Computed Tomography as tools for patient-individualized radiation therapy in locally advanced non-small cell lung cancer.

Background and objectives:

Retrospective analysis has shown that the volumetric decrease on daily megavoltage computed tomography (MV-CT) images obtained during chemoradiation for LA-NSCLC is predictive for local response and has prognostic value. The primary objective of this prospective trial is validating volumetric response analysis on CT as a predictive tool for local response. The secondary objective is determining the feasibility of repeated adaptive planning on decreased gross tumor volume (GTV), as a mean to spare normal tissue.

Inclusion criteria:

1) Histologically or cytologically confirmed unresectable stage III NSCLC
2) Stage IIIB based on the presence of malignant pleural or pericardial effusion and patients with major component of atelectasis or tumor volume < 5 ml (interferring with MVCT response analysis) are excluded.

Study plan:

Patients will be treated with concurrent or sequential chemoradiation. For patients undergoing concurrent chemoradiation, a dose of 67.2 Gy will be delivered in 30 fractions of 2.24 Gy with weekly chemotherapy (docetaxel and cisplatin 20 mg/m² each) over six weeks. Patients receiving sequential chemoradiation will be treated up to a dose of 70.5 Gy in 30 fractions after induction chemotherapy. Daily CT images obtained on the linac will be analyzed. Patients will undergo a diagnostic CT 3 weeks after initiation of treatment and PET-CT scanning at 3 months after chemoradiation for response analysis.