681 / 1096
S665
ESTRO 36
_______________________________________________________________________________________________
Widder
1
1
University Medical Center Groningen, Radiation
Oncology, Groningen, The Netherlands
Purpose or Objective
Survival results for limited-stage-SCLC are more
favourable for accelerated BID compared with OD
chemoradiotherapy (CRT) to nominally equal doses
(Turrisi et al. NEJM 1999), but were not further improved
by escalating once-daily doses from 45 Gy to 66 Gy
(CONVERT-trial). However, concerns regarding acute
toxicity with BID CRT do exist. We report prospectively
assessed patient-reported outcome measures (PROMs) on
dysphagia and dyspnea from an institutional cohort where
patients receive BID CRT as preferred treatment, and OD
in case of adverse patient- or tumour-related baseline
factors suggesting they would not tolerate the accelerated
schedule.
Material and Methods
All consecutive patients with LS-SCLC treated with
VMAT/IMRT or 3D-CRT between 2013 and 2016 within our
prospective data registration program (clinicaltrials.gov)
were included. The BID schedule was given in 3 weeks to
45 Gy (30*1.5 Gy), OD CRT was given in 5 weeks to 45–50
Gy (25*1.8–2.0 Gy), concurrent or sequential cisplatin-
etoposide was scheduled with both regimens. The primary
endpoint was PROM-dysphagia within (acute) and after 3
months of inclusion (late). Secondary endpoints were
PROM-dyspnea, physician-rated dysphagia, radiation
pneumonitis, and survival. Toxicities were related with
esophageal and pulmonary DVH-parameters, respectively.
Results
Out of 74 patients, 38 received BID and 36 received OD
CRT with no difference in number of cisplatin-etoposide
cycles between groups. In line with the institutional
policy, the BID cohort was younger (62 versus 68 years,
p=0.017), had smaller tumour volumes at planning CT (79
cc versus 127 cc, p=0.056), and tended to be in a better
general WHO performance status (PS) (45% versus 25% at
PS 0, p=0.075). At median follow-up of 9.4 months for
surviving patients, unadjusted as well as adjusted survival
(adjusted for age, WHO PS, stage and GTV) was not
significantly better for BID (HR=0.60, 95%CI 0.3–1.4 and
HR=0.70, 95%CI 0.3–1.8, respectively). PROMs regarding
dysphagia and dyspnea as well as physician-rated
toxicities and radiation pneumonitis were not different
between groups (figure). Mean esophageal V35 and mean
pulmonary V20 were different between BID and OD cohorts
(30 Gy versus 41 Gy; p=0.027, and 20 Gy versus 23 Gy;
p=0.061, respectively), in line with GTV differences
between groups.
Conclusion
Treatment selection based on tumour volume and patient
condition effectively limited PROMs and physician-rated
acute and late dysphagia in BID CRT. This can be explained
by the significantly lower esophageal V35 due to smaller
GTVs in patients receiving BID treatment. Also, acute and
late PROM-dyspnea and radiation pneumonitis did not
differ between BID and OD CRT. Treatment allocation
could be further improved by dose-volume-fractionation
modelling for esophagitis.
EP-1233 Early results of SBRT as a salvage treatment
after thoracic radiotherapy.
A. Navarro-Martin
1
, I. Guix
1
, J. Mases
1
, M. Mutto
2
, E.
Nadal
3
, F. Guedea
1
1
Institut Català d'Oncologia, Radiation Oncology,
L'Hospitalet de Llobregat, Spain
2
European Oncology Institue, Radiation Oncology,
Milano, Italy
3
Institut Català d'Oncologia, Medical Oncology,
L'Hospitalet de Llobregat, Spain
Purpose or Objective
Isolated intrathoracic relapse is common across distinct
tumors and especially in lung cancer. Patients who
received previous radiotherapy treatment (PRT) are not
suitable for salvage surgery and chemotherapy provides
poor local control. This study aimed to assess the toxicity
and outcome of SBRT re-irradiation (reRT) in patients with
solid tumors who developed an intrathoracic relapse.
Material and Methods
35p treated with PRT who received salvage SBRT were
identified in our database and their medical records were
retrospectively
reviewed.
All
patients
underwent complete pulmonary function tests (cPFTs)
(including DLCO, FEV1 and FVC) and PET-CT scan was
performed before and after receiving lung reRT.
Treatment planning was based on image fusion with the
previous treatment plan and calculating the cumulative
total nominal dose. Survival estimations were performed
using Kaplan-Meier and differences between PFTs prior
and post-reRT were analyzed using Student T-Test. Early
toxicity was defined when it occurred up to 6 months.
Results
Median age: 68 (r53-81); 29p (83%) were male The previous
treatments SBRT in 17p (49%), 3D-RT 4p (11%) and CT+RT
14p (40%) Mean RT dose 60,4Gy (r34-74). Primary tumors:
lung 24 (69%), colorectal 9 (25%), oesophagus 2 (6%). For
lung cancer p, the stage distribution was: IA 8 (23%), IB 2
(6%), IIA 2 (5.7%), IIB 1 (3%), IIIA 5 (4%), IIIb 4 (11%), IV 2
(6%). For other primaries, 8p (23%) were non metastatic at
diagnosis and developed oligoprogressive disease in thorax
which was treated with SBRT and 3 (8.5%) were
oligometastatic. The location of reRT site: same lobe 17
(48%), ipsilateral different lobe 7 (20%), contralateral
lobes 11 (32%). Median delivered dose of salvage SBRT was
50Gy (50-60) in 10 fractions (r3-10). Median accumulated
dose in the lung was 81Gy (r60.10Gy-176Gy).
With a median follow-up of 10m local control rate was 74%
(IC95%; 0.59-0.9) and 1-year OS was 84% (IC 95%;0.67-1).
The metabolic complete response rate was 23%. No
differences in the baseline and post re-irradiation PFTs
were observed: FEV1, FVC and DLCO difference and CI95%
were 2.41 (-1.79-6.62); 65 (-125-257) and 12.5 (-95 - 121).
Asthenia GII in 12p (31%) was the most frequent acute
toxicity, no long-term toxicities were detected.
Conclusion
Salvage SBRT for treating isolated intrathoracic relapses
achieved an outstanding local control and overall survival
in selected p . This treatment did not impair post-
reirradiation PFT and long-term toxicities were not
observed.
EP-1234 Prophylactic Cranial Irradiation (PCI) in Small-
Cell Lung Cancer: a single-institution experience.
M. Konkol
1
, M. Matecka-Nowak
1
, M. Trojanowski
2
, A.
Kubiak
2
, P. Milecki
1
1
Greater Poland Cancer Centre, I Radiotherapy Dept.,
Poznan, Poland