ESTRO 36 Abstract Book

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S645 ESTRO 36 2017
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overall survival compared with RT, including CFRT and
SBRT. Considering the strength of the evidence, additional
randomized controlled trials are needed before each
treatment modality can be recommended routinely.
EP-1202 A lot to a little or a little to a lot - dose-
volume relationships in thoracic tumors
C. Schröder1, R. Engenhart-Cabillic2, A. Buchali3
1 Universität Giessen, Klinik für Strahlentherapie und
Radioonkologie- Universitätsklinikum Giessen und
Marburg, Giessen, Germany
2 Universität Marburg, Marburg, Germany
3 Ruppiner Kliniken GmbH, Klinik für Strahlentherapie
und Radioonkologie, Neuruppin, Germany
Purpose or Objective
The purpose of this prospective randomized trial was to
determine which constellation of dose and corresponding
volume of the lung tissue as seen in the dose-volume-
histogram (DVH) - either a lot to a little or a little to a lot
- should be preferred to ensure the best possible outcome
for patients with thoracic carcinomas. To ensure a wider
approach we focused on both objective and subjective
parameters like clinical outcome, changes in pulmonary
function tests (PFT), radiological changes and quality of
life (QoL).
Material and Methods
From 04/12 to 10/15 81 patients with NSCLC, SCLC or
esophageal carcinoma were randomized and treated with
either a 4-field-IMRT (Arm A) or a VMAT (Arm B) technique.
Patients with NSCLC were treated with a total dose of 74
Gy, those with SCLC with 60 Gy and those with esophageal
tumors with 66 Gy. Fraction dose/day was 2 Gy each.
Patients were treated with or without concurrent or
sequential chemotherapy according to intradepartmental
standards. Data regarding clinical outcome (survival, side
effects, local and distant control), PFT (ventilation and
diffusion parameters) and quality of life (EORTC QLQ-C30
and QLQ-LC13) were collected before RT, 6 weeks, 12
weeks and 6 months after treatment. QoL data was
additionally collected 1 year post RT. Radiological follow-
up via CT focusing on lung density changes was done 12
weeks and 6 months after RT.
Results
The median follow up was 34,5 weeks. There was no
significant difference regarding the local (p = 0,954) and
distant (p = 0,206) outcome, side effects (all p > 0,05) or
survival (p = 0,633) of patients in the two treatment arms
at any follow up appointment. The comparison of the PFT
showed a statistically significant difference for the DLCO
6 weeks post RT (p = 0,028). All other parameters did not
differ significantly at any follow up appointment.
Regarding the QoL there was no statistically significant
difference between the summarized value for the QLQ-
C30 and the QLQ-LC13 at any follow up appointment (p >
0,1). There was a statistically significant difference
between the mean density of the lung parenchyma at 12
weeks (p < 0,0005) and 6 months post RT (p < 0,0005).
Conclusion
Since there was no significant and relevant difference
between both treatment arms regarding PFT, clinical
outcome and QoL it doesn’t seem to relevant how the DVH
is shaped exactly as long as certain established dose
constrains are respected. As to whether the difference
between the CT density changes is not only significant but
also clinically relevant further analysis is needed.
EP-1203 Changes in pulmonary function after high
dose intrathoracic radio(-chemo)therapy up to 74 Gy
C. Schröder1, R. Engenhart-Cabillic2, A. Buchali3
1 Universität Giessen, Klinik für Strahlentherapie und
Radioonkologie- Universitätsklinikum Giessen und
Marburg, Giessen, Germany
2 Universität Marburg, Klinik für Strahlentherapie und
Radioonkologie- Universitätsklinikum Giessen und
Marburg, Marburg, Germany
3Ruppiner Kliniken GmbH, Klinik für Strahlentherapie
und Radioonkologie, Neuruppin, Germany
Purpose or Objective
There are numerous ways to examine radiation therapy
(RT) related injuries to the lung tissue. Next to obvious
factors like treatment induced side effects, the changes
in pulmonary function are a simple way to quantify the
effects of RT on a patient’s lung. In this study we
prospectively collected patient-related, dose-related and
PFT data before RT and at several follow up visits after RT
to analyze the time course of PFT changes and influencing
factors.
Material and Methods
From 04/12 to 10/15 81 patients with NSCLC, SCLC or
esophageal carcinoma where treated with high dose
radiation therapy. Patients with NSCLC where treated
with a total dose of 74 Gy, those with SCLC with 60 Gy and
those with esophageal tumors with 66 Gy. Fraction dose
was 2 Gy each. Patients were treated with or without
concurrent or sequential chemotherapy according ti
intradepartmental standards. Data regarding PFT
(ventilation and diffusion parameters) was collected
before treatment, 6 weeks, 12 weeks and 6 months after
RT. The following lung function parameters were
analyzed: vital capacity (VC), total lung capacity (TLC),
forced expiratory volume in 1 second (FEV1), diffusion
capacity for carbon monoxide (DLCO) and capillary blood
gas analysis. Additionally the influence of patient and
treatment related factors on PFT was analyzed.
Results
The mean FEV1 constantly declined during the follow up
(p = 0,001). In total 68 % of patients had a reduced FEV1
at 6 months. The general linear model (GLM) with
repeated measures determined that the FEV1 differed
statistically significant over time (p = 0,001). The mean VC
didn’t change during the follow up (p > 0,05). The mean
TLC showed a constant decline after RT (p = 0,026). At 6
months 60 % of patients showed a decline in VC and 73 %
in TLC. The GLM revealed no significant changes of the VC
over time. There was a difference between the TLC before
RT and at 6 months post RT (p = 0,026). The mean DLCO
had declined at 6 and 12 weeks but showed a slight
recovery at 6 months (p < 0,0005). At 6 months 86 % of
patients had a reduced DLCO. The GLM determined that
there where statistically significant differences of the
DLCO over time (p < 0,0005). There was an increase in
pCO2 and a decrease in pO2 after treatment (p > 0,05). At
6 months approximately 60 % had a decline in pO2 and an
increase in pCO2. Only the pre-treatment PFT
classification had a significant influence on the FEV1 after
RT. The GLM determined no statistically significant
changes of the blood gas parameters over time. Only the
pre-treatment PFT classification had a significant
influence on the FEV1 after RT.
Conclusion
The DLCO seems to be the most reliable indicator for lung
tissue damage after thoracic radiotherapy. Although there
might be some significance ventilation parameters appear
to be less reliable. Only the pre-treatment PFT
classification had a significant influence on the FEV1 after
RT.
EP-1204 Treatment Outcomes and Patterns of
Radiologic Injury after Tomotherapy-based SBRT for
Lung Tumours
S. Arcangeli1, L. Falcinelli2, S. Bracci 3, A. Greco3, A.
Monaco 1, J. Dognini1, C. Chiostrini1, R. Bellavita2, C.
Aristei2, V. Donato1
1San Camillo-Forlanini Hospitals, Radiation Oncology,
Rome, Italy
2S. Maria della Misericordia University Hospital,
Radiation Oncology, Perugia, Italy