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1. NI LARASATI KS, S.Pd, M.Si
BRAKHITERAPI

8. INTRACAVITY

9. INTERSTITIAL

14. SURFACE PLAQUE

15. INTRALUMINAL

16. INTRAOPERATIVE

17. INTRAVASCULAR

18. APPLICATOR

31. Brachytherapy Treatment
Planning
 In contrast to external beam radiotherapy, the
treatment planning procedure in brachytherapy
includes an additional and specific component,
namely the identification and reconstruction of the
radiation emitters, the radioactive sources for
permanent implants itself, or of the catheters and
applicators used for brachytherapy applications.
 This means that although the dosimetric
properties and kernels of the sources used are
known, their actual position in the patients body
has to be firstly defined/reconstructed.

32. Brachytherapy Treatment
Planning
 The brachytherapy treatment planning procedure
consists generally of the following steps:
 Definition of the planning target volume (PTV) and
organs at risk (OARs)
 Reconstruction of the implanted sources or
catheters and applicators
 Calculation and optimization of the dose distribution
 Evaluation of the dose distribution
 All components above can be approached using
2D representations or using 3D imaging
techniques

33. Treatment Planning 2D
 Projectional imaging methods, such as X-ray fl
uoroscopy or radiographs, are used for verifying and
documenting the placement of usually a single
catheter or applicator.
 The treatment delivery itself is then based on
preexisting standard plans with isodose distribution
documentation.
 Due to the rigidity of such kind of applicators, the
main item/challenge here is to check the correct
placement of the catheter in the patient.
 The 2D treatment planning procedure is mainly
applicator oriented/based.
 When the placement of the applicator is validated
using simple X-rays and is found to be at the
adequate position, then the dose delivery to the
anatomy around the applicator can be assumed as
appropriate for such kind of simple geometries and

34. Treatment Planning 3D
 The target and organ at risk localization as well
as the catheter reconstruction are based on 3D
methods using modern imaging modalities.
 The same is valid for the dose calculation and
evaluation.
 A common procedure, at least in the past for
gynaecological and other intracavitary
applications, was based on two or more X-ray fi
lms, which are mainly used for the 3D
reconstruction of the used catheters or
applicators.
 This method of reconstruction is called
projectional reconstruction method

39. Dose Calculation (TG-43)
 Dose rate at point P:

40. Dose Calculation
 Air Kerma Strength (Sk):

41. Dose Calculation
 Dose rate constant:

42. Dose Calculation
 Geomteri function:

43. Dose Calculation

44. Dose Evaluation
 Seperti External Beam Therapy, evaluasi dosis
menggunakan kurva isodosis/DVH

62. Luas (cm2) pinggir Daerah bidang
< 25 2/3 1/3
25 – 100 1/2 1/2
> 100 1/3 2/3
Proporsi relatif kekuatan sumber total yang diletakkan
pada pinggir dan daerah implantasi planar (sistem
Manchester)

63.  Tabel Paterson-Parker digunakan untuk
menentukan waktu implant.
 Tabel digunakan pada preimplant untuk
menentukan aktivitas total yang dibutuhkan untuk
memberikan dosis preskripsi dalam waktu yang
ditentukan dan untuk luas daerah tertentu.
 Selanjutnya setelah implantasi dan pengukuran
luas implantasi, table digunakan untuk
menentukan waktu perlakuan.

79. KISI-KISI
 Menghitung MU
 Membuat treatment planning 3D CRT
 Istilah dalam brakhiterapi
 Dvh dan homogenity index
 Karakteristik terapi elektron
 Open note dan boleh menggunakan kalkulator
 Tabel PDD, TMR, OF, print sendiri