ABSTRAK
Dengan menggunakan TLD dan dosimeter dioda EDD - 53G, telah diukur dosisorgan kritis mata, tiroid, medula spinalis , dan gonad pada berbagai perlakuanradioterapi dengan sinar X 6 MV. Pengukuran dilakukan pada fantom rando yangdiberi simulasi perlakuan radioterapi dengan berbagai jenis kanker, utamanya kankernasofaring. Perencanaan simulasi terapi 3 D dilakukan dengan TPS ISIS berdasarkandata hasil pengamatan pada beberapa pasien kanker nasofaring yang telah menjalaniradioterapi di RSPAD. Perlakuan diberikan dengan 2 lapangan plan parallel dan teknikSAD (source axis distance), ukuran lapangan radiasi 18.5 x 17 cm2, dosis preskripsi 2Gy/fraksi. Sesuai dengan perlakuan pada pasien, kemudian lapangan diperkecil untukmelindungi medulla spinalis, menjadi 9 x 16 cm2. Dengan cara yang sama, dosis organkritis ditentukan dari simulasi radioterapi kanker paru, tulang bahu, abdomen, pelvisdan tulang paha. Perencanaan setiap perlakuan diakukan berdasarkan data seorangpasien yang telah menjalani radioterpi di RSPAD . Pada umumnya dosis organ kritisyang berjarak 0 – 4 cm dari tepi lapangan berbeda dengan hasil kalkulasi TPS sampai61% bila diukur dengan TLD, dan berbeda sampai 80% bila diukur dengan diode.Untuk organ yang terletak relatif lebih jauh dari tepi lapangan radiasi, hasil pengukurandengan kedua dosimeter menunjukkan hasil sama, berbeda sampai lebih 100% dengankalkulasi TPS. Dosis pada pasien 5000 cGy, maka mata menerima dosis mencapai 209cGy pada perlakukan kanker nasofaring dan mencapai 400 cGy pada perlakukan kankerotak. Organ kritis tiroid dimungkinkan menerima dosis dari perlakuan kanker paru,kanker nasofaring, dan kanker tulang bahu, berturut turut mencapai 284 cGy, 192 cGy,dan 312 cGy. Organ kritis Gonad pada perlakuan radioterapi kanker abdomen menerimadosis sebesar 524 cGy dan kanker sarkoma tulang paha mencapai 372 cGy.

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ABSTRACT
By using TLD and diode dosimeter EDD - 53G, critical organ doses weremeasured eye, thyroid, spinal cord, and gonads at various radiotherapy treatment with 6MV X-rays. Measurements were taken at rando phantom given radiotherapy treatmentsimulations with various types of cancer, especially nasopharyngeal cancer. 3 Dtreatment planning simulations performed with ISIS TPS based observed data on someof nasopharyngeal cancer patients who had undergone radiotherapy in the armyhospital. Treatment was given with 2 field parallel plan and technique of SAD (sourcedistance axis), the radiation field size 18.5 x 17 cm2, prescription dose 2 Gy / fraction.In accordance with the patient's treatment, then the field is reduced to protect the spinalcord, at 9 x 16 cm2. In the same way, the dose of the critical organ is determined fromthe simulation radiotherapy of lung cancer, bone shoulder, abdomen, pelvis and femur.Planning any transactions are carried out based on the data treatment of a patient whohad undergone radiotherapy at the RSPAD. In general, the critical organ dose within 0-4cm from the edge of the field in contrast to the results of calculations TPS to 61% whenmeasured with the TLD, and vary up to 80% when measured with the diode. For anorgan that is located relatively far from the edge of the radiation field, with bothdosimeter measurements showed similar results, approximately over 100% differentfrom the TPS calculations. The dose given to patient at 5000 cGy, the eyes receiveddose until 209 cGy at simulation nasofaring cancer and until 400 cGy at simulationbrain cancer. Critical organs received doses of thyroid possible treatment of lung cancer,nasofaring cancer, and shoulder bone cancer, the dose received in a row to reach 284cGy, 192 cGy, and 312 cGy. Gonad organ critical in the abdomen cancer radiotherapytreatment received a dose of 524 cGy and bone sarcoma cancer at 372 cGy.