P2.16-16 SABRTOOTH: A Fasibility Study of SABR Versus Surgery in Patients with Peripheral Stage I NSCLC Considered to be at Higher Risk for Surgery

Abstract

patients treated with linear accelerator-based SABR between 2009 and 2016 were retrospectively studied. Impact of patient, tumor, and treatment parameters on LC, OS and toxicity-free survival (TFS) were evaluated by multivariate analyses. Result: Forty-eight PL and 22 OM lesions were analyzed, including 20 (28%) re-irradiation (Re-RT) cases. Median total, fractionated, and biological equivalent doses in BED10 and BED3 were 55 (30-60), 9.75 (4-18), 110 (41-151), and 228 (90-378) Gy, respectively. Doses given as Re-RT were lower (median Re-RT BED10 dose 94 vs. 110 Gy, P¼0.009). Complete response (CR) was obtained in 43 (61%) lesions. None of the analyzed factors correlated to CR. After a median follow-up of 57 (48-65, 95%CI) months, 10 (14%) lesions had relapsed and 37 (57%) patients had died (2 and 5year LC and OS rates were 84/70% and 52/28%, respectively). In univariate analysis, 2-year LC was lower for lesions with no CR and for colorectal cancer lesions. Only "no CR" was significant (100 vs. 51%; HR¼18.2, CI 2.3-146, P¼0.006) in final multivariate analyses. Median OS was significantly lower in patients with grade 3+ toxicity (5 months after grade 3+ toxicity, vs. 39 months in others [HR 4.7,P<0.0001]). OS was marginally lower in patients with primary lung cancer compared to patients with OM tumors (19 vs. 49 months, HR 2.3, CI 1-5.6, P¼0.06). Among 17 toxicities, 5 reached grade 5. For patients with grade 3+ toxicities, TFS was lower after Re-RT (2-year TFS 63% vs. 96%, HR 5.1, CI 1.3-20.3, P¼0.022) but did not differ significantly for lesions abutting TBT (2-year TFS 69% vs. 93.4%, HR 3.5, CI 0.9-13.9, P¼0.08). Conclusion: SABR is an effective treatment modality in centrally located lung tumors. SABR to re-irradiated lesions and possibly lesions abutting TBT may have the higher risks for serious toxicities. Further studies are indicated.

Patients’ confidence in treatment decisions for early stage non-small cell lung cancer (NSCLC)

“…Although current treatment guidelines do not recommend SABR as first-line treatment for NSCLC moderate risk patients(1), multiple observational studies have suggested therapeutic equipoise exists between SABR and surgery in those patients with multiple comorbidities (8,9). The lack of long term QoL data from these two treatments has highlighted the importance of understanding whether a truly informed "shared treatment decision" between patients and clinicians can be made.…”

Cost-effectiveness of stereotactic body radiation therapy versus video assisted thoracic surgery in medically operable stage I non-small cell lung cancer: A modeling study

“…Randomized controlled trials (RCTs) are seen as the highest quality of evidence, because the randomization process can prevent bias [5]. Some RCTs that compared SBRT to VATS resection in operable patients have been discontinued due to low patient accrual [6][7][8]. A pooled analysis of two discontinued RCTs suggested equal effectiveness, although small sample size and short follow-up prohibited definitive conclusions [9].…”

Patients’ confidence in treatment decisions for early stage non-small cell lung cancer (NSCLC)

“…Although current treatment guidelines do not recommend SABR as first-line treatment for Non-Small Cell Lung Cancer (NSCLC) moderate risk patients [1], multiple observational studies have suggested therapeutic equipoise exists between SABR and surgery in those patients with multiple comorbidities [8,9]. The lack of long term QoL data from these two treatments has highlighted the importance of understanding whether a truly informed, shared treatment decision between patients and clinicians can be made.…”