Detection of Sentinel Lymph Nodes in Gynecologic Tumours by Planar Scintigraphy and SPECT/CT

Skin Cancer Pathobiology at a Glance: A Focus on Imaging Techniques and Their Potential for Improved Diagnosis and Surveillance in Clinical Cohorts

Early diagnosis is essential for completely eradicating skin cancer and maximizing patients' clinical benefits. Emerging optical imaging modalities such as reflectance confocal microscopy (RCM), optical coherence tomography (OCT), magnetic resonance imaging (MRI), near-infrared (NIR) bioimaging, positron emission tomography (PET), and their combinations provide non-invasive imaging data that may help in the early detection of cutaneous tumors and surgical planning. Hence, they seem appropriate for observing dynamic processes such as blood flow, immune cell activation, and tumor energy metabolism, which may be relevant for disease evolution. This review discusses the latest technological and methodological advances in imaging techniques that may be applied for skin cancer detection and monitoring. In the first instance, we will describe the principle and prospective clinical applications of the most commonly used imaging techniques, highlighting the challenges and opportunities of their implementation in the clinical setting. We will also highlight how imaging techniques may complement the molecular and histological approaches in sharpening the non-invasive skin characterization, laying the ground for more personalized approaches in skin cancer patients.

Utility of indocyanine green as a single tracer for sentinel node biopsy in endometrial cancer

AIM

Our study aims to investigate the safety and effectiveness of sentinel lymph node biopsy using indocyanine green (ICG) for the surgical staging of early-stage endometrial cancer in comparison to technetium-99 m use.

METHODS

We conducted an observational retrospective study with patients diagnosed of endometrial cancer and FIGO stages I-II. All participants were injected technetium-99m the day prior to the surgery and underwent lymphoscintigraphy along with single-photon emission computed tomography. In addition, all patients were administered intraoperatively ICG injection to detect sentinel lymph node biopsy. The surgical staging was then completed according to the European Society for Medical Oncology preoperative risk category. Data obtained from the analysis of technetium-99m detection was compared to ICG detection.

RESULTS

A total of 53 women with endometrial cancer were included in the study, 49 (92.5%) of them showed drainage preoperatively in the single-photon emission computed tomography and/or lymphoscintigraphy. The intraoperative bilateral detection rate for technetium-99 m was 26 (49.1%) patients compared to 40 (75.5%) patients with ICG (p = 0.013). We observed a 42.5% increase in the mean number of lymph nodes retrieved by ICG compared to technetium-99m (2.85 vs 2,0 nodes; p = 0.002). We intraoperatively identified 164 lymph nodes, 104 (63.4%) located in both obturator areas and external iliac vessels.

CONCLUSION

The use of ICG for the performance of sentinel node biopsy in patients with endometrial cancer seems safe and could be superior to technetium-99 m, since it offers a higher bilateral detection rate and nodal retrieval, resulting in the possibility to perform safely less full staging lymphadenectomies.

Sentinel Lymph Node Mapping in Endometrial Cancer: A Comprehensive Review

Endometrial cancer (EC) is known as a common gynecological malignancy. The incidence rate is on the increase annually. Lymph node status plays a crucial role in evaluating the prognosis and selecting adjuvant therapy. Currently, the patients with high-risk (not comply with any of the following: (1) well-differentiated or moderately differentiated, pathological grade G1 or G2; (2) myometrial invasion< 1/2; (3) tumor diameter < 2 cm are commonly recommended for a systematic lymphadenectomy (LAD). However, conventional LAD shows high complication incidence and uncertain survival benefits. Sentinel lymph node (SLN) refers to the first lymph node that is passed by the lymphatic metastasis of the primary malignant tumor through the regional lymphatic drainage pathway and can indicate the involvement of lymph nodes across the drainage area. Mounting evidence has demonstrated a high detection rate (DR), sensitivity, and negative predictive value (NPV) in patients with early-stage lower risk EC using sentinel lymph node mapping (SLNM) with pathologic ultra-staging. Meanwhile, SLNM did not compromise the patient’s progression-free survival (PFS) and overall survival (OS) with low operative complications. However, the application of SLNM in early-stage high-risk EC patients remains controversial. As revealed by the recent studies, SLNM may also be feasible, effective, and safe in high-risk patients. This review aims at making a systematic description of the progress made in the application of SLNM in the treatment of EC and the relevant controversies, including the application of SLNM in high-risk patients.

Fusion imaging of ultrasound and MRI in the assessment of locally advanced cervical cancer: a prospective study

BACKGROUND

Fusion imaging is a new diagnostic method that integrates MRI and ultrasound. It may improve the detection and staging of locally advanced cervical cancer.

OBJECTIVE

To evaluate the feasibility and accuracy of fusion imaging in patients with locally advanced cervical cancer.

METHODS

Patients with suspicion of locally advanced cervical cancer at clinical examination and/or imaging, who were candidates for neoadjuvant treatment (chemotherapy or chemoradiation) followed by surgery, were prospectively enrolled between March and November 2018. MRI, ultrasound, and fusion images were obtained before and after neoadjuvant treatment. Feasibility, success of the fusion examination, and time needed to perform fusion studies were evaluated. The rates of concordance between MRI and ultrasound before and after performing fusion, using Cohen, Spearman, and McNemar tests were calculated. The agreement between MRI and ultrasound examination, and the agreement between radiologist and gynecologist during the fusion technique in assessing local extension of disease and the presence of residual disease after neoadjuvant therapy, were also analyzed. The rates of concordance between MRI and ultrasound examination before and after performing fusion imaging, using Cohen's kappa and Spearman's rank correlation coefficient were calculated. A McNemar test was used to assess if there were statistical significant differences in the parameters' agreement before and after performing fusion imaging.

RESULTS

40 patients were selected and of these, 33 were analyzed. A total of 52 fusion examinations were performed: 33 (63.5%) of 52 at the time of diagnosis and 19 (36.5%) of 52 after neoadjuvant treatment. Fusion imaging was feasible in 50 (96%) of 52 studies. The median overall time of fusion execution was 13 min (range 6-30) and the time spent in performing a fusion examination decreased from the first to the last examination (20 vs 6 min). The agreement between MRI and ultrasound parameters increased after performing fusion, particularly for parametrial infiltration (74% vs 86%, p=0.014 for the right posterior parametrium; 66% vs 80%, p=0.008 for the left posterior parametrium, 70% vs 82%, p=0.014 for the right lateral parametrium).

CONCLUSIONS

Fusion of MRI and ultrasound is feasible in patients with locally advanced cervical cancer and may increase the diagnostic accuracy of the single imaging methods. Fusion provides multiple diagnostic opportunities in gynecological oncology.

Lymphoscintigraphy and sentinel lymph node biopsy in vulvar carcinoma: update from a European expert panel

PURPOSE

This study aimed to update the clinical practice applications and technical procedures of sentinel lymph node (SLN) biopsy in vulvar cancer from European experts.

METHODS

A systematic data search using PubMed/MEDLINE database was performed up to May 29, 2019. Only original studies focused on SLN biopsy in vulvar cancer, published in the English language and with a minimum of nine patients were selected.

RESULTS

Among 280 citations, 65 studies fulfilled the inclusion criteria. On the basis of the published evidences and consensus of European experts, this study provides an updated overview on clinical applications and technical procedures of SLN biopsy in vulvar cancer.

CONCLUSIONS

SLN biopsy is nowadays the standard treatment for well-selected women with clinically negative lymph nodes. Negative SLN is associated with a low groin recurrence rate and a good 5-year disease-specific survival rate. SLN biopsy is the most cost-effective approach than lymphadenectomy in early-stage vulvar cancer. However, future trials should focus on the safe extension of the indication of SLN biopsy in vulvar cancer. Although radiotracers and optical agents are widely used in the clinical routine, there is an increasing interest for hybrid tracers like indocyanine-^99mTc-nanocolloid. Finally, it is essential to standardise the acquisition protocol including SPECT/CT images, and due to the low incidence of this type of malignancy to centralise this procedure in experienced centres for personalised approach.

Fusion of ultrasound and 3D single-photon-emission computed tomography/computed tomography to identify sentinel lymph nodes in vulvar cancer: feasibility study

OBJECTIVE

To evaluate the feasibility of fusion of ultrasound imaging and three-dimensional (3D) single-photon-emission computed tomography/computed tomography (SPECT/CT) in detecting sentinel lymph nodes in women with vulvar cancer.

METHODS

This was a prospective pilot single-center study. Patients with vulvar cancer who were candidates for sentinel lymph-node biopsy were enrolled between December 2018 and February 2019. Fusion imaging virtual navigation using 3D SPECT/CT and ultrasound was performed to investigate the tumor-draining lymph node. All clinical, imaging, surgical and histological information was collected prospectively and entered into a dedicated Excel file. Feasibility and success of fusion imaging virtual navigation and time needed to perform the three steps of fusion imaging were evaluated.

RESULTS

Ten lymph-node sites were evaluated in five consecutive women with a histological diagnosis of vulvar cancer. Fusion imaging virtual navigation was feasible and completed successfully for all (10/10) draining sites. Median overall time to perform fusion imaging was 32 (range, 25-40) min and the time decreased from the first to the last examination.

CONCLUSIONS

The present study demonstrated that fusion imaging virtual navigation using 3D SPECT/CT and ultrasound is feasible and able to detect sentinel lymph nodes in women with vulvar carcinoma. Fusion imaging using ultrasound for detection of sentinel lymph nodes opens up multiple diagnostic and therapeutic opportunities in gynecological oncology. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The sentinel node approach in gynaecological malignancies

This review discusses the state-of-the-art of sentinel lymph node mapping in gynaecological malignancies, including cervical cancer, endometrial cancer, and vulvar cancer, with an emphasis on new technological advances. For this objective, PubMed/MEDLINE was searched for relevant studies about the sentinel lymph node procedure in gynaecology. In particular, the use of preoperative lymphatic mapping with lymphoscintigraphy and single photon emission tomography/computed tomography (SPECT/CT) was identified in 18 studies. Other recent advances as hybrid tracers (e.g. ICG-^99mTc-nanocolloid) and intraoperative tools (portable γ-camera and 3D navigation devices) appear to also represent a useful guide for the surgeon during the operation. Concerning vulvar and cervical cancers, the sentinel lymph node procedure has been incorporated to the current guidelines in Europe and North America, whereas for endometrial cancer it is considered investigative.

The use of SPECT/CT for anatomical mapping of lymphatic drainage in vulvar cancer: possible implications for the extent of inguinal lymph node dissection

PURPOSE

To determine the lymphatic drainage pattern using SPECT/CT in clinically node-negative (cN0) patients with vulvar cancer, and to evaluate the possible implications for the extent of inguinal lymph node dissection.

METHODS

A total of 83 patients with vulvar cancer scheduled for sentinel node (SN) biopsy were injected peritumorally with radioactive nanocolloid particles followed by lymphoscintigraphy and SPECT/CT for anatomical localization. The SN and higher-echelon nodes on SPECT/CT were located in different zones in the groin and pelvic region. The groin was divided into five zones according to Daseler et al.: four zones obtained by drawing two perpendicular lines over the saphenofemoral junction and one zone directly overlying this junction. The nodes in the pelvic region were classified into three zones: external iliac/obturator, the common iliac and the paraaortic zones.

RESULTS

A total of 217 SNs and 202 higher-echelon nodes were localized on SPECT/CT. All SNs were located in the five zones according to Daseler et al.: 149 (69%) in the medial superior region, 31 (14%) in the medial inferior region, 22 (10%) in the central region, 14 (6.5%) in the lateral superior region and only 1 (0.5%) in the lateral inferior region. The higher-echelon nodes were located both in the groin (15%) and in the pelvic region (85%).

CONCLUSION

In patients with cN0 vulvar cancer, lymphatic drainage occurs predominantly to the medial regions of the groin. Drainage to the lateral inferior region of the groin is only incidental and in SN-positive patients this zone might be spared in subsequent extended lymph node dissection. This may lead to a decrease in the morbidity associated with this procedure. SPECT/CT is able to personalize lymphatic mapping, providing detailed information about the number and anatomical location of SNs for adequate surgical planning in the groin.

SPECT/CT for SLN dissection in vulvar cancer: Improved SLN detection and dissection by preoperative three-dimensional anatomical localisation

OBJECTIVE

In this study, we assessed the feasibility and clinical advantages of single photon emission computed tomography with CT (SPECT/CT) for sentinel lymph node (SLN) detection in vulvar cancer.

METHODS

This is a unicentric prospective trial. Vulvar cancer patients underwent preoperative SLN marking (10MBq Technetium (TC)-99m-nanocolloid) and subsequent planar lymphoscintigraphy (LSG) and SPECT/CT for SLN visualization. Directly before surgery, a patent blue dye was injected. We assessed detection rates of SPECT/CT and those of planar LSG and intraoperative detection. We analyzed the sensitivity, negative predictive value and false negative rate.

RESULTS

At Hannover Medical School, 40 vulvar cancer patients underwent SLN dissection after preoperative LSG and SPECT/CT. The mean diameter of all tumors in final histology was 2.23 (0.1-10.5) cm with a mean tissue infiltration of 3.93 (0.25-11) mm. In preoperative imaging, SPECT/CT identified significantly more SLNs (mean 8.7 (1-35) LNs per patient) compared to LSG (mean 5.9 (0-22) LNs, p<0.01). In addition, SPECT/CT led to a high spatial resolution and anatomical localization of SLNs. Thus, SPECT/CT identified aberrant lymphatic drainage in 7/40 (17.5%) patients. There were no significant differences, but significant correlation was found between SPECT/CT and intraoperative SLN identification. Regarding inguino-femoral LNs, for all patients who underwent complete groin dissection, sensitivity was 100%, NPV was 100% and false negative rate was 0%.

CONCLUSION

SPECT/CT leads to higher SLN identification compared to LSG in vulvar cancer. Due to its higher spatial resolution and three-dimensional anatomical localisation of SLNs, SPECT/CT provides the surgeon with important additional information, facilitates intraoperative SLN detection and predicts aberrant lymphatic drainage.

99mTc SPECT/CT Versus Planar Lymphoscintigraphy for Preoperative Sentinel Lymph Node Detection in Cervical Cancer: A Systematic Review and Metaanalysis

We aimed to compare SPECT/CT and lymphoscintigraphy on overall and bilateral sentinel lymph node (SLN) detection in cervical cancer patients.

METHODS

A systematic search was performed on August 1, 2014, in PubMed, Embase, Scopus, and the Cochrane library. The syntax was based on synonyms of the terms cervical cancer, SPECT/CT, and lymphoscintigraphy. Retrieved articles were screened on their title/abstract and considered eligible when an SLN procedure was performed using both imaging modalities and if detection results were reported. Two independent reviewers assessed all included studies on methodologic quality using QUADAS-2. Studies were pooled on their odds ratios (ORs) with a random-effects model.

RESULTS

The search yielded 962 unique articles, of which 8 were ultimately included. The studies were recent retrospective or prospective cohort studies of limited size (n = 7-51) but sufficient methodologic quality. The median overall detection (≥1 SLN in a patient) was 98.6% for SPECT/CT (range, 92.2%-100.0%) and 85.3% for lymphoscintigraphy (range, 70.0%-100.0%). This corresponded to a pooled overall SLN detection OR of 2.5 (95% CI, 1.2-5.3) in favor of SPECT/CT. The reported median bilateral detection (≥1 SLN in each hemipelvis) was 69.0% for SPECT/CT (range, 62.7%-79.3%) and 66.7% for lymphoscintigraphy (range, 56.9%-75.8%), yielding a pooled OR of 1.2 (95% CI, 0.7-2.1). No significant difference in the number of visualized SLNs was observed at a pooled ratio of 1.2 (95% CI, 0.9-1.6).

CONCLUSION

In cervical cancer patients, preoperative SLN imaging with SPECT/CT results in superior overall SLN detection in comparison with planar lymphoscintigraphy.

Feasibility and performance of lymphoscintigraphy in sentinel lymph node biopsy for early cervical cancer: results of the prospective multicenter SENTICOL study

Objective

To evaluate feasibility, SLN detection rate, and SLN location of lymphoscintigraphy in sentinel lymph node (SLN) biopsy for early cervical cancer.

Methods

Ancillary analysis of data from the multicenter prospective SENTICOL study (January 2005–June 2007) of patients with early cervical cancer (FIGO stage IA with emboli to IB1) was conducted. Preoperative lymphoscintigraphy was performed after intracervical administration of 60 or 120 MBq of ^99mTc-labeled radiocolloid on the day before (long protocol) or morning of (short protocol) surgery. SLNs were identified intraoperatively using combined radioactivity/patent blue detection. SLNs were sampled electively and routine bilateral pelvic lymphadenectomy was performed by laparoscopy. A centralized review of lymphoscintigraphies was performed to assess feasibility, detection rates, and anatomic SLN location.

Results

Of 139 patients included in the SENTICOL study, 133 received radiocolloid injection, and 131 (98.5 %) underwent preoperative lymphoscintigraphy, with the long protocol in three-fourths of cases. The lymphoscintigraphic detection rate was 87.8 %, with a median of 2 (1–4) SLNs per patient. By multivariate analysis, factors independently associated with lymphoscintigraphic SLN detection were age [odds ratio (OR) 0.91, 95 % confidence interval (95 % CI) 0.87–0.96; P < 0.001], and protocol (long vs. short; OR 8.23, 95 % CI 1.87–36.25; P = 0.005). Bilateral SLN identification by lymphoscintigraphy occurred in 67 % of cases and was independently influenced by age (OR 0.95, 95 % CI 0.92–0.98, P < 0.001) and protocol (OR 5.42, 95 % CI 2.21–13.27; P < 0.001). Although 60.5 % of preoperative SLNs were in the external iliac territory, unusual drainage patterns included the common iliac (19.6 %), para-aortic (10.8 %), and parametrial (6 %) basins.

Conclusions

Our study demonstrates the feasibility and good detection rate of preoperative lymphoscintigraphy, with better detection in younger patients and with the long protocol. The high proportion of SLN basins in unexpected territories is of interest to guide intraoperative detection. Further studies are needed to better evaluate preoperative detection and to assess the contribution of lymphoscintigraphy to intraoperative detection.

Sentinel node biopsy for lymph nodal staging of uterine cervix cancer: a systematic review and meta-analysis of the pertinent literature

BACKGROUND

We reviewed the available literature on the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers.

METHODS

MEDLINE and Scopus were searched by using "sentinel AND (cervix OR cervical)" as key words. Studies evaluating the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers were included if enough data could be extracted for calculation of detection rate and/or sensitivity.

RESULTS

Sixty-seven studies were included in the systematic review. Pooled detection rate was 89.2% [95% CI: 86.3-91.6]. Pooled sensitivity was 90% [95% CI: 88-92]. Sentinel node detection rate and sensitivity were related to mapping method (blue dye, radiotracer, or both) and history of pre-operative neoadjuvant chemotherapy. Sensitivity was higher in patients with bilaterally detected pelvic sentinel nodes compared to those with unilateral sentinel nodes. Lymphatic mapping could identify sentinel nodes outside the routine lymphadenectomy limits.

CONCLUSION

Sentinel node mapping is an accurate method for the assessment of lymph nodal involvement in uterine cervical cancers. Selection of a population with small tumor size and lower stage will ensure the lowest false negative rate. Lymphatic mapping can also detect sentinel nodes outside of routine lymphadenectomy areas providing additional histological information which can improve the staging. Further studies are needed to explore the impact of sentinel node mapping in fertility sparing surgery and in patients with history of neoadjuvant chemotherapy.

Value and advantages of preoperative sentinel lymph node imaging with SPECT/CT in cervical cancer

OBJECTIVE

Precise detection of sentinel lymph nodes (SLNs) seems to be a crucial factor for optimized treatment of cervical cancer. We assess the use of single photon emission computed tomography combined with computed tomography (SPECT/CT) as an alternative to lymphoscintigraphy (LSG) for preoperative identification of SLN.

METHODS

This study was performed in a prospective, unicentric setting. Patients with cervical carcinoma were scheduled for surgery and additional SLN labeling by peritumoral injection of 10 MBq technetium-99m-nanocolloid and patent blue. Thirty minutes after injection, LSG and SPECT/CT were carried out. We evaluated the number of SLNs detected intraoperatively in LSG and SPECT/CT and the histologic findings of SLN and non-SLN. Subsequently, we determined the impact of these results on the therapeutic approach.

RESULTS

This represents the largest study about SPECT/CT for SLN detection in cervical cancer so far. Between August 2008 and March 2013, 59 cervical cancer patients underwent intraoperative SLN detection. In addition, 51 of these patients underwent preoperative LSG and SPECT/CT. Imaging with SPECT/CT detected singular SLN at significantly higher rate (47/51, 92.2%) than that with planar LSG (43/51, 84.3%, P = 0.044). Furthermore, SPECT/CT performed better than LSG regarding the total number of detected SLN (SPECT/CT median, 3 [0-18]; LSG median, 2 [0-15]) and detection rates per pelvic side (SPECT/CT 76.9%, LSG 69.2%, P < 0.01). Whenever SLN detection succeeded, histologic evaluation of SLN correctly predicted the lymph node status per patient's side. Using this type of diagnostic approach for lymph node staging, we reached sensitivity of 100% and negative predictive value of 100% at a rate of false-negative results of 0% even in tumors larger than 4 cm.

CONCLUSIONS

Single photon emission computed tomography combined with computed tomography imaging leads to improved rates of SLN detection and better anatomic correlation compared with planar LSG. Thus, intraoperative detection of SLN can be improved by preoperative SPECT/CT imaging. This enhances the clinical value of SLN technique and improves the oncologic safety of SLN concept.

Growth plate uptake of Tc-99m-phytate on lymphoscintigraphy images

We report two pediatric cases with the history of lower extremity edema who were referred to the nuclear medicine department for lower limb lymphoscintigraphy as lymphedema workup. Subcutaneous injection of Tc-99m phytate in the interdigital webs was used for both patients, followed by early and delayed whole body lymphoscintigraphy imaging. Images of both patients showed Tc-99m phytate accumulation in the growth plates of the lower limbs. This biodistribution could interfere with popliteal lymph node visualization and should always be taken into account in lymphoscintigraphy of pediatric patients. We also review the medical literature regarding biodistribution Tc-99m phytate after interstitial injections.

Sentinel lymph node evaluation in women with cervical cancer

Lymph node status is the most important prognosticator of survival in women with early stage cervical cancer. Thus many patients with cervical cancer will undergo pelvic lymphadenectomy as part of the treatment. This procedure is associated with substantial morbidity. Use of the sentinel lymph node technique in women with cervical cancer has the potential to decrease this morbidity. Multiple studies have suggested that sentinel lymph node mapping in these patients is feasible, with excellent detection rates and sensitivity. This review examines the current body of literature about sentinel lymph node biopsy in women with cervical cancer.

Pelvic kidney visualization on the lymphoscintigraphy images of a patient with uterine cervix cancer: importance of the delayed imaging

We reported an unusual visualization of a pelvic kidney on the lymphoscintigraphy images of a patient with uterine cervix cancer, which was mistaken with para-aortic sentinel nodes. Delayed imaging clearly showed the nature of this activity. Our case underscores the importance of delayed pelvic lymphoscintigraphy imaging in the sentinel node mapping of gynecological cancers.

Molecular imaging agents for SPECT (and SPECT/CT)

The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers.

SPECT/CT and tumour imaging

Scintigraphic techniques are sensitive imaging modalities in the diagnosis and follow-up of cancer patients providing the functional and metabolic activity characteristics of the tumour. Hybrid SPECT/CT improves the diagnostic accuracy of these well-established imaging techniques by precise anatomical localization and characterization of morphological findings, differentiation between foci of physiological and pathological tracer uptake, resulting in a significant impact on patient management and more definitive interpretations. The use of SPECT/CT has been studied in a variety of applications in tumour imaging which are reviewed in this article. By combining functional and anatomical information in a single imaging session, SPECT/CT has become a one-stop cancer imaging modality.

Is sentinel lymph node dissection an appropriate standard of care for low-stage endometrial cancers? A review of the literature

BACKGROUND/AIMS

To review the literature and compare detection rates, false negative (FN) rates, and negative predictive values (NPVs) of sentinel lymph node (SLN) biopsy in endometrial cancer to those in breast and vulvar cancer. Secondary objectives were to evaluate techniques of SLN biopsy in endometrial cancer.

METHODS

The PubMed database was searched for applicable scientific articles. Detection rates, FN rates, and NPVs were calculated for all studies. Studies were stratified by techniques and compared.

RESULTS

Nineteen articles met criteria for this review. The overall detection rates ranged from 62 to 100%, the FN rate ranged from 0 to 50%, and the NPVs ranged from 95 to 100%. There is no technique that is definitively superior to any other with regard to surgical modality, injectant used, injection site, or pathologic techniques.

CONCLUSIONS

Studies on SLN biopsy in endometrial cancer have a large range of detection rates and FN rates, and larger studies including more patients with metastatic disease are needed for comparison with breast and vulvar cancers. While no techniques are definitively superior to others, minimally invasive surgery, cervical injection, and pathologic analysis utilizing HE staining, immunohistochemistry, and ultrastaging may be clinically advantageous.