Background and recommendations Flashcards
(52 cards)
1
Q
Borders of the anal canal?
A
- Anorectal ring, where the rectum enters the puborectalis sling 2. Anal verge, the palpable junction between the internal sphincter and subcutaneous part of external sphincter
2
Q
What is the dentate line?
A
The site where mucosa changes from nonkeratnized squamous epithelium to colorectal columnar mucosa
3
Q
What is the most common histology?
A
SCCa 75-80%
4
Q
What HPV strains are associated with anal squamous cell carcinoma?
A
16, 18, 31, 33, and 35
5
Q
T1
A
2 cm or less in size
6
Q
T2
A
> 2 cm to 5 cm or less
7
Q
T3
A
More than 5 cm in size
8
Q
T4
A
Tumor invading the vaginal, urethra, bladder
9
Q
N1
A
Perirectal nodes
10
Q
N2
A
Unilateral internal iliac and/or inguinal nodes
11
Q
N3
A
Bilateral inguinal or bilateral internal iliac nodes or Perirectal and inguinal nodes
12
Q
Stage I
A
T1 N0 M0
13
Q
Stage II
A
T2-3 N0 M0
14
Q
Stage IIIA
A
T1-3 N1 or T4 N0
15
Q
Stage IIIB
A
T4 N1 or Any T N2-3
16
Q
Stage IV
A
M1
17
Q
Important factors in the history to consider
A
- Risk factors for HIV
- Bowel incontinence
- Pain or bleeding with bowel movements
18
Q
Important elements of PE
A
- DRE to determine tumor size, location, and sphincter tone
- Inguinal nodal exam
- Female speculum exam and bimanual exam may be needed to rule out vaginal invasion and any other HPV associated tumors
19
Q
What imaging is needed at diagnosis?
A
- Diagnostic CT of chest, abdomen, pelvis
20
Q
How do do you make a tissue diagnosis?
A
Proctoscopy and biopsy FNA any suspicious inguinal nodes
21
Q
What labs are needed at diagnosis
A
- BMP
- CBC
- HIV test, CD4 count, viral load
22
Q
Which patients can have a local excision alone?
A
- T1 N0
- Well differentiated
- Negative margins
- No LVSI
23
Q
What patients do we treat with CRT?
A
- T2-4 or Node positive
24
Q
When can RT alone be delivered?
A
T1 N0
25
What is the standard concurrent chemo regimen?
1. MMC 10 mg/m2 q 4 weeks x 2 cycles (HUS/TTP and BM toxic) 2. 5FU 750 mg/m2 q 4 weeks x 2 cycles (mucositis)
26
What is the recommended chemotherapy regimen to be given concurrently with RT?
5-FU 1000 mg/m2/day CI on days 1-4 q4 weeks x 2 cycles
MMC 10 mg/m2 bolus on days 1 q 4 weeks x 2 cycles
27
What are the challenges for HIV+ patients?
1. Lower LC (1/2)
2. More side effects (2 x)
28
What is the main toxicity of MMC?
Acute hematologic toxicity
29
What is the 1st alternate for concurrent chemo? Important side effects?
1. 5FU 1000 mg/m2 q4 weeks x 2 cycles (mucositis) 2. cisplatin 75 mg/m2 q4 weeks x 2 cycles (nephrotoxic, BM toxic, ototoxic)
30
CT simulation
Supine
Arms on chest
Indexed bag
Oral contrast for small bowel
Full bladder
Frog leg hips
Anal contrast
Perineal marker
Consider bolus for positive inguinal nodes
31
How is the initial CTV around the primary defined?
CTV: 2 cm caudad to gross disease, including coverage of the entire mesorectum to pelvic floor, and 2 cm around the anal verge or areas of perianal skin involvement. Superiorly the volume should extend to the pelvic sidewall, 1 cm anteriorly in the posterior bladder, including the obturator nodes. The superior border should be the recto-sigmoid junction and atleast 2 cm on gross disease.
32
What is included in the initial RT fields
1. Internal iliac from bifurcation of common iliac vessles 2. Presacral space and pelvis to the sidewall, entire mesorectum to pelvic floor 3. Rectum 2 cm proximal to gross tumor and 2cm around anal verge/perianal skin 4. Inguinal nodes and the inferior border is 2 cm inferior to top of lesser trochanter or junction of saphenous/femoral junction
33
How is the boost field developed?
2 cm around gross disease EFAB but including the mesorectum and presacral space at that level
34
PTV volume? PTV eval?
PTV: 7 mm on CTV
PTV eval: subtract 3 mm from skin
35
What is the standard dose for anal cancer?
T1 N0: Pelvic field: 45 Gy at 1.8 Gy/fx
T2 or N+(3 cm or less): Pelvic field to 45 and 9 Gy boost to nodes and primary at 1.8 Gy/fx
T3-4: Pelvic field to 45 Gy and boost gross disease to 14.8 Gy in 8 fractions
36
What does IMRT spare more than conventional therapy?
1. Femoral neck 2. Bowel 3. Bladder 4. External genetalia
37
What is the benefit of IMRT?
Reduced GI and GU toxicity Less skin toxicity
38
What dose constraints for the bladder?
V40 \< 35%
V35\<50%
39
What dose constraints for the femoral head?
V30\< 50%
V44\<5%
40
Small bowel constraint?
V30 \< 300 cc
V45 \< 150 cc
41
What dose constraints for the external genitals?
V20 \< 50%
V30\<35%
42
What is the median time to tumor regression?
3 months but it can take up to 12 months
43
What is the recommended follow up?
1. Examine at 8 weeks post-tx 2. Consider biopsy at 12 weeks if there is substantial persistent disease, progression or new symptoms like bleeding or pain 3. Even if biopsy is positive, unless there is progression, wait another 3 months before considering salvage If a CR is obtained, follow every 3 months for 2 years then every 6 months for 3 years. Performed DRE, anoscopy, nodal evaluation. Peformed pelvic CT annually for 3 years.
44
How is the CTV nodal defined?
Perirectal
Presacral
Internal iliac
External Iliac
Inguinal: contour 2 cm caudad to saphenous/femoral junction. Include any nodes visible.
7 mm margin around vessels but consider 10 mm anteriorly
45
How long do you wait after RT before considering salvage if the patient's disease is still regressing?
6 months
46
When patients fail, what is the predominant form of failure?
80% fail locally
47
What is the risk for toxicity with CRT including MMC and 5FU?
23% get G3+ skin toxicity
21% get G3+ GI toxicity
58% get G3+ hem toxicity
48
What is the 5 year OS and sphincter preservation rate after CRT?
5 year OS: 70% 5 year sphincter preservation rate: 65-75%
49
What study supports chemoRT vs. RT alone?
ACT I
RT alone
vs.
CRT
CRT reduced local failure by 46% and reduced death from anal cancer by 29%
50
What study supports the use of MMC with CRT?
RTOG 8704
1. 5FU/RT
vs.
2. 5FU/MMC/RT
MMC reduced LR by 19% and improved DFS by 17% at 5 years
51
What study supports the use of IMRT?
RTOG 0529
Dose painting IMRT
It reduced G3 GI and skin toxicity compared to RTOG 9811
52
What study did not support neoadjuvant chemo?
RTOG 9811
1. Neoadjuvant cisplatin + 5FU x 2 cycles, followed by CRT
vs.
2. 5FU+MMC+RT
Neoadjuvant cisplatin and 5FU regimen did worse in terms of OS and DFS
