Positron emission tomography changes management, improves prognostic stratification and is superior to gallium scintigraphy in patients with low-grade lymphoma: results of a multicentre prospective study

© Springer-Verlag 2008Purpose: Positron emission tomography (PET) was evaluated in low-grade non-Hodgkin lymphoma (NHL) to determine its impact on staging and management and to compare PET and gallium scans. Methods: PET resulted in management plan changes in 74 patients with untreated low-grade NHL stages I to III. Patient outcomes to 12 months were documented. Results: PET identified additional lesions in 50% of patients, led to a change in stage in 32%, and had a significant impact on management in 34%. Inferior progression-free survival was noted in patients with additional lesions detected by PET (p=0.001) and in the 28% of patients upstaged by PET to stage III or IV (p=0.024). In a subset of 16 patients undergoing both PET and gallium scans, PET was found to be superior. Conclusion: PET has a major role in the management of low-grade NHL in addition to its proven role in aggressive lymphoma.Andrew M. Scott, Dishan H. Gunawardana, Joseph Wong, Ian Kirkwood, Rodney J. Hicks, Ivan Ho Shon, Jayne E. Ramshaw and Peter Robin

Relationship between CT-derived gross tumour volume (GTV) and the FDG-PET/CT-derived metabolic tumour volume (MTV): An exploratory study in non-small cell lung cancer patients treated with radical radiotherapy

Poster presentation from The Royal Australian and New Zealand College of Radiologists 65th Annual Scientific Meeting, 29 October-1 November 2015, Adelaide, Australi

The registration of diagnostic versus planning fluorodeoxyglucose positron emission tomography/computed tomography in radiotherapy planning for non-small cell lung cancer

Aims Radiotherapy for non-small cell lung cancer (NSCLC) increasingly utilises fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) fusion. However, it is unknown whether a PET/CT scan conducted in the treatment position results in more accurate registration to the radiotherapy planning CT (rCT) than a diagnostic PET/CT scan. The aim of this study was to compare the accuracy of registration of the CT components of the planning PET/CT scan (pCT) and diagnostic PET/CT scan (dCT) scan with the rCT. Materials and methods Ten patients with stage I–III NSCLC underwent an rCT immediately followed by a planning PET/CT scan, both carried out with arms placed above the head and immobilisation in the treatment position. All previously underwent a diagnostic FDG PET/CT, which was carried out with the arms above the head, but without custom immobilisation. dCT and pCT were registered to the rCT using a rigid body mutual information algorithm. Four observers identified 12 anatomical points on each scan and differences in their absolute location were analysed. Results At the carina, the mean absolute error (MAE) for pCT–rCT compared with dCT–rCT was 4.37 versus 5.73 mm (P = 0.028). However, there was no significant difference in the root mean squared error (RMSE) for that point. There were no significant differences in MAE or RMSE for all other anatomical points. The MAE for all points was 4.11 versus 4.15 mm (P = NS) and RMSE was 4.40 versus 4.48 mm for pCT–rCT compared with dCT–rCT (P = NS). Conclusions There is an average of 4 mm of misregistration when registering the CT components of PET/CT scans to the rCT for NSCLC. Using a rigid registration technique, the registration of a diagnostic PET/CT is as good as the registration of a planning PET/CT