a significant increase in errors due to background noise in operating

ABSTRACT Uvod: Karcinom glave i vrata čini 3-5 % svih malignih oboljenja, koji je većinom zastupljen kod muškaraca. Napretkom radioterapije omogućen je optimalniji pristup u liječenju karcinoma glave i vrata, sa poboljšanim ishodom liječenja. Primjena savremenih imidžing tehnika u verifikaciji preciznosti tretmana znatno je promijenila tok radioterapije u liječenju malignih bolesti u smislu eskalacije doze na ciljni volumen uz veću poštedu zdravih struktura. Svrha rada je dokazati značaj i ulogu slikovne verifikacije CBCT imidžing metodom u preciznosti liječenja i kontroli tumora tokom tretmana. Materijal i metode: Istraživanje je provedeno prospektivno u trajanju od 6 mjeseci, na Klinici za onkologiju, Kliničkog centra Univerziteta u Sarajevu. U studiju je uključeno 30 pacijenata sa karcinomom glave i vrata, kod kojih je primjenom slikovne verifikacije CBCT-om uočen gubitak tjelesne težine ili promjena ciljnog volumena. Pacijenti su zračeni VMAT tehnikom na linearnom akceleratoru TrueBeam. Rezultati: Rezultati istraživanja su pokazali da je većina pacijenata bila muškog spola (19), starije životne dobi, sa karcinom larinksa koji je bio prisutan u čak 11 ispitanika. Jači nusefekti bili su prisutni samo kod 3,33% pacijenata, a najzastupljenije neželjene reakcije bile su blaga promuklost, suhoća usta, zamor, otežano gutanje. Od ukupnog broja pacijenata, kod 16 pacijenata uočeno je smanjenje volumena targeta koji je inicijalno prosječno iznosio 80,16 cm3, dok je nakon prosječno 18 frakcija zračenja iznosio 77,58 cm3, što je sigifikanto statistički dokazano (p= 0,007). Utvrđeno je smanjenje volumena lijeve parotidne žlijezde nakon reskeniranja u odnosu na inicijalnu vrijednost (17.37±7.55/16.93±7.06 cm3). Kod svih pacijenata na CBCT volumetrijskim slikama uočen je gubitak tjelesne težine. Zaključak: Radioterapija karcinoma glave i vrata jedan je od učinkovitih modaliteta liječenja, koji moće biti praćen određenim neželjenim reakcijama. Primjena IGRT-a na osnovu kompjuterizirane tomografije konusnog snopa (CBCT), uveliko doprinosi peciznoj isporuci propisane doze zračenja, uz smanjenu toksičnost tretmana. Volumetrijski prikaz anatomskih struktura CBCT metodom, omogućio je da se promijeni tok kursa radioterapije u smislu prilagođavanja PTV margina u toku tretmana, odnosno primjenu adaptivne radioterapije.  

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

The SARS-CoV-2 pandemic has been the main public health issue since the end of 2019. The vaccination campaign in Bosnia and Herzegovina started in April 2021, with several vaccines available. Our study aimed to evaluate the acceptance, effects, and tolerability of vaccines against SARS-CoV-2 among cancer patients. We conducted a cross-sectional, observational study between 22 October and 30 November 2021, at the Clinic of Oncology, Clinical Center University of Sarajevo. Patients were enrolled during their regular visit to the Clinic of Oncology by agreeing to complete an individual paper questionnaire. The study included 1063 patients with malignant diseases, of whom 681 (64.1%) were adequately vaccinated patients. In the study population, 76.9% of patients reported that they did not experience any side effects due to vaccination, while only 0.5% had side effects, causing a delay in their treatment. Among adequately vaccinated patients, there were 40 patients (3.8%) who were infected with SARS-CoV-2 after the second or booster dose of the vaccine. Five patients (0.5%) were hospitalized due to COVID-19 after being adequately vaccinated. The findings of our study suggest that cancer patients have a higher acceptance of vaccines against SARS-CoV-2 than the general population in Bosnia and Herzegovina. Vaccination side effects are tolerable and do not cause major delays in specific cancer treatment. The protective effects of COVID-19 vaccines in the cancer patients presented in our study are comparable to available results of similar studies, which included the general population.

Aim To determine the predictive value of phosphorylated human epidermal growth factor receptor 2 (pHER2Y1248) status in breast cancer (BC) patients undergoing trastuzumab-based adjuvant therapy. Methods Immunohistochemical status of pHER2Y1248, EGFR/HER1, HER3, and HER4 was determined in 124 consecutive HER2-positive BC patients (median age [range] = 57 years [49.0-64.0]) treated at the University Hospital for Tumors, Zagreb, between 2008 and 2011. The median follow-up was 84 months (60.0-84.0). Prognostic factors of disease free survival (DFS) rate were evaluated with Kaplan-Meier/log-rank test and Cox regression analysis. Results pHER2Y1248, HER1, HER3, and HER4 were expressed in 66.1%, 9.7%, 70.2%, and 71.0% of patients, respectively. Disease progression (DP) was observed in 17.1% of pHER2Y1248-positive and 47.6% of pHER2Y1248-negative BCs (P = 0.001). Kaplan-Meier analysis showed a worse five-year DFS in pHER2Y1248-negative patients who were older than 60 years (P < 0.001) and had positive lymph node status (P < 0.001); tumor size >2.0 cm (P < 0.001); higher histological grade (P < 0.001); HER2E intrinsic subtype (P < 0.001), negative hormone receptors (P < 0.001); negative HER1 status (P < 0.001), positive HER3 (P = 0.002); and/or positive HER4 (P = 0.002) status. The only negative prognostic factor for five-year DFS in multivariate Cox regression analysis was pHER2Y1248-negative (hazard ratio [HR] 3.6, 95% confidence interval [CI] 1.8-7.2, P < 0.001) and lymph node-positive status (HR 3.6, 95% CI 1.3-9.8, P = 0.014). Conclusion pHER2Y1248 predicts sensitivity to trastuzumab and a better five-year DFS regardless of any other prognostic parameter. In HER2-positive BC patients. Non-phosphorylated HER2Y1248 is a strong predictor of trastuzumab resistance and a poor DFS.

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: 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.