Lower GI 2016

Improving IMRT in anal cancer: skin tox

- Reducing skin toxicity ? (Joseph 2015)

Ajani et al. [ 2 ] - RTOG 9811

Milano et al. [ 12 ]

Salama et al. [ 13 ]

Kachnic et al. [ 9 ] -RTOG 0529

Study

Han et al. [ 8 ] Current study

324

13

53

52

58

57

No. of patients

3D-CRT

IMRT

IMRT

DP-IMRT

IMRT

HT

RT technique

Target

Phase1: pelvis, perineum, inguinal nodes, anus sup border at L5/S1& inf border 2.5cm below anus Phase2: sup border reduced to bottom of SI joint Phase3 Boost: Tumor/Node +2- 2.5cm

Phase1: pelvic field: GTV + all regional nodes, sup border 1cm below L5-S1 Phase2 boost: GTV +1cm

CTV: GTV and areas at risk (nodal region) +1cm PTV: CTV +1cm

CTV T CTV N

: GTV +2.5cm

CTV T

: GTV +1.5cm sup/inf &

CTV T 1.5cm PTV T CTV N0 PTV N

/N+ve: GTV +1-

: GTV +1cm PTV: CTV +1cm

1cm radially PTV T

: CTV +7mm

: CTV T

/N+ve +1cm

CTV N0 CTV N+

: Vessel +1.5-2cm;

: Vessel +7mm

: Node +1cm

: CTV N0

+1cm

PTV: CTV +7mm

Dose

Phase1: 30.6Gy/17fr Phase2: 14.4Gy/8fr Phase3 boost: 10-14Gy/5-7fr

Phase1: 45Gy/25fr Phase2: 9Gy/5fr

Phase1: 45Gy/25fr Phase2: 9Gy/5fr

T2N0: 42Gy to PTV N0

&

T1: 45Gy/25fr T2 (2.1-4cm): 54Gy/30fr T2-4(>4cm): 63Gy/35fr N0: 27Gy/15fr N+ve: 58.5-63Gy/35fr

PTV T PTV N0

: 54Gy/30fr : 45Gy/30fr

50.4Gy to PTV T /28fractions T3-4N0-3: 45Gy to PTV N0 ; 50.4Gy to PTV N <3cm & 54Gy to PTV N >3cm; 54Gy to PTV T

Percent of patients with acute toxicity scores (%)

Gastrointestinal Grade 2 Grade ≥ 3 Dermatologic Grade 2 Grade ≥ 3 Hematologic Grade 2 Grade ≥ 3 Genitourinary Grade 2 Grade ≥ 3

38% 35%

69% 0%

57% 15%

52% 21%

59% 9%

53% 18%

?

60 % 11 %

35% 48%

100% 0%

55% 38%

52% 23%

45% 47%

23% 61%

15% 69%

21% 59%

15% 58%

26% 40%

26 % 46 %

19% 3%

0% 0%

11% 0%

13% 2%

19% 0%

14 % 4 %