1. در مرکز پزشکی هسته ای دکتر دباغ – دکتر صادقی
در خدمت شما هستیم
مشهد، ملاصدرا 11 ، پلاک 1/4
Tel:+98(51) ; +98(51)

2. LYMPHOSCINTIGRAPHY Sentinel Node
Ramin Sadeghi, M.D.
Nuclear Medicine Specialist
Associate Professor
DSNMC
Nuclear Medicine Research Center (NMRC; MUMS)

3. Lymphoscintigraphy Indications: Evaluation of lymphedema
Sentinel node detection
Melanoma
Breast cancer
Evaluation of chyle stasis

4. Lymphoscintigraphy Normal Primary lymphedema Secondary lymphedema
Prompt cephalic migration of radiocolloid to the illioinguinal lymph node groups in min.
Primary lymphedema
Marked decreased visualization of the ilioinguinal nodes of the affected side as well as an absence of any diffuse interstitial activity.
Secondary lymphedema
Marked interstitial accumulation of radiocolloid (diffuse activity throughout the involved extremity and poor visualization of primary channels)

5. SENTINEL NODE DETECTION

11. Lymphatic flow is orderly and predictable
Sentinel node concept
Lymphatic flow is orderly and predictable
Tumor

12. Tumor cells disseminate sequentially
Sentinel node concept
Tumor cells disseminate sequentially
Tumor

13. Sentinel node :Not involved
Sentinel node concept
Tumor
Sentinel node :Not involved
Other lymph nodes:
Not involved

14. Sentinel node :Involved
Sentinel node concept
Tumor
Sentinel node :Involved
Other lymph nodes:
May be involved

15. Sentinel node detection
Probe detection
Alone
With imaging
Blue dye detection
With probe detection

20. Radiopharmaceuticals
Narrow particle size range
99mTc labeled
Stable on storage
Lymph channel transport
Rapid transport
Retention in sentinel node

23. Radiopharmaceuticals
capillary
Lymphatics
< 4 nm
>1000 nm
Retention in site nm

25. Radiopharmaceuticals
Non-particulate (< 4nm):
99mTc-HSA
99mTc-Dextran
Particulate:
99mTc-antimony sulfide colloid (15-50 nm)
99mTc-nanocoll(albumin colloid) (~80 nm)
99mTc-Albumin microcolloid ( nm)
99mTc-sulfur colloid
Filtered ( nm)
Unfiltered ( nm)
99mTc-phytate

26. Radiopharmaceuticals
The smaller the size of tracer, the more lymph nodes are detected

36. Injection site Melanoma Breast cancer Intradermal Subdermal
Intra-tumoral
Peri-tumoral
Peri-areolar
Subdermal + peri-tumoral

40. Injection site (cont.)
Subdermal injection is sub-optimal for internal mammary nodes
Subdermal + peri-tumoral is the preferred method of injection

42. Imaging Why imaging is necessary? Helpful in incision planning
Smaller incision is performed
Surgical time is shortened
Not all hot lymph nodes should be excised

66. Melanoma
In more than 10% of melanoma, lymphatic drainage goes to 2 or 3 node groups
Sometimes lymphatic drainage is unpredictable:
Around Sappey’s line

74. Melanoma: Technique Radiotracer injections:
0.1mL MBq (100 μCi) Tc-99m SC
4–8 peritumoral intradermal injections
Within 1 cm from the melanoma
Avoid radioactive contamination
Gentle finger massage
20% of the activity is absorbed systemically

75. Melanoma: Technique Dynamic imaging In-transit nodes
30 sec/f for 2–30 min and/or sequential static images every 5 min for up to 1 h or until the sentinel lymph node is identified.
In-transit nodes
For extremity lesions, the knee or elbow regions in the field of view.

76. Melanoma In Head & Neck injection should not be inferior to the tumor
Sentinel node is not the hottest node in 30% of cases

80. Breast carcinoma: Lymphatic drainage
There are 3 pathways:
Axillary
Internal mammary
Supra or infra-clavicular
9% have regions with exclusive drainage to internal mammary nodes
Never to the opposite axilla or contralateral internal mammary

87. Breast carcinoma: Technique
High specific activity in injectate
Adminstered activity aiming for at least 10 MBq activity in the patient at the time of surgery
15 – 20 MBq for same-day surgery, 20 –40 MBq for imaging day before surgery
Injection:
Subdermal
Intra-tumoral
Peri-tumoral

89. Breast carcinoma: Technique (cont.)
Injection:
The only difference is internal mammary node visualization
Subdermal + peritumoral is the preferred method
After injection:
Hot towel placement on the breast
Massaging the injection site

90. Breast Technique Emission: Transmission (Co-57 flood source)
Anterior oblique 5 min (400,000 – 500,000 counts), 30 degree.
Lateral 5 min - with arm abducted
Anterior (if internal mammary nodes visualised)
Transmission (Co-57 flood source)
Anterior oblique, lateral and anterior (if anterior emission image acquired) after their emission image
If all images negative further imaging either 6 hrs post injection or next morning

93. Indications T1 and T2 stage invasive breast carcinoma
High risk and microinvasive ductal carcinomas in situ
Good prognostic group tumours (tubular, medullary, mucinous,papillary)
Following primary chemotherapy

94. Breast carcinoma: Not indicated : Palpable axillary lymph nodes.
Primary tumor more than 4 cm in diameter
Multicentric tumor
Prior axillary dissection or injury
Pregnancy or lactation

96. Breast carcinoma: Technique
Technical aspects should be followed carefully to have a successful lymphoscintigraphy

98. Conclusion Lymphoscintigraphy
Becoming a standard procedure for several malignancies
Is >95% successful in experienced hands
Can decrease morbidity of lymph node dissection significantly