Hakulinen, M.

Heikkilä, J.

Laitinen, T.

Mäkitalo, J.M.

Seppälä, J.

Virén, T.

Voutilainen, L.

Elsevier - Publisher Connector 

EP-1174: Local dose-effects of lung perfusion utilizing SPECT/CT after VMAT lung cancer radiotherapy 

S638                                                                                                                                         3rd ESTRO Forum 2015 
 
Results: The internal movements of the tumour during the 
treatment were in average around 1 mm L-R; 1,2 mm C-C; 1 
mm A-P. 
 
 
Conclusions: ALART is a possible method of treatment for 
very selected patients which need a high qualified multi-
disciplinary team. It is necessary more studies and a possible 
randomized clinical trial with pO2 increase and/or light 
hyperthermia. 
   
EP-1174   
Local dose-effects of lung perfusion utilizing SPECT/CT 
after VMAT lung cancer radiotherapy 
J.M. Mäkitalo1, T. Virén1, J. Heikkilä1, L. Voutilainen1, M. 
Hakulinen2, T. Laitinen2, J. Seppälä1 
1Kuopio University Hospital, Cancer Center, Kuopio, Finland  
2Kuopio University Hospital, Clinical Physiology and Nuclear 
Medicine, Kuopio, Finland  
 
Purpose/Objective: Radiation pneumonitis (RP) is clinically 
important toxicity in radical non-small cell lung cancer 
(NSCLC) radiotherapy (RT). Changes in lung perfusion can be 
discovered before the actual radiation injury develops into 
RP. In this study voxel based analysis for the radiation 
damage from the volumetric-arc therapy (VMAT) treatments 
was investigated by using the lung perfusion as a measure for 
radiation injury. 
Materials and Methods: This study included six patients (age 
67 ± 14 y) with histologically confirmed NSCLC. The patients 
were imaged with a SPECT/CT-scanner (Philips Precedence, 
Philips Healthcare) after Tc-99m labeled macroaggregated 
albumin injection of 118 ± 9 MBq. Patients were imaged in 
treatment position with a slice thickness of 2 mm. Scans 
were acquired before RT (pre-RT) and 3 months after RT 
(post-RT). Planning target volumes (348 ± 134 cm3) and lungs 
were delineated on the CT images. In addition, the lungs 
were divided into three different areas based on the lung 
perfusion, the activities being 0-40%, 40-60% and 60-100% 
from the value of maximum perfusion counts. VMAT 
treatment plans were created in Monaco® treatment 
planning system using energy of 6 MV and Monte Carlo 
calculation algorithm. Lung doses were converted to 2Gy 
equivalents using LQ-model and α/β ratio of 3Gy. Patients 
were treated using Elekta Infinity linear accelerator (Elekta 
AB, Sweden) to a prescription doses of 10×3Gy (n=2) or 
30×2Gy (n=4) with daily CBCT matching. The decrease in the 
perfusion (pre-RT – post-RT) as a function of total dose 
delivered was recorded with a voxel size of 3×3×3 mm3. 
Voxels closer than 9mm to the lung borders and negative 
perfusion reduction were excluded, thus the reperfusion of 
the lung tissue was excluded from the analysis. 
Results: Mean lung dose (MLD) of the studied patients was on 
average 9.0 ± 4.6 Gy. Figure 1 shows an average dose-effect 
relation to lung perfusion after 3 months of RT. With high 
doses (> 30Gy) the relative reduction of the perfusion was 
greatest in the well perfused areas. Furthermore, there was 
a tendency that MLD, volume of the dose of 5Gy and 20Gy 
correlated with perfusion reduction (data not shown). 
However, the variation between individual patients was large 
and the number of patients was limited. 
 
 
 
Figure 1. Changes in perfusion (3 months post-RT) for the 
total lung volume and three different perfusion volumes 
(<40%, 40-60%, >60%) as a function of total dose delivered. 
 
Conclusions: The incorporation of SPECT/CT can take into 
account the variation of inhomogeneous lung perfusion of 
NSCLC patients. There was an increased perfusion defect 
noted in well perfused areas. Severe radiation injury in well 
perfused areas could thus increase the risk of RP. Additional 
data is needed to identify the predictors of lung injury 
caused by RT. Enrollment for further studies are ongoing. 
   
EP-1175   
Image-guided hypofractionated 3D-CRT in patients with 
inoperable advanced stage NSCLC 
L. Agolli1, S. Bracci1, L. Nicosia1, M. Valeriani1, T. Falco1, G. 
Minniti1, V. De Sanctis1, M.F. Osti1, R. Maurizi Enrici1 
1University of Rome "Sapienza" Sant'Andrea Hospital, 
Radiation Oncology, Roma, Italy  
 
Purpose/Objective: Hypofractionated radiotherapy (HypoRT) 
can potentially improve local control with a higher biological 
effect and shorter overall treatment time. Response, local 


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EP-1174: Local dose-effects of lung perfusion utilizing SPECT/CT after VMAT lung cancer radiotherapy

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