Gamma Probe Guidance Research Articles

Single-Photon Emission Computed Tomographic Reverse Lymphatic Mapping for Groin Vascularized Lymph Node Transplant Planning.

Superficial inguinal (groin) vascularized lymph node transplantation is the most common option for the treatment of lymphedema, particularly in combination with free abdominal flap breast reconstruction. This study examines the utility of single-photon emission computed tomographic (SPECT/CT) lymphoscintigraphy for lower extremity reverse lymphatic mapping in presurgical planning for groin vascularized lymph node transplantation and appraises the physiologic lymphatic drainage to the superficial inguinal lymph nodes. All patients who underwent bilateral lower extremity SPECT/CT reverse lymphatic mapping over a 5-year period were included. Retrospective case note analysis was performed to collect demographic, surgical, and outcomes data. The study included 84 patients; 56 of these subsequently underwent groin vascularized lymph node transplantation (58 flaps). Fifty-four of these flaps were combined with free abdominal flaps for breast reconstruction (55 flaps). Using SPECT/CT reverse lymphatic mapping investigation of 168 inguinal regions, drainage to at least one superficial inguinal region was visualized in 38.1 percent of patients; in 13.1 percent, drainage was visualized to both superficial inguinal regions. Using this information for presurgical planning, groin vascularized lymph node flap harvest was performed from the contralateral side in 57 of 58 cases (98.3 percent) using intraoperative gamma probe guidance, and no patient developed donor lower extremity lymphedema during follow-up (mean ± SD, 34.5 ± 15.4 months). The authors' use of presurgical SPECT/CT reverse lymphatic mapping together with limited flap dissection and intraoperative gamma probe guidance resulted in no clinical cases of iatrogenic donor lower extremity lymphedema. The high incidence of drainage from the lower extremity to the superficial inguinal region mandates the use of reverse lymphatic mapping when performing groin vascularized lymph node transplantation. Therapeutic, IV.

Innovative Approach of Endosonographic Radioactive Labeling of an Ectopic Parathyroid Adenoma by Technetium-99m Human Serum Albumin: A Case Report

Primary hyperparathyroidism caused by parathyroid adenoma requires surgical resection. To confine the extent of surgery to the very minimum and to exclude an atypical adenoma location, preoperative imaging aims at identifying the suspicious gland. For this purpose, Technetium-99m (99mTc)-sestamibi scintigraphy and SPECT have become the international imaging standard, in inconclusive cases also with C-11 methionine and F-18 choline PET/CT. We present a case of surgery for an ectopic retroesophageal adenoma resected under gamma probe guidance after preoperative radioactive targeting. A 73-year-old patient, who was diagnosed with primary hyperparathyroidism, presented to our outpatient clinic. The patient was symptom-free, but during a routine check-up, parathormone levels of 127 pg/ml (normal range 15-65) were detected. Parathyroid MIBI scintigraphy, including SPECT/CT, failed to locate an adenoma. Therefore, a PET/MRI scan with 164 MBq F-18 choline was applied and a single parathyroid adenoma was detected in a very untypical retroesophageal and prevertebral position, respectively. Due to its esophageal proximity and to enable a very confined surgery, endosonography was performed and the adenoma was transesophageally injected with 75 MBq 99mTc-human serum albumin (HSA). The next day gamma probe-guided minimally invasive resection was performed without any intra- or postoperative complications. Minimally invasive resection of parathyroid adenomas should be the standard but may be difficult in deep collar and atypical locations. Marking the adenoma with a radioactive nanocolloid tracer for gamma probe-guided surgery can be considered an innovative approach to maintain minimal invasive therapy for ectopic adenomas.

A critical reappraisal of sentinel lymph node biopsy for non-small cell lung cancer

Because of unsatisfactory accuracy of preoperative imaging and/or of mediastinoscopy, current guidelines recommend routine dissection of mediastinal lymph nodes for patients with operable non-small cell lung cancer (NSCLC). However, at final histopathology this surgical procedure, which is performed mostly for staging purposes and implies a non-negligible rate of severe complications, turns out to be unnecessary in a quite large proportion of patients with early NSCLC. These considerations explain the interest in exploring the potential of sentinel lymph node biopsy (SLNB) in patients with NSCLC, an approach based on the same rationale that has led to establish SLNB as the standard of care in patients with cutaneous melanoma or breast cancer (especially if performed with intraoperative gamma probe guidance after injection at the tumor site of a radiolabeled agent for lymphatic mapping). However, in the case of NSCLC objective anatomic difficulties prevent the possibility to access the primary tumor for injection of the lymphatic mapping agent through an easy and minimally invasive administration route and with adequate timing so to allow for adequate preoperative imaging. Although different methodological approaches have been explored to overcome these difficulties, the clinical evidence so far acquired does not justify the use of SLNB as a routine clinical procedure to stage the tumor status of mediastinal lymph nodes in patients with NSCLC. Nonetheless, the search is continuing for the optimal combination of techniques to optimize and validate the SLNB approach for NSCLC; promising perspectives in this regard include a combination of multimodal techniques, for instance intraoperative gamma probe guidance combined with detection of either an optical and/or a magnetic signal.

The efficacy of low and high dose 99mTc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism

ObjectiveThe aim of this study was to compare the efficacy of low- and high-dose 99mTc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands via gamma probe in secondary hyperparathyroidism. Material and MethodsThis retrospective study was conducted using a prospective database of 59 patients who had undergone radioguided subtotal parathyroidectomy between 2004-2012. The patients were studied in 2 groups. Group 1 (n=31) received 37 MBq 99mTc-MIBI intravenously in the surgical room approximately 10min before the beginning of the intervention and surgery was performed under gamma probe guidance. Group 2 (n=28) received 555 MBq 99mTc- MIBI intravenously 2h before surgery, which was also performed under gamma probe guidance. Intraoperative gamma probe findings, laboratory findings, and histopathological findings were evaluated together. ResultsUsing acceptance of the histopathological findings as gold standard, sensitivity and specificity of intraoperative gamma probe for identifying hyperplastic parathyroid glands was 98% and 100%, respectively, in both groups. ConclusionsIn the light of these findings, it is concluded that the low-dose 99mTc-MIBI protocol might be preferable for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism patients because it was observed to be as effective as the high-dose 99mTc-MIBI protocol. Furthermore, the low-dose protocol does not have the disadvantages that are associated with the high-dose protocol.

Sentinel node biopsy for early‐stage oral cavity cancer: the VU University Medical Center experience

Sentinel node biopsy (SNB) in head and neck cancer is recently introduced as the staging technique of oral squamous cell carcinoma. We report the results of SNB in patients diagnosed with a T1-T2 oral squamous cell carcinoma and clinically negative (N0) neck in a single center. A retrospective analysis of 90 previously untreated patients who underwent SNB between 2007 and 2012 was performed. The SNB procedure consisted of preoperatively performed lymphoscintigraphy, intraoperative detection using blue dye, and gamma probe guidance and histopathologic examination including step-serial sectioning (SSS) and immunohistochemical (IHC) staining. A positive SNB was followed by neck dissection, whereas regular follow-up with ultrasound-guided fine-needle aspiration cytology (FNAC) was done in case of a negative SNB. The lymphoscintigraphic identification rate was 98% (88 of 90 patients) and the surgical detection rate was 99% (87 of 88 patients). The upstaging rate was 30%. Sensitivity of SNB was 93% and the negative predictive value was 97%. The median follow-up was 18 months (range, 2-62 months). Overall survival (OS) and disease-free survival (DFS) for SNB negative were 100% and 84% and for SNB positive patients 73% and 88%, respectively. SNB is a reliable diagnostic staging technique for the clinically negative neck in patients with early-stage (T1-T2, cN0) oral squamous cell carcinoma.

The efficacy of low and high dose 99mTc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism

The aim of this study was to compare the efficacy of low- and high-dose (99m)Tc-MIBI protocols for intraoperative identification of hyperplastic parathyroid glands via gamma probe in secondary hyperparathyroidism. This retrospective study was conducted using a prospective database of 59 patients who had undergone radioguided subtotal parathyroidectomy between 2004-2012. The patients were studied in 2 groups. Group 1 (n=31) received 37 MBq (99m)Tc-MIBI intravenously in the surgical room approximately 10 min before the beginning of the intervention and surgery was performed under gamma probe guidance. Group 2 (n=28) received 555 MBq (99m)Tc- MIBI intravenously 2h before surgery, which was also performed under gamma probe guidance. Intraoperative gamma probe findings, laboratory findings, and histopathological findings were evaluated together. Using acceptance of the histopathological findings as gold standard, sensitivity and specificity of intraoperative gamma probe for identifying hyperplastic parathyroid glands was 98% and 100%, respectively, in both groups. In the light of these findings, it is concluded that the low-dose (99m)Tc-MIBI protocol might be preferable for intraoperative identification of hyperplastic parathyroid glands in secondary hyperparathyroidism patients because it was observed to be as effective as the high-dose (99m)Tc-MIBI protocol. Furthermore, the low-dose protocol does not have the disadvantages that are associated with the high-dose protocol.

Intraoperative gamma probe guidance with 99mTc-pertechnetate in the completion thyroidectomy

Intraoperative gamma probe (GP) guidance with (99m)Tc-pertechnetate in the completion total thyroidectomy after a first thyroidectomy was investigated in this prospective study. The study group comprises of fourteen consecutive patients (14 females, age mean 50.2 +/- 12.0 years, age range 29-73 years). All patients underwent a second thyroidectomy due to inadequate (5/14 patients) and complementary (9/14 patients) interventions. Serum-free three iodothyronine, free thyroxin and thyroid stimulating hormone measurements, a neck ultrasonography (USG) and thyroid scintigraphy (TS) were performed in the preoperative and postoperative period. After a 185 MBq (5 mCi) injection of (99m)Tc-pertechnetate, background (BG), left thyroid lobe (LTL), right thyroid lobe (RTL) and pyramidal tyroid lobe (PTL) regions were counted in time before and after resection of thyroid remnants by intraoperative GP. All resection materials were evaluated by histopathologic examination. Preoperative TSH was less than 30 mIU/mL (mean 21 +/- 7) in all patients. Functioning thyroid remnants were shown in 13/14 patients on the preoperative TS and USG, which were diagnosed by USG in one but by TS in other one. We calculated that percentage median (minimum-maximum) values were 220.90% (56.00-411.11%) in LTL, 80.43% (11.54-471.05%) in RTL and 66.60% (-3.33 to 158.33%) in PTL for counts before resection, on the other hand, 15.96% (-20.55 to 47.62%) in LTL, 17.59% (-15.07 to 38.46%) in RTL and 17.59% (-1.96 to 57.14%) in PTL regions for counts after resection. There were statistically significant differences between these values belonging to before and after resection for LTL (p = 0.001), RTL (p = 0.001) and PTL (p = 0.008). Bilateral small foci in a patient and unilateral focus in other patient were observed in postoperative TS. Unilateral focus was detected on the RTL by GP, but not bilateral foci. Postoperative TSH levels increased to 30 mIU/mL (mean 69 +/- 26) at least. There was a statistically significant difference between preoperative and postoperative TSH values (p < 0.001). Histopathologic confirmation revealed that all removed materials were the thyroid tissues. Gamma probe guidance with (99m)Tc-pertechnetate seemed to be a good option and easy available method in patients undergoing the completion total thyroidectomy.

123I MIBG Mapping with Intraoperative Gamma Probe for Recurrent Neuroblastoma

Intraoperative gamma probe guidance has become widely utilized for sentinel lymph node dissection in patients with breast cancer and melanoma, using (99m)Tc sulfur colloid. However, new indications are possible and need to continue to be investigated. We report the use during a wedge liver biopsy of a new hand-held gamma probe designed for (123)I intraoperative guidance. The patient studied is a 5-year-old boy with history of stage 4 high-risk neuroblastoma. Anatomic imaging (CT, MRI), (99m)Tc bone scintigraphy and 2-deoxy-2-[F-18]fluoro-d-glucose-positron emission tomography/computed tomography (FDG-PET/CT) were negative, but the (123)I MIBG scintigraphy suggested recurrent liver disease. A decision was made to biopsy these lesions to obtain histopathological confirmation. Intraoperative gamma probe mapping of the liver identified areas with signal above the background, but these were prove to be hemosiderin deposits on histo-pathology examination.

Lymphatic Mapping and Sentinel Lymphadenectomy for 106 Head and Neck Lesions: Contrasts Between Oral Cavity and Cutaneous Malignancy

The objectives of this prospective series were to present our results in 106 sequential cases of lymphatic mapping and sentinel lymph node biopsy (SLNB) in the head and neck region and contrast the experience in oral cancer with that for cutaneous lesions. SLNB has an acceptably low complication rate in the head and neck. Lymphatic mapping and gamma probe-guided lymphadenectomy can improve the management of malignancies of the head and neck by more accurate identification of the nodal basins at risk and more accurate staging of the lymphatics. For appropriately selected patients, radionuclide lymphatic mapping may safely allow for minimally invasive sentinel lymphadenectomy without formal completion selective lymphadenectomy. One hundred six patients underwent intralesional radionuclide injection and radiologic lymphoscintigraphy (LS) on Institutional Review Board-approved protocols and 103 of these underwent successful SLNB. These included 35 patients with malignant melanoma, 10 cutaneous squamous cell carcinomas, four lip cancers, eight Merkel cell carcinomas, two rare cutaneous lesions, and 43 oral cancers. Mean follow up was 24 months. Patients with oral cavity malignancy underwent concurrent selective neck dissection after narrow-exposure sentinel lymph node excision. In this group, the SLNB histopathology could be correlated with the completion neck specimen histopathology. Patients with cutaneous malignancy underwent SLNB alone and only received regional lymphadenectomy based on positive histology or clinical indications. Data were tabulated for anatomic drainage patterns, complications, histopathology, and patterns of cancer recurrence. Surgical complications were rare. No temporary or permanent dysfunction of facial or spinal accessory nerves occurred with sentinel node biopsy. Lymphatic drainage to areas dramatically outside of the expected lymphatic basins occurred in 13.6%. Predictive value of a negative sentinel node was 98.2% for cutaneous malignancies (based on regional recurrence) and 92% with oral cancer (based on pathologic correlation). Gross tumor replacement of lymph nodes and redirection of lymphatic flow represented a significant technical issue in oral squamous cell carcinoma. Sixteen percent of patients with oral cancer were upstaged from N0 to N1 after extended sectioning and immunohistochemistry of the sentinel node. LS and SLNB can be performed with technical success in the head and neck region. Complications are minimal. More accurate staging and mapping of lymphatic drainage may improve the quality of standard lymphadenectomy. The potential for minimally invasive surgery based on this technology exists, but there is a small risk of missing positive disease. Whether the failure rate is greater than that of standard lymphadenectomy without gamma probe guidance is not known. New studies need to focus on refinements of technique and validation of accuracy as well as biologic correlates for the prediction of metastases.

Sentinel Lymph Node Biopsy: A Rational Approach for Staging T2N0 Oral Cancer

For oral cancer patients, the presence of neck nodal metastases is the most important disease prognosticator. However, a significant proportion of clinically N0 patients harbor occult microscopic nodal metastasis. Our objective was to determine the feasibility and accuracy of sentinel node biopsy (SNB) in the staging of T2N0 oral carcinoma patients. Prospective analysis. Twenty patients with previously untreated N0 oral cavity squamous cell carcinoma were studied. Each patient had an SNB performed using preoperative technetium sulfur colloid lymphoscintigraphy, intraoperative gamma probe guidance, and intraoperative peritumoral injection of 1% isosulfan blue. All patients underwent neck dissection. The sentinel lymph nodes (SLNs) were sectioned in 2- to 3-mm intervals, formalin fixed, and sectioned at three levels. The non-SLNs were sectioned in a routine manner for histologic examination. SLNs were identified in all patients (100%) and accurately predicted the pathologic nodal status in 18 of 20 patients (90%). Tumor was found exclusively in the SLNs in six patients (30%). Two patients had positive SLNs at multiple neck levels. Two patients had a negative SLN and a positive non-SLN (false-negative findings). Occult nodal metastases were present in 60% of the cohort. SNB is a technically feasible and accurate procedure for staging the neck in oral carcinoma patients. However, SNB accuracy is lower for floor of the mouth lesions. The rate of occult nodal metastases identified in this cohort is higher than previously reported in the literature. These results suggest that SNB warrants further multi-institutional studies.

Identification of Sentinel Lymph Nodes in Breast Cancer by Lymphoscintigraphy and Gamma Probe Guidance: Dependence on Route of Injection and Tumour Location

Background: Sentinel lymph node detection with radiocolloids is confronted with the same problem as the blue dye (BL) method: Even now there is no standardized procedure as regards the application method, the amount of radioactivity and injected volume of the radiocolloid (RC). Therefore, our aim was to find out the most reliable application method and to evaluate a possible tumour-site dependence of detectability.

Präoperative Identifikation und chirurgische Entfernung des Sentinel-Lymphknotens bei malignen Hauttumoren

The sentinel lymph node is a reliable indicator for a lymphogenous metastasis of malignant tumors. Its operative removal followed by histological examination enables an exact staging of the nodal status. Micrometastases can be detected at a very early time of tumor dissemination and high-risk patients can be selected for further operative and/or medicamentous therapeutic modalities. A close cooperation of surgeon, pathologist and nuclear medicine physician is necessary for optimum results. Preoperative identification must be performed by dynamic lymphoscintigraphy after peritumoral injection of a radiotracer. For the surgical removal of the SLN a combined approach by gamma-probe guidance and blue-dye is the procedure of choice. Complete cutting of the SLN and immunohistochemical stainings facilitate the detection of the often tiny micrometastases. By the described technique the identification and extirpation of the SLN succeded in nearly 100% of the more than 400 patients. During a 6-year follow-up only one patient with a negative SLN developed a lymph-node recurrence. This corresponds to a false-negative rate of less than 0.3%. However, it is not sure in which tumors a SLNE is indicated. We recommend the SLNE in all new diagnosed melanoma patients in clinical stages Ib to IIIa and other high-risk skin malignancies. The detection of tumor cells in the SLN is an indication for a radical lymph node dissection, but there is also no consensus concerning this point. Nevertheless studies have to show whether the removal of the SLN is more than a very sensitive diagnostic method or whether patients will profit from this early knowledge of metastases. Hitherto no influence on overall survival can be shown.

Ultrasound imaging of the sentinel lymph node in malignant melanoma

In the therapy of malignant melanoma sentinel lymph node(SLN) excision has assumed increased importance. The localization of the sentinel node is possible by lymphoscintigraphy and gamma probe guidance. Aim of the study was to prove whether SLN can be identified sonographically. 23 patients (16 women, 7 men; average age 42.7 years) with malignant melanoma required SLN excision. Before the patient underwent lymphoscintigraphy, sonography of the regional lymph nodes was performed. The position of lymph nodes (LN) with asymmetrical extension of the cortical substance was marked cutaneously according to the probe position in two axis (M1). During lymphoscintigraphy the gamma probe position orthograd to the skin with the highest count rate was marked (M2). Then a second sonography of the region was performed. In all patients M1 and M2 marked the same point. During the operation the sonographically documented position of the SLN could be confirmed in all cases. The second sonography after the lymphoscintigraphy showed a more blurred distinction between the cortical substance and the center of the lymph nodes. Our results show that sonography allows an identification of SLN. We think that the preoperative sonography of the SLN is an important supplementary method in addition to lymphoscintigraphy.

Primary therapy of malignant melanomas: sentinel lymphadenectomy.

Each melanoma is drained by one or, occasionally, several individual lymph nodes within the nearest lymph node region (sentinel lymph node). By histopathologic examination of the removed sentinel lymph node (SLN), it is possible to select patients clinically according to stage I or II (UICC classification), but who, microscopically, represent stage III. Sentinel lymphadenectomies (SLNEs) were performed initially by the vital blue dye technique, and later by gamma-probe guidance only. The removed SLNs were examined by hematoxylin and eosin as well as immunohistochemical stains (S100, and HMB 45). We have performed 115 gamma-probe-guided SLNEs in 100 patients. The SLN could be found in all cases. In pT3 + 4 melanomas, 27.5% of the SLNs were positive; in only one patient with a pT2 tumor were micrometastases found. gamma-Probe-guided SLNE is a reliable procedure with minimal complications that should be performed in all pT3 + 4 (intraoperative frozen section histology) melanomas without clinically evident metastases.

The impact of dynamic lymphoscintigraphy and gamma probe guidance on sentinel node biopsy in melanoma.

In cutaneous melanoma, biopsy of the first tumour-draining lymph node (sentinel node, SN) may replace routine elective lymph node dissection (ELND). Even in experienced hands the original technique using vital dyes fails to localise the SN in 20% of cases. In this study we investigated whether the procedure benefits from lymphoscintigraphy and the use of a gamma probe. In 41 patients technetium-99m-colloidal albumin was injected intracutaneously around the scar of the excised tumour. This was followed by dynamic and late static imaging. The first focal accumulation was assumed to be the SN. In all patients at least one SN was found, in 95% within the first 20 min. By showing multiple or ramifying lymphatic channels, dynamic lymphoscintigraphy differentiated between spill and multiple SNs. In all cases the initial focus retained the highest fraction of radioactivity for at least 18 h. The gamma probe was especially useful in the axilla and neck, where it accurately showed the optimal incision site and facilitated the search for deep-seated nodes. Gamma probe-localised SNs were dye-positive in 93% of cases. The SN contained metastases in 20% of the patients. Only in these patients was ELND performed, which revealed that the SN had been the only metastatic node in four of eight cases. We conclude that dynamic lymphoscintigraphy is essential for SN localisation, that tracer kinetics allow flexible timing of surgery, and that the surgical procedure benefits from use of the gamma probe.