 |
 |
||
 |
|
||
 |
|
 |
|
 |
|||
|
|
 |
|
 |
 |
|---|
| |||||||||||||||||||
|
Report from the first UK centre to use Co-60 for HDR treatments Portsmouth Hospitals NHS Trust, UK, have now been using the IBt Bebig HDR Multisource unit ( supplied via SeeDOS Ltd ) with a Co-60 source for over four months, having previously used the treatment unit with Ir-192 for a year.
Recent brochures : Please click here for the Latest HDR MultiSource Applicators & Accessories Brochure Please click here for the Latest HDRplus Software Brochure Recent posters include : ASTRO :
"Does the choice of isotope,Co-60 or Ir-192, effect treatment planning
techniques and outcomes for high dose rate (HDR ) brachytherapy ?". Palmer A,
Mzenda B, Hayman O, Nagar Y, Queen Alexandra Hospital, Portsmouth Hospitals NHS
Trust, UK. Please click here for a copy in pdf format. Following a comprehensive commissioning programme and a number of studies comparing Co-60 with the more conventional Ir-192 source, Portsmouth are very happy with their choice of both isotope and HDR equipment. The physicists and clinicians at Portsmouth are currently preparing a journal manuscript to report on their experiences using Co-60, but a preview of some results is presented below and in the above linked posters. The long half-life of Co-60 compared to Ir-192 has economic and practical benefits, but it is important to consider the affect of the higher energy of Co-60 on treatment planning approaches. Figure 1 gives result from one patient in a comparative study between Co-60 and Ir-192 in gynaecological brachytherapy.
Fig 1. Percentage difference in dose distribution between Co-60 and Ir-192 sources with the IBt-Bebig HDR MultiSource® brachytherapy unit, in sagittal plane, for a typical 3 channel gynaecological treatment prescribed to ICRU Point A. Colour wash shows the +2% to -2% difference range. The applicator outlines of the HR-CTV and OARs are shown. In general, Co-60 delivers higher doses within the HR-CTV and lower doses to the organs at risk, except along the extension of the source axis: most clearly seen as elongated higher dose regions in the sagittal view. Evaluation of doses to OARs across the range of treatment plans showed that the choice of prescription technique and the optimisation parameters used were more significant than the physical differences between the two isotopes, with HR-CTV D90 being near-identical in all cases. The physical differences in dose distribution around the IBt-Bebig Co-60 and Ir-192 sources have a negligible effect on the resulting clinical treatment plan quality parameters, especially when dwell optimisation via inverse planning techniques is used. However, Co-60 will deliver higher doses than Ir-192 along the extension of the IUT due to anisotropy differences, > 10% at 5cm distal to the applicator. Significant cost savings may be achieved with Co-60 since source replacements are required every 4-5 years compared to Ir-192 where new sources are needed every 3-4 months. Equipment down-time and physics support time is also reduced by around 40% with Co-60 in comparison to Ir-192. Over 60 treatments have now been performed using the IBt-Bebig HDR Multisource at Portsmouth, UK; approximately half of these were treated with an Ir-192 source before moving to a Co60 source. Further information may be obtained from Tony Palmer: antony.palmer@porthosp.nhs.uk Please contact cwalters@seedos.com for a quotation or more detailed Product Specifications of the HDR MultiSource System including the HDRplus treatment planning software and HDR MultiSource Applicators. |
| ||||||||||||||||||||||||||||||||
