Stereotactic Radiotherapy for Ultra-Central Lung Oligometastases in Non-Small-Cell Lung Cancer

Abstract

Background: Stereotactic body radiotherapy (SBRT) in ultra-central (UC) lung tumors, defined in the presence of planning target volume (PTV) overlap or direct tumor abutment to the central bronchial tree or esophagus, may be correlated to a higher incidence of severe adverse events. Outcome and toxicity in oligometastatic (≤3 metastases) non-small-cell lung cancer (NSCLC) patients receiving SBRT for UC tumors were evaluated. Methods: Oligometastatic NSCLC patients treated with SBRT for UC were retrospectively reviewed. Local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS) and overall survival (OS) were calculated. Incidence and grade of toxicity were evaluated. Statistical analysis was performed to assess the impact of clinical and treatment-related variables on outcome and toxicity occurrence. Results: Seventy-two patients were treated to a median biologically effective dose (BED) of 105 (75–132) Gy10. Two-year LC, DMFS, PFS, and OS were 83%, 46%, 43%, and 49%. BED>75 Gy10 was correlated to superior LC (p = 0.02), PFS (p = 0.036), and OS (p < 0.001). Grade ≥3 toxicity rate was 7%, including one fatal esophagitis. No variables were correlated to DMFS or to occurrence of overall and grade ≥3 toxicity. Conclusions: SBRT using dose-intensive schedules improves outcome in NSCLC patients. Overall toxicity is acceptable, although rare but potentially fatal toxicities may occur.

Toxicity and efficacy of stereotactic body radiotherapy for ultra-central lung tumours: a single institution real life experience

“…In the present study, a prescribed BED 10 < 50 Gy was correlated with an increasing risk of local recurrence. Loi et al found BED 10 > 75 Gy was associated with higher LC rate [14]. In a modelling study, Klement et al showed that in lung SBRT, the following BED 10 of PTV were predictive of LC rate: D 1% , prescribed dose [30].…”

Toxicity and Efficacy of Stereotactic Body Radiotherapy for Ultra-central Lung Tumours: a Single Institution Real Life Experience

“…The BED 10 ranged from 75 to 132 Gy. The most commonly described SBRT schedule for ultra-central tumours was 60 Gy in 8 fractions of 7.5 Gy [14,15]. In our study, we mostly used 5 fractions (68.9% of treatments).…”

“…For other studies they are tumours contacting the proximal bronchial tree only [9,13]. Conversely, other reports add tumours whose PTV contact with the oesophagus or the pulmonary vein or artery [12,14]. Finally, some authors include tumours contacting with the pericardium or the heart [15].…”

Oligometastatic Disease in Non-Small-Cell Lung Cancer: An Update

“…However, for lesions located centrally, defined as being within 2 cm from midline structures, such as the bronchial tree, heart, great vessels, and other mediastinal organs, the adverse effects of radiation therapy were high. Some life-threatening conditions, such as hemorrhage or broncho-esophageal fistula have been reported in patients receiving a dose of approximately 60 Gy in 12 fractions [ 126 , 127 , 128 ]. Mauro et al reported the application of SABR to ultra-central lung oligometastases in NSCLC at a relatively high dose.…”