Our group has shown that the omission of elective nodal irradiation on the basis of CT scans in patients with LD-SCLC lead to a higher than expected isolated nodal recurrence in the ipsilateral supraclavicular area. We have previously also shown that selective mediastinal nodal radiation on basis of FDG-PET scans in NSCLC is safe and reduces the radiation fields and hence toxicity. As the accuracy of FDG-PET scans is also in SCLC higher than CT, we will investigate the safety of selective nodal irradiation in LD-SCLC patients treated with concurrent chemo-radiation.

Eligible patients (see below) will receive radiotherapy to the primary tumor and the initially involved mediastinal lymph nodes on FDG-PET scan to a dose of 45 Gy in 30 fractions in 3 weeks (1.5 Gy BID with minimum 6 h interfraction interval).

Dose-constraints: MLD > 20 Gy. In that case, CT-based replanning will be done after 1 week of treatment and shrinking field techniques will be used if appropriate.

The radiation doses will be specified according to ICRU 50. Lung density corrections will be applied, as well as all standard QA procedures. Technical requirements are the same as in standard practice at MAASTRO clinic.

Radiotherapy shall start during the first cycle of carboplatin and etoposide chemotherapy.

Chemotherapy (standard schedule in the Comprehensive Cancer Centre Limburg region):

• carboplatin AUC 5 day 1
• etoposide 120 mg/m2 days 1-3

Q 3 weeks; 5 cycles

In patients with no progression and a WHO PS 0-2, after the completion of chemotherapy, PCI will be given (25 Gy in 10 fractions, QD)

Inclusion Criteria:

• Histological or cytological proven SCLC
• UICC stage I-III, "limited disease"
• Performance status 0-2
• FeV 1 and DLCO at least 30% of the age-predicted value

Exclusion Criteria:

• Not SCLC or mixed SCLC and other histologies (e.g. non-small cell lung carcinoma)
• UICC stage IV
• Performance status 3 or more
• FeV 1 and DLCO < 30% of the age-predicted value

• Histological or cytological proven SCLC
• UICC stage I-III, "limited disease"
• Performance status 0-2
• FeV 1 and DLCO at least 30% of the age-predicted value