Chapter 1 addresses the introduction to the thesis and provides epidemiology, etiology, metastatic spread, current diagnostics and clinical need of new biomarker for risk stratification of prostate cancer.
Chapter 2 provides a detailed analysis of the distribution pattern of the three most used choline tracers: 18F-methylcholine, 11C-choline, and 18F-ethylcholine in metabolically and anatomically disease-free patients. The ranges of SUVmax, SUVmean and standard deviations have been presented. Potential pitfalls in evaluation of “non-avid” but clinically significant presentation of different disease entities are also addressed. The chapter provides overview of the variations in choline uptake pattern which is vital for assessment of various organs when imaging is performed for evaluation of metastatic disease.
Chapter 3 presents the feasibility of assessing dynamic 18F Ethyl Choline PET with a view to do kinetic modelling in clinical setting of biochemical relapse of Prostate Cancer. This critical piece of work underpins the quantification, tracer kinetics and demonstrates that cancerous tissue shows abnormal perfusion. From these observations I was able to conclude that 18F Choline can act as a biomarker to assess angiogenesis in prostate cancer and introduces 18F Choline as a biomarker for further work presented in chapter 4-8.
Chapter 4 addresses the detection of clinically significant and insignificant prostate cancer on 18F-FECH PET/CT and I correlated findings with template guided prostate mapping biopsy (TPM). Sensitivity and Specificity data of 8F-FECH PET/CT has been provided.
Chapter 5 addresses the accuracy of 18F Choline PET/MR which is compared to reference standard (template guided prostate mapping biopsy). This work suggests that data obtained from 18F Choline PET/MR can allow detection of clinically significant and insignificant prostate cancer. I noted that multiple previous treatments can give false positive results and 18F Choline PET/MR is the imaging investigation of choice post HIFU. Moreover, false negative results with 18F Choline PET/MR can be due to very small volume (=/<2 mm) disease.
Chapter 6 presents the differential diagnosis of abnormal tracer accumulation in the Prostate and periprostatic tissue.
Chapter 7 provides spectrum of skeletal findings on dual-phase 18F-fluoroethylcholine (FECH) PET/CT performed during the work-up of patients referred for suspected prostate cancer relapse. I have provided quantification data and explained that SUVmax in isolation cannot be used to characterize these lesions as benign or malignant. Minimal overlap of benign and malignant lesions also exists.
Chapter 8 addresses the clinical utility of 18F Choline in the setting of clinical trial in collaboration with Uro-oncology, Nuclear Medicine and Radiology departments. This critical work compares 18F Choline PET-CT and Whole-Body MRI in assessment and decision-making process for salvage treatment of focal radio-recurrent prostate cancer. This chapters concludes that at present WB-MRI cannot be used alone as imaging modality for investigation of biochemical relapse of Prostate Cancer.
Chapter 9 is a summary of main findings and discussions from chapters in this thesis. It also highlights the potential applications and future perspectives of novel biomarkers for imaging of prostate cancer
