Cancer Research in Nuclear Medicine
We are undertaking research projects about a range of cancers, most of which involve angiogenesis in cancer tumours.
In the UK, a patient is informed of their cancer diagnosis every two minutes. Nationally, there has been a twofold increase in patients surviving cancer within the last 40 years. However, a broad variation in survival rates still occurs within different tumour types [source: Cancer Research UK].
Angiogenesis plays an important role in cell proliferation and is the study of how new blood vessels form to supply cells with the nutrients and oxygen they require to survive. Cancer cells grow rapidly and require increased vasculature to support their incessant cell division. They can secrete endogenous chemical signals to stimulate the growth of new blood vessels [source: National Cancer Institute].
The inner lining of any blood vessel is composed of a thin layer of simple or squamous cells called endothelial cells. On their cell membranes they have binding receptors to which a broad range of identified proteins can attach. These proteins can be categorised into either angiogenic ‘activators’ (promotes growth) or angiogenic ‘inhibitors’ (interferes with growth).
The formation of new blood vessels (neoangiogenesis) for cancer cells is dependent upon the balanced interaction of activators and inhibitors. Examples of angiogenic activators include the family of Vascular Endothelial Growth Factors (VEGF), basic Fibroblast Growth Factor (bFGF), Interleukin 8 and Transforming Growth factor (TGF). VEGF now plays an important role and is considered a very powerful angiogenic activator in both cancerous and normal tissue [source: Angiogenesis in Cancer, 2006].
Pathological staining of post-surgical tumour specimens can identify a range of angiogenic activators and inhibitors. The in vivo measurements of tumour vasculature from imaging perfusion techniques along with functional information yielded from a range of PET tracers are being studied to investigate angiogenesis for a range of tumour types. In vivo tumour characterisation that underpins precision medicine in cancer is a major drive in oncology today.
Lung Cancer Research
Angiogenesis in lung tumours. This project uses a range of PET tracers to visualise lung tumours in patients in non-small cell lung cancer. We have also investigated the use of PET / MRI and CT perfusion scanning.
Oesophageal Carcinoma Project
Angiogenesis in upper GI tumours project. This project uses FDG PET/MRI and PET/CT to visualise lung tumours in patients with a range of upper GI cancers. We have also investigated the use CT perfusion scanning.
According to Cancer Research UK, there were c. 9,000 new cases of oesophageal cancer in the UK each year between 2013-2015. It is the 13th most common cancer in the UK. Approximately 12% of the people in England and Wales survive their disease for five years or more.
Accurate estimates of patient survival with oesophageal cancer can aid oncologists in making better treatment outcome decisions. The use of clinical information, pathological data, dynamic and molecular imaging can be used to assess to see whether they can provide prognostic information and personalised estimates of survival which may influence the treatment choices used.
Both dynamic contrast-enhanced computed tomography and CT texture analysis can provide an invaluable non-invasive method of quantifying tumour heterogeneity and estimating tumour vascularization in-vivo and have the potential to provide information on tumour aggression and predict patient survival.
In addition, dynamic contrast-enhanced MRI can be used to assess vascular permeability and can potentially be used in follow up imaging of patients eliminating the use of radiation.
The objective of this single institution tertiary centre study is to evaluate whether a combination of pre-treatment dynamic contrast-enhanced computed tomography parameters (tumour volume, arterial flow, blood volume and permeability), tumour heterogeneity (with the use of CT texture analysis), metabolic uptake of the tumour on PET-CT imaging and metabolic markers in relation to hypoxia (with the use of histology staining patterns) can predict patient tumour aggression and prognosis of oesophageal or gastroesophageal junction cancer.
This will be continued as a prospective study in combination with functional and anatomical imaging with the use of PET-MR.
Figure 1: Metabolic uptake in oesophageal cancer on PET-CT (left) and on PET-MR (right)
Figure 2: CT perfusion images illustrates perfusion of the average entire tumour volume:
