RESUMEN
PURPOSE: The present study aimed to analyze the operative duration of image-guided brachytherapy (IGBT) for cervical cancer performed at our institution. METHODS: We enrolled cervical cancer patients who had undergone tandem and ovoid-based intracavitary brachytherapy (ICBT) or intracavitary and interstitial brachytherapy (IC/ISBT) between 2020 and 2024. Cone beam computed tomography (CBCT), CT, or CTâ¯+ MRI were used for IGBT. For each IGBT session, we retrospectively reviewed the following: application time (AT-defined as the duration from entry into the operating room to the initial image acquisition); planning time (PT-defined as the duration from the initial image acquisition to the start of irradiation); and total operation time (TOT- defined as the duration from entry to exit of the operating room). RESULTS: We analyzed a total of 126 sessions in 36 patients, consisting of 99 ICBT-only sessions and 27 IC/ISBT sessions. The IC/ISBT sessions had a significantly longer mean operative duration than the ICBT-only sessions. The IC/ISBT sessions with three or more interstitial needles had significantly longer AT and TOT. However, the IC/ISBT sessions with one needle showed no significant difference in operative duration compared to ICBT-only sessions. CBCT, CT, and CTâ¯+ MRI were used in 42, 76, and 8 sessions, respectively. In the ICBT patients, CTâ¯+ MRI had the longest PT. However, there was no significant differences in TOT among CBCT, CT, and CTâ¯+ MRI. CONCLUSIONS: IC/ISBT sessions with one needle had no significant difference in operative duration compared to ICBT-only sessions. There was no significant difference in TOT between CTâ¯+ MRI-based IGBT and CT-based IGBT.
RESUMEN
The sounding mechanism of a recorder-like air-jet instrument at low Strouhal number is numerically investigated by three-dimensional direct aeroacoustic simulation and acoustic simulation. Howe's energy corollary is applied to estimate the acoustic energy generation and absorption induced by an oscillating jet and vortex shedding. The quantitative results show that the main acoustic energy generation occurs in the jet downstream, and the absorption occurs in the jet upstream. It is found that the region defined by the Q-criterion identifies the main acoustic energy generation (absorption) region in the downstream (upstream) region of the jet. The results indicate that the vortex shedding mainly induced by the jet deflection gives additional contributions to the acoustic energy absorption. The shed vortices affect the temporal structure of the acoustic energy transfer, in particular, the timing of the double peaks with respect to the jet displacement. If we focus only on the air-jet, the dominant peak is observed when the jet crosses the edge from the inside to the outside of the pipe, as reported in previous experimental works. However, when we include the contributions of shed vortices, the dominant peak appears when the jet dives under the edge, which is consistent with the jet-drive model.