Intercomparison of treatment concepts for MR image assisted brachytherapy of cervical carcinoma based on GYN GEC-ESTRO recommendations.
OBJECTIVE
To perform a multicentre intercomparison study of treatment concepts for MRI assisted brachytherapy of cervix cancer based on recommendations of the Gynaecological GEC-ESTRO Working Group.


METHODS
Each participating centre (IGR Paris, University Hospital Leuven, Medical University of Vienna) contributed data of one patient with comparable clinical features. GTV, High Risk CTV (HR CTV), Intermediate Risk CTV (IR CTV) and organ walls of bladder, rectum and sigmoid colon were delineated at the time of each brachytherapy fraction on axial MR images with the applicator in place. Dose-volume histograms were calculated to evaluate doses to tumour, target volumes and organs at risk. Dose values were biologically normalised to equivalent doses in 2 Gy fractions (EQD(2), equivalent to 50 cGy/h low dose rate) applying the linear-quadratic model.


RESULTS
Total doses to point A from external beam therapy plus brachytherapy ranged from 85 to 91 Gy and were close to the dose covering 90% of HR CTV (D90=85-87 Gy). D90 of IR CTV was within 69-73 Gy. Doses to organs at risk were comparable.


CONCLUSIONS
This study indicates the feasibility of the GEC-ESTRO recommendations. Despite different treatment concepts, biologically normalised total doses to tumour, target volumes and organs at risk were comparable.
Lang
Stefan
S
Department of Radiotherapy and Radiobiology, Medical University of Vienna, Austria. stefan.lang@akhwien.at
Nulens
An
A
Briot
Edith
E
Kirisits
Christian
C
De Brabandere
Marisol
M
Dumas
Isabelle
I
Dimopoulos
Johannes
J
Petrow
Peter
P
Georg
Dietmar
D
Van Limbergen
Erik
E
Haie-Meder
Christine
C
Pötter
Richard
R
D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods; D002277:Carcinoma / Q000532:radiotherapy*; D002588:Cesium Radioisotopes / Q000627:therapeutic use; D012809:Colon, Sigmoid / Q000528:radiation effects; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal; D012007:Rectum / Q000528:radiation effects; D012062:Relative Biological Effectiveness; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder / Q000528:radiation effects; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*
D002588:Cesium Radioisotopes; D007496:Iridium Radioisotopes; D019275:Radiopharmaceuticals