Technological advances in Brachytherapy Ekkasit Tharavichitkul, MD The 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 Brachytherapy Developments in BT • • • • • Source and loading methods Imaging developments Applicator developments Planning developments Clinical research developments Source and loading method Radioisotope sources and loading methods • From Radium --- Iridium • From LDR --- HDR --- PDR • From manual loading to remote afterloading Radium--Iridium Manual and remote loading LDR vs. HDR พารามิเตอร ์ LDR HDR < 2 Gy/ชวั่ โมง >12 Gy/ชวั่ โมง + - +++ + Unexpect shift of applicators + - Ward + - Number of patient per day 1 มากกว่า 1 ราย Time for loading ชัว ่ โมง นาที Cost of machine + +++ Dose rate Problem of radiation hazard Discomfort • 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 Imaging Imaging developments • Modern imagingtechniques: -US, CT, MRI • 3D dosimetry -More accurate dose distribution -DVH relation to outcome for target + OAR X-ray base Ultrasound guidance U/S guidance Applicators Applicator developments • More compatible with imaging • CT/MR applicator • Gynecological cancers • Plastic catheter • Breast cancer • Prostate cancer Standard applicators Nucletron.com Scatter; metallic applicator CT/Applicator Breast BT mammosite Multicatheter Clearpath Polgar, 2009 Volume concepts 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 Ultrasound CTV prostate GEC-ESTRO handbook,2002 Target volume: HDR Volume concepts of cervix CHM, 2005 Diagram of CTVs •HR-CTV •Bladder •Rectum •Sigmoid D90 HR-CTV D2cc B D2cc R D2cc S Chiang Mai Breast cancer Polgar, 2009 Planning developments 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 studies Cervix Breast BT Polgar, 2009 Clinical studies EVL, Estro course 2008 Toxicity profile Niehoff Clinical developments All RCTs NSABP B-39/RTOG 0413 (4800 pts enrolled) WBI 50 Gy plus boost to 60-66 Gy versus Multicatheter (34Gy)/Mammosite(34 Gy) /3DCRT(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 Our research:MRI From Feb 2009- nowadays Planned 14 pts will be enrolled MRI guided treatment: Dx, 1st BT, after treatment With GEC-ESTRO recommendations Now 6 patients finished Pending results