Sonderheft Spekula Abstracts 2006 - Dr. Harald Lass - Die Frau im ...

24. Jahrgang, Sonderheft 1/2006local control, without increasing late side effects.Clinical results of two patient cohorts are analysedtreated at Vienna University within the same clinicalsetting, in two consecutive time periods withevolving approaches in MRI assisted treatmentplanning and performance.Material and Methods: The study includes 145 consecutivecervical cancer patients (median age 60 yrs[26–92]) who received definitive radiotherapy (45Gy EBT) ± weekly cis-platin based chemotherapy(40 mg/m 2 ) at Medical University of Vienna from1998–2003. FIGO stage distribution was: I = 14, II= 87, III = 37, IVA = 7. In 78 patients tumour sizewas larger than 5 cm. Brachytherapy was intracavitaryin 116 pts and intracavitary + interstitial in 29pts. A dose of 4 × 7 Gy was prescribed to point A from1998–2000 (group A: 73 pts.) and to a High Risk-CTV (Haie-Meder et al. R & O 2005) from 2001–2003 (group B: 72 pts.), respectively, correspondingto 84 Gy EQD2 (α/β 10). MRI assisted treatmentplanning was carried out in all patients, 1–2 out of4 fractions in group A, all fractions in group B. Ingroup B, systematic individualised MRI based treatmentplanning was performed for each fraction,with contouring of GTV, HR-CTV, bladder, sigma,and rectum and prospective evaluation of dose volumeparameters for HR-CTV (D90, D100) and organsat risk (0.1/1/2 cc), using the linear-quadraticmodel. In group A, no systematic MRI based planningwas carried out because of missing comprehensiveconcepts for target contouring, DVH analysis,and biological modelling. Late adverse side effectswere evaluated according to LENT-SOMAscore. Median follow up for surviving patients was39 months. Kaplan-Meier method and log-rank testwas used for statistical analysis.Results: Complete response at 3 months after treatmentbased on MRI and clinical findings wasachieved in 138 out of 145 pts (95%). After median39 months follow up, 15 recurrences were observedwithin the true pelvis: group A 11 local recurrences(LR), group B 4 LR. Actuarial 3 yrs continuous completeremission (CCR) rate was 88 % (total 15 LR),actuarial local control (LC) rate 85 % (total 22 LR)(Table 2). Overall, 8 late genitourinary and digestivegrade 3 and 4 adverse late side effects wereobserved, 6 in group A and 2 in group B.Conclusion: The clinical results of two approacheswith evolving concepts in MRI based treatmentplanning and performance supported by growingclinical experience indicate the following: Systematicindividualised MRI assisted treatment planningincluding GTV and HR CTV contouring, DVHanalysis and biological modelling with additionalinterstitial brachytherapy in advanced disease improveswithin an experienced clinical setting significantlylocal CCR in cervix cancer, while the rateof late adverse side effects remains small. Withouta systematic approach no significant improvementwas achieved during the “learning period” by usingMRI. Evaluation of results with regard to dose-volume-effectsand survival parameters are needed tofurther explore the potential of 3D MRI based gynaecologicalbrachytherapy.Table 2. Dimopoulos J et al. Actuarial continuouscomplete remission rate at 3 years and absolute totalnumber of local recurrences (LR)Tumor size Vienna Group A: Group B:93–97* 98–00 01–03(n = 189) (n = 73) (n = 72)Overall (LR) 78 % (25) 83 % (11) 95 % (4)< 5 cm (LR) 90 % (4) 96 % (1) 100 % (0)≥ 5 cm (LR) 67 % (21) 72 % (10 ) 91 % (4)*Pötter et al. Cancer Radioth 200040