Comments on: Medical Event Criteria in Prostate Seed Implant / Prostate Brachytherapy http://www.mdphysics.com/medical-event-criteria-in-prostate-seed-implant-prostate-brachytherapy/ A weblog for and by the medical physics community Fri, 28 Oct 2011 02:49:26 -0600 http://wordpress.org/?v=2.8.6 hourly 1 By: Ronald Scala http://www.mdphysics.com/medical-event-criteria-in-prostate-seed-implant-prostate-brachytherapy/comment-page-1/#comment-517 Ronald Scala Tue, 16 Mar 2010 18:37:14 +0000 http://www.mdphysics.com/?p=625#comment-517 I do not agree with many criteria listed above. The D90 criteria sounds rational but you must keep in mind that the pre-implant plan can never be exactly duplicated at implant. Hence the possibility that irreversible seed placement could be such that the dose is outside this criteria. I do not feel that this is a ME if the physician has done his/her best to comply with the plan. The 0.5Sv and 50% criteria are also problematic. Radiation therapy cannot be delivered w/o dose to adjacent tissues. The skin receives more than 0.5Sv in Ext Beam but is not considered a ME. This criteria is only intended for dose delivery mistakes that cause organ irradiation to 0.5Sv above what is expected or otherwise unavoidable. Likewise with the 50% criteria. Seed placement is cannot be exact enough to ensure a "tissue" will not receive 50% more than the pretreatment plan showed. Last, three seeds in the bladder wall is in no way a meaningful criteria since seed dislodging is not a always or often the result of incorrect seed placement. R Scala, MS I do not agree with many criteria listed above.
The D90 criteria sounds rational but you must keep in mind that the pre-implant plan can never be exactly duplicated at implant. Hence the possibility that irreversible seed placement could be such that the dose is outside this criteria. I do not feel that this is a ME if the physician has done his/her best to comply with the plan. The 0.5Sv and 50% criteria are also problematic. Radiation therapy cannot be delivered w/o dose to adjacent tissues. The skin receives more than 0.5Sv in Ext Beam but is not considered a ME. This criteria is only intended for dose delivery mistakes that cause organ irradiation to 0.5Sv above what is expected or otherwise unavoidable. Likewise with the 50% criteria. Seed placement is cannot be exact enough to ensure a “tissue” will not receive 50% more than the pretreatment plan showed. Last, three seeds in the bladder wall is in no way a meaningful criteria since seed dislodging is not a always or often the result of incorrect seed placement.

R Scala, MS

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