Repeated Multimodality Ablative Therapies for Oligorecurrent Pulmonary Metastatic Disease.

Stereotactic body radiotherapy (SBRT) and percutaneous thermal ablation (TA) are alternatives to surgery for the management of pulmonary oligometastases. In this collaborative work, we retrospectively analyzed patients who had undergone iterative focal ablative treatments of pulmonary oligometastases. We hypothesized that repeated ablative therapies could benefit patients with consecutive oligometastatic relapses. Patients treated with SBRT and/or TA for pulmonary oligometastases in two French academic centers between October 2011 and November 2016 were included. A total of 102 patients with 198 lesions were included; 45 patients (44.1%) received repeated focal treatments at the pulmonary site for an oligorecurrent disease (the "multiple courses" group). Median follow-up was 22.5 months. The 3-year overall survival rates of patients who had a single treatment sequence (the "single course" group) versus the "multiple courses" were 73.9% and 78.8%, respectively, which was not a statistically significant difference (p = 0.860). The 3-year systemic therapy-free survival tended to be longer in the "multiple courses" group (50.4%) than in the "single course" group (44.7%) (p = 0.081). Tolerance of repeated treatments was excellent with only one grade 4 toxicity. Thereby, multimodality repeated ablative therapy is effective in patients with pulmonary oligorecurrent metastases. This strategy may delay the use of more toxic systemic therapy.

Multivariate normal tissue complication probability modeling of vaginal late toxicity after brachytherapy for cervical cancer.

PURPOSE: To explore the best variables combination for a predictive model of vaginal toxicity in cervical cancer patients undergoing brachytherapy (BT). METHODS AND MATERIALS: Clinical and 3-dimensional dosimetric parameters were retrospectively extracted from an institutional database of consecutive patients undergoing intracavitary BT after external beam radiation therapy from 2006 to 2013 for a cervical cancer. A least absolute shrinkage and selection operator selection procedure in Cox's proportional hazards regression model was performed to select a set of relevant predictors for a multivariate normal tissue complication probability model of Grade ≥2 vaginal late toxicity. Outcomes reliability was internally assessed by bootstrap resampling method. RESULTS: One hundred sixty-nine women were included in the present study with a median followup time of 3.8 years (interquartile range [IQR], 1.9-5.6 years). The 2 years and 5 years cumulative incidence rates of Grade ≥2 late vaginal toxicity were 19.9% and 27.5%, respectively. Among 31 metrics and six clinical factors extracted, the optimal model included two dosimetric variables: V70Gy and D5% (the percentage volume that received a dose greater or equal to 70 Gy and the minimum dose given to the hottest 5% volume, respectively). Area under the ROC curve at 2 and 5 years of followup were 0.85 and 0.91, respectively. Regarding internal validation, median area under the ROC curve of bootstrap predictions was 0.83 (IQR, 0.78-0.88) and 0.89 (IQR, 0.85-0.93) at 2 and 5 years of followup, respectively. CONCLUSIONS: A multivariate normal tissue complication probability model for severe vaginal toxicity based on two dosimetric variables (V70Gy and D5%) provides reliable discrimination capability in a cohort of cervical cancer treated with external beam radiation therapy and BT.

Flattening Filter Free vs. Flattened Beams for Lung Stereotactic Body Radiation Therapy.

BACKGROUND/AIM: To assess the clinical impact of high dose rate stereotactic body radiation therapy (SBRT) in patients with lung neoplastic lesions. PATIENTS AND METHODS: From January 2014 to June 2016, a single-center retrospective analysis was performed including all patients treated by either flattening filter free (FFF) beams or flattening filter beams (FF) three-dimensional (3D) SBRT for lung neoplastic lesions. RESULTS: A total of 99 SBRT were performed on 75 patients. Among these, 29 SBRT were performed using a FFF technique while 70 other SBRT were done using a FF technique. Median follow-up time was 12.9 months. Overall, no difference between the two groups was found except for the mean beam on time which was reduced by 3.3 to 0.9 minutes in the FFF group (p<0.001). CONCLUSION: We report a low toxicity rate and a shortened beam on time in patients treated with 3D FFF SBRT for lung neoplastic lesions.