Cálculo de la barrera de transmisión primaria en el bunker del acelerador lineal para haces de energías de fotones sin filtro aplanador en el Instituto del cáncer SOLCA núcleo de Cuenca enero 2024 - junio 2024

Abstract

Background: Medical linear accelerators can generate flattening filter (FF) and non-flattening filter (FFF) photon beams. Current consensus indicates that FFF beams have lower primary barrier transmission than FF beams. Objective: To determine the primary transmission barrier, B, in the bunker of the linear accelerator H192678 from the Instituto del Cáncer Solca Núcleo de Cuenca, for high- energy photon beams with flattening filter of 06MV and 10 MVand also for high-energy beams without flattening filter of 06 FFF and 10 FFF. Methodology: A descriptive study of primary transmission barriers was conducted by measuring the instantaneous air kerma rate, 𝐾 ̇ 𝑎 . Three barriers were analyzed: upper floor bordering the warehouse (BB), exterior side wall (BE) and dressing room side wall (BV). Results: For 06 MV, the transmissions −7 −8 (BE), and 5.242×10 −9 −8 −8 (BE), and .001×10 −9 −6 (BB), 3.735×10 (BB), 2.305×10 (BB), 7.222×10 −7 −7 (BE), and 5.196×10 (BV). For 06 FFF, the transmissions (BV). For 10 MV, the transmissions (BV). For 10 FFF, the transmissions were 1.506×10 were 9.938×10 were 1.487×10 were 9.929×10 −7 (BB), 5.503×10 −7 −7 (BE), and 3.540×10 (BV). The 𝐵𝐹𝐹𝐹 /𝐵𝐹𝐹 ratios were less than 1 for all barriers and energies except for the BV barrier at 06 MV. The percentage differences between the estimated 𝑇𝑉𝐿𝐹𝐹𝐹 and 𝑇𝑉𝐿𝑒 (NCRP No. 151) were less than 6.3%. Conclusion: It was concluded that the FFF beam modality requires less shielding