Research project

Analysis of Sites of Recurrence for Upper Third Oesophageal Squamous Cell Carcinoma

Radiotherapy Physics
Lee Moorhead
Training location
Medical Physics, Saint James Hospital, Leeds


To assess geometric agreement of volumes derived from pre-treatment diagnostic FDG-PET and post-treatment CT for patients with upper third oesophageal cancer recurrence. High agreement may allow the delineation of radio-resistant sub-volumes to be targeted for dose escalation in radiotherapy treatment planning, possibly increasing overall survival by reducing recurrence and toxicity risks.


Validations: two methods were employed to determine the percentage of Maximum Standard Uptake (%SUVmax) used to generate PET volumes; Deformable Image Registration (DIR) methodology was assessed; rigid registration error was determined. PET and post-treatment CT data from one patient was deformably registered onto their planning CT, %SUVmax volumes generated and post-treatment CT recurrence volume contoured; these structures were deformably mapped onto the planning CT and overlap metrics generated. Recurrence was classified using the MD Anderson method.

Results and Discussion

43%SUVmax and 45%SUVmax values delineated PET volumes to known volumes most accurately. These and 50%SUVmax were used to generate volumes on patient data. The DIR methodology demonstrated parity with literature comparisons. Patient data showed a moderate overlap and a type B failure (MD Anderson classification). Geometric uncertainties from large registration deformation (superior/inferior data extents) may significantly affect the overlap.


The study aim was partially achieved. A workflow was constructed and tested using data from one patient, indicating moderate agreement between %SUVmax and recurrence volumes. Adjustments to the DIR methodology and additional data and would enable more statistically significant conclusions to be drawn.

Last updated on 4th October 2022