SBRT of hilar lymph nodes from lung cancer: outcomes, toxicity and role of CTV
Margherita Rotondi,
Italy
PO-1307
Abstract
SBRT of hilar lymph nodes from lung cancer: outcomes, toxicity and role of CTV
Authors: Margherita Rotondi1, Ilaria Angelicone1, Riccardo Carlo Sigillo1, Donatella Caivano2, Maurizio Valeriani1, Mattia Falchetto Osti1
1Università degli Studi di Roma "La Sapienza", A.O.U Sant'Andrea M-P, Radiation Oncology, Rome, Italy; 2Santa Maria Goretti Hospital, Radiation Oncology, Latina, Italy
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Purpose or Objective
To evaluate efficacy and tolerance of stereotactic body radiation therapy (SBRT) of mediastinal and hilar lymph nodes (LN) in patients (pts) with lung cancer, in terms of clinical outcomes, toxicities and relationship between clinical tumor volume (CTV) and prognosis.
Material and Methods
From 2009 to 2020 forty-eight patients with lung cancer underwent SBRT on LN (56 lesions overall) including 82% (46 pts) were from non-small cell lung cancer (NSCLC), 7% (4 pts) were from small cell lung cancer (SCLC) and 10% (6pts) from others histologies. The state of patients at moment of treatment was classified as oligorecurrent (52%), oligoprogression (27%), oligometastatic (9%) and oligopersistent (12%). The median age was 69 years (range: 54-90 years) and the Performance Status was ≤2. Thirty-eight pts underwent Intensity Modulated Radiotherapy (IMRT), while eighteen pts underwent Volumetric Modulated Arc Therapy (VMAT) technique, and the schedule of treatment most represented was 48 Gy in 8 fractions (range 23-60 Gy in 1-8 fractions). The medium BED10 was 86 Gy (range 48-120 Gy). The medium volume of CTV treated was 10 cc (range 0.74-60.3 cc). Toxicity assessment has been considered in acute and in late (more than 3 months after SBRT) for pulmonary district, according to Common Terminology Criteria for Adverse Events (CTCAE v4.0) scoring system. Survival outcomes were calculated through Kaplan-Meier curves.
Results
Median survival was 23 months. The acute and late toxicities was < Grade 2 for all parameters for all pts. At 1- and 3-years survival probability were as follows: local control (LC) 89% and 83%, loco regional nodal control (LRNC) 81% and 70%, distant nodal control (DNC) 92% and 88%, distant metastasis free survival (DMFS) 49% and 36%, overall survival (OS) 66% and 35% respectively. At univariate analysis, the volume of CTV (> 10 cc) was associated with worst results in terms of DMFS and OS with statistically significant data (P = 0,0281 and P = 0,0015 respectively).
Conclusion
The application of SBRT for mediastinal and hilar LN, especially in the oligometastatic patient with lung cancer, improve local control (LC) and other outcomes with limited toxicity, with evidence that CTV volume is an unfavorable factor in terms of DMFS and OS.