PET with fluorodeoxy glucose combined with computed tomography is a major tool for the diagnosis, staging, and monitoring of treatment response in clinical oncology. 3'-18Fluoro-3'-deoxy-L-thymidine (18F-FLT) is a PET radiotracer that quickly accumulates in proliferating cells and can be used to assess tumor cell proliferation in various cancers as PET radiotracer offers a non-invasive assessment of cell proliferation in vivo.~Myeloproliferative Neoplasms (MPNs) are clonal hematopoietic stem disorders characterized by high rate of effective proliferation of one or more cell lineage. MPNs are overlapping syndromes that can progress to fibrotic stage or evolute into acute leukemia. Preliminary results of a pilot study (5) suggested that this technique could be useful to assess bone marrow (BM) activity and extramedullary hematopoiesis in patients with Myelofibrosis (MF).~The current standard for follow- up of these patients is based on pathological markers (peripheral blood counts and/ bone marrow histomorphology) and molecular markers. Although, bone marrow examination could be considered as a standard gold method as it gives detailed information about cellularity, the morphology of each lineage, a degree of fibrosis, transformation and dysplastic features. However, many patients are reluctant to go for this invasive technique which precludes precise assessment of disease activity at the desirable frequencies. Non- invasive techniques which may act as the good clinical surrogate are lacking.~The objective of this study is to study the uptake pattern of FLT-PET in cases, and it is value in assessing the malignant hematopoiesis in cases of Pre-PMF and ET, regarding diagnosis, staging and monitoring response to therapy.~Identifying different patterns of uptake in patients with Pre-PMF and ET in various clinical settings.~Evaluating FLT-PET as a novel non-invasive technique in cases with Pre-PMF and ET, in comparison to the standard bone marrow biopsy about disease diagnosis, assessment of disease activity, detection of transformation, monitoring of treatment response and grading of fibrosis.~Study the ability of FLT-PET to differentiate between Pre-PMF and ET. the investigators also aim to investigate the association of FLT-PET uptake patterns with different genetic makeup (JAK2, CALR, MPL, or Triple negative disease) or allele burden in cases of Pre-PMF and ET.
The main purpose of this project is to study the uptake pattern of FLT-PET in cases, and it is value in assessing the malignant hematopoiesis in cases of Pre-PMF and ET, regarding diagnosis, staging and monitoring response to therapy. Identifying different patterns of uptake in patients with Pre-PMF and ET in various clinical settings.~Evaluating FLT-PET as a novel non-invasive technique in cases with Pre-PMF and ET, in comparison to the standard bone marrow biopsy about disease diagnosis, assessment of disease activity, detection of transformation, monitoring of treatment response and grading of fibrosis.Study the ability of FLT-PET to differentiate between Pre-PMF and ET.~the investigators also aim to examine the association of FLT-PET uptake patterns with different genetic makeup (JAK2 (Janus kinase 2), CALR (Calreticulin), MPL (myeloproliferative leukemia protein), or Triple negative disease) or allele burden in cases of Pre-PMF and ET.