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"Radioterapi masih menjadi pilihan utama terapi kanker baik di dunia maupun di Indonesia. Pengobatan dengan radioterapi dimulai dengan tahap perencanaan radioterapi pada Treatment Planning System (TPS). Perencanaan radioterapi ini mutlak diperlukan untuk menghidari kecelakaan radiasi berupa over dosis atau under dosis pada pasien. Tujuan dari penelitan ini adalah mengevaluasi ketidakpastian dosimetri pada Teknik 3D-CRT dan IMRT sehingga didapatkan gambaran ketepatan/akurasi dan penyimpangan dosis radiasi yang diterima pasien dengan dosis yang direncanakan di TPS. Penelitian untuk teknik 3D-CRT menggunakan phantom CIRS thorak model 002LFC dan IMRT menggunakan solid water phantom mengikuti protokol standar pengujian sesuai Tecdoc 1583 tahun 2008 dan pengujian sesuai rekomendasi AAPM Task Group 119. Pengukuran dosis dilakukan menggunakan bilik ionisasi volume aktif 0,65 cm3 pada Linac energi 6 MV pada tujuh Linac. Besarnya prosentase titik pengukuran yang berada diluar toleransi ke tujuh Linac berturut-turut adalah sebesar 6,66%, 10%, 17,39%, 10%, 26,66%, 56,66%, 30%. Beberapa Linac melebihi tolerasi karena algoritma TPS tidak mampu memodelkan dengan baik penggunaan wedge. Besarnya deviasi dosis untuk 3D-CRT yang berada diluar rentang toleransi pada umumnya terjadi pada kasus uji empat untuk titik 10, yang pada perencanaannya menggunakan berkas tangensial pada material inhomogen, kasus uji 6 yang menggunakan blok dan material inhomogen. Hasil penelitian pada teknik IMRT dilihat dari nilai confidence limit (CL) yang menggambarkan kesesuaian hasil pengukuran dosis dengan hasil perencanaan. Nilai CL untuk pengukuran dosis titik perencanaan IMRT pada daerah dosis tinggi pada Linac A sampai Linac F berturutturut adalah sebesar 3,95%, 2,83%, 6,30%, 2,33%, 5,49%, 9,27% dengan batasan yang ditetapkan TG 119 adalah 4,07%. Nilai Confidence Limit (CL) hasil pengukuran dosis titik perencanaan IMRT pada daerah dosis rendah pada Linac A sampai Linac F berturut-turut adalah sebesar 4,64%, 3,96%, 4,88%, 5,05%, 3,33%, 10,40% dengan batasan yang ditetapkan TG 119 adalah 4,05%. Hasil pengujian IMRT, Linac yang memakai algoritma AAA secara umum menghasilkan deviasi yang berada dalam rentang toleransi, sedangkan yang memakai algoritma superposisi banyak pengukuran dengan deviasi yang berada di luar rentang toleransi. Kata Kunci : 3D-CRT, IMRT, TG-119, Confidence Limit

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Radiotherapy is still the main choice of cancer therapy both in the world and in Indonesia. Radiotherapi’s treatment begins with the radiotherapy planning stage in the Treatment Planning System (TPS). This planning is absolutely necessary to avoid radiation accidents in the form of over dose or under dose to the patient. The purpose of this study was to evaluate the uncertainty of dosimetry in the 3D-CRT and IMRT techniques in order to obtain an overview of the accuracy and the amount of radiation dose deviation received by the patient with the planned dose at the TPS. Research for 3D-CRT technique using phantom CIRS thorax model 002LFC and IMRT using solid water phantom following the standard testing protocol according to Tecdoc 1583 in 2008 and testing according to the recommendations of AAPM Task Group 119. The dose measurement was carried out using an active volume ionization chamber of 0.65 cm3 on Linac energy 6 MV on seven Linac.The magnitude of the deviation of the dose calculated from the TPS with the measured dose for 3D-CRT on the seven Linacs was 6,66%, 10%, 17,39%, 10%, 26,66%, 56,66%, 30%. Some Linacs exceed the tolerance because the TPS algorithm is not able to properly model the use of wedges. The magnitude of the dose deviation for 3D-CRT which is outside the tolerance range generally occurs in the four test case for point 10, which is designed to use tangential beams on inhomogeneous materials, test case 6 using inhomogeneous blocks and materials. The results of research on the IMRT technique, the value of the confidence limit (CL) which describes the suitability of the dose measurement results with the planning results, for dose measurement of IMRT planning points in the high-dose area on Linac A to Linac F respectively 3.95%, 2.83%, 6.30%, 2.33%, 5.49%, 9.27% with the limit set by TG 119 is 4.07%. The Confidence Limit (CL) measurement results of the IMRT planning point in the low dose area in Linac A to Linac F are 4.64%, 3.96%, 4.88%, 5.05%, 3.33%, respectively. 10.40% with the limit set by TG 119 is 4.05%. The result of the IMRT test, Linac using the AAA algorithm generally produces deviations that are within the tolerance range, while those using the superposition algorithm have many measurements with deviations that are outside the tolerance range. Keywords: 3D-CRT, IMRT, TG-119, Confidence Limit."

"[ABSTRAKTujuan dari penelitian ini adalah mengevaluasi akurasi perencanaan danpemberian perlakuan volumetric modulated arc therapy (VMAT) menggunakanrekomendasi AAPM Task Group (TG) 119 di Departemen Radioterapi MRCCCSiloam Hospitals Semanggi. TG 119 menetapkan dua tes pendahuluan dan limates menyerupai kondisi klinis, serta confidence limit (CL) sebagai nilai standarpengujian. Perencanaan intensity modulated radiation therapy (IMRT) danVMAT dibuat lokal mengikuti preskripsi dosis dan sasaran perencanaan yangditetapkan oleh TG 119, kemudian hasil perencanaan lokal dibandingkan denganhasil TG 119. Pengukuran dosis titik dari pemberian perlakuan IMRT dan VMATpada daerah dosis tinggi dan rendah diukur menggunakan tiga bilik ionisasidengan volume aktif yang berbeda, sedangkan pengukuran dosis penampangmenggunakan detektor 2D array, distribusi dosis penampang dianalisa dengankriteria indeks gamma 3 %, 3 mm dan 2 %, 2 mm. CL hasil pengukuran dosis titikIMRT pada daerah dosis tinggi dan rendah 1.06 % dan 0.82 % (CC01), 1.19 %dan 1.58 % (CC13), 1.37 % dan 3.02 % (FC65G). Untuk VMAT 1.47 % dan 1.17% (CC01), 1.71 % dan 1.95 % (CC13), 2.08 % dan 3.96 % (FC65G). Hasilpengukuran menggunakan bilik ionisasi CC01 dan CC13 mampu memenuhikriteria yang ditetapkan TG 119 dibawah 3 %, sedangkan bilik ioisasi FC65Gtidak memenuhi kriteria tersebut. Hasil CL analisa indeks gamma IMRT dengankriteria gamma 3 %, 3 mm dan 2 %, 2mm sebesar 3.68 dan 11.71 (96.32 % dan88.29 % pass), sedangkan untuk VMAT sebesar 1.44 dan 6.33 (98.56 % dan93.67 % pass), kedua hasil indeks gamma tersebut masuk dalam kriteria TG 119dibawah 12.4. Berdasarkan hasil tersebut, rekomendasi TG 119 dapatdiimplementasikan untuk menguji akurasi perencanaan dan pemberian perlakuanVMAT, hasil tersebut juga menunjukkan keakurasian yang cukup dariperencanaan dan pemberian perlakuan VMAT di institusi lokal.

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ABSTRACTThe purpose of this study was to evaluate the accuracy of treatment planning anddelivery of Volumetric Modulated Arc Therapy (VMAT) using recommendationof AAPM Task Group (TG) 119 in the Department of Radiotherapy MRCCCSiloam Hospitals Semanggi. TG 119 establishes two preliminary tests and fivetests resemble a clinical condition, as well as the confidence limit (CL) as abenchmark data. Dose prescriptions and planning objectives recommended by TG119 report were followed to generate Intensity Modulated Radiation Therapy(IMRT) and VMAT treatment planning, and then the local planning resultscompared with the results of TG 119. Point dose measurements were done usingthree ionization chambers with different active volume at high dose and low doseregions. The planar dose measurements were measured using a 2D detector arrayand the planar dose distribution was analyzed for percentage of points passing thegamma criteria of 3 %, 3 mm and 2 %, 2 mm. For IMRT plans, the CLs obtainedfor point dose measurement in areas of high and low doses were 1.06 % and 0.82% (CC01), 1.19 % and 1.58 % (CC13), 1.37 and 3.02 % (FC65G), whereas avalue of 1.47 and 1.17 % (CC01), 1.71 % and 1.95 % (CC13), 2.08 % and 3.96 %(FC65G) for CL VMAT. Point dose measurement results using ion chamberCC01 and CC13 were able to meet the criteria set by TG 119 below 3 %, whilefor ion chamber FC65G could not meet these criteria. From gamma analysis, CLIMRT for gamma criteria 3 %, 3 mm and 2 %, 2 mm were 3.68 and 11.71 (96.32% and 88.29 % pass), while for VMAT were 1.44 and 6.33 (98.56 % and 93.67 %pass), gamma index results falls within the criteria TG 119 under 12.4. Based onthe results, TG 119 recommendations can be implemented on commissioningVMAT treatment planning and delivery, these results also indicate adequateaccuracy of VMAT treatment planning and delivery in local institution, The purpose of this study was to evaluate the accuracy of treatment planning anddelivery of Volumetric Modulated Arc Therapy (VMAT) using recommendationof AAPM Task Group (TG) 119 in the Department of Radiotherapy MRCCCSiloam Hospitals Semanggi. TG 119 establishes two preliminary tests and fivetests resemble a clinical condition, as well as the confidence limit (CL) as abenchmark data. Dose prescriptions and planning objectives recommended by TG119 report were followed to generate Intensity Modulated Radiation Therapy(IMRT) and VMAT treatment planning, and then the local planning resultscompared with the results of TG 119. Point dose measurements were done usingthree ionization chambers with different active volume at high dose and low doseregions. The planar dose measurements were measured using a 2D detector arrayand the planar dose distribution was analyzed for percentage of points passing thegamma criteria of 3 %, 3 mm and 2 %, 2 mm. For IMRT plans, the CLs obtainedfor point dose measurement in areas of high and low doses were 1.06 % and 0.82% (CC01), 1.19 % and 1.58 % (CC13), 1.37 and 3.02 % (FC65G), whereas avalue of 1.47 and 1.17 % (CC01), 1.71 % and 1.95 % (CC13), 2.08 % and 3.96 %(FC65G) for CL VMAT. Point dose measurement results using ion chamberCC01 and CC13 were able to meet the criteria set by TG 119 below 3 %, whilefor ion chamber FC65G could not meet these criteria. From gamma analysis, CLIMRT for gamma criteria 3 %, 3 mm and 2 %, 2 mm were 3.68 and 11.71 (96.32% and 88.29 % pass), while for VMAT were 1.44 and 6.33 (98.56 % and 93.67 %pass), gamma index results falls within the criteria TG 119 under 12.4. Based onthe results, TG 119 recommendations can be implemented on commissioningVMAT treatment planning and delivery, these results also indicate adequateaccuracy of VMAT treatment planning and delivery in local institution]"

"Peningkatan keakuratan dan kepresisian dalam pengobatan radioterapi dapat dilakukan menggunakan teknologi lanjut radioterapi seperti Volumetric Modulation Arc Therapy (VMAT). Pemanfaatan teknik VMAT terhadap pemilihan orientasi gantri arc yang bersamaan dengan pergerakan multileaf collimator (MLC) perlu dilakukan verifikasi untuk memastikan ketepatan distribusi dosis pada saat perencanaan dan pengukuran. Tujuan dari penelitian ini adalah mengevaluasi dosis radioterapi teknik VMAT partial arc dan full arc berdasarkan struktur target yang disediakan oleh protokol AAPM TG 119 dan diverifikasi menggunakan protokol AAPM TG 218. Phantom dipindai menggunakan CT Simulator, hasil pemindaian dikirim ke Treatment Planning System (TPS) untuk dilakukan perencanaan teknik VMAT dengan variasi gantri arc. Penyinaran pada saat pengukuran dilakukan dengan metode true composite, dengan pengukuran dosis titik menggunakan bilik ionisasi CC13, pengukuran dosis planar field by field menggunakan EPID dan dosis planar composite menggunakan detektor 2D array MatriXXFFF. Kriteria gamma index yang digunakan 3%/2mm dan 2%/2mm. Hasil perencanaan teknik double arc menghasilkan distribusi dosis lebih baik dibandingkan dengan single arc, karena terjadi peningkatan modulasi selama optimasi. Hasil data pengukuran dosis titik lebih tinggi dibandingkan nilai perencanaan di TPS, hal ini karena adanya kebocoran efek tongue and groove pada saat pengukuran. Tingkat kelulusan gamma secara field by field mampu memenuhi kriteri 3%/2mm, namun tidak untuk penyinaran secara composite. Kemudian terjadi penurunan tingkat kelulusan gamma pada kriteria 2%/2mm. Confidence limit yang diperoleh secara universal tidak memenuhi kriteria yang diberikan artinya dosis perencanaan dengan dosis hasil pengukuran tidak konsisten seperti yang direkomendasikan oleh AAPM TG 119 dan AAPM TG 218. Evaluasi dosis VMAT dengan variasi gantri arc secara true composite pada penelitian ini menunjukkan bahwa terdapat metode pengukuran yang tidak sesuai dengan alat ukur yang digunakan dan kriteria gamma index yang terlalu ketat, sehingga diperlukan penggunaan alat ukur yang tepat dan parameter verifikasi yang sesuai.

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Advanced technology, such as Volumetric Modulation Arc Therapy (VMAT), can enhance the precision and accuracy of radiotherapy treatment. However, the reliability of the dose distribution during planning and measurement, the VMAT technique's gantry arc orientation selection, and multileaf collimator (MLC) movement need to be verified. This study aims to evaluate partial arc and full arc VMAT radiotherapy doses, utilizing the target structure provided by the American Association of Physicists in Medicine (AAPM) TG 119 protocol and verified using the AAPM TG 218 protocol. A CT Simulator scanned the phantom, and the scan results were integrated into the Treatment Planning System (TPS) for VMAT technique planning with varied gantry arc settings. During irradiation and measurement, the true composite method was employed, with point dose measurements using a CC13 ionization chamber, field-by-field planar dose measurements using EPID, and planar composite doses using a 2D array detector MatriXXFFF. The gamma index criteria employed were 3%/2mm and 2%/2mm. The results indicated that planning a double arc technique yielded superior dose distribution compared to a single arc, owing to increased modulation during optimization. Nevertheless, point dose measurement data exceeded the TPS planning values due to the leakage of the tongue and groove effect during measurement. While the field-by-field gamma pass rate met the 3%/2mm criteria, it did not suffice for composite irradiation. Furthermore, there was a further decrease in the gamma pass rate for the 2%/2mm criterion. The universally obtained confidence limit failed to meet the criteria, revealing inconsistencies between the planning dose and the dose measurement results, as recommended by AAPM TG 119 and AAPM TG 218. The evaluation of VMAT doses with gantry arc variations using true composite demonstrated that certain measurement methods did not align with the chosen measuring instrument, and the gamma index criteria proved excessively stringent. Therefore, using appropriate measuring instruments and verification parameters is crucial."