of patients.

Introduction: Lymph node metastases (NMs) are a common site of tumor spread that can occur at different times of the disease. Stereotactic body radiation therapy (SBRT) can be a therapeutic option for the treatment of NMs in the setting of oligometastatic disease (OMD). The aim of this study was to evaluate as primary end points the local control (LC) and secondary end points the locoregional nodal control (LRNC), distant nodal control (DNC), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS), and concurrently to assess the predictive factors of response. Methods: This is a retrospective study that analyzes a group of patients treated with SBRT on NMs from different primary tumors, with a of maximum five metastasis. Treated lesions were divided into four groups: oligometastatics, oligorecurrents, oligoprogressives, and oligopersistents. Results: From 2007 to 2021, 229 NMs were treated in 174 patients with different primary tumor. The schedule most represented was 30 Gy in five fractions. The LC was obtained in 90% of NMs treated by SBRT with rates at 1, 3, and 5 years of 93%, 86%, and 86%, respectively. The LRNC was reached in 84% of cases with rates at 1, 3, and 5 years of 88%, 83%, and 77%, respectively. The DNC was obtained in 87% of cases with rates at 1, 3, and 5 years of 92%, 82%, and 78%, respectively. The DMFS was obtained in 38% of cases with rates at 1, 3, and 5 years of 57%, 40%, and 30%, respectively. The rate of PFS were 44%, 23%, and 13% at 1, 3, and 5 years, respectively. The rates at 1, 3, and 5 years of OS were 78%, 48%, and 36%, respectively. Conclusion: SBRT is an option for the treatment of NMS, with high rates of LC, improving survival, and with a good safety and tolerance. Tumor volume, tumor burden, lesion site, and doses can be predictive factors of response; however, multi-institutional studies with a greater number of patients could be helpful to better select patients and understand the right integrations between ablative treatment and systemic therapies.

Clinical Outcomes of Stereotactic Body Radiotherapy (SBRT) for Oligometastatic Patients with Lymph Node Metastases from Gynecological Cancers.

BACKGROUND: To evaluate clinical outcomes of stereotactic body radiation therapy (SBRT) as a local treatment for lymph node metastases from gynecological cancers. METHODS: Between November 2007 and October 2021, we retrospectively analyzed 29 lymph node metastases in 22 oligometastatic/oligoprogressive patients treated with SBRT. The Kaplan-Meier method was used to estimate the rates survival. Univariate analysis for prognostic factors were performed with the log-rank test, and Cox proportional hazards regression was used to estimate hazard ratios (HR). RESULTS: Median age was 62 years (IQR, 50-80 years). Median follow-up was 17 months (IQR 10.5-31 months). The median survival was 22 months (CI 95%: 4.2-39.7, IQR: 12.5-34.5 months). Six months, one year and two year overall survival (OS) were 96.6%, 85.2%, and 48.7%, respectively. Median local control (LC) was not reached. Six months, 1one year and 2 year were 93.1%, 87.9%, and 79.9%, respectively. Distant metastasis free survival (DMFS) at one year, and two year was 53% and 37.1%, respectively Four patients (18%) experienced acute G1-G2 toxicities. No G3-4 acute toxicity was reported, and no late toxicity was observed. CONCLUSIONS: SBRT for lymph node recurrence offers excellent in-field tumor control with safe profile and low toxicities. Size, number of oligometastases, and time primary tumor to RT seem to be significant prognostic factors.

Stereotactic and Hypofractionated Radiotherapy Associated With Immune Checkpoint Inhibitor Drugs: Analysis of Local Control, Toxicity, and Outcome in a Single Research Centre Case Study.

BACKGROUND/AIM: We evaluated local control and toxicity in patients receiving radiotherapy associated with immune check point inhibitors and analyzed which oligometastatic disease setting benefits the most from local ablation in terms of advantage in overall survival. PATIENTS AND METHODS: We retrospectively identified 60 oligoprogressive patients treated with a PD-1 inhibitor in association with radiotherapy on the site of progression (119 lesions). RESULTS: After a median follow-up of 11.7 months (range=1-39 months), we observed complete response (CR) in 45/119, partial response (RP) in 42/119, and stable disease (SD) in 30/119 patients. Nine radionecrotic events occurred. Two patients experienced grade 3 toxicities and 32 patients reported grade 2 toxicities. The number of radiologically evident metastatic organs in patients who received concomitant PD-1 inhibitors and radiotherapy showed a significant increase in survival (respectively, 73% after 12 months and 47% after 24 months) in patients with 0-3 metastatic organs compared to those with more than 3 organ sites involved (p<0.0001). CONCLUSION: Radiotherapy associated with PD-1 inhibitors is overall safe and efficacious. Patients eligible for intensification of local treatments should have less or equal to 3 metastatic organ sites.