Radioguided Sentinel Node Biopsy Research Articles

Diagnostic accuracy of combined optical- and radio-guided SNB for neck staging of oral squamous cell carcinoma lesions in the anterior oral cavity

PurposeThe purpose was to investigate the diagnostic performance of bimodal optical and radio-guided sentinel node biopsy (SNB) for oral squamous cell carcinoma (OSCC) sub-sites in the anterior oral cavity.MethodsProspective study of 50 consecutive patients with cN0 OSCC scheduled for SNB was injected with the tracer complex Tc99m:ICG:Nacocoll. A near-infrared camera was applied for optical SN detection. Endpoints were modality for intraoperative SN detection and false omission rate at follow-up.ResultsIn all patients, a SN could be detected. In 12/50 (24%) of cases, the SPECT/CT showed no focus in level 1, but intraoperatively a SN in level 1 was optically detected. In 22/50 cases (44%), an additional SN was identified only due to the optical imaging. At follow-up, the false omission rate was 0%.ConclusionOptical imaging appears to be an effective tool to allow real-time SN identification comprising level 1 unaffected by possible interference of radiation site from the injection.

Sentinel Lymph Node Biopsy after Previous Radical Lymphadenectomy of the Same Lymph Node Basin

Purpose: This study aimed to determine the feasibility of preoperative lymphoscintigraphy and intraoperative radio-guided sentinel lymph node biopsy (SLNB) in patients previously submitted to complete lymphadenectomy (CL) in the same region. There is no current proposal to stage patients diagnosed with a new melanoma after SLNB if the regional lymph node (LN) was removed, preventing this specific population from adjuvant treatments due to understaging. Methods: We assessed six cases of patients with a previous cancer diagnosis (melanoma, breast, or thyroid cancer) who had undergone CL and later developed a new cutaneous melanoma in the same extremity submitted to CL. They underwent preoperative lymphoscintigraphy to locate the sentinel lymph node (SLN), followed by a radio-guided SLNB with the assistance of patent blue dye. A pathologist then evaluated the excised SLN. Results: We had 100% feasibility, all six patients had their SLN located, and three (50%) patients tested positive for metastasis in the excised LNs. Conclusions: All these patients met the criteria to undergo SLNB, but no previous reports demonstrated and corroborated the performance of this procedure in this situation. SLNB with expected drainage for regions previously submitted to a radical lymphadenectomy is a safe and effective procedure. A lymphoscintigraphy allows locating the SLN that is likely to be resected in surgery. In this scenario, we had a 50% positivity, providing how relevant and essential this information is for the prognosis and practical therapeutical approaches for this rare but relevant melanoma population.

Sentinel lymph node biopsy for papillary thyroid cancer: the effect of dose, tracer and application of massage.

In patients with papillary thyroid cancer (PTC), sentinel lymph node (SLN) radio-guided biopsy is not routinely used for detection of involved neck lymph nodes (NLN); 99mTc- antimony sulfide colloid (99mTc- ASC) has been used for this purpose. In this study, besides 99mTc-ASC another radiotracer, 99mTc-phytate (99mTc-P) with different doses and injection methods were evaluated. Twenty-two patients, scheduled to undergo thyroidectomy for PTC, were injected for radio-guided SLN biopsy in the morning of operation in 3 groups: intra tumoral injection of about 1 mCi 99mTc-P (group A; n=5); peritumoral injection of less than 3 mCi 99mTc-ASC (group B; n=6); and peritumoral injection of 3 to 5 mCi 99mTc-ASC with application of massage (group C; n=9). A patient refused to complete the study. A patient with follicular thyroid cancer was also excluded. No NLN was detected in the pre-operative ultra-sonographic examinations of all patients. Central neck dissection was done for all the participants. The presence of radio guided detected NLN and results of pathology were assessed. In group A and B, no SLN was detected. NLNs were resected in 4 patients in group A and B; 2 of them involved by the tumor. In group C, 6 out of 9 patients (66.7%) had between 1 to 6 SLNs; the procedure failed to detect NLN in a patient in group C with surgically resected reactive NLN (failure rate 1 out of 7). The results underscored the significance of SLN radio guided biopsy in patients with PTC; the radiotracer, dose and method of injection may affect the detection rate.

Radioguided sentinel node biopsy to avoid unnecessary neck dissection in T1-T2N0 oral cavity squamous cell carcinoma: personal experience with same day protocol.

Data from literature show a mean incidence of occult metastases of 33% in early OCSCC. The gold standard for most authors is a selective neck dissection and a routine pathological examination. 60-70% of unnecessary neck dissections with associated morbidity, can be avoided by using SNB. The aim of this study is to present the results of one of the major Italian centres for the SNB procedure, reserving neck dissection only for proven positive lymphatic metastases. From July 2004 to March 2015, 48 patients with transorally resectable cT1-T2N0 oral SCC were submitted to a lymphoscintigraphic examination one-three hours before surgery and a radio-guided SNB (same day protocol). Patients with a negative SNB were checked every 3months by ultrasound examination. The minimum follow-up was 5years. Sentinel nodes were found in all cases, with 71% localized in the ipsilateral neck only in levels I-II. Metastases were found in 15 out of 48 cases (31.2%), on levels I, II and III. Further metastatic nodes were found in 6 cases in the neck dissection specimen. In the cohort of 33 patients with SNB negative at 5years, no-one had a recurrence on the ipsilateral neck. This study confirms the accuracy of SNB in predicting the presence of occult metastases, sparing the need for unnecessary neck dissection in 70% of cases. The same day protocol is designed to detect sentinel nodes, which are almost always on neck level I-II, thereby limiting the number of nodes examined and the extension of the surgical approach.

Low-cost Fluorescein as an Alternative to Radio-colloid for Sentinel Lymph Node Biopsy-a Prospective Validation Study in Early Breast Cancer.

Sentinel lymph node biopsy (SLNB) using radio-pharmaceutical (RP) and a blue dye is gold standard for axillary staging in clinically node-negative early breast cancer. High costs and limited availability of RP and/or gamma probe are major deterrents in performing SLNB in developing countries. Fluorescence-guided SLNB can obviate the need for RP and gamma probe. Fluorescein is an inexpensive fluorescent lymphatic tracer. In this study, we compared SLN identification rate (SLN-IR) and false negative rates (FNR) of fluorescein-guided SLNB and radio-guided SLNB using 99mTc-Sulfur-colloid, in isolation, or in combination with methylene blue dye (MBD). Sixty-five cN0 early and large operable breast cancer patients underwent validation SLNB using fluorescein (and blue LED light), 99mTc-Sulfur-colloid (and gamma probe) and MBD. Inj Fluorescein 4% was injected, 1ml each peri-tumoral and sub-areolar five minutes before axillary incision. Axillary dissection was performed irrespective of SLNB histology. The SLN-IR and FNR with various tracers and their combinations were compared. The mean number of SLNs identified was 3.5 ± 1.8 (range 1-6). The SLN-IR using RP alone was 94%, fluorescein alone was 92%, and MBD alone was 82%. The SLN-IR using fluorescein plus MBD combination was 95.4%, compared to 97% using MBD plus RP combination. FNR was 6.3% using fluorescein plus MBD, as well as RP plus MBD combinations. SLN-IR of > 90% and SLN-FNR of < 10% using fluorescein plus MBD combination are in acceptable range, and are comparable to that of RP plus MBD combination. Fluorescein can replace RP for performing SLNB, in combination with MBD.

Pregnancy-associated breast cancer – Case report

Introduction: Mammographic screening is recommended yearly after the age of 40; however, many pregnant women are younger and should undergo the test. In these cases, anamnesis and clinical examination of the breasts are essential to detect any breast change. In case of clinical suspicion, it is recommended to undergo mammography with abdominal protection, and breast ultrasound is the examination of choice to assess the extension of the injury and guide the percutaneous biopsy. Breast surgery is safe, and can be performed in the three trimesters of pregnancy. It is important to emphasize the importance of the type of surgery according to gestational age. The reference axillary surgery during pregnancy is axillary lymphadenectomy. However, some articles present the safety of the sentinel lymph node biopsy. The use of technetium (Tc-99m) with lymphoscintigraphy is an acceptable technique, with fetal exposure to radiation inferior to the teratogenic limit of 50 mGv. Objective: To emphasize the importance of mammary propedeutics during pregnancy. Case report: 37 year-old patient, primiparous, of 34 weeks, referred a nodule in the right breast for 1 year. She denies having family history of carcinoma. At clinical examination, she presented with turgid breasts, absence of palpable nodules and negative axilla. Current mammography with presence of architectural distortion in the inferolateral quadrant of the right breast, and ultrasound with irregular and spiculated 2 cm nodule , both BIRADS category 5. Percutaneous biopsy showed invasive breast carcinoma of no special type, histological grade 2, and immunohistochemical with positive hormone receptors (estrogen and progesterone receptor with 90%), negative HER2 and Ki 67 of 20%&gt; The conduct was conserving surgery (excision of the breast injury and radio-guided sentinel lymph node biopsy) on the 36th week of pregnancy. The intraoperative assessment of the sentinel lymph node showed presence of macrometastasis and, as a consequence of the exclusion of pregnancy in the ACOSOG Z0011 study, the patient was submitted to axillary lymphadenectomy. The definitive anatomopathological result was invasive breast carcinoma of no special type, histological grade 3, measuring 2.1 cm, and 1 lymph node compromised by macrometastasis of 15 dissected nodes (pT2 pN1a). The multidisciplinary team chose to wait for delivery, from 2 to 4 weeks, and a Cesarean section was performed after 40 weeks of pregnancy. The chemotherapy was scheduled to begin 4 weeks after delivery. The patient was referred to genetic counselling. Conclusions: The treatment of breast cancer during pregnancy is challenging for the multidisciplinary team, which must focus on maternal and fetal well-being. Therapy should be carried out similarly to non-pregnant patients, respecting the procedures that are allowed in each gestational trimester. It is important to mention how essential it is to not delay the treatment, in order to not compromise the patient’s prognosis.

Effect of Sentinel Node Biopsy in Clinically N0, BRAF V600E-Mutated, Small Papillary Thyroid Carcinoma: A Pilot Study.

BRAF V600E mutation papillary thyroid cancer (PTC) is more aggressive with a higher risk of lymph node involvement and a poorer prognosis. Prior studies failed to demonstrate the superiority of prophylactic lymphadenectomy. We investigated the utility of additional radio-guided sentinel node biopsy (SNB). We analyzed 15 patients with N0 PTC by ultrasound and BRAF mutation on preoperative biopsy treated with total thyroidectomy (TT) or TT + prophylactic central neck dissection (PCND) alone or with SNB. Conventional surgery was performed before SNB. We recorded primary tumor diameter, multifocality, extrathyroid infiltration, neoplastic emboli, and tall cell variant. At follow-up, we evaluated basal and stimulated thyroglobulin and ultrasound or radioiodine scintigraphy. Of 15 consecutive patients, 5 received conventional surgery alone, and 10 had SNB. For the first group, 4 underwent TT, and 1 had TT + PCND. Among the SNB group, 1 had no sentinel node detected and underwent a simple TT, 2 had TT + PCND+ SNB in the lateral compartment, and 7 had TT + SNB in 1 to 3 neck compartments. Micrometastases were found in 1 of 3 PCND specimens. Sentinel node biopsy revealed metastasis in 3 of 6 central compartment biopsies, in 2 of 6 biopsies in the ipsilateral lateral compartment, and in none of 2 biopsies in the contralateral compartment. Sentinel node biopsy allowed the removal of micrometastases in 4 of 10 patients. At 53 months' (mean) follow-up, no relapse was documented. Radio-guided SNB correctly and efficiently stages cN0 BRAF-mutated PTC patients. Sentinel node biopsy could limit time-consuming, risk-exposing compartmental prophylactic dissections.

Radioguided sentinel lymph node biopsy in patients with papillary thyroid carcinoma.

The ATA guidelines do not recommend prophylactic central compartment neck dissection in patients with T1-T2 papillary thyroid carcinoma (PTC) with no clinical evidence of lymph node metastasis, however patients' staging is recommended. Lymph node metastasis may be present also in small PTC, but preoperative ultrasound identifies suspicious cervical lymphadenopathy in 20-30% of patients. The role of sentinel lymph node biopsy (SLNB) remain open to debate. It has been shown that the identification rate of SLN in PTC patients is improved using a radiotracer compared to a dye technique. The aim of this systematic review was to evaluate the role of radioguided SLNB (rSLNB) in the treatment of PTC patients. A systematic search was performed in the PubMed and Embase database to identify all original articles regarding the application of rSLNB in PTC patients. The primary outcome was false negative rate (FNR) of the rSLNB; the secondary outcomes were SLN intraoperative identification rate (IIR), site of lymph node metastasis, and persistent disease during follow up. Twelve studies were included. Most of PTC patients were T1-T2. The overall SLN IIR, SLN metastatic rate, and FNR were 92.1%, 33.6%, and 25.4%, respectively. Overall, lymph node metastasis were found in the central compartment (23.0%) and in the lateral compartments (10.6%). The persistent disease in patients who underwent SLNB associated to lymph node dissection (LND) in the same compartment of the SLN regardless of the SLN status was 0.6%. In all PTC patients, also in T1-T2 stage, due to the high FNR the SLNB performed alone should be abandoned and converted into a technique to guide the lymphadenectomy in a specific neck compartment (i.e., central or lateral) based on the radioactivity, regardless of the SLN status, for better lymph node staging and selection of patients for postoperative radioiodine ablation.

The Role of SPECT/CT Lymphoscintigraphy and Radioguided Sentinel Lymph Node Biopsy in Managing Papillary Thyroid Cancer.

Single-photon emission computed tomography/computed tomography (SPECT/CT) and radioguided sentinel lymph node biopsy (rSLNB) are techniques that could potentially benefit surgeons and pathologists in the identification of sentinel lymph node (SLN) metastases in patients with papillary thyroid carcinoma (PTC). Evidence suggests that these novel techniques lead to substantial changes in PTC management by reducing understaging and of occult lymph node (LN) metastases and optimizing neck surgery by increasing the necessity of lateral lymphadenectomy and decreasing central lymphadenectomy. To correlate the presence of LN metastases in PTC with clinical and pathological features using SPECT/CT and rSLNB. For this prospective cohort study from June 2010 to November 2013, 42 patients with thyroid nodules suspicious for papillary carcinoma or classified as malignant on cytology examination without suspicion of lymph node metastases by clinical and ultrasound examinations were recruited from a single public medical institution. All 42 patients underwent preoperative lymphoscintigraphy after an ultrasound-guided peritumoral injection of Technetium Tc 99m nanocolloid. Cervical images were acquired with a SPECT/CT scanner 15 minutes after radiotracer injection. Approximately 2 hours after lymphoscintigraphy, the patients were submitted to intraoperative rSLNB using a handheld gamma probe. All SLNs identified were removed alongside with non-SLNs from the same compartment. Papillary thyroid carcinoma, SLNs and non-SLNs were submitted for histopathology and immunohistochemical analyses. Of the 42 patients initially enrolled, 37 were included in analysis, including 6 men and 31 women with a mean (range) age of 47 (22-83) years. Overall, T stage was as follows: T1, 23 patients (62.2%); T2, 8 patients (21.6%); and T3, 6 patients (16.2%). Sentinel lymph nodes were identified in 92% of the patients, and among these metastases were present in 17 patients (46%). The SLNs were false-negative in 3 patients. Metastases in the lateral compartment ocurred in 7 patients (18%). There was a significant association between LN metastases and tumor size (odds ratio, 1.06; 95% CI, 1.00-1.13; P = .02), with a Cohen d effect of 0.683 (medium to large effect). Overall, 17 patients (46%) with LN metastases had management changed because they were submitted to higher radioiodine ablation doses and closer clinical surveillance. Radioguided SLNB is able to detect occult cervical lymph node metastases in patients with papillary thyroid carcinoma, and in 7 patients (18%) rSLNB detected lymph node metastases in the lateral compartments. The rSLNB technique lead to management change in 14 patients (37.8%).

Fusion of freehand SPECT and ultrasound: First experience in preoperative localization of sentinel lymph nodes.

Radioguided sentinel lymph node biopsy (SLNB) is the standard of care in breast cancer and melanoma. Additional preoperative Single-photon emission computed tomography (SPECT/CT) for improved anatomical co-registration of the SLNs causes additional radiation exposure and is time-consuming and expensive. The aim of this prospective study was to evaluate a novel approach involving real-time fusion of freehand SPECT (fhSPECT) and ultrasound (US) for anatomical co-registration of SLNs. From February 2015 to February 2016, 153 patients were included in this prospective study. All patients underwent lymphoscintigraphy according to practical guidelines and 151 (118 cases of breast cancer, 30 cutaneous malignancies, and three cases of vulvar cancer) of the 153 patients were additionally investigated with fhSPECT-US. FhSPECT connected to a hand-held gamma detector generates three-dimensional images of the radioactivity distribution in the scanned area. For co-registration and real-time fusion of fhSPECT and subsequently performed US, an infrared stereo tracking system was used. In all patients an SLN was found on lymphoscintigraphy, and the fhSPECT detected corresponding hotspots in all but one patient. In 72% of patients and 73% of lymph node basins, real-time anatomical co-registration with US was feasible. The rate of success in achieving good co-registration increased from 60 to 75% after training by a radiologist specialized in breast imaging. A higher co-registration rate (78%) was observed in patients with only one SLN than in those with two SLNs (68%) or three or more SLNs (0%). Real-time fusion of fhSPECT and US for preoperative anatomical co-registration of SLNs is feasible. However, before this approach can completely replace preoperative lymphatic imaging, further technical developments are needed.

Portable Gamma Camera Guidance in Sentinel Lymph Node Biopsy: Prospective Observational Study of Consecutive Cases

BackgroundSentinel lymph node biopsy is the most important tool available for node staging in patients with melanoma. ObjectivesTo analyze sentinel lymph node detection and dissection with radio guidance from a portable gamma camera. To assess the number of complications attributable to this biopsy technique. MethodsProspective observational study of a consecutive series of patients undergoing radioguided sentinel lymph node biopsy. We analyzed agreement between nodes detected by presurgical lymphography, those detected by the gamma camera, and those finally dissected. ResultsA total of 29 patients (17 women [62.5%] and 12 men [37.5%]) were enrolled. The mean age was 52.6 years (range, 26-82 years). The sentinel node was dissected from all patients; secondary nodes were dissected from some. In 16 cases (55.2%), there was agreement between the number of nodes detected by lymphography, those detected by the gamma camera, and those finally dissected. The only complications observed were seromas (3.64%). No cases of wound dehiscence, infection, hematoma, or hemorrhage were observed. ConclusionsPortable gamma-camera radio guidance may be of use in improving the detection and dissection of sentinel lymph nodes and may also reduce complications. These goals are essential in a procedure whose purpose is melanoma staging.

Biopsia selectiva del ganglio centinela radioguiada mediante gammacámara portátil. Estudio observacional sobre serie de casos incluidos prospectivamente de forma consecutiva

IntroductionSentinel lymph node biopsy is the most important tool available for node staging in patients with melanoma. ObjectivesTo analyze sentinel lymph node detection and dissection with radio guidance from a portable gamma camera. To assess the number of complications attributable to this biopsy technique. MethodsProspective observational study of a consecutive series of patients undergoing radioguided sentinel lymph node biopsy. We analyzed agreement between nodes detected by presurgical lymphography, those detected by the gamma camera, and those finally dissected. ResultsA total of 29 patients (17 women [62.5%] and 12 men [37.5%]) were enrolled. The mean age was 52.6 years (range, 26-82 years). The sentinel node was dissected from all patients; secondary nodes were dissected from some.In 16 cases (55.2%), there was agreement between the number of nodes detected by lymphography, those detected by the gamma camera, and those finally dissected. The only complications observed were seromas (3.64%). No cases of wound dehiscence, infection, hematoma, or hemorrhage were observed. ConclusionsPortable gamma-camera radio guidance may be of use in improving the detection and dissection of sentinel lymph nodes and may also reduce complications. These goals are essential in a procedure whose purpose is melanoma staging.

Changing the Intraoperative Nodal Status of a Breast Cancer Patient Using Freehand SPECT for Sentinel Lymph Node Biopsy

Radio-guided sentinel lymph node biopsy in early-stage breast cancer is standard of care. Freehand SPECT is a system for intraoperative visualization of radioactivity in the body. It generates a 3-dimensional image of the radioactivity distribution complementing the acoustic information of the gamma probe by providing depth and radioactive uptake information. In the reported case, freehand SPECT was used in a breast cancer patient as a control method after conventional sentinel lymph node biopsy. Freehand SPECT identified an additional lymph node, changing the original stage from pN1(mic) (micrometastasis) to pN1a (nodal positive), resulting in an axillary lymph node dissection.

165. Feasibility of 3D intraoperative freehand SPECT probe imaging for radioguided tumor excision and sentinel node biopsy in breast cancer

165. Feasibility of 3D intraoperative freehand SPECT probe imaging for radioguided tumor excision and sentinel node biopsy in breast cancer

561 Feasibility of 3D Intraoperative Freehand SPECT Probe Imaging for Radioguided Tumour Excision and Sentinel Node Biopsy in Breast Cancer

561 Feasibility of 3D Intraoperative Freehand SPECT Probe Imaging for Radioguided Tumour Excision and Sentinel Node Biopsy in Breast Cancer

William Ramsay

<b>270</b> <h3><b>Objectives:</b></h3> Detection of sentinel lymph node (SLN) is important to evaluate tumor staging and therapeutic decision-making during surgery (<i>1</i>) (<i>2</i>) (<i>3</i>). In this experiment, our aim was to develop...

Simultaneous Detection of Breast Tumor Resection Margins and Radioguided Sentinel Node Biopsy Using an Intraoperative Electronically Collimated Probe With Variable Energy Window

Simultaneous Detection of Breast Tumor Resection Margins and Radioguided Sentinel Node Biopsy Using an Intraoperative Electronically Collimated Probe With Variable Energy Window

Changing paradigms in radioguided surgery and intraoperative imaging: the GOSTT concept

Ever since the first descriptions as an aid for sentinel lymph node biopsy in the early 1990s [1, 2], interest in radioguided surgery has been rising sharply and continues to do so with respect to both the number of articles published in the medical literature and the amount of procedures performed. In Europe, lymphoscintigraphic imaging procedures for sentinel lymph node biopsy have markedly increased, by about 17.5%, between the years 2005 and 2008 (source: European Association of Nuclear Medicine), a period during which single photon imaging procedures in general were expected to remain substantially stable or actually show some decline attributed to competition by the growing number of positron emission tomography (PET) studies. Several reasons can be envisaged to explain the popularity of radioguided surgery. In particular, prior to the introduction of intraoperative radioguidance, professional skills and dexterity of surgeons had to build on the a priori knowledge of anatomy and while in the operation theatre primarily rely on two senses, sight and palpation. Introducing intraoperative gamma probe counting has forced surgeons to integrate a third sense, hearing, in addition to the prior two. In fact, this “upgrade” proved to be very convenient; the increasing intensity and pitch of the sound as a function of increasing count rates was adopted as a primary guide for the surgeon, in order not to distract him/her from focusing on the surgical field while performing gamma probe exploration, as a solution more superior than observing the numerical display of the count rates [3]. Another important reason for the wide acceptance of the radioguided surgery concept can be attributed to alignment and synergy with current trends of oncological surgery adopting less aggressive and invasive approaches; in this regard, the possibility of identifying with highest accuracy those patients who can be spared unnecessary lymph node dissection (a procedure fraught with a high incidence of morbidity and long-term complications) is certainly a crucial asset that radioguided sentinel node biopsy has brought about in clinical practice, concerning especially early breast cancer and cutaneous melanoma [4, 5]. The success of radioguided sentinel lymph node biopsy in patients with breast cancer or with cutaneous melanoma, where this technique has now become an integral part of the standard of care [6], has driven countless clinical trials aimed at validating the same approach in the management of other solid tumours [7]. J. J. Zaknun (*) Section of Nuclear Medicine, Division of Human Health, International Atomic Energy Agency (IAEA), 5 Wagramerstrasse, PO Box 200, Room A-2278, 1400 Vienna, Austria e-mail: J.Zaknun@iaea.org

Optimal Detection of Sentinel Lymph Node Metastases by Intraoperative Radioactive Threshold and Molecular Analysis in Patients with Melanoma

The aim of this study was to optimize a protocol for radioguided biopsy of the sentinel lymph node (SLN) in patients with melanoma. The protocol was based on a combination of ex vivo counting of the nodes detected intraoperatively and analysis of the harvested nodes by hematoxylin and eosin staining plus immunohistochemistry (conventional histopathology [PATH]) and by molecular biology (reverse-transcriptase polymerase chain reaction [RT-PCR]). A total of 124 patients with primary clinical stage I-II (according to the American Joint Committee on Cancer) cutaneous melanoma underwent successful radioguided SLN biopsy. SLNs harvested for analysis included any additional nodes whose ex vivo counting rate exceeded 20% of the hottest node. All removed SLNs were examined by conventional PATH and with RT-PCR analysis for the expression of messenger RNA for tyrosinase and the melanoma antigens recognized by T cells. Complete lymph node dissection (CLND) was performed only in the case of SLN metastasis detected by PATH. Different combinations of the intraoperative parameters (only the hottest node and all nodes harvested) and of analysis (PATH and RT-PCR) were tested as predictors of clinical outcome on the basis of long-term follow-up (12-81 mo; median, 55 mo). A total of 197 SLNs were harvested, 41 of which harbored metastasis as detected by RT-PCR analysis; PATH detected metastasis in only 24 of 41 metastatic SLNs. In 5 of 41 instances, metastasis was not in the hottest SLN. The main factor determining correct classification of the SLN status was RT-PCR, which significantly improved detection of metastasis, even if applied only to the hottest node (P < 0.0001 vs. PATH analysis of either the hottest SLN or all nodes above the 20% threshold). Metastatic disease recurred locally in 5 patients who had not undergone CLND; RT-PCR analysis showed metastasis in 4 of these patients. The false-negative rate of SLN biopsy progressively decreased when applying PATH only to the hottest node (32.1%), additional RT-PCR to the hottest node (21.4%), PATH to all nodes (17.9%), and RT-PCR to all nodes (3.6%, P = 0.015 vs. PATH analysis of only the hottest SLN). On the basis of long-term follow-up (the gold standard for final clinical outcome of SLN biopsy), both 20% threshold and RT-PCR analysis should be applied for optimal detection of nodal metastases in patients with melanoma.

The impact of superficial injections of radiocolloids and dynamic lymphoscintigraphy on sentinel node identification in oral cavity cancer: a same-day protocol

To evaluate the role of dynamic lymphoscintigraphy with a same-day protocol for sentinel node biopsy in oral cavity cancer. Twenty-two consecutive patients affected by cT1-2N0 squamous cell carcinoma of the oral cavity were enrolled between September 2001 and November 2005. After a local anaesthetic (10% lidocaine spray), a dose of 30-50 MBq of Tc human serum albumin nanocolloid, in ml saline, was injected superficially (1-2 mm subendothelial injection) into four points around the lesion. Dynamic lymphoscintigraphy was acquired immediately (256x256 matrix, 5 min pre-set time, LEGP collimator) in lateral and anterior projections. The imaging was prolonged until the lymph nodes of at least two neck levels were visualized (time required min). About 3 h later (same-day protocol) the patients had a radioguided sentinel node biopsy. Elective neck dissection was performed in the first 13 patients; whereas the last nine patients had elective neck dissection only if the sentinel node was positive. Sentinel nodes were dissected into 1 mm thick block sections and studied by haematoxylin & eosin staining and immunohistochemistry (anticytokeratin antibody). The sentinel nodes were found on the 1st neck level in 13 cases, on the 2nd neck level in eight cases, and on the 3rd neck level in one case (100% sensitivity). The average number of sentinel nodes was 2.2 for each patient. The sentinel node was positive in eight patients (36%); with six of them having the sentinel node as the exclusive site of metastasis. No skip metastases were found in the 14 patients with negative sentinel node (100% specificity). Our preliminary data indicate that superficial injections of radiocolloid and dynamic lymphoscintigraphy provide a high success rate in sentinel node identification in oral cavity cancers. Dynamic lymphoscintigraphy helps in distinguishing sentinel node from second-tier lymph nodes. The same-day protocol is advisable in order to correctly identify the first sentinel node, avoiding multiple and unnecessary node biopsies, without reducing sensitivity.