Attenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric Fat
High-intensity focused ultrasound (HIFU) is an attractive therapy for kidney cancer, but its efficacy can be limited by heat deposition in the pre-focal tissues, notably in fat around the kidney (peri-nephric fat), the acoustic properties of which have not been well characterized. Measurements of at...
| Main Authors: | , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2013
|
| _version_ | 1826270967037427712 |
|---|---|
| author | Ritchie, R Collin, J Coussios, C Leslie, T |
| author_facet | Ritchie, R Collin, J Coussios, C Leslie, T |
| author_sort | Ritchie, R |
| collection | OXFORD |
| description | High-intensity focused ultrasound (HIFU) is an attractive therapy for kidney cancer, but its efficacy can be limited by heat deposition in the pre-focal tissues, notably in fat around the kidney (peri-nephric fat), the acoustic properties of which have not been well characterized. Measurements of attenuation were made using a modified insertion-loss technique on fresh, unfixed peri-nephric fat obtained from patients undergoing kidney surgery for cancer. The de-focusing effect of changing the position of the fat layers was also investigated using fresh subcutaneous fat from euthanized pigs. The mean attenuation of human peri-nephric fat was found to be 11.9 ± 0.9 Np/m (n= 10) at 0.8 MHz, the frequency typically used for HIFU ablation of kidney tumors, with a frequency dependence of f1.2. A typical 2- to 4-cm thickness of peri-nephric fat would result in a de-rated intensity of 3%-62% at 0.8 MHz compared with a hypothetical patient with no peri-nephric fat. Through the use of freshly excised porcine subcutaneous fat, the presence of fat 100 mm in front of the focus was found to have a de-focusing effect of approximately 1 mm in both transverse directions, which corresponds to a full HIFU beam width off-target. Peri-nephric fat may significantly affect both the intensity and accuracy of HIFU fields used for the ablation of kidney cancer. © 2013 World Federation for Ultrasound in Medicine and Biology. |
| first_indexed | 2024-03-06T21:49:11Z |
| format | Journal article |
| id | oxford-uuid:4aa87242-c89f-47a0-b23b-0e0666d17d0d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T21:49:11Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | oxford-uuid:4aa87242-c89f-47a0-b23b-0e0666d17d0d2022-03-26T15:38:51ZAttenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric FatJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4aa87242-c89f-47a0-b23b-0e0666d17d0dEnglishSymplectic Elements at Oxford2013Ritchie, RCollin, JCoussios, CLeslie, THigh-intensity focused ultrasound (HIFU) is an attractive therapy for kidney cancer, but its efficacy can be limited by heat deposition in the pre-focal tissues, notably in fat around the kidney (peri-nephric fat), the acoustic properties of which have not been well characterized. Measurements of attenuation were made using a modified insertion-loss technique on fresh, unfixed peri-nephric fat obtained from patients undergoing kidney surgery for cancer. The de-focusing effect of changing the position of the fat layers was also investigated using fresh subcutaneous fat from euthanized pigs. The mean attenuation of human peri-nephric fat was found to be 11.9 ± 0.9 Np/m (n= 10) at 0.8 MHz, the frequency typically used for HIFU ablation of kidney tumors, with a frequency dependence of f1.2. A typical 2- to 4-cm thickness of peri-nephric fat would result in a de-rated intensity of 3%-62% at 0.8 MHz compared with a hypothetical patient with no peri-nephric fat. Through the use of freshly excised porcine subcutaneous fat, the presence of fat 100 mm in front of the focus was found to have a de-focusing effect of approximately 1 mm in both transverse directions, which corresponds to a full HIFU beam width off-target. Peri-nephric fat may significantly affect both the intensity and accuracy of HIFU fields used for the ablation of kidney cancer. © 2013 World Federation for Ultrasound in Medicine and Biology. |
| spellingShingle | Ritchie, R Collin, J Coussios, C Leslie, T Attenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric Fat |
| title | Attenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric Fat |
| title_full | Attenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric Fat |
| title_fullStr | Attenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric Fat |
| title_full_unstemmed | Attenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric Fat |
| title_short | Attenuation and De-focusing During High-Intensity Focused Ultrasound Therapy Through Peri-nephric Fat |
| title_sort | attenuation and de focusing during high intensity focused ultrasound therapy through peri nephric fat |
| work_keys_str_mv | AT ritchier attenuationanddefocusingduringhighintensityfocusedultrasoundtherapythroughperinephricfat AT collinj attenuationanddefocusingduringhighintensityfocusedultrasoundtherapythroughperinephricfat AT coussiosc attenuationanddefocusingduringhighintensityfocusedultrasoundtherapythroughperinephricfat AT lesliet attenuationanddefocusingduringhighintensityfocusedultrasoundtherapythroughperinephricfat |