Hellenic journal of nuclear medicine最新文献

Differentiated thyroid cancer is composed of papillary (85%), follicular (13%) with their subtypes and anaplastic (<2%) thyroid cancer, derived from follicular dedifferentiation. In the majority of cases (85%), treatment is succeeded with thyroxine suppression and radioiodine ablation. However, there is a small percentage of patients presenting with local recurrence or metastases during follow up. In such cases, reoperation and radioiodine treatment are the treatments of choice. 10% of the aforementioned patients appear resistance to radioiodine treatment and they are considered refractory to iodide. As refractory to radioiodine is defined a patient who fulfills one of the following criteria: 1. Negative RAI Uptake 2. RAI uptake in some but not all metastases 3. Disease progression 6-12 months after Radioiodine ablation 4. Disease progression after radioiodine treatment more of than 600mCi.

Technetium-99m (^99mTc)-pertechnetate can be taken up by both gastric mucosa and thyroid tissue. Ectopic gastric mucosa of upper esophagus found in thyroid scintigraphy is rare. We reported a 31-year-old woman who underwent ^99mTc-pertechnetate thyroid static scintigraphy for abnormal ultrasound findings. A focal uptake lesion was found in her upper chest. Single photon emission computed tomography/computed tomography (SPECT/CT) imaging showed increased uptake in multiple sites of the upper esophagus without significant thickening. Eventually, gastroscopic findings revealed multiple ectopic gastric mucosa of upper esophagus.

Artificial Intelligence (AI) currently occupies the headlines in the media as well as the medical press, with messages of its emerging unlimited potential, but also tales of doom and gloom predicting risks for the extinction of humanity! One such headline in the London TIMES of 6^th June 2023 reads: - "Two years to save the world, says AI adviser". To the uninformed, AI is nothing more than the processing of a colossal amount of data with lightning speed, now achievable with the latest spectacular developments in computing. However, could such power be harnessed to accurately predict the therapeutic potential of a new treatment emerging from Phase I, or Phase II trials, without the need to proceed to Phase III randomised, at times placebo controlled, trials? The deontological and ethical concerns about randomised trials have frequently occupied the medical literature as several clinical researchers feel uncomfortable with this kind of clinical research, especially when a placebo is allocated to patients with cancer, enlisted in a Phase III trial. Others have argued that in contrast to the belief that randomised controlled trials are more reliable estimators of the efficacy of a treatment, investigators have found that, in some settings, observational studies did not overestimate the size of the treatment effect compared with their randomised counterparts. An accurate prediction of the true potential of a novel treatment with AI, thus obviating the need of a phase III, randomised trial, could save time, effort, and finances, as well as relieve the ethical burden of allocating treatment at random to patients with cancer and limited life expectancy.

Technetium-99m- diphosphono-1,2-propanodicarboxylic acid (^99mTc-DPD) is currently used in Europe for the diagnosis of cardiac amyloidosis, being able to distinguish light chain (AL) from transthyretin (TTR) type. We are reporting obvious spleen visualization in two patients suffering the first from proven TTR and the second from AL type of cardiac amyloidosis, with myocardial uptake-as anticipated-only in the first one. We raise the hypothesis that a common uptake mechanism exists for the spleen amyloid regardless of the type of the disease (AL or TTR), and is possibly different than the cardiac uptake mechanism.

The carcinoid syndrome (CS) is a constellation of symptoms attributed to hypersecretion of amines, prostaglandins and polypeptides. The cardinal symptoms of CS are flushing, diarrhea and bronchospasm; however, CS may present with various symptoms and signs, as: Skin: cutaneous flushes, cyanosis, pellagra, Gastrointestinal: diarrhea, nausea, abdominal cramps, vomiting, Heart: tricuspid and pulmonic valve thickening causing right heart failure, edema, Respiratory: wheezing, dyspnea.

Neuroendocrine tumors are a heterogenous group of rare neoplasms with different morphological features, immunophenotype, molecular profile, and clinical presentation. They can derive from any neuroendocrine cell throughout the body, but the majority of NENs is developed in the gastrointestinal tract. They can be divided into two groups, based on hormone secretion, functioning and non-functioning NENs. The first group is characterised from the secretion of specific substances, defining the clinical manifestations. Functional NENs can be divided into carcinoid tumors, with serotonin overproduction, and functional GEP NEN's (mostly located in pancreas) that may secrete insulin, VIP, gastrin, glucagon or somatostatin. Non-functioning NENs, comprise approximately 85% of NEN's. As these tumors lack specific symptoms, they come to clinical attention later, when they have a large size or metastases. Apart from the specific biomarkers that functional NENs are producing, there are some general markers that are produced from all NENs and play a major role in the diagnosis, prognosis and follow up of these patients. These are chromogranin (CgA), neuron-specific enolase (NSE) and 5-hydroxyindolic acetic acid (5-HIAA).

Multiple myeloma (MM) is a neoplastic disease characterized by the proliferation of clonal plasma cells. This disease arises from an initial asymptomatic stage known as monoclonal gammopathy of unknown significance (MGUS). The clinical phenotype that lies between MGUS and MM is commonly known as smoldering multiple myeloma (SMM). In individuals with MGUS and SMM, the risk of progression to MM persists constantly. In MGUS, the progression rate to MM or a related malignancy is around 1% per year, while in SMM, the progression rate to MM is approximately 10% per year. Recently, myeloma was defined as a clonal proliferation of malignant plasma cells that results in end organ damage or myeloma-defining events. MM is a genetically complex disease that exhibits clinical and biological diversity. Currently, the revised International Staging System (R-ISS) is used for prognostication in newly diagnosed patients. For transplant-eligible patients with newly diagnosed MM, the standard of care treatment (SoC) regimen is induction therapy, followed by ASCT and maintenance therapy. In general, the recommended induction therapy is a triplet or quadruplet-agent therapy consisting of a proteasome inhibitor, an immunomodulatory compound, and/or a CD38 antibody in combination with dexamethasone. Myeloma patients who are ineligible for a transplant are typically treated with a triplet combination, which necessitates specialized knowledge of treatment adverse effects. Although the prognosis for patients with MM has significantly improved over time due to advances in treatment, the disease remains incurable and relapses are common. Because various immunotherapeutic agents, new drugs and combinations have become available, selecting the most effective treatment for patients with relapsed/refractory MM needs both art and science.

Lung cancer is the leading cause of cancer-related mortalities with the rate of incidence reaching about 1.5 million cases per year worldwide. Approximately 350 people die each day from lung cancer in USA-nearly 2.5 times more than the number of people who die from colorectal cancer (CRC), which is the second leading cause of cancer death overall. In 2023, an estimated 238,340 people (117,550 men and 120,790 women) will be diagnosed with lung cancer, and 127,070 people will die from the disease. Although approximately 80% of lung cancers are caused by cigarette smoking, the toll among people who have never smoked is substantial, ranking among the top 10 causes of cancer death when categorized separately. Lung cancer encompasses a variety of biologically distinct tumours. The two primary types of lung cancer are non-small cell lung cancer (NSCLC), which accounts for 81% of cases, and small cell lung cancer (SCLC), which accounts for 14% of cases. NSCLC is further categorized as adenocarcinoma, which is slightly more common in women, followed by squamous cell carcinoma and large cell carcinoma.

Introduction: Personalized dosimetry is tending to become the "gold standard" in Molecular Radiotherapy (MRT). Setting up carefully all the procedures involved in the workflow is crucial for the final clinical result.

Aim: Individualized MRT dosimetry using a recently installed commercial system, comprising of a dual SPECT/CT camera, a treatment planning software (TPS) and a dose calibrator was implemented on patients undergoing ¹⁷⁷Lu-DOTATATE and ¹⁷⁷Lu-PSMA therapies. The clinical workflow implemented in our department is presented in detail. Measurement and calculation of the Calibration Factor (CF) to translate the count rate into activity concentration (quantitative data), and system's commissioning, was discussed.

Materials and methods: Calibration of the dose calibrator, the SPECT/CT system and the TPS, measured using the clinical acquisition protocol, were analyzed along with potential errors introduced by the procedure and means of future optimization. In addition, image acquisition parameters, image reconstruction and image registration were discussed. Anatomical contouring of the organs at risk (OARs) and functional contouring of the lesions, followed by the dose calculation of the aforementioned structures, with the use of different calculation algorithms, were presented, compared and evaluated.

Results and discussion: According to our experience, different fitting of each organ's activity curve, results in differences in the final calculated dose. Use of bi-exponential fitting seems to better approach physical and metabolic decay. Calculated absorbed doses for the OARs were found similar to those expected from literature. Finally, department's future work was discussed, including reproducible patient setup for image acquisition, high dose CT for finer contouring and comparison of the calculated doses with other TPSs.