Metabolic control probability in tumour subvolumes or how to guide tumour dose redistribution in non-small cell lung cancer (NSCLC): An exploratory clinical study

• Published in: Radiotherapy and oncology Vol. 91; no. 3; pp. 393 - 398
• Main Authors: Petit, Steven F, Aerts, Hugo J.W.L, van Loon, Judith G.M, Offermann, Claudia, Houben, Ruud, Winkens, Bjorn, Öllers, Michel C, Lambin, Philippe, De Ruysscher, Dirk, Dekker, André L.A.J
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.06.2009
• Subjects: Carcinoma, Non-Small-Cell Lung - metabolism; Carcinoma, Non-Small-Cell Lung - pathology; Carcinoma, Non-Small-Cell Lung - radiotherapy; Dose escalation; Dose-painting; Fluorodeoxyglucose F18 - pharmacokinetics; Hematology, Oncology and Palliative Medicine; Humans; Logistic Models; Lung cancer; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Lung Neoplasms - radiotherapy; Neoplasm Staging; NSCLC; Radiation Injuries - prevention & control; Radiopharmaceuticals - pharmacokinetics; Radiotherapy Dosage; Tomography, Emission-Computed; Tomography, X-Ray Computed; Treatment Outcome; Tumor Burden; Voxel control probability; NSCLC; Dose escalation; Voxel control probability; Lung cancer; Dose-painting
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2009.02.020

Abstract Purpose To characterize the relationship between pre-radiotherapy18 Fluorodeoxyglucose (FDG) uptake in a tumour voxel, radiation dose and the probability to achieve metabolic control in the tumour voxel after radiotherapy. Materials and methods Thirty-nine patients with inoperable stage I-III non-small cell lung cancer, treated with radiotherapy (RT) alone or sequential chemo radiation were analysed retrospectively. Twenty-two showed metabolic active areas in the tumour 3 months post-radiotherapy, which is known to be a surrogate for persistent local tumour failure and worse survival. Pre- and post-RT FDG-PET-CT scans were registered and the metabolic active zones within the tumour after RT were projected on the pre-RT scan. Multi-level logistic regression was performed to determine the relation between the FDG uptake if a voxel pre-RT and its metabolic state after RT. Results The probability that a voxel is metabolically controlled (mVCP), decreased significantly with increasing FDG uptake in a voxel (SUV) (OR = 0.72), increasing tumour volume (20 cm3 ) (OR = 0.89) and increasing dose (Gy) (OR = 0.99). Inter-patient differences in mVCP were substantial. Conclusion A methodology was presented to derive relationships between FDG uptake, dose and metabolic control. Although no strong dose effect relation was demonstrated, mVCP decreased with increasing FDG uptake and tumour volume.