Aleksandar Tomasevic

Dr. Aleksandar Tomasevic

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
12 January 2024 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
MMMladen Marinkovic
Mladen Marinkovic
SSSuzana Stojanovic-Rundic
Suzana Stojanovic-Rundic
ASAleksandra Stanojevic
Aleksandra Stanojevic
ATAleksandar Tomasevic
Aleksandar Tomasevic
RJRadmila Jankovic
Radmila Jankovic
Marko RadulovicMarko Radulovic
Marko Radulovic
(1) Background: This study aimed to develop a machine learning model based on radiomics of pretreatment magnetic resonance imaging (MRI) 3D T2W contrast sequence scans combined with clinical parameters (CP) to predict neoadjuvant chemoradiotherapy (nCRT) response in patients with locally advanced rectal carcinoma (LARC). The study also assessed the impact of radiomics dimensionality on predictive performance. (2) Methods: Seventy-five patients were prospectively enrolled with clinicopathologically confirmed LARC and nCRT before surgery. Tumor properties were assessed by calculating 2141 radiomics features. Least absolute shrinkage selection operator (LASSO) and multivariate regression were used for feature selection. (3) Results: Two predictive models were constructed, one starting from 72 CP and 107 radiomics features, and the other from 72 CP and 1862 radiomics features. The models revealed moderately advantageous impact of increased dimensionality, with their predictive respective AUCs of 0.86 and 0.90 in the entire cohort and 0.84 within validation folds. Both models outperformed the CP-only model (AUC = 0.80) which served as the benchmark for predictive performance without radiomics. (4) Conclusions: Predictive models developed in this study combining pretreatment MRI radiomics and clinicopathological features may potentially provide a routine clinical predictor of chemoradiotherapy responders, enabling clinicians to personalize treatment strategies for rectal carcinoma.

11 March 2025 in Medicina
Verified
Journal Article
Open access
PDF file
SSSuzana Stojanovic-Rundic
Suzana Stojanovic-Rundic
MMMladen Marinkovic
Mladen Marinkovic
ASAleksandra Stanojevic
Aleksandra Stanojevic
DGDusica Gavrilovic
Dusica Gavrilovic
RJRadmila Jankovic
Radmila Jankovic
MCMilena Cavic
Milena Cavic
Background and Objectives: The standard treatment for locally advanced rectal cancer (LARC) includes neoadjuvant chemoradiotherapy (nCRT), followed by surgery with or without adjuvant chemotherapy (CT). This study evaluated the efficacy and safety of dose-escalated radiotherapy (RT) using the volumetric modulated arc therapy–simultaneous integrated boost (VMAT–SIB) technique in patients with LARC compared to 3D conformal radiotherapy (3D-CRT). Materials and Methods: This study prospectively enrolled 75 patients with LARC. All patients received nCRT using VMAT–SIB, delivering a tumor dose (TD) of 54 Gy in 25 fractions, with concomitant CT following the 5-fluorouracil and leucovorin (5-FU–LV) protocol. To compare the treatment outcomes and toxicity associated with the increased RT dose, a retrospective cohort of 62 patients treated with the 3D-CRT technique was analyzed. The 3D-CRT group received a TD of 50.4 Gy in 28 fractions with the same CT. Outcomes, including pathological complete response (pCR), tumor regression grade (TRG), and sphincter preservation rates, were compared. Results: Among operated patients, the group treated with VMAT–SIB demonstrated improved rates of pCR (20.6% vs. 8.9%), with a statistically significant trend (p = 0.06). Sphincter-preserving surgeries were performed in 49 out of 63 operated patients (77.8%) in the VMAT–SIB group, compared to 35 out of 56 (62.5%) in the 3D-CRT group. Analysis of the definitive postoperative stage revealed a significantly higher prevalence of lower T categories (T0–2) (p < 0.01), negative N status (p < 0.05), and lower stages (I + II) (p < 0.05) in patients treated with the intensified RT approach. However, no significant differences in acute toxicity were observed. Conclusions: The implementation of intensified treatment with a higher dose using the VMAT–SIB technique demonstrated significant benefits in downsizing and downstaging compared to the standard treatment approach. These findings support its integration into clinical practice. However, further prospective, multi-center studies are needed to validate these results and assess long-term outcomes.

3 February 2025 in Preprints.org
Verified
Preprint
Open access
PDF file
SSSuzana Stojanovic-Rundic
Suzana Stojanovic-Rundic
MMMladen Marinkovic
Mladen Marinkovic
ASAleksandra Stanojevic
Aleksandra Stanojevic
DGDusica Gavrilovic
Dusica Gavrilovic
RJRadmila Jankovic
Radmila Jankovic
MCMilena Cavic
Milena Cavic
Background and Objectives: The standard treatment for locally advanced rectal cancer (LARC) includes neoadjuvant chemoradiotherapy (nCRT), followed by surgery with or without adjuvant chemotherapy (CT). This study evaluated the efficacy and safety of dose-escalated radiotherapy (RT) using the volumetric modulated arc therapy-simultaneous integrated boost (VMAT-SIB) technique in patients with LARC compared to 3D conformal radiotherapy (3D-CRT). Materials and Methods: This study prospectively enrolled 75 patients with LARC. All patients received nCRT using the VMAT-SIB, delivering a tumor dose (TD) of 54 Gy in 25 fractions, with concomitant CT following the 5-fluorouracil and leucovorin (5-FU-LV) protocol. To compare the treatment outcomes and toxicity associated with the increased RT dose, a retrospective cohort of 62 patients treated with 3D-CRT techique was analyzed. The 3D-CRT group received a TD of 50.4 Gy in 28 fractions with the same CT. Outcomes, including pathological complete response (pCR), tumor regression grade (TRG), and sphincter preservation rates, were compared. Results: Among operated patients, the group treated with the VMAT-SIB demonstrated improved rates of pCR (20.6% vs. 8.9%), with a statistically significant trend (p = 0.06). Sphincter-preserving surgeries were performed in 49 out of 63 operated patients (77.8%) in VMAT-SIB group, compared to 35 out of 56 (62.5%) in 3D-CRT group. Analysis of definitive postoperative stage revealed a significantly higher prevalence of lower T categories (T0-2) (p < 0.01), negative N status (p < 0.05), and lower stages (I+II) (p < 0.05) in patients treated with intensified RT approach. However, no significant differences in acute toxicity were observed. Conclusions: The implementation of intensified treatment with a higher dose using the VMAT-SIB technique demonstrated significant benefits in downsizing and downstaging compared to the standard treatment approach. These findings support its integration into clinical practice. However, further prospective, multi-center studies are needed to validate these results and assess long-term outcomes.

1 January 2020
Verified
Journal Article
Closed access
ATAleksandar Tomasevic
Aleksandar Tomasevic
VKVesna Plesinac Karapandzic
Vesna Plesinac Karapandzic
SRSuzana Stojanovic Rundic
Suzana Stojanovic Rundic
SVSandra Vuckovic
Sandra Vuckovic
PMPetar Milenkovic
Petar Milenkovic
PPPredrag Petrasinovic
Predrag Petrasinovic

21 March 2024 in Preventive Paediatrics
Verified
Journal Article
Open access
PDF file
ATAleksandar Tomasevic
Aleksandar Tomasevic
MKMira Karadžić
Mira Karadžić
MMMirjana Miković
Mirjana Miković
VVVesna Veković
Vesna Veković
MTMilena Tomašević
Milena Tomašević
In addition to developed prevention and modern, successful treatment modalities, cervical cancer still represents a major social and epidemiological problem in the world, especially in underdeveloped and developing countries. According to the cervical cancer incidence and mortality, Serbia has been at the top of the list of European countries for decades. The proven central role of chronic HPV infection and the persistent presence of viral DNK in the genetic material of the cells of the cervical mucosa has led to the development of successful prevention measures. Primary prevention is presented through HPV immunization of the population in childhood/early adolescence. Secondary prevention is presented through screening to detect asymptomatic premalignant changes or early stages of invasive disease. It has been shown that the population benefit from vaccination is achieved when the level of immunization exceeds 50%. In Serbia, the nine-valent HPV vaccine is currently available, although the vaccination itself is not mandatory but at the level of recommendation, which with insufficient information about HPV infection, combined with the already widespread negative opinion towards vaccination in general, results in a low overall percentage. Also, there is still no adequately developed organized screening, it is most often carried out as opportune screening, based on colposcopy with PAP testing, while HPV testing is carried out on a much smaller scale, all of which represent the reasons for the high incidence and mortality from cervical cancer in Serbia. I pored razvijenih sistema prevencije, ali i savremenih, uspešnih modaliteta lečenja, karcinom grlića materice predstavlja i dalje veliki socijalni i epidemiološki problem u svetu, naročito izražen u nerazvijenim zemljama i zemljama u razvoju. Prema incidenci i mortalitetu od karcinoma grlića materice, Srbija se decenijama unazad nalazi u vrhu liste evropskih zemalja. Dokazana centralna uloga hronične HPV infekcije i perzistentnog prisustva virusne DNK u genetskom materijalu ćelija cervikalne sluznice, dovela je i do razvoja uspešnih mera prevencije. Primarna prevencija je predstavljena kroz HPV imunizaciju populacije u dečijem/ranom adolescentnom dobu, što omogućava smanjenje učestalosti HPV infekcije, a time i smanjenje incidence patoloških promena na sluznici grlića. Sekundarna prevencija je predstavljena kroz skrining sa ciljem otkrivanja asimptomatskih premalignih promena ili ranih stadijuma invazivne bolesti. Pokazano je da se populacioni benefit od vakcinacije postiže kada nivo imunizacije pređe 50%. U Srbiji je trenutno dostupna devetovalentna HPV vakcina, mada sama vakcinacije nije obavezna već je na nivou preporuke, što uz nedovoljnu informisanost o HPV infekciji, udruženo sa već naširoko rasprostranjenom negativnom senzibilizacijom opšte populacije u Srbiji prema vakcinaciji uopšte, daje ukupno nizak procent vakcinisanih. Takođe, još uvek ne postoji adekvatno razvijen organizovani skrining, on se najčešće sprovodi kao povremeni, oportuni skrining, baziran na kolposkopiji sa PAP testiranjem, dok se HPV testiranje sprovodi u znatno manjem obimu, što sve predstavlja razloge visoke incidence i mortaliteta od karcinoma grlića materice u Srbiji.

14 November 2020
Verified
Conference Paper
Closed access
ATAleksandar Tomasevic
Aleksandar Tomasevic
Introduction/Background 3D brachytherapy (BRT) planning, based on magnetic resonance (MR) imaging, has become a standard approach in cervical ca |