UCL. Rectum Adenocarcinoma. Quality of conformal radiotherapy Impact for the surgeon P. Scalliet & K. Haustermans

Transcription

1 Rectum Adenocarcinoma Quality of conformal radiotherapy Impact for the surgeon P. Scalliet & K. Haustermans Fifth Belgian Surgical Week May 6th, 2004, Oostende

2 SOR rectum adenocarcinoma Indication of radiotherapy Decreases local relapse by 3/4. A local recurrence is a major threat to QoL. Better anal preservation. Secundary dissemination is prevented. Survival is perhaps improved.

3 Low dose Overall mortality with and without radiotherapy (pre-op or post-op op). (Lancet,, 2001) high dose 0.5 % P = % P = % P = 0.06

4 Effect of RT on risk of isolated local relapse in 11 trials pre-op op. and 7 trials post-op op. subgroup analysis par sous-groupes according tp BED. (Lancet,, 2001)

5 Non-rectal cancer death was increased in RT series (pre- and post-op op). It is thought to be technique dependant (Lancet,, 2001) 51.9 % 43.6 % 2p = % 14.6 % 2p = 0.001

6 Swedish Rectal Cancer Trial Preop RT Surgery P - value Local Failure 12 % 27 % < Yr Survival 58 % 48 % 0.04 NEJM, 1997

7 Analyse critique de la méta-analyse analyse The Swedish trial cannot be considered optimal regarding the surgical technique (and pathology?). Is RT only good enough to compensate for lousy surgery?

8 CKVO TME + RT Trial 5 x 5 Gy TME T1-3 TME * * = postop 50 Gy if margins positive

9 CKVO TME + RT Trial

10 Results of multivariate analysis of local recurrence among the 1748 eligible patients with a macroscopically complete resection (N Eng J Med, 2001, 345: 638) variable Hazard ratio P value (95% CI) Treatment group <0.001 RT + surgery 1.00 < Surgery 3.41 ( ) Distance from 0.03 anal verge cm cm 2.13 ( ) 0.02 Š 5 cm 2.78 ( ) 0.02 TNM stage <0.001 Stage I 1.00 Stage II 3.44 ( ) 0.02 Stage III 9.69 ( ) <0.001 Stage IV 16.2 ( ) <0.001 Type of resection is not a significant parameter

11 CKVO RT + S S p Overall post-op complications 48 % 41 % Blood loss 1100 ml 1000 ml <0.001 Mortality 4 % 3.3 % ns. Median operating 180 min 180 min ns. time Median hospital stay 15 d 14 d ns. Marijnen et al, JCO 2002, 20: 817

12 CKVO TME + RT Trial (update( update) % LF % 4y survival % DM TME RT + TME

13 Early morbidity CKVO patients had to stop preop RT due to neurotoxicity Blood loss 1000 ml (RT-TME) vs 900 ml (TME) (p<0.001) Perineal wound complications 26 % (RT-TME) vs 18 % (TME) (p=0.05)

14 The Lyon experience 13 times 3 Gy Short Interval Long Interval Clinical response 53.1% 71.7% (p= 0.007) Path Downstaging 10.3% 26% (p= 0.005) SphincterSS 68% 76% (p= 0.27) Francois et al, JCO 1999

15 German study: RESULTS Preop CRT Postop CRT At randomisation deemed suitable for APER = 75/313 At randomisation deemed suitable for APER = 74/315 Sphincter sparing procedures = 35% Sphincter sparing procedures = 19% ASTRO 2003

16 Interval between radiation and surgery Repopulation of tumor cells within surgical margins is not relevant Repopulation of tumor cells outside surgical margins is not relevant as any number of surviving clonogens beyond future surgical margins is recurrence from day 0 Downsizing during the interval will make surgery easier WAIT till regression!

17 Selection of patients!

18 Rectum adenocarcinoma : conformal 3D radiotherapy technique (3D-CRT) bladder tumour (CTVt) node (CTVn) margin (PTV) Organ and tumour identification On each CT slice (30-80)

19 Clinical target volume : mesorectum (1)

20 Clinical target volume (2)

21 Clinical target volume (3) 9 10 Site of recurrence ANT POST Le CTV is enlarged toward iliacal nodal drainage CTV is longer posteriorly peritoneum mesorectum

22 rectum adenocarcinoma Small bowel bladder PTV reconstruction 3D Anal canal spared

23 Rectum Adenocarcinoma Critical structure Complication Dose limits Contour 3D Hip Ankylosis 45 Gy Necrosis of femoral head Bladder Radiation cystitis 50 y on 100% 60 Gy on 50% 70 Gy <20% Small bowel Radiation ileitis (*) 50 Gy on 250cc 45 Gy > 250cc Nervous plexus Plexitis (pain, 60 Gy incontinence) Blood vessels Arterial stenosis 60 Gy (*) potentially lethal

24 Rectum adenocarcinoma Megavoltage radiation beams

25 Rectum adenocarcinoma: : 3 or 4 beams beam eye s view Anterior beam Mutlileaf collimator Anal canal and perineal skin are preserved

26 Rectum adenocarcinoma Lateral beam Anal canal is preserved

27 Summary : total mesorectal radiotherapy mesorectum CRM mesorectum CRM distal margin

28