Santrauka:
Baigiamąjį bakalaurinį darbą sudaro trys dalys. Pirmoji – teorinė dalis skirta literatūros analizei, antroji – empirinio tyrimo darbo metodui ir organizavimui, trečioji – tyrimo rezultatams ir viso darbo apibendrinimui. Darbo tikslas: nustatyti prostatos vėžiu sergančių pacientų pozicionavimo paklaidų įtaką dozės pasiskirstymui gydant spinduline terapija.
Darbo uždaviniai: 1. Aprašyti prostatos vėžio planavimo ir gydymo etapus. 2. Įvertinti pozicionavimo paklaidų įtaką dozės pasiskirstymui simuliuojant paklaidas su gydymo planavimo sistema. 3. Palyginti gautus duomenis su užsienio mokslininko Paddanyil darbo rezultatais.
Rezultatai ir išvados: 1. . Diagnozavus prostatos vėžį, gydytojas onkologas ir medicinos fizikai sudaro gydymo planą, parenka reikiamą paciento poziciją bei imobilizavimo priemones, nustato gydymui reikalingą švitinimo dozę bei frakcijų skaičių. Šiame procese dalyvauja ir radiologijos technologai, kurie laikosi nustatytų pozicionavimo nurodymų, paruošdami pacientus prieš švitinimo procedūras 2. Visiems pacientams didžiausią įtaką dozių nuokrypiams turėjo 6 ir 8 mm paklaidos. Vidutinė dozė šlapimo pūslei ir tiesiajai žarnai didėjo nežymiai, PTV tūriui dozė mažėjo su visomis paklaidomis. 3. Autorės ir užsienio mokslininko Paddanyil et.al darbuose gauti vidutinės dozės pokyčiai yra panašūs. Lyginat duomenis abejose darbuose didžiausią įtaką dozės nuokrypiams turi 4 ir -4 mm paklaidos
Description:
Significance of the study. Prostate cancer is one of the most common forms of cancer among men not only in the world but also in Lithuania, with about 3,000 new cases registered every year and this number is growing (Tamošauskienė, 2014). One of the main methods of treatment for patients with cancer is radiation therapy. Patient positioning is important in the design of treatment plans and implementation of treatment procedures, as a patient’s position and irradiation fields must be accurately reproduced during the radiotherapy fractions for a successful treatment.
Aim of the research: to determine the influence of prostate cancer patient positioning inaccuracies on dose distribution in radiation therapy.
The tasks:
1. To describe the stages of prostate cancer planning and treatment in radiotherapy.
2. To evaluate the influence of positioning inaccuracies on dose distribution by simulating inaccuracies with the treatment planning system.
3. To compare the data obtained with the results of the foreign scientist Paddanyil.
Methods of the research: The study was performed at the Radiation Therapy Department of The Hospital of Lithuanian University of Health Sciences (LSMUL) Kauno Klinikos in February and March 2019. The authorization of bioethics (No. BEC-KK(B)-55) was obtained to conduct this research. In the Varian Eclipse treatment planning system, positioning inaccuracies were simulated on 5 prostate cancer patients. The theoretical part analyzes the scientific literature on prostate cancer; the empirical part analyzes the obtained data with Microsoft Excel program.
The results and conclusions: After diagnosis of prostate cancer, the oncologist and medical physicists make a treatment plan, select the appropriate patient position and immobilization measures, determine the dose of irradiation needed for treatment and the number of fractions. Radiologists are also involved in this process and follow established positioning instructions to prepare patients before irradiation procedures. The inaccuracies of 6 and 8 mm had the greatest influence on dose deviations for all the patients. The average dose to the bladder and rectum increased slightly, and the dose for PTV decreased with all the inaccuracies. Changes in the average dose obtained by the author and the ones mentioned by foreign scientist Paddanyil et.al studies are similar. When comparing the data in both works, 4 and -4 mm inaccuracies have the most influence on the deviation of the dose.