Avtor/Urednik		Grabec, Daša; Strojan, Primož
Naslov		Missing tissue compensation with wax filter compensators in radiotherapy of the head and neck region
Prevedeni naslov		Voščeni filterski kompenzatorji pri obsevanju tumorjev glave in vratu
Tip		članek
Vir		Radiol Oncol
Vol. in št.		Letnik 39, št. 3
Leto izdaje		2005
Obseg		str. 219-24
Jezik		eng
Abstrakt		Background. In the conventional radiotherapy of the head and neck region, the inhomogeneity of the absorbed dose in certain clinical situations can exceed ? 5% of the nominal dose. Depending on the pattern of dose inhomogeneity, treatment related toxicity is more pronounced and disease control reduced. The aim of our report is to present the wax filter compensation technique used in our department. Case report. A 46-year-old male with inoperable carcinoma of the oropharynx of clinical stage T3N2c was irradiated with 5 MV linear accelerator photon beams and conventional 3 field technique. In order to obtain more homogenous dose distribution in treated volume, the opposed lateral fields were modified using 2Dwax filter compensators. Results. Using conventional wedge filter compensation, the planed absorbed dose deviations in the treated volume were in the range of 94% to 113% of the prescribed dose. By modification of the opposed lateral fields with 2D wax filter compensators, the variations of the absorbed dose were reduced to the range from 93% to 105% of the prescribed dose. In the article, the planning and manufacturing as well as dosimetric checking of wax filter compensators are described. Conclusions. With the use of 2D wax filter compensators, the inhomogeneity of absorbed dose distribution was significantly reduced, and the quality of treatment considerably improved.
Izvleček		Izhodišča. Ob uporabi konvencionalne radioterapije področja glave in vratu lahko odstopanja absorbirane doze od predpisane presežejo ± 5%. Vzorec dozne nehomogenosti lahko vpliva na stopnjo izraženosti obsevalnih poškodb in uspeh zdravljenja. V članku želimo predstaviti uporabo voščenih filterskih kompenzatorjev na Onkološkem inštitutu v Ljubljani. Prikaz primera. 46-letni bolnik z neoperabilnim karcinomom ustnega žrela kliničnega stadija T3N2cM0, je bil obsevan na linearnem pospeševalniku s fotonskim snopom energije 5MV in konvencionalno tehniko treh polj. Za dosego večje stopnje homogenosti razporeditve doze v obsevanem volumnu, sta bili nasprotno ležeči lateralni polji modificirani z voščenima 2D-filtrskima kompenzatorjema. Rezultati. Ob uporabi konvencionalne kompenzacije s klinastimi filtri je znašalo predvideno odstopanje absorbirane doze znotraj obsevalnega volumna med 94% in 113% predpisane doze. Z modifikacijo nasprotno ležečih lateralnih polj z voščenima 2D filtrskima kompenzatorjema se je zmanjšalo nihanje absorbirane doze na vrednosti od 93% do 105% predpisane doze. V članku predstavljamo načrtovanje obsevanja z voščenimi filtrskimi kompenzatorji, njihovo izdelavo, ter rezultate dozimetričnega preverjanja pred in med obsevanjem. Zaključki. Z uporabo 2D-voščenih filtrskih kompenzatorjev smo uspeli znatno zmanjšati nehomogenost v porazdelitvi absorbirane doze, s tem pa občutno izboljšali kakovost zdravljenja.
Deskriptorji		HEAD AND NECK NEOPLASMS RADIOTHERAPY DOSAGE MIDDLE AGE