Table of Contents:
In literature it has been shown that a high local control for small intrapulmonal tumours
is reached with a precise patient supposition and an exact application of the
total dose. To lead a lethal dose into the tumour a time consuming and conformal
treatment planning is necessary. Before treatment the patients experienced a second
CT to get repositioned. After this CT-study a setup-vector has to be determined
to calculate the difference between the two CT. In literature this value is about 6,0 –
6,8 mm. In this paper we tried to optimize the published methods to reach a faster
but conformal stereotactic radiotherapy.
Material and method:
We tested a new method of an extracranial radiotherapy to treat patients with medical
non-small cell lung cancer (NSCLC) or single metastases of the lung. They all
had contraindications for or refused surgery. The patients were immobilised only
once; for planning-CT, treatment planning and radiation with a vacuum body cast
and an abdominal press, fixed on a steretactic body frame. Patients could be
treated even of a bad lung function because no special breathing exercises are
necessary and the total procedure needs only less than 2 hours so that a tolerable
position was confirmed by all of them.
Because of the patient’s continuous positioning we avoided a deviation of the body
and so a second CT for repositioning. Virtual treatment-planning using a planning
library, auto-segmentation and a fast planning system were the conditions for an
optimized therapy for peripheral lung tumours. During the treatment we controlled –
using a film option of the portal imaging system – the intrathoracical tumour movement
by using DRRs, produced with the planning-CT. The result of this method was
a small setup-vector which showed a reduced patient’s movement during therapy
so that a moving target could be radiated successfully.
Disease free survival and overall survival without worse secondary effects are
comparable with the literature so that this new method is a fast and efficient therapy
for patients with peripheral intrapulmonal and inoperable tumours.