Evaluasi Fungsi Optimasi Radiobiologi (gEUD, TCP, NTCP) pada Kasus Nasofaring dengan Teknik IMRT Menggunakan Fantom Kepala-Leher

Budi Rahayu, Rizki (2026) Evaluasi Fungsi Optimasi Radiobiologi (gEUD, TCP, NTCP) pada Kasus Nasofaring dengan Teknik IMRT Menggunakan Fantom Kepala-Leher. Masters thesis, Institut Teknologi Sepuluh Nopember.

	Text 6001241002-Master_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (6MB) | Request a copy
	Text Close access.PDF - Other Restricted to Repository staff only Download (361kB) | Request a copy

Abstract

Perencanaan radioterapi kanker nasofaring memerlukan keseimbangan antara cakupan dosis pada volume target dan proteksi organ berisiko, yang dapat ditingkatkan melalui fungsi optimasi radiobiologi berbasis generalized Equivalent Uniform Dose (gEUD) dengan parameter sensitivitas biologis jaringan (k). Penelitian ini bertujuan mengetahui nilai k yang terbaik untuk distribusi dosis organ, Tumor Control Probability (TCP) dan Normal Tissue Complication Probability (NTCP), serta mengevaluasi kelayakan rencana radioterapi melalui Pre-treatment Specific Quality Assurance (PSQA). Objek yang digunakan adalah tiga fantom kepala dan leher dengan volume tumor yang berbeda 29,96 cm3 (ID1), 56,16 cm3 (ID2), dan 75,37 cm3 (ID3). Perencanaan radioterapi menggunakan Treatment Planning System (TPS) Monaco dengan teknik IMRT. Perencanaan yang dibuat menggunakan variasi nilai k berdasarkan jenis organ, untuk parotis k = 1, 3, 6, dan 9, sedangkan untuk batang otak dan sumsum tulang belakang menggunakan k = 12, 15, 18, dan 20. Hasil penelitian menunjukkan bahwa peningkatan nilai k cenderung menurunkan dosis pada organ berisiko (parotis, batang otak, dan sumsum tulang belakang) tanpa mengganggu cakupan organ target (PTV). Untuk parotis, nilai k terbaik diperoleh sebesar 1, sedangkan untuk batang otak dan sumsum tulang belakang diperoleh nilai k sebesar 18 dan 20. Selanjutnya, dalam penelitian ini menggunakan tiga perencanaan, yaitu Plan0 tanpa optimasi (k = 0), Plan1 (k = 18), dan Plan2 (k = 20). Sebelum penyinaran, dilakukan uji PSQA dengan kriteria gamma sebesar 3%/3mm, 3%/2mm, dan 2%/2mm. Hasil optimasi radiobiologi yang didapat menunjukkan bahwa pasien ID2 dan ID3 memenuhi seluruh kriteria PSQA untuk Plan0, Plan1 dan Plan2, sementara untuk pasien ID1 memenuhi seluruh kriteria PSQA hanya untuk Plan0 dan Plan2. Fungsi optimasi radiobiologi berbasis gEUD mampu meningkatkan kualitas perencanaan radioterapi IMRT, yang ditunjukkan nilai TCP mencapai 100% dan NTCP mendekati 0% untuk seluruh OAR pada Plan1 dan Plan2. Hasil uji PSQA menunjukkan bahwa kelayakan penyampaian dosis dipengaruhi oleh kompleksitas organ PTV berdekatan dengan batang otak dan sumsum tulang belakang, sehingga pemilihan nilai k perlu mempertimbangkan keseimbangan antara keuntungan radiobiologis dan aspek klinis.
==================================================================================================================================
Planning radiotherapy for nasopharyngeal cancer requires a balance between dose coverage in the target volume and protection of organs at risk, which can be improved through radiobiological optimization based on generalized equivalent uniform dose (gEUD) with tissue biological sensitivity (k) parameters. This study aimed to determine the best k value for organ dose distribution, Tumor Control Probability (TCP), and Normal Tissue Complication Probability (NTCP), as well as to evaluate the feasibility of radiotherapy plans through pre-treatment or patient specific quality assurance (PSQA). This study was conducted using three head and neck phantoms with different tumor volumes of 29.96 cm3 (ID1), 56.16 cm3 (ID2), and 75.37 cm3 (ID3). Radiotherapy planning was performed using TPS Monaco with IMRT technique. The planning was made using variations in k values based on organ type, for the parotid glands k = 1, 3, 6, and 9, while for the brainstem and spinalcord k = 12, 15, 18, and 20. The results showed that increasing the k value tended to reduce the dose to organs at risk (parotid gland, brainstem, and spinalcord) without compromising the coverage of the target organ (PTV). For the parotid gland, the best k value was 1, while for the brainstem and spinalcord, were 18 and 20, respectively. Furthermore, this study used three plans, namely Plan0 without optimization (k = 0), Plan1 (k = 18), and Plan2 (k = 20). Before irradiation, PSQA was performed with gamma criteria of 3%/3mm, 3%/2mm, and 2%/2mm. The radiobiological optimization results obtained show that patients ID2 and ID3 conform all PSQA criteria for Plan0, Plan1, and Plan2, while patient ID1 conform all PSQA criteria only for Plan0 and Plan2. Thus, the gEUD-based radiobiological optimization function is capable of improving the quality of IMRT radiotherapy planning, as demonstrated by a TCP value of 100% and an NTCP value close to 0% for all OARs in Plan1 and Plan2. The PSQA results show that the feasibility of dose delivery is still influenced by the complexity of the PTV organs adjacent to the brainstem and spinalcord, so that the selection of the k value needs to consider the balance between radiobiological benefits and clinical aspects.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Kata kunci: generalized Equivalent Uniform Dose (gEUD), Normal Tissue Complication Probability (NTCP), Pre-treatment specific quality assurance (PSQA), Radioterapi, Tumor Control Probability (TCP). Key word: generalized Equivalent Uniform Dose (gEUD), Normal Tissue Complication Probability (NTCP), Pre-treatment specific quality assurance (PSQA), Radiotherapy, Tumor Control Probability (TCP).
Subjects:	Q Science > QC Physics Q Science > QC Physics > QC795.5 Radioactivity and radioactive Instruments and apparatus (General)
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Physics > 45101-(S2) Master Thesis
Depositing User:	Rizki Budi Rahayu
Date Deposited:	04 Feb 2026 06:32
Last Modified:	04 Feb 2026 06:32
URI:	http://repository.its.ac.id/id/eprint/131995

Actions (login required)

View Item