PRediction of Outcomes and PERsonalized Radiotherapy by Biomarkers and Functional Imaging

This is a monocentric, exploratory experimental study on tissues (peripheral blood), which is why the enrollment of a limited number of patients has been planned. The results obtained from the study should not be considered conclusive but rather as generators of research hypotheses for potential subsequent studies to be conducted on larger populations. The qualitative and quantitative characteristics of the vesicles and their miRNA content will be analyzed descriptively.

The primary objective will be considered achieved if values of CD69+ vesicles > 349 absolute units correctly predict the response to radiotherapy in at least 80% of patients. Subsequently, the investigators aim to verify if CD86+ vesicles > 10 absolute units and CD3+ > 4 absolute units correctly predict the response to radiotherapy in at least 80% of cases. Additionally, the association between the values of the three indicated vesicles (both original and dichotomized as above or below the specified cut-offs, derived from preliminary results of our research group) and the time to disease recurrence at two years will be tested.

Patients will be treated according to clinical practice in accordance with the physician's judgment and the information provided in the Technical Data Sheet of each individual product of any concomitant therapies administered as per clinical practice. The diagnostic-therapeutic pathway of the patients will not be influenced in any way by the results of tissue tests conducted for the study.

The TC-PET investigations, as part of the normal diagnostic-therapeutic process, will be performed at the Nuclear Medicine Unit of the IRCCS University Hospital of Bologna. Molecular investigations will be carried out at the laboratory of the Immunogenetics and Transplant Biology Unit (IBT) affiliated with the IRCCS University Hospital of Bologna, S. Orsola Polyclinic. The study is aimed at patients undergoing neoadjuvant RT for locally advanced rectal tumors within one year. The study is expected to begin on 01/05/2023, and in any case, only after approval from the Ethics Committee and the subsequent release of the company's authorization.

Patients will be enrolled during the first visit at the Radiotherapy Unit of the IRCCS University Hospital of Bologna, prior to any sampling necessary for the specific study analyses. It should be noted that investigations on the total quantification of DNA and epigenetic changes (methylation and miRNA expression) do not involve genome sequencing. The DNA molecules will be examined without considering individual specificity; therefore, the individual's genetic code remains unknown after the examination. A sample of 10 ml of venous blood will be collected using a vacutainer with EDTA from each patient, and plasma will be collected for each experimental point. Biological samples will be pseudonymized and labeled with the progressive number RT/NEO/00N. All samples will be stored in specially marked RT containers in a locked freezer located in the IBT laboratory until their use. Transport will be carried out using a sealed and temperature-controlled dedicated container by the personnel involved in the project.