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followed by lymphoscintigraphy, without the use of blue There was no agreement in which would be the adequate
dye. Its use may also facilitate SLN detection during surgery number of SN biopsied. This fact remains controversial
but there were no significant differences in terms of SS or in OSCC because of the possibility of great number of
NPV. It highlights the fact that the lowest value of SS was SN, variability of different lymphatic echelons, frequent
obtained in a job that used blue dye. [18] contralateral migration, etc. Perhaps it would be wise to
excise at least, all hot cervical nodes found in the images.
False-negatives can occur through multiple mechanisms,
including incomplete or inadequate peritumoral injection, Histological techniques
obscuring of the SN by shine-through of the radioactive Histological techniques employed are a crucial point in
signal at the primary tumor site, and lymphatic obstruction the SNB process. All items with available data, except
secondary to tumor-obstructed nodes resulting in one, employed HE, SSS and IHC analysis for citokeratin.
redirection of lymphatic flow. [14] All remarked the importance of the three techniques for
reaching the highest accuracy. On the other hand, one of
Nine authors employed dynamic images in a trend to the biggest potential downsides to a strategy of SNB as
identify the lymphatic migration to the sentinel nodes. To compared with upfront elective ND is the need to return to
date; the predominant clinical experience with SNB has been the operating room on a separate occasion for a completion
with oral cavity tumors. There is still some debate in the ND for a positive SLNB. Although immediate intraoperative
literature regarding the accuracy of SNB for floor of mouth frozen section can identify a significant proportion of
tumors compared to other oral locations. [38-40] The argument patients with a positive SNB, there remains a subset of
by those who report a lower sensitivity and negative patients whose occult disease will only become apparent
predictive value for floor of mouth tumors compared to with SSS and IHC analysis. The increased morbidity, cost
[25]
other locations is that tumors in the floor of mouth lie in and delay in healing that comes from a second procedure
very close proximity to level I nodes leading to difficulty are viewed by many as an obstacle to the implementation
[2]
in identifying and harvesting SLNs. [14,40] Antonio et al. of SNB. Some authors attempted to develop a more
state that the minimum treatment of the neck is probably efficient method for the intraoperative genetic detection
dissection of the levels between the primary tumour and of lymph node metastasis in head and neck aquamous cell
the level containing the SN(s). carcinoma using the one-step nucleic acid amplification
(OSNA) method of cytokeratin-19. [41]
This problem can be solved by means of tomographic
imaging techniques that can separate tracer uptake of Perspectives
adjacent organs, especially the hybrid techniques such as The data founded showed that any type of neoplastic
SPECT-CT that by their much greater anatomical resolution spread to the SN imply significant differences in terms of
and image quality are much more appropriate. It is survival [Table 2]. The presence of micrometastases and
noteworthy that only three authors use these techniques macrometastases must be followed by ND in order to
to help more accurately identifying lymph node stations control the disease. This probably means that more survival
in various forms, as well as its relations with adjacent specific studies are necessary to clarify the role of ITC
structures. [13] in SN. According to the guidelines in early breast cancer,
complete axillary lymph node dissection is recommended
Intraoperative procedure if SNB is positive except for ITCs. However, the reviewed
[42]
In the surgical room, radioguided surgical probe was studies suggested that the presence of even small tumor-cell
employed in 11 articles; one of them with a portable deposits in lymph nodes reflects the potential of the primary
intraoperative gamma-camera added. [16] When we use tumor to metastasize and, for the time being, completion
exclusively a probe it is recommended to previously identify elective neck dissection should be performed irrespectively
the SN and its anatomical location based upon the images of the size of metastases. [24,26]
examination and labeling marks on the skin of the patient.
For this, a close collaboration between the physicians of Based upon this review, we can resume the protocol of SNB
nuclear medicine and surgeons is recommended. In order to as follows: (1) close collaboration between the departments
avoid or minimize the shine-through effect, the surgeon must of maxillofacial surgery, oncology, radiology and nuclear
perform a lumpectomy before the SNB. After lumpectomy, medicine is recommended; (2) the selection of radiotracer
additional images can be acquired with portable gamma- is based more on local availability than on differences in
camera and identify the SN of the regions close to the tumor SLN detection. In our mean, Tc99m-nanocolloid should be
that could be missed in the initial images. employed. In the future, attention must be focused on new
tracers; (3) activity dose per injection will range between
[20]
Bluemel et al. used a new detection system based on a 37-74 MBq if surgery is performed the day after the tracer
freehand SPECT performed in the operating room before administration; (4) peritumoral injection will be performed
surgery and even intraoperatively after lumpectomy in a trying to surround the lesion as much as possible to avoid
short period of time (less than 2 min) that eliminated the false negative results; (5) the volume per dose recommended
peritumoral tracer activity and improved the location of will reach 0.5 mL in a trend to completely surround the
those lymphatic echelons close to the tumor and eliminating tumor in a total volume of 1-2 mL; (6) imaging techniques
the shine-through effect. should include tomographic studies, especially hybrid SPECT-
Plast Aesthet Res || Volume 3 || May 25, 2016 147