ESTRO 36 Abstract Book

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S649 ESTRO 36 2017
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When considering one of the highest impact trials
published during the study period - RTOG 9410 - key
inclusion criteria were Stage II, IIIA or IIIB NSCLC patients
with ECOG PS 0, 1 or 2, ≤5% weight loss, serum creatinine
level ≤1.5g/L, and no prior thoracic or neck radiotherapy.
There were 268 clinic patients classified as Stage II, IIIA or
IIIB, and trial entry criteria would have rendered 61 (23%)
of these patients ineligible for trial enrolment.
Conclusion
Patients enrolled in trials for NSCLC are highly selected
and do not reflect the clinic population, leading to
uncertainty about the applicability of clinical practice
guidelines in some patients.
EP-1212 Parenchymal and functional lung changes
after stereotactic body radiotherapy for early-stage
NSCLC
J. Rieber 1, J. Dern1, D. Bernhardt1, L. König1, S.
Adeberg1, A. Paul1 , J. Kappes2, H. Hoffmann3, J. Debus1,
C.P. Heussel4, S. Rieken1
1 University Hospital Heidelberg, Radiooncology,
Heidelberg, Germany
2 Thoraxklinik- University Hospital Heidelberg,
Pneumology, Heidelberg, Germany
3 Thoraxklinik- University Hospital Heidelberg, Thoracic
Surgery, Heidelberg, Germany
4 Thoraxklinik- University Hospital Heidelberg, Diagnostic
and Interventional Radiology, Heidelberg, Germany
Purpose or Objective
Stereotactic body radiotherapy (SBRT) has been
increasingly used for patients with early-stage non-small
cell lung cancer (NSCLC) who are classified medically
inoperable due to severe pulmonary comorbidities.
However, main toxicity following SBRT is detected in the
already impaired lung tissue in this patient group and
might further influence quality of life and survival.
Material and Methods
Parenchymal and functional lung changes were evaluated
in 70 patients with early-stage NSCLC treated with SBRT
between February 2004 and May 2015 at the University
Hospital Heidelberg and for whom more than one year of
CT follow-up scans were available. In total, 393 CT scans
were examined. Incidence, morphology and severity of
lung abnormalities as well as pulmonary function changes
were analyzed and correlated with outcome.
Results
Median follow- up time was 28.6 months with 2- year and
3-year overall survival (OS) of 75.5% and 54.1% and 2-year
and 3-year local progression-free survival (LPFS) of 88.4%
and 79.9%.
Regarding acute parenchymal lung changes within the first
6 months after SBRT, 10% of the cases showed no increased
density, while 11% were classified as patchy ground-glass
opacity, 25% diffuse ground-glass opacity, 25% patchy
consolidation and 29% diffuse consolidation. Late CT
changes after 6 months were detected in all patients with
10% scar-like fibrosis, 7% mass-like fibrosis and a modified
conventional pattern of fibrosis in 83% of the patients.
In general, most patients only suffered from mild to
moderate CT abnormalities. Maximum severity score for
parenchymal changes was significantly associated with
ipsilateral lung dose in biological effective dose (BED)
(p=0.014) and PTV size (p<0.001), but not with any further
investigated risk factor. Furthermore, patients with no or
mild parenchymal lung changes showed significantly
improved 2-year and 3-year OS of 79.6% and 61.9%, while
moderate to severe changes had 1-year and 3-year OS of
40% and 30%, respectively (p=0.043).
Regarding functional lung changes, baseline lung function
was generally poor with mean forced expiratory volume in
1 second (FEV1) of 1.5l (predicted 54.1%), mean total lung
capacity (TLC) of 5.7 and forced vital capacity (FVC) of
2.7l. SBRT treatment significantly reduced post-SBRT lung
function: TLC (-0.41l; p=0.001); FVC (-0.17l, p<0.001),
FEV1 (-0.8l, p<0.001), FEV1% (-28.2%, p<0.001) and air way
resistance (+0.1, p=0.003). While pre- and post-treatment
lung function parameters did not significantly affect OS
(p>0.05), higher absolute reduction in FVC was
significantly associated with worse OS (p=0.005).
Conclusion
SBRT was generally tolerated well with only mild toxicity.
However, this is the first study illustrating that both
parenchymal and functional lung changes following SBRT
might impair survival.
EP-1213 Long-term outcomes of Stereotactic Ablative
Radiotherapy for stage I non-small cell lung cancer
S. Lee1, S.Y. Song1, S.S. Kim1, S.W. Lee1, S.D. Ahn1, S.M.
Yoon1, Y.S. Kim1, J.H. Park 1, J.H. Kim1, E.K. Choi1
1Asan Medical Center- Univ of Ulsan, Radiation Oncology,
Seoul, Korea Republic of
Purpose or Objective
To investigate long-term clinical outcomes of stereotactic
ablative radiotherapy (SABR) in patients with medically
inoperable stage I non-small cell lung cancer (NSCLC)
Material and Methods
A retrospective analysis was performed on a total of 169
patients with 178 lesions, 9 patients with synchronous
cancer, of stage I non-small cell lung cancer treated with
SABR at a single institution from June 2000 to May 2015.
Patients with recurrent lung cancer, another primary
malignancy, or prior history of RT to chest were excluded.
Dose scheme of SABR was 48 Gy in four fractions in early
phase, but was escalated to 60 Gy in four fractions from
June 2009. CyberKnife™ was also introduced at June 2011.
Patterns of failure and survival were evaluated. All
failures were identified during total follow-up period, not
as initial presentation. Survival was calculated from the
date of initiation of radiotherapy. Toxicity was graded
using the Common Terminology Criteria for Adverse Events
(CTCAE) version 4.03 except rib fracture.
Results
Median age was 73 years (range, 40-91). Pathologic
diagnosis was done in 173 tumors (97%); Adenocarcinoma
in 87 tumors (49%), squamous cell carcinoma in 78 tumors
(44%), unspecified NSCLC in 5 tumors (3%) and others in 3
tumors (2%) were identified. There were 39 tumors (22%)
with T1a, 70 tumors (39%) were T1b, and 69 tumors (39%)
with T2a. Twenty-five (14%) tumors were located at
central area. Fractionation schemas were 60 Gy in four
fractions (46%), 48 Gy in four fractions (29%), and 54 or 60
Gy in three fractions (16%). Forty-four tumors (25%) were
treated with CyberKnifeTM.
Median follow-up time was 32 months. The 3-and 5-year
overall survival rates were 69.5% and 46.7% respectively.
The 3-year progression free and cancer-specific survival
rates were 62.3% and 86.8%. The 3-year and 5-year
actuarial local control rates were 86.3% and 79.3%. Tumor
size was an independent prognostic factor for survival. No
relapse occurred in tumor ≤ 2cm irrespective of SABR
dose. Escalated dose around 60 Gy/4fx (150 Gy10) achieved
higher local control compared with 48 Gy/4fx (106 Gy10),
76.2% versus 60.6% at 5-year (p=0.022) in tumors larger
than 2cm diameter. However, escalated dose could not
reach improved overall survival. Grade 5 toxicities were
noticed in two patients; radiation pneumonitis in 1 and
fatal hemoptysis in the other patient with centrally-
located tumor.
Conclusion
SABR provides satisfactory long-term local control and
overall survival in medically inoperable stage I NSCLC.
Relatively lower dose, 48 Gy/4fx, is enough for T1a tumor,
but dose escalation to 60 Gy/4fx improves local control for
tumor larger than 2cm diameter.
EP-1214 Stereotactic Ablative Radiotherapy in Clinical
Stage I (&lt;5cm) Non-Small Cell Lung Cancer