151. Dose coverage impacts local control in ultra-central lung oligometastases treated with stereotactic radiotherapy.
- Author
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Loi M, Franceschini D, Dominici L, Chiola I, Franzese C, D'Agostino GR, Navarria P, Marzo M, Paganini L, Comito T, Mancosu P, Tomatis S, Cozzi L, Alifano M, and Scorsetti M
- Subjects
- Adult, Aged, Aged, 80 and over, Bronchi radiation effects, Esophagitis etiology, Esophagus radiation effects, Female, Follow-Up Studies, Hemoptysis etiology, Humans, Kaplan-Meier Estimate, Male, Mediastinum radiation effects, Middle Aged, Progression-Free Survival, Proportional Hazards Models, Radiation Injuries etiology, Radiation Injuries prevention & control, Radiation Pneumonitis etiology, Radiotherapy Dosage, Treatment Outcome, Lung Neoplasms secondary, Lung Neoplasms surgery, Radiosurgery adverse effects
- Abstract
Introduction: The use of Stereotactic Body Radiotherapy (SBRT) is controversial in Ultra-Central lung tumors, a subset of central lung tumors characterized by proximity to critical mediastinal structures. This is of interest in oligometastatic (≤3 metastases) patients, who can yield survival benefit from local treatments. The aim of our study is to assess the determinants of efficacy and toxicity in this setting., Materials and Methods: Clinical and dosimetric parameters were reviewed in a cohort of oligometastatic patients treated with SBRT for ultra-central tumors. Local control rate (LC) and toxicity were assessed. Statistical Analysis was carried out to assess the impact of those predictors on local recurrence and adverse events., Results: One-hundred-nine consecutive patients were included. A median Biologic Effective Dose (BED) of 105 (75-132) Gy10 was prescribed. At a median follow-up of 17 (range 3-78) months, 2-year LC was 87%. Improved LC was correlated to Planning Treatment Volume (PTV) covered by 95% of the prescription dose (V95% PTV) > 85% (HR 0.15, 95%CI 0.05-0.49, p = 0.0017) and to Gross Tumor Volume (GTV) < 90 cm
3 (HR 0.2, 95%CI 0.07-0.56, p = 0.0021). Overall and grade ≥ 3 toxicity incidence was 20% and 5%, respectively. Patients experiencing acute and late toxicities received significantly higher dose to 1 cm3 (D1cm3 ) of esophagus and lung volume receiving ≥5 Gy (V5Gy) (p = 0.016 and p = 0.013), and higher dose to 0.1 cm3 (D0.1cm3 ) of heart (p = 0.036), respectively., Conclusion: V95% PTV > 85% and GTV < 90 cm3 are independent predictors of LC. Dose to esophagus, lung and heart should be carefully assessed to minimize treatment-related toxicities.- Published
- 2021
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