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.

Contouring, planning and dose calculation in treatment planning systems (TPS) are based on computedtomography (CT) images. Therefore, it is important to have developed, optimized and adapted scanning protocolsfor specific anatomic regions and special radiotherapy modalities such as stereotactic radiosurgery (SRS). The aimof this study was to determine influence of tube voltage, field of view size (FOV) and reconstruction kernels on CTnumbers and the resulting radiotherapy (RT) dose calculation.This study was performed at Clinic of Oncology, Clinical Center University of Sarajevo. Verification electrondensity and CT number values was performed using CIRS Thorax 002LFC phantom, while anthropomorphic CIRS038 phantom for stereotactic end-to-end verification was used for the purpose of dose plan calculation analysis withlarge bore CT simulator Canon Aquillion LB.The significant correlation between the tube voltage and the measuredvalues of CT numbers is significant for all materials (p < 0.05), except for water (p = 0.310). No significantcorrelation between FOV and obtained values of CT numbers was found in any of the evaluated tissue equivalentmaterials. Evaluating the impact of reconstruction kernels on Hounsfield units (HU), significant deviations werefound for the FC62, FC68 and FC07 reconstruction kernels. Also, analyzing the influence of reconstruction kernelson the RT dose calculation, the extreme values are associated with Dmin/D in PTV for kernels FC41 and FC68, wheredeviations from the values obtained using the baseline scanning parameters were -1.3% and -1.9%. For deviation of1 HU in muscle tissue of CIRS 002LFC, the calculated Dmin/D in PTV of CIRS STEEV phantom will reduce by0.79%. Similarly, the reduction of D₉₈ and D₂ would be 6.8 cGy and 3.03 cGy for 1 HU, respectively. Change of thereconstruction kernels caused differences of 0.4% in Dmin/D calculation in clinical target volume (CTV).CT scanning and reconstruction parameters may affect Hounsfield units, which could have an impact on dosecalculations in RT plan. Hence, it is recommended to standardize the scanning protocol used in calibration curvegeneration for TPS. One should avoid use of different tube voltages and kernels, while according to this study, thechange of FOV will have no impact on dose calculations

Introduction: Glioblastoma in children (pGBM) occurs somewhat less frequently than in adults. Pediatric pGBMs have a different molecular profile than GBM for adults. The aim of the presentation of this case is the possibility of the effectiveness of the GBM radiation method and the evaluation of magnetic resonance imaging, and the monitoring of the treatment outcome of the patient.Material and methods: The case study is of the retrospective-prospective type. Medical documentation, magnetic resonance imaging, and chronologically monitored evaluation of the findings from November 2018 to August 2021 were used to present the study. The postoperative course was analyzed, as well as the effect of concurrent chemoradiotherapy, VMAT radiotherapy and adjuvant chemotherapy with Temozolomide in a patient aged 4 years and 6 months, comparing treatment outcome with median and overall survival in glioblastoma.Results: The pediatric patient after being diagnosed with high-grade glioma in 2018 is so far in very good general condition, without signs of physical and psycho-social defects, which compared to the scientifically proven median of survival indicates a good therapeutic effect. Volumetrically modulated arc radiotherapy with the use of modern IGRT verification techniques and with the use of chemotherapy with Temozoloimod, has proven to be a still effective oncological method treatment of GBM. For the final outcome of the disease and the effect of therapeutic modalities, the patient's condition and evaluation of magnetic resonance imaging will be monitored. The result supports further research into this therapeutic regimen.Conclusion: Glioblastoma is a very aggressive tumor, which occurs somewhat less frequently in the pediatric population than in adults, but is a very fatal disease. Surgical resection followed by concurrent chemoradiotherapy, with adjuvant Temozolomide is still the method of choice in the treatment of glioblastoma.

Introduction: Prostate cancer has been the leading type of cancer to affect male population, and as such, it is a subject to efforts to furthermore diagnostic tools already in existence as well as development of new ones which will Aid early diagnostic, treatments as well as a follow up procedures and clinical trials. Bone scan index is a useful and objective biomarker used as a valuable tool for determination as to precise bone involvement in advanced cases, as well as a tool to predict the outcome in prostate cancer patients in clinical trials.Methods: This paper is a non-experimental (qualitative) research, that is, a scientific review of the literature.Results: The results we analyzed in this paper were collected from published academic journals.Conclusion: As a new imaging biomarker, bone scan index has potential to predict therapeutic effects and survival of patients with prostate cancer. Using measurable diagnostic image parameters, the bone scan index is important for determining metastatic bone changes in prostate cancer patients.

Introduction: Radiation therapy has long played an integral role in the manage¬ment of locally advanced head and neck cancer (HNC), both for organ preservation and to improve tumor control in the postoperative setting. The aim of this research is to investigate the effects of adaptive radiotherapy on dosimetric, clinical, and toxicity outcomes for patients with head and neck cancer undergoing radiation therapy treatment. Many sources have reported volume reductions in the primary target, nodal volumes, and parotid glands over treatment, which may result in unintended dosimetric changes affecting the side effect profile and even efficacy of the treatment. Adaptive radiotherapy (ART) is an interesting treatment paradigm that has been developed to directly adjust to these changes.Material and methods: This research contains the results of 15 studies, including clinical trials, randomized prospective and retrospective studies. The researches analyze the impact of radiation therapy on changes in tumor volume and the relationship with planned radiation dose delivery, as well as the possibility of using adaptive radiotherapy in response to identified changes. Also, medical articles and abstracts that are closely related to the title of adaptive radiotherapy were researched.Results: The application of ART significantly improved the quality of life of patients with head and neck cancer, as well as two-year locoregional control of the disease. The average time to apply ART is the middle of the treatment course approximately 17 to 20 fractions of the treatment.Conclusion: Based on systematic review of the literature, evidence based changes in target volumes and dose reduction at OAR, adaptive radiotherapy is recommended treatment for most of the patients with head and neck cancer with the support of image-guided radiotherapy.