Ssentinel lymph node mapping in the modern management of gynae malignancy TOG 2023

Question 1

For which gynae cancers can SLN biopsy be used?

Answer 1

Used vulval cancer and increasingly in endometrial and cervical

Question 2

Where does the lyphatic drainage of vulval go primarily?

Answer 2

Ipsilateral inguinofemoral lymph node
Can cross midline if involved midline structures

Question 3

Where are the superficial lymph nodes identified?

Answer 3

Medial to saphenous vein above cribriform fascia, with deep nodes found deeb to cribriform fascia

Question 4

What is the closets node and where does it drain?

Answer 4

Most cephalad deep node under inguinal ligament t

Drains into external iliac

Question 5

What is the primary lymph drainage of the cervix?

Answer 5

Paracervical, parametiral, obturator, hypogastric, external iliac and pre sacral lymph notes

→ Common iliac, para-aortic and inguinal

Sentile node: iliac, obstructor or parametrial regions

Question 6

Lymph drainage of uterus

Answer 6

Complex bilateral

Lower segment → Pelvic lymph nodes

Upper segment → Para-aortic

Question 7

Definition of mactomets, micrometers, and isolated tumour cells

Answer 7

Marcomet: tumor depost >2mm
Micro: 0.2mm-2mm
Isolated tumour cells <0.2mm

Question 8

in vulval cancer SNL reduced the risk of lymphoedema by how much?

Answer 8

From 25% to 2%

Question 9

How is SLN mapping performed?

Answer 9

Tracer injected into area around tumour, tracer travels through lymphatic channels to region lymph nodes 1st node detect & removed & assessed for malignancy.

Question 10

Which dye has best detection rate & sensitivity for
1) Endometrial cancer
2) Cervical cancer
3) Vulval cancer

Answer 10

1) Endometrial cancer
ICG and Technetium-99m
2) Cervical cancer
ICG
3) Vulval cancer
Technetium 99m - blue dye

Question 11

Blue die is viable Jew long after injection, how long can it be visualised?

Answer 11

Detectable 10-20 mins
Seen consistently 30 mins and dissipates at 50 mins

Question 12

What is Indocyanine green (ICG)?

Answer 12

Water soluble tricarbocyanine that fluoresces in near infrared light which can be detected.

Question 13

For which patients can Indocyanine green (ICG) not be used?

Answer 13

Iodine allergy or significant liver dysfunction

5% iodine and hepatic metabolism

Question 14

SLN mapping false +ve, sensitiva and NPV for
1) Cervical cancer
2) Endometrial cancer

Answer 14

False +ve Both 2%
Sensitivity 92, 98%
NPV Both 99%

Question 15

What is ultra staging?

Answer 15

Serial section of SLN 50-250uM section and assessing each slice with haematoxylin and eosin
Additional immunohistochesmisty is performed on a single slice

Question 16

Effect of ultra staging on detect rate for
1) Cerivcal cancer
2) Endometrial cancer

Answer 16

1) Improve 10-15%
2) Improve 40%

Question 17

For vulval cancer when is SLN bx now recommended

Answer 17

Unifocal tumour <4cm, no suspicious lymph nodes

If within 1cm of midline, bilateral detection, otherwise side specific

Question 18

For cervical and endometrial cancer, how many site of injection on the cervix?

Answer 18

2 or 4

Should feel resistance at time of insertion

Question 19

In endometrial cancer if uterine manipulator is used, when should it be inserted?

Answer 19

After injection of transducer

Question 20

For early stage endometrial cancer does pelvic lymphadenectomy improve survival or relapse free survival?

Answer 20

No & increased surgical morbidity

Therefore if failed SLN mapping, unclear if pelvic lymphadenectomy should be performed

Question 21

How does surgical experience impact SLN detection rate?

Answer 21

Higher with more experienced surgeon

Question 22

What proportion or Stage 1A and 1B cervical cancers have positive lymph nodes?

Answer 22

0-22%

Question 23

Should frozen section of SLNs be used in cervical cancer?

Answer 23

No frozen section fails to idenifty 50% of node +ve disease