Conventional 3D staging PET/CT in CT simulation for lung cancer: impact of rigid and deformable target volume alignments for radiotherapy treatment planning

Objective: Positron emission tomography (PET)/CT scans can improve target definition in radiotherapy for non-small cell lung cancer (NSCLC). As staging PET/CT scans are increasingly available, we evaluated different methods for co-registration of staging PET/CT data to radiotherapy simulation (RTP) scans.

Methods: 10 patients underwent staging PET/CT followed by RTP PET/CT. On both scans, gross tumour volumes (GTVs) were delineated using CT (GTVCT) and PET display settings. Four PET-based contours (manual delineation, two threshold methods and a source-to-background ratio method) were delineated. The CT component of the staging scan was co-registered using both rigid and deformable techniques to the CT component of RTP PET/CT. Subsequently rigid registration and deformation warps were used to transfer PET and CT contours from the staging scan to the RTP scan. Dice’s similarity coefficient (DSC) was used to assess the registration accuracy of staging-based GTVs following both registration methods with the GTVs delineated on the RTP PET/CT scan.

Results: When the GTVCT delineated on the staging scan after both rigid registration and deformation was compared with the GTVCT on the RTP scan, a significant improvement in overlap (registration) using deformation was observed (mean DSC 0.66 for rigid registration and 0.82 for deformable registration, p50.008). A similar comparison for PET contours revealed no significant improvement in overlap with the use of deformable registration.

Conclusions: No consistent improvements in similarity measures were observed when deformable registration was used for transferring PET-based contours from a staging PET/CT. This suggests that currently the use of rigid registration remains the most appropriate method for RTP in NSCLC.

Assessing the image quality of pelvic MR images acquired with a flat couch for radiotherapy treatment planning

Objectives: To improve the integration of MRI with radiotherapy treatment planning, our department fabricated a flat couch top for our MR scanner. Setting up using this couch top meant that the patients were physically higher up in the scanner and, posteriorly, a gap was introduced between the patient and radiofrequency coil.

Pitfalls in Strategic Planning: Lessons for Legitimacy

The paper considers how planning as a political activity is underpinned by concepts of justice and how professional practitioners are consistently faced with making ethical choices in the public interest. The key objective is therefore to identify the centrality of ethics in praxis. In this context, political liberal theory is empirically useful in exploring both the role of participants and the processes employed in strategic planning. A case study analysis generates key issues which are relevant to planning in the wider arena and an extensive series of interviews provides interesting insights into the dynamic between those involved and the effectiveness of procedures followed.

Planning in young children: A review and synthesis

Research on the development of planning is reviewed in the context of a framework that considers the role of three types of cognitive flexibility in planning development: event-independent temporal representation, executive function, and self-projection. It is argued that the emergence of planning abilities in the preschool period is dependent upon the development of event-independent temporal representation. Research on the development of executive function suggests that its sub-components, in particular inhibitory control, may be linked to developmental improvements on planning tasks. Recently, new paradigms have established that self-projection to the future appears to develop over the preschool period. We consider how these different forms of cognitive flexibility may themselves be related in development. (C) 2011 Elsevier Inc. All rights reserved.

Skills, Conflict and Spatial Planning in Northern Ireland

The skills to manage sustainable and cohesive communities have placed a particular emphasis on collaborative and consensual methods of working. This paper suggests that in ethnically divided places, the notion of collaboration is largely conceptual and that more agonistic strategies provide a sounder basis for marginal communities to advance their claims and rights. Specifically, it draws on research conducted in Northern Ireland to suggest that situated approaches to territorial competition can place learning, the sharing of knowledge, and the transformation of conflict at the heart of the skills debate.

Justice as Fairness in Planning Policy-Making

This paper considers a moral basis for planning theory and endeavours to establish principles of justice which might be relevant to the regulation of development. Whilst the investigation recognises that there is a need for a deeper understanding of the dynamics of governance, it suggests that many of the inefficiencies, inequities and public disquiet concerns relating to planning centre on a drift from a perception that the system is both fair and just, and that practice needs to be anchored on founding values concerned with redistribution and equality. In this context, John Rawls’ theory of justice is employed as a vehicle to capture moral ideas of equality and liberty within a constitutional democracy and as a basis for scrutinising emerging justice based issues which impact upon planning. Using National Policy Statements as a case study, the paper concludes that, whilst there are serious concerns over current policymaking practices, the principles of justice offer a foundation for practical critique which can help overcome problems of mistrust.