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Brachyterapy for cancer of the cervix 3D Dose distributions for new ring applicator using BrachyVision, for clinical use

Holmgren-Andersson, Marita (2006)
Medical Physics Programme
Abstract (Swedish)
Curative radiotherapy for cancer of the cervix consists of a combination of extern beam radiotherapy (EBRT) and brachytherapy (BT). The most important prognostic factors are tumour size, tumour extension and lymph node involvement.Traditional dose planning for BT of cervix cancer is based on two orthogonal films with the applicators in place in cervix. The dose distribution is related to the applicator geometry. The target volume consists of the tumour in the cervix, the cervix, part of the vaginal mucosa, part of the corpus and the parimetria. The whole target volume should be inside the specification isodose surface. The critical organs considered are the bladder and the rectum.The doses to organs-at-risk are calculated at reference... (More)
Curative radiotherapy for cancer of the cervix consists of a combination of extern beam radiotherapy (EBRT) and brachytherapy (BT). The most important prognostic factors are tumour size, tumour extension and lymph node involvement.Traditional dose planning for BT of cervix cancer is based on two orthogonal films with the applicators in place in cervix. The dose distribution is related to the applicator geometry. The target volume consists of the tumour in the cervix, the cervix, part of the vaginal mucosa, part of the corpus and the parimetria. The whole target volume should be inside the specification isodose surface. The critical organs considered are the bladder and the rectum.The doses to organs-at-risk are calculated at reference points based on the orthogonal films. If the total dose is too high, the BT dose is often lowered the last fraction. With the new 3D treatment planning system BrachyVision, together with new CT and MR compatible ring applicators, we can use 3D CT- and MR-images as a base for the treatment planning. We can see patient anatomy together with the applicators in the cervix, and thus optimize the BT dose distribution to the actual patient geometry.The tumour itself can not be defined with CT alone. Thus, with treatment plans based on CT, a predefined standard dose distribution for the applicator used can be adapted to minimize the dose to the organs-at-risk and still cover the target defined above in words.With accesses to MR images with applicators in place we can define both the tumour, the target and the organ-at-risk and optimize the dose to the target while minimizing the dose to the risk organs. In this paper we have studied and verified the geometry, for the new ring applicators. We have also evaluated some standard plans, to be used and adapted in CT- and MR- based brachytherapy. The rings are now ready to use in the clinic, starting with the Lund old method, follow by CT-based treatments. (Less)
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author
Holmgren-Andersson, Marita
supervisor
organization
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Strålterapi
language
English
id
2156980
date added to LUP
2011-09-13 15:10:35
date last changed
2011-09-13 15:10:35
@misc{2156980,
  abstract     = {Curative radiotherapy for cancer of the cervix consists of a combination of extern beam radiotherapy (EBRT) and brachytherapy (BT). The most important prognostic factors are tumour size, tumour extension and lymph node involvement.Traditional dose planning for BT of cervix cancer is based on two orthogonal films with the applicators in place in cervix. The dose distribution is related to the applicator geometry. The target volume consists of the tumour in the cervix, the cervix, part of the vaginal mucosa, part of the corpus and the parimetria. The whole target volume should be inside the specification isodose surface. The critical organs considered are the bladder and the rectum.The doses to organs-at-risk are calculated at reference points based on the orthogonal films. If the total dose is too high, the BT dose is often lowered the last fraction. With the new 3D treatment planning system BrachyVision, together with new CT and MR compatible ring applicators, we can use 3D CT- and MR-images as a base for the treatment planning.  We can see patient anatomy together with the applicators in the cervix, and thus optimize the BT dose distribution to the actual patient geometry.The tumour itself can not be defined with CT alone. Thus, with treatment plans based on CT, a predefined standard dose distribution for the applicator used can be adapted to minimize the dose to the organs-at-risk and still cover the target defined above in words.With accesses to MR images with applicators in place we can define both the tumour, the target and the organ-at-risk and optimize the dose to the target while minimizing the dose to the risk organs. In this paper we have studied and verified the geometry, for the new ring applicators. We have also evaluated some standard plans, to be used and adapted in CT- and MR- based brachytherapy. The rings are now ready to use in the clinic, starting with the Lund old method, follow by CT-based treatments.},
  author       = {Holmgren-Andersson, Marita},
  keyword      = {Strålterapi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Brachyterapy for cancer of the cervix 3D Dose distributions for new ring applicator using BrachyVision, for clinical use},
  year         = {2006},
}