Impact of Reduced Acquisition Time on Bone Single-photon Emission Computed Tomography Images in Oncology Patients.

Background: The use of resolution recovery (RR) in bone and myocardial perfusion imaging is becoming increasingly popular in nuclear medicine departments. RR produces reconstructed images that show improved spatial resolution and signal-to-noise ratio compared with conventional single-photon emission computed tomography (SPECT) images. Objective: To evaluate the impact of the ordered subset expectation maximization (OSEM) RR modality on preserving noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) for short SPECT acquisition. Methods: This prospective study was conducted on 80 patients. Full SPECT acquisition was performed as a standardized protocol, while reduced acquisition was achieved with the Poisson resampling method. Noise, SNR, and CNR were measured for different reconstruction parameters for the same image levels. The impact of surface area and body mass index was also measured for the same reconstruction parameters. Results: The results show significantly higher SNR and CNR for the Evolution for Bone protocol compared to the other two reconstruction protocols for full and reduced SPECT acquisition. With the shortening of the SPECT acquisition, an increase in the value of noise was recorded. SNR and CNR decreased with the reduction in SPECT acquisition. Conclusion: The Evolution for Bone protocol for all three analyzed acquisition protocols had the lowest noise values. The highest SNR and CNR were recorded in the Evolution for Bone protocol for the three acquisition protocols and SPECT acquisition time can be reduced from 20 to 10 min for bone SPECT.

Role of 18F-FDG PET/CT in the Follow-up of Colorectal Cancer.

INTRODUCTION: Colorectal cancer (CRC) is the third most common cancer worldwide with the incidence of about 1,8 million newly diagnosed cases in 2018. According to the World Cancer Report 2014, in Bosnia and Herzegovina 6700 people died of cancer in 2014, and CRC was the cause of mortality in 724 patients (10%). Prevention programs including screening, state-of-the-art diagnostic modalities and therapeutic approaches to CRC are being constantly improved. AIM: Our study was designed to address the diagnostic accuracy of 18F-FDG PET/CT in the follow-up of CRC in patients with normal or elevated CEA. METHODS: We retrospectively analyzed 50 patients previously diagnosed with CRC who were initially surgically treated. All patients were suspicious of recurrence and were referred to as 18F-FDG PET/CT for restaging between February 2014 and February 2019. Possible recurrence was indicated by rising CEA, equivocal radiological findings or clinical findings. RESULTS: Out of a total of 50 patients for whom the follow-up of at least six months was available, 27 had CRC confirmed with the gold standard, and all 27 patients had 18F-FDG PET/CT positive for recurrence, giving a sensitivity of 18F-FDG PET/CT in detecting the recurrence of CRC of 100.0% (0.0% of false-negative - FN results). Out of 23 patients with no signs of CRC recurrence on the gold standard, 19 were also 18F-FDG PET/CT negative, giving a specificity of 18F-FDG PET/CT in detecting the recurrence of CRC of 82.6%, and 17.4% of false-positive - FP results. Out of 31 patients who were 18F-FDG PET/CT positive, 27 had it confirmed pathophysiologically or clinically, giving positive predictive value (PPV) of 18F-FDG PET/CT in detecting CRC recurrence of 87.1%; negative predictive value (NPV) was 100.0%, meaning all 19 patients showing no signs of CRC recurrence when imaged with 18F-FDG PET/CT were gold standard negative as well. CONCLUSION: 18F-FDG PET/CT proves to be a valid diagnostic tool in detecting recurrence in patients with CRC.

The Prognostic Value of SUVmax of 18F-FDG PET/CT in Patients with Metastatic Colorectal Cancer.

OBJECTIVE: The aim of the study was to evaluate the prognostic value of the maximum standardized uptake value (SUVmax) of 18F-Fluorodeoxyglucose (18F-FDG) PET/CT in patients with metastatic colorectal cancer, and to compare it with classical prognostic markers. MATERIALS AND METHODS: The study included 70 patients with metastatic colorectal cancer who had not been treated for the metastatic disease. The patients underwent 18F-FDG PET/CT as part of their routine diagnostic reevaluation. During the analysis, the value of the largest tumor diameter and SUVmax was determined for the lesion with the highest SUVmax observed. The values of CEA and CA 19-9 were recorded 7 days before the PET/CT analysis. RESULTS: SUVmax and Carbohydrate antigen (CA)19-9 were found to be independent prognostic markers of disease progression within 12 months. Based on the Receiver Operating Characteristics (ROC) curve analysis, the patients could be divided into two groups: SUVmax≤4.1 vs. SUVmax>4.1. Patients with SUVmax values of 4.1 or less had significantly better progression-free survival within 12 months with an HR (95% CI) of 2.97 (1.4-6.3), relative to patients with SUVmax values above 4.1. CONCLUSION: SUVmax may be used as a novel prognostic marker of disease progression among patients with metastatic colorectal cancer. Values of SUVmax can be used to select patients with a more aggressive type of disease and higher risk for progression within 12 months of PET/CT analysis.

Lifestyle risk factors and comorbidities of cancer patients in a country with limited resources.

Aim To investigate quality of life and exposure to lifestyle risk factors of cancer patients in Bosnia and Herzegovina and a correlation of cancer type with lifestyle risk factors. Methods This was a cross-sectional study conducted on 200 cancer patients from the Clinical Centre of the University of Sarajevo. The respondents completed an anonymous questionnaire consisting of seven sections: basic patient information, physical activity, dietary habits including alternative medicine, tobacco use, alcohol consumption, anxiety, and comorbidities. Results A total of 150 (75%) patients were overweight with 113 (56%) of them being less physically active after the confirmed diagnosis. After the diagnosis, 79 (40%) patients ate less food, and 154 (77%) healthier; 130 (65%) reported consumption of alternative medicine and food supplements, 39 (30%) spent >1/4 of average monthly salary on these products. Majority never consumed alcohol, 135 (68%) and 101 (51%) patients reported history of tobacco use. Being obese was an independent predictor for colorectal carcinoma; being less obese was linked to a decreased risk of breast cancer diagnosis. Physical activity was linked to a decreased risk of lung cancer diagnosis. Many patients (122; 61%) reported having chronic comorbidities, mostly hypertension, while 44 (22%) patients were proven to be clinically anxious. Conclusion Our data suggest lack of public awareness of the consequences of unhealthy lifestyles. Risk factors such as alcohol consumption and tobacco use differed from other European countries. Significance of lifestyle changes after the diagnosis for reducing mortality and cancer recurrence requires further research. Prevention programs and more data are needed.

Positron Emission Tomography Scan (PET/CT) During the COVID-19 Pandemic: a Case Series.

INTRODUCTION: A number of nuclear medicine procedures significantly dropped worldwide during the COVID-19 pandemic. Every nuclear medicine department has faced changed working environment in terms of the type of requested procedures, number of requests and personal protection issues. Also, some specificities emerged that affect standard operating procedures. AIM: The aim here is to present different clinical scenarios related to RT PCR molecular testing and COVID-19-associated pulmonary findings on PET/CT in oncologic patients. METHODS: A case series of four patients imaged on oncologic PET/CT is presented. Short clinical history followed by description of significant PET/CT findings and their importance from the perspective of COVID-19 pandemic and interpretation of PET/CT findings is presented. CONCLUSION: PET/CT imaging remains of paramount importance for oncologic patients during the pandemic. Under the unprecedented circumstances, interpretation of PET/CT findings has become more complex having some specificities that must be kept in mind.

Value of Positron Emission Tomography/Computed Tomography (PET-CT) in Suspected Non-small Cell Lung Cancer Recurrence and Impact on Patient Management.

INTRODUCTION: Positron emission tomography/computed tomography (PET-CT) is very sensitive for diagnosis of recurrent NSCLC and has a significant impact on change of management. Preliminary data suggest superiority of PET-CT comparing to CT alone for lung cancer restaging. MATERIALS AND METHODS: This is a retrospective study which aim is to validate usage of PET-CT in suspected non-small cell lung carcinoma recurrence and its impact on further patient management. Total number of 31 patients with non-small cell lung carcinoma and uncertain diagnosis of recurrent disease or its extent after routine clinical and CT work-up were enrolled in this study. DISCUSSION: We found in our study that PET-CT diagnosed recurrent disease in 65% of patients who were previously presented with an indeterminante CT. In 85% of patients there were change in further management. CONCLUSION: We suggest that PET should be performed on patients who have suspected relapse after potentially curative treatment, particularly if active treatment is being considered. PET-CT improved the diagnosis of recurrent NSCLC and this resulted in a significant impact and change in further patient management.

Advantages of Combined PET-CT in Mediastinal Staging in Patients with Non-small Cell Lung Carcinoma.

INTRODUCTION: Precise mediastinal lymph node staging in patients with non-small cell lung carcinoma (NSCLC) provides important prognostic information and it is obligatory in treatment strategy planning. 18Fluoro-deoxy-glucose (18F-FDG) positron emission tomography - computerized tomography (PET-CT) based on detection of metabolic activity showed superiority in preoperative staging of lung carcinoma. MATERIALS AND METHODS: Total number of 26 patients diagnosed with NSCLC were included in this retrospective, cross-sectional study. Status of mediastinal lymph nodes was assessed in all patients comparing contrast enhanced CT and 18F-FDG PET-CT findings. DISCUSSION: We found in our study that 50% of patients had different N stage on contrast enhanced CT comparing to 18F-FDG PET-CT findings. Among the total number of patients which had different nodal status on PET-CT comparing to CT alone, we found in our study that 54% of patients had change in further therapy protocol after PET-CT change of nodal stage. CONCLUSION: Combined PET-CT which offers advantages of both modalities is excellent method for nodal (N) staging, so it is recommended in initial staging in patients with NSCLC. PET-CT used preopratively for mediastinal nodal staging has significant impact on further therapy planning and also has an consequential impact on health system savings.

Regadenoson in Myocardial Perfusion Study - First Institutional Experiences in Bosnia and Herzegovina.

INTRODUCTION: Myocardial perfusion imaging (MPI) is widely used in the evaluation of known and suspected coronary artery disease (CAD). Imaging of heart in stress and rest enables the comparison of myocardial uptake of radiotracer in proportion to the needs and coronary flow, which is used for detection of perfusion defects. Exercise stress and pharmacologic agents are used for the stressing purpose. Novel pharmacologic stressor regadenoson is A2A selective adenosine agonist, which selectively binds to the adenosine receptors in coronary arteries causing coronary dilatation. MATERIALS AND METHODS: We analyzed 50 myocardial perfusion studies performed with regadenoson as a pharmacologic agent that was injected before Tc99m-sestamibi in stress imaging. Stress and rest sets of images were evaluated for relative uptake of Tc99m-sestamibi in order to detect and characterize perfusion defects. After the injection of regadenoson, hemodynamic parameters and potential side-effects were closely monitored. Side-effects were stratified per severity as mild, moderate and severe. Studies were read by nuclear medicine physicians using quantitative perfusion SPECT software. Additional diagnostic information such as wall motion and wall thickening were provided by gating. RESULTS: Thirty-three patients (66%) experienced one or more side-effects upon the administration of regadenoson, most commonly warmth and chest discomfort. In all patients but one (98%), the symptoms were mild, of short duration and self-limiting. Out of all side-effects registered, 44 (96%) were mild, and 2 (4%) were moderate. Two moderate side-effects developed in one patient with a prior history of asthma, and included shortness of breath and cough. Heart rate changed by 16 +- 31 bpm. Highest increase in blood pressure was 30 mm Hg for systolic, and 10 mm Hg for diastolic. One case of significant decrease in blood pressure was noted from the hypertensive basal values, 50 mm for systolic, and 30 mm Hg for diastolic. ST segment depression of up to 1 mm occurred in 4 cases (8%), and T-wave changes in 3 cases (6%). No conduction abnormalities, significant hypotension, symptomatic bradycardia or cardiac arrest ocurred. CONCLUSION: Our first institutional experiences proved regadenoson as A2A selective adenosine agonist as a pharmacologic stressor to be safe, tolerable and easily used. Its safety profile enabled the study to be performed in patients with respiratory disease also.

Investigation of IVS14 + 1G > A polymorphism of DPYD gene in a group of Bosnian patients treated with 5-Fluorouracil and capecitabine.

Adverse drug reactions still pose an important clinical problem. Dihydropyrimidine dehydrogenase (DPD) is an enzyme that regulates 5-FU quantities available for anabolic processes and hence affects its pharmacokinetics, toxicity and efficacy. There are several studies describing a hereditary (pharmacogenetic) disorder in which individuals with absent or significantly reduced DPD activity may even develop a life-threatening toxicity following exposure to 5-FU. The most common mutation is known as the DPYD*2A or as the splice-site mutation (IVS14 + 1G A) leading to creation of a dysfunctional protein. An objective behind the study was to ascertain existence of the IVS14 + 1G A mutation among the population of Bosnia and Herzegovina. Our research has undeniably attested to existence of one heterozygote for the DPYD gene mutation, i.e. one heterozygote for IVS14 + 1 G > A, DPYD*2A mutation.