1. IMPACT OF PHYSICAL DOSE RATE EFFECT ON THE LONG TERM RESULTS OF THE CF-252 BRACHYTHERAPY OF CERVIX CARCINOMA E. Janulionis; K.P.Valuckas; V.Atkocius; V.Samerdokiene Institute of Oncology, Vilnius University, Lithuania 2011-04-17-21, Porto Alegre, Brazil

3. PURPOSE EVALUATE EFFECT OF Cf-252 DOSE RATE ON THE LONG TERM CLINICAL RESULTS AFTER COMBINED RADIATION THERAPY FOR STAGE IIB AND IIIB OF CERVIX UTERI CARCINOMA

4. PATIENTS 1994-1999 Ca cervicis uteri, IIB and IIIB 342 PTS TREATED BY EBRT ( 60 Co) + 252 Cf BRACHYTHERAPY No chemotherapy

7. CALCULATION OF THE DOSES FROM 252Cf SOURCES (J.S. Rjabukin, 1985)

9. MOST FREQUENTLY USED 252Cf BRACHY REGIMEN 5 x 8 iGy=40iGy 5 x (1,32÷1,44) neutron Gy + 5 x (0,88÷0,96) gamma Gy 6,6÷7,2 neutron Gy + 4,4÷4,8 gamma Gy

10. PATIENTS BY YEAR AND STAGE Year FIGO Total IIBIIIB 1994253762 1995225375 1996234871 1997206787 199872734 19995813 Total102240342

11. 252 Cf BRACHYTHERAPY BY FRACTIONATION FIGO Total IIBIIIB 5-6 x 8 iGy9090223223313 5 x 9 iGy8161624 4x 10 iGy415 Total102240342

12. IRRADIATION TIME AND PHYSICAL DOSE RATE YEAR FRACTION DOSE, iGy PHYSICAL DOSE neutron+gamma, Gy IRRADIATION TIME, h PHYSICAL DOSE RATE AT POINT A, Gy/h 1994.018iGy 2,2-2,4 0,5-0,73,7-4,8 1997.018iGy12,2 1999.128iGy1,6-2,01,2-1,4

13. LATE COMPLICATIONS, IIB + IIIB, % (GRADE 2-3) IIBIIIBIIB + IIIB CYSTITIS8.48.78.6 PROCTITIS2.12.62.5 TOTAL10.511.311.1

14. LATE COMPLICATIONS (CYSTITIS + PROCTITIS), IIB + IIIB, 1994-1996 vs. 1997-1999 1994-19961997-1999 22+8=306+0=6 14,4%5,2% Statisticaly significant higher late complications rate in 1994-1996 Exact Sig. (2 sided) Fisher's Exact Test0.010

15. SIGNIFICANCE OF SURVIVAL IIB 1994, 1995, 1996, 1997, 1998, 1999 no significance Sig. Log Rank (Mantel-Cox)0.518 Breslow (Generalized Wilcoxon) 0.422 Tarone-Ware0.462 1994-1996 vs. 1997-1999 no significance Sig. Log Rank (Mantel-Cox)0.921 Breslow (Generalized Wilcoxon) 0.918 Tarone-Ware0.914 yr months yr months

16. SIGNIFICANCE OF SURVIVAL IIIB 1994, 1995, 1996, 1997, 1998, 1999 no significance Sig. Log Rank (Mantel-Cox)0.086 Breslow (Generalized Wilcoxon) 0.141 Tarone-Ware0.109 1994-1996 vs. 1997-1999 statisticaly significant higher survival in 1997-1999 Sig. Log Rank (Mantel-Cox)0.035 Breslow (Generalized Wilcoxon) 0.053 Tarone-Ware0.042 yr months yr months

17. CONCLUSIONS  During period 1994-1999 342 pts with Ca cervicis uteri received combined RT: EBRT( 60 Co) + Brachytherapy ( 252 Cf)  The brachytherapy physical dose rate (or irradiation time) changed about 4-fold  The overall survival rate was the same for each year of treatment  The statistically significant difference was found for survival of stage IIIB and late complications (1994-1996 vs 1997-1999)  There was not found clinical proof of the Cf-252 dose rate effect on overall survival

19. Thank you for attention