Elise Champeaux, Abstract Co-Author: Nothing to Disclose

Thierry Wachter MD, Abstract Co-Author: Nothing to Disclose

Helene Bouscayrol, Abstract Co-Author: Nothing to Disclose

Isabelle Barillot MD, Presenter: Nothing to Disclose

Surgery is the main treatment of early stage non small cell lung cancer. However many patients can't benefit from this treatment because they are medically inoperable. The alternative consists on conventional radiotherapy with poor results compare to surgery and severe acute side effects. Extracranial stereotactic radiotherapy is a recent alternative with better results in term of local control and toxicity. This report is to evaluate the clinical outcomes of three dimensional conformal hypofractioned treatments of lung tumours using a stereotactic body frame (SBF).

Between June 2000 and January 2007, 28 patients with stage I NSCLC were treated with hypofractioned high dose using a SBF. The immobilization device includes diaphragmatic controller or active breathing controller for each patient. 2 CT-scan were realized a week apart, to determinate the accuracy of patient repositioning in the SBF, the CTV and, the margins for ITV .The PTV margins (2-5mm) were always applied according to these 2 CT-scan and a previous estimation on more than 100 patients treated with the SBF for various localisation. The median CTV 1, CTV 2, ITV, PTV were respectively 30cm3, 35 cm3, 40 cm3 and 75 cm3. 5 or 6 coplanar and non-coplanar fields were usually set up to achieve a conformal dose distribution. A total of 50 Gy in 10 fractions or 40 Gy in 10 fractions according to the size of the tumours was delivered. (Equivalent BED>100 Gy)

The median follow-up was 16 months. Complete response or partial remission are obtained in 14 patients (50%, 7 T1 and 7 T2), 8 patients are stable (29%, 4 T1 and 4 T2) and 6 patients are in progression (21%, 2 T1 and 4 T2). The median disease free survival is 10 months. No acute side effects up to grade II according to the CTC AE 3.0 were observed. The more frequents are increased cough, oesophagitis and skin reaction respectively. Due to the short actual follow-up, we aren't able to provide a relevant assessment of late toxicity. Until now, we have just noticed on CT-Scan a mild asymptomatic degree of pulmonary fibrosis within the treated fields.

When patients aren't suitable for radical surgery, hypofractioned high dose radiotherapy using the stereotactic body frame is an alternative treatment for a majority of patients. Moreover it's well tolerated in this population with poor lung function and severe comorbidity.

Champeaux, E, Wachter, T, Bouscayrol, H, Barillot, I, Stereotactic Radiotherapy for Early Stage Lung Cancer: Interesting Results for 28 Patients Using the Stereotactic Body Frame.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/7100164.html