Technological advances in Brachytherapy
Ekkasit Tharavichitkul, MDThe Division of Therapeutic Radiology
and Oncology, Faculty of Medicine, Chiang Mai University
History
• Greek word = short
–Interstitial brachytherapy
–Contact brachytherapy→ surface mould BT→ intracavitary BT→ endolumina BT
Brachytherapy history
• 1896: Becquerel• 1898: MarieSklodowska-Curie• 1901: Danlosand Block: Paris• 1905Abbe: US Radium implantations
• Different empirical methods and rules•Stockholm method for Gyne (1914)
•Paris method for Gyne (1919)
•Manchester system (1934) Paterson-Parker, Meredith
•Paris System for IS : Pierquin, Chassagne, Dutreix
• Discovery of artificial radioactive isotopes
• 1934 Irene Curie -FrédericJoliot
• 1958 Iridium-I92: U. Henschke• Development of afterloading concept
• 1958 -65 U. Henschke-D. Chassagne• Developmentof 3D dosimetry and fundamental rules of
dosimetry
• 1965 B. Pierquin-D. Chassagne-A. Dutreix
Developments in BT
• Source and loading methods• Imaging developments• Applicator developments• Planning developments• Clinical research developments
Radioisotope sources and loading methods
• From Radium --- Iridium • From LDR --- HDR --- PDR• From manual loading to remote after-
loading
LDR vs. HDR
พารามิ�เตอร LDR HDR
Dose rate < 2 Gy/ชั่��วโมิง >12 Gy/ชั่��วโมิงProblem of radiation hazard
+ -
Discomfort +++ +
Unexpect shift of applicators
+ -
Ward + -
Number of patient per day
1 มิากกว�า 1 ราย
Time for loading ชั่��วโมิง นาที�
Cost of machine + +++
• Manual or remote control afterloading– Gynecological applicators– Guide needles: straight and curved– Plastic tubes– Moulds– Hypodermic needles– Silk wires– Endo-luminal catheters
• Remote control afterloaders
• Modern imagingtechniques:
-US, CT, MRI
• 3D dosimetry-More accurate dose distribution-DVH relation to outcome for target + OAR
Imaging developments
Applicator developments
• More compatible with imaging• CT/MR applicator
• Gynecological cancers
• Plastic catheter• Breast cancer• Prostate cancer
Volume concepts
• 1985 ICRU 38 :Gynecological brachytherapy• 1997 ICRU 58 :Interstitial and intraluminal brachytherapy• 2000 GEC-ESTRORec: Prostate Permanent Implants• 2001 GEC-ESTRO Rec: Endovascular brachytherapy• 2005 GEC-ESTRORec: Prostate Temporary Implants• 2005 GEC-ESTRORec: 3D-GYNE
Planning developments
• Shifting from 2D to 3D• Target volume definition• Algorithm: AAPM TG43 to Monte Carlo• Inverse planning
• IPSA (Inverse Planning Simulated Annealing)• HIPO (the Hybrid Inverse Planning and
Optimization)
Clinical developments
All RCTsNSABP B-39/RTOG 0413 (4800 pts
enrolled) WBI 50 Gy plus boost to 60-66 Gy versus
Multicatheter (34Gy)/Mammosite(34 Gy) /3D-CRT(38.5Gy)
GEC-ESTRO working group trial (1170 pts enrolled) WBI 50 Gy plus boost 10 Gy versus HDR and
PDR
Pending for results
Conclusions
• Modern brachytherapy which is high Ballistic selectivity and adaptivity is a competitive tool in the multidisciplinary treatment of cancer patients
• A strong collaboration between-Radiation oncologists-Organ specialists-Medical physicists-Radiation technologists
is necessary to obtain optimal results for the patient(s)
Our researches: CT
From July 2008 - Dec 2009 16 pts in CT-based planning in EBRT and BT BT 6.5 Gy x Fx GEC-ESTRO recommendations concepts Image-guided planning (optimized plan) can
reduced the dose to the bladder and sigmoid colon with compromised dose to the target