Intensity modulated radiotherapy (IMRT) has become widely used as a standard radiation therapy technique for the treatment of localized prostate cancer. The transition from conformal radiotherapy (3D CRT) to a more complex IMRT technique triggered the need for more thorough verification of the accuracy in the dose delivery. In this work we present the clinical workflow and the results of patient specific quality assurance (PSQA) procedures for 40 prostate cancer patients who have been treated with step and shot IMRT ever since its implementation in our routine clinical practice. PSQA procedures include dosimetric verification of each treatment plan with dedicated rotational phantom and high-resolution matrix detector system Octavius 4D (PTW Freiburg) that allows three-dimensional comparison of the calculated and delivered radiation dose distribution. Our results proved the compliance with the universal tolerance limits recommended for those procedures (1), assuring the safety of the treatment and providing the possibility for the adoption of more stringent constraints in the future. Key words: prostate IMRT, patient specific QA Radioterapija moduliranog intenziteta (eng intensity modulated radiotherapy -IMRT) u posljednjem desetljecu je postala uobicajena radioterapijska metoda za terapiju lokaliziranih karcinoma prostate. Prelazak s konformalne radioterapije na napredniju i tehnicki slozeniju IMRT tehniku, donio je i potrebu za detaljnijom i sveobuhvatnom provjerom tocnosti isporuke doze zracenja. U ovom radu predstavljamo provodenje postupaka dozimetrijske verifikacije radio terapijskih planova poznatih pod engleskim nazivom patient specific QA (PSQA) te rezultate za 40 bolesnika s karcinomom prostate koji su primili IMRT terapiju. U tu svrhu koristimo posebni dozimetrijski sustav s rotacijskim fantomom i visoko razlucivom detektorskom matricom, Octavius 4D (PTW Freiburg). Pokazalo se kako su sva dobivena odstupanja izmedu planirane i mjerene trodimenzionalne raspodjele doze bila unutar preporucenih tolerancija (1) sto nam daje povjerenje u sigurnost provodenja ovakve terapije te otvara mogucnost za primjenu strozijih ogranicenja u buducnosti. Kljucne rijeci: radioterapija moduliranog intenziteta (IMRT) karcinoma prostate, dozimetrijska verifikacija plana, patient specific QA (PSQA)