Rectum

Question 1

Histopathological variation of rectum

Answer 1

Adenocarciinoma:
-ulcerative
Exophytic
Annular
Submucosal
Other:
Mucinous
Signet ring
Adenosquamous
Undifferentiated
Carcinoids
Leiomyosarcomas
Lymphomas

Question 2

IMRT dose of rectum

Answer 2

T3,T1-2,N+= ptvhr: 50.4 gy at 1.8 gy/ fx,

PTV-SR: 45 gy at 1.8 gy/fx
T4 same according to dobbes

Question 3

Rectum dose constraints for small bowel: Nancy

Answer 3

V45gy< 195cc ( quantec)
RTOG 0822
V40gy< 100cc
Dmax<50gy

Question 4

Rectum bladder constraints

Answer 4

QUANTEC
Dmax < 65 Gy
V65Gy < 50 %
RTOG 0822
V40Gy < 40 %
V45Gy < 15 %
Dmax < 50 Gy

Question 5

Carcinoma rectum femoral head constraints

Answer 5

RTOG 0822
V40Gy < 40 %
V45Gy < 25 %
Dmax < 50 Gy

Question 6

Points to see in rectal MRI before neoadjuvant treatment

Answer 6

*Distance from the anal verge or anorectal junction to the lower aspect of the tumor
• Tumor length
• T-stage of primary mass
• Tumor deposits within the mesorectum b • Involvement of the MRF and the smallest distance (mm) between the tumor and the MRF and its location • N-stage
• Presence/absence of suspicious extramesorectal lymph nodes • Additional findings that can be provided in synoptic report:
The circumferential location of the tumor
In T3 tumor, the extent (mm) of extramural growth or depth of invasion
Number of suspicious lymph nodes
Presence/absence of extramural vascular invasion (EMVI)
Morphologic pattern of tumor growth (eg, annular, polypoid, mucinous, ulcerated, perforated)

Question 7

Points see in HPR in rectal cancer

Answer 7

The following parameters should be reported:
NCCN Guidelines Index Table of Contents Discussion
Grade of the cancer
Depth of penetration (pT), the pT stage, is based on viable tumor. Acellular mucin pools are not considered to be residual tumor in those
cases treated with neoadjuvant therapy.
Number of lymph nodes evaluated and number positive (N). Acellular mucin pools are not considered to be residual tumor in those cases
treated with neoadjuvant therapy. 11,12 Status of proximal, distal, circumferential (radial), and mesenteric margins.
CRM13-17 15,16,18-20 Neoadjuvant treatment effect
Lymphovascular invasion15,16,21 Perineural invasion (PNI)22-24 Tumor deposits25,2

Question 8

When transanal resection is done

Answer 8

<30% circumference of bowel
; <3 cm in size;
margin clear (>3 mm);
mobile,
Nonfixed
; within 8 cm of anal verge;
T1 only;
endoscopically removed polyp with cancer or indeterminate pathology;
no lymphovascular invasion or PNI;
well to moderately differentiated;
no evidence of lymphadenopathy on pretreatment imaging;
full-thickness excision must be feasible

Question 9

Side effect of RT to rectum

Answer 9

acute
Skin: dry to moist desquamation
Fatigue
Anorexia
Nausea
Acute cystitis, proctitis
Diarrhea
Tenesmus
Crampy abdominal discomfort
chronic
Anal stenosis
Fecal incontinence
Telangiectasia
Infertility
Menopause