Primerjava elektronskega in fotonskega dodatka k dozi pri obsevanju raka dojke : diplomsko delo

Arnuga, Sašo (author), Fuks, Kristijan (author), Žager Marciuš, Valerija (mentor), Novak, Gregor (co-mentor)

Uvod: Dojki sta parni kožni žlezi, ki ostaneta pri moških vse življenje rudimentirani, pri ženskah pa se razvijeta, rasteta in diferencirata po puberteti. Dojko delimo na štiri kvadrante, aksilarni podaljšek, prsno bradavico in centralni del ali areolo. Rak dojke je najpogostejši maligni tumor pri ženskah, saj prizadene približno vsako deveto žensko. Najbolj ozdravljiv je, kadar ga odkrijemo v zgodnjem stadiju. Raka dojke delimo na neinvazivne in invazivne. Pri zdravljenju raka dojke uporabljamo tri načine onkološkega zdravljenja: kirurško in sistematsko zdravljenje ter obsevanje. Določitev načina zdravljenja je odvisna od stadija bolezni ob diagnozi, tipa tumorja in splošnega zdravstvenega stanja bolnika. Tumorje obsevamo z linearnimi pospeševalniki. Obsevamo lahko z elektroni ali fotoni. Standardno obsevanje vsebuje 2 ali več obsevalnih polj, s skupno dozo 42,72 ali 50 Gy, ki jo bolnik prejme v 3–6 tednih z eno frakcijo na dan. Temu lahko kasneje sledi dodatna doza na ležišče tumorja, ki jo navadno frakcioniramo 5–8-krat in jo uporabljamo z namenom boljše lokalne kontrole tumorja. Namen: Primerjati pogostost uporabe elektronske dodatne doze, fotonske dodatne doze in uporabe standardnega obsevanja (brez dodatne doze). Metode dela: V raziskavo smo vključili podatke bolnikov z rakom dojke, ki so bili obsevani na določenih obsevalnih aparatih v določenem časovnem intervalu. Podatke smo pridobili iz internega programa Onkološkega inštituta Ljubljana in sistema na obsevalnih aparatih. Pridobili smo podatke 671 bolnikov. Obdelali smo jih s pomočjo programa za statistično obdelavo podatkov. Rezultati: Po obdelavi podatkov smo ugotovili, da pri obsevanju raka dojke v večini primerov dodatna doza ni bila potrebna. Kadar je bila uporabljena, je bila v večini primerov elektronska, saj se je obsevanje s fotonsko dodatno dozo uporabilo v manj kot eni dvajsetini vseh obsevanih bolnikov. Razprava in zaključek: Z elektronsko dodatno dozo obsevamo ležišča tumorjev, ki ležijo bližje površini telesa, s fotonsko pa ležišča tumorjev, ki ležijo globlje v tkivu. To pojasnimo z dejstvom, da je prodornost elektronov v primerjavi s fotoni nižja. Rezultati naše raziskave povedo, da se elektronska dodatna doza v primerjavi s fotonsko uporablja pogosteje. Takšni rezultati so bili pričakovani, saj večina avtorjev v svojih raziskavah ugotavlja podobno.

• Language: Slovenian
• Keywords: rak dojke, obsevanje, dodatna doza, elektronska dodatna doza, fotonska dodatna doza
• Work type: Bachelor thesis/paper
• Organization: ZF - Faculty of Health Sciences
• Year: 2017
• PID: 20.500.12556/RUL-94578
• COBISS.SI-ID: 5340011
• Publication date in RUL: 05.09.2017

Secondary language

• Language: English
• Title: Comparison of electron and photon boost in breast cancer radiotherapy : diploma thesis

Abstract

Introduction: Breasts are paired skin glands that stay rudimental for the whole life of males, however, in females, they develop, grow and differentiate after puberty. We divide the breast into four quadrants: axillary extension, breast nipple and the central part or areola. Breast cancer is the most common malignant tumour among women, since approximately every ninth woman is affected. We have the best chance at curing it if it is discovered in its early stages. Breast cancer can be invasive or non-invasive. We use three methods of oncologic treatment: surgical, radiotherapy and systematic treatment. The choice of the treatment method depends on the stage of the disease, type of tumour and general health condition of the patient. Tumours are irradiated using linear accelerators. We can irradiate using electrons or photons. Standard radiotherapy includes 2 or more irradiation fields with a total dosage of 42.72 or 50 Gy, which the patient receives in 3–6 weeks with one fraction a day. After that, the patient may receive a boost to tumour bed. The boost is usually divided into 5–8 fractions. The boost is used with the intention of better local control of the tumour. Purpose: To compare the frequency of use of electron and photon boost, and the use of standard irradiation (no boost). Methods: In the research, we included the data of patients with breast cancer, which were irradiated on specified linear accelerators in the specified time interval. We gathered the data from an internal software in the Institute of oncology Ljubljana. We gathered data from 671 patients, which were processed with the use of data processing software. Results: After the processing of data, we found out that in most cases the use of boost was unnecessary. If the boost was used, it was usually electron boost since the photon boost was used in less than one twentieth of all cases. Discussion and conclusion: We use the electron boost to irradiate the tumour bed of those tumours that lie near the surface of the skin, and the photon boost when the tumour bed lies deeper in the tissue. This can be explained with the fact that the penetration of electrons is lower in comparison to the photons. The results of our research show that the electron boost is used more frequently than the photon boost. These results were to be expected, since the majority of authors got similar results.

• Keywords: breast cancer, radiotherapy, boost, electron boost, photon boost