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Page 8 of 12 Galvez et al. Mini-invasive Surg 2020;4:86 I http://dx.doi.org/10.20517/2574-1225.2020.86
[50]
A retrospective analysis of 4,069 US veterans by Bryant et al. , with 449 SABR and 634 SLR (414 wedge
and 220 anatomical segmentectomies), found no statistical differences in cancer-specific survival (HR = 1.25;
95%CI: 0.93-1.68; P = 0.15) or OS (HR = 1.17; 95%CI: 0.90-1.53; P = 0.85) between both treatments, while
lobectomy was superior to SABR.

[51]
A National Cancer Database study was conducted by Wu et al. . After propensity score matching, 9,967
patients treated by SABR resulted in shorter OS compared to 9,967 SLR patients. Both wedge resection
and anatomical segmentectomy showed longer OS, whereas segmentectomy patients had longer median
survival than wedge patients (71.4 years vs. 58.0 years; P < 0.001). In tumors less than 2 cm in diameter,
SABR had higher hazard of mortality than SLR (P < 0.001).

[7]
A meta-analysis by Cao et al. , in 2019, compared SABR and surgery in NSCLC. There was no limitation
to early stage NSCLC, and no subgroup analysis in stage I. In the subgroup analysis of sublobar resections,
OS was superior in SLR compared to SABR in unmatched patients from 6 studies (OR = 1.54; 95%CI: 1.36-
1.75; P < 0.00001), but there were insufficient matched patients to perform a meta-analysis. All these studies
are summarized in Table 2.

There is one randomized trial in course, the VALOR trial (NCT02984761), comparing anatomical
pulmonary resection (lobectomy and segmentectomy) with SABR in stage I biopsy-proven NSCLC. The
estimated accrual is 670 patients and the primary endpoint is 5-year OS, and the expected completion date
is 2027.

[52]
Guidelines of the American Society of Radiation Oncology do not recommend SABR out of a clinical
trial in patients with standard operative risk for lobectomy with systematic lymph node dissection.
But as many recent studies advocate for lung-preserving SLR in early stages, the question that remarks
unanswered is: In those cases, does SABR constitutes an alternative treatment due to better toxicity profile?
Or does the advantages of a surgical exploration (e.g., visualization of cavity and other lobes, lymph node
assessment, and resection of primary lesion) makes SLR the optimal treatment?

Sublobar resection and SABR in nodules detected during lung cancer screening tests
[53]
The National Lung Screening Trial (NLST) found that 68% of NSCLC rightly diagnosed by CT were stage
[12]
I , and reported a 20% decrease in lung cancer specific mortality (P = 0.004) and 6.7% in overall mortality
(P = 0.02) compared to the radiography group. Several other lung screening trials have supported these
[54]
results . But not all these newly diagnosed small nodules are malignancies, so it raises the controversy of
how to deal with these nodules. Surgical resection offers the possibility of assessing hilar and mediastinal
lymph nodes (20% occult nodal metastasis in clinical stage I [12,55] , although lower in screening-detected
[56]
tumors ), and also obtains a complete nodule resection for assessing pathological prognostic factors.
Other potential disadvantages of SABR when compared to surgery are the overtreatment of false positive
lesions, and the fact that nodules are not resected, so follow-up implies the careful performance and
analysis of residual scar lesions and their potential growth .
[55]

An issue that makes SABR an attractive alternative in screening detected tumors is the toxicity profile,
which seems to be less severe for SABR. Also, a mean 30-day mortality of 10% in severe chronic obstructive
pulmonary disease stage I NSCLC after surgery makes a less toxic algorithm appear as a desirable option .
[57]
For peripheral screen detected early stage NSCLC in patients amenable to surgery, this seems the most
suitable option because it also offers accurate staging, definitive diagnosis, and pathological prognostic
factors assessment . In patients at high-risk for surgery or patients who are inoperable, SABR should be
[55]
offered to patients in a shared decision-making process as it provides similar disease control with better