thesis
Stereotactic Radiotherapy for Stage I Non-Small Cell Lung Cancer using Real-Time Tumor Tracking
- Publication date
- 14 June 2011
- Publisher
- Lung cancer is the most commonly diagnosed cancer world-wide (1.61 million; 12.7% of
the total) and also the leading cause of cancer death (1.38 million; 18.2% of the total).
In the Netherlands, lung cancer was diagnosed in almost 11,000 patients in 2007 (website
Netherlands Cancer Registry; www.ikcnet.nl). The majority of these patients (77%) have
non-small cell lung cancer (NSCLC) and of these patients approximately 20% present with a
resectable tumor (website Netherlands Cancer Registry; www.ikcnet.nl). Although surgery is
the treatment of choice for patients with resectable tumors, many patients are inoperable due
to smoking-related comorbidity. These patients were commonly treated with conventional
radiotherapy (≥60 Gy in 2 Gy fractions), but the results were disappointing (51% local tumor
control rate and a 15% survival rate at 5 years). Stereotactic body radiotherapy (SBRT)
is an alternative treatment currently used for inoperable patients with stage I NSCLC. SBRT
delivers a high radiation dose to the tumor in a small number of fractions over a short overall
treatment time (typically 48-60 Gy in 3-6 fractions). Although the total dose may seem equal
to that in conventional radiotherapy, the high dose per fraction of SBRT (20 Gy versus 2 Gy)
is biologically more potent. Thus the biological effective dose (BED) is greater in SBRT than
in conventional radiotherapy (BED >100 Gy versus 60 Gy).