Intraoperative Hand-Held Imaging γ-Camera for Sentinel Node Detection in Patients With Breast Cancer: Feasibility Evaluation and Preliminary Experience on 16 Patients

Smaller is better? Compact vs. Conventional gamma camera for sentinel lymph node localization in patients with breast cancer

PURPOSE

Sentinel lymph node biopsy (SLNB) has been recognized as "the gold standard" for axillary staging in early breast cancer patients with clinically negative lymph nodes, resulting in significant morbidity decrease and quality of life improvement. This study aims to validate the performance of a newly developed handheld portable gamma camera (PGC) produced by Imagensys (Italy), in detecting and locating sentinel lymph nodes (SLNs) during the preoperative and intraoperative phases in breast cancer patients compared to conventional lymphoscintigraphy.

METHODS

Adult female patients with histologically confirmed breast cancer, candidates for surgery and SLNB, were prospectively enrolled in this open-label, pre-marketing clinical trial. All patients underwent pre- operative assessment using both the PGC and conventional lymphoscintigraphy. The performance of the two devices was compared using the Poisson regression model for incidence rate ratios (IRRs). The intrinsic sensitivity of the devices was compared using the Wilcoxon Ranked Sign Test. The utility of PGC during intra-operative procedures was also evaluated. The manoeuvrability of the devices was evaluated using operator-satisfaction questioner.

RESULTS

Sixty-eight patients (median age 50 years, BMI 21.4) were enrolled, including two patients with bilateral breast cancer, who underwent SLNB on both axillae. The PGC demonstrated superior preoperative lymph node detection rate (IRR 8.01, 95% CI 6.11-10.50; p < 0.0001) and intrinsic device sensitivity (mean counts per second 409 ± 286 vs. 255 ± 1173 for conventional device, p = 0.0003) compared to the conventional gamma camera. Intra-operative assessment with PGC was performed in 62 patients and no additional lymph nodes were visualised. However, the conventional gamma camera demonstrated superior manoeuvrability (p < 0.0001).

CONCLUSION

The PGC handheld gamma camera showed promising results for preoperative SLN assessment in patients with breast cancer. The limited manoeuvrability may be related to the operator's experience leading to higher inter-operator variability. Appropriate training and frequent use of nuclear medicine and surgical equipment could overcome this limitation.

Intraoperative Gamma Cameras: A Review of Development in the Last Decade and Future Outlook

Portable gamma cameras suitable for intraoperative imaging are in active development and testing. These cameras utilise a range of collimation, detection, and readout architectures, each of which can have significant and interacting impacts on the performance of the system as a whole. In this review, we provide an analysis of intraoperative gamma camera development over the past decade. The designs and performance of 17 imaging systems are compared in depth. We discuss where recent technological developments have had the greatest impact, identify emerging technological and scientific requirements, and predict future research directions. This is a comprehensive review of the current and emerging state-of-the-art as more devices enter clinical practice.

Pelvic lymph node dissection in high-risk prostate cancer

INTRODUCTION

The therapeutic role of pelvic lymph node dissection (PLND) in prostate cancer (PCa) is unknown due to absence of randomized trials.

OBJECTIVE

to present a critical review on the therapeutic benefits of PLND in high risk localized PCa patients.

MATERIALS AND METHODS

A search of the literature on PLND was performed using PubMed, Cochrane, and Medline database. Articles obtained regarding diagnostic imaging and sentinel lymph node dissection, PLND extension, impact of PLND on survival, PLND in node positive "only" disease and PLND surgical risks were critically reviewed.

RESULTS

High-risk PCa commonly develops metastases. In these patients, the possibility of presenting lymph node disease is high. Thus, extended PLND during radical prostatectomy may be recommended in selected patients with localized high-risk PCa for both accurate staging and therapeutic intent. Although recent advances in detecting patients with lymph node involvement (LNI) with novel imaging and sentinel node dissection, extended PLND continues to be the most accurate method to stage lymph node disease, which may be related to the number of nodes removed. However, extended PLND increases surgical time, with potential impact on perioperative complications, hospital length of stay, rehospitalization and healthcare costs. Controversy persists on its therapeutic benefit, particularly in patients with high node burden.

CONCLUSION

The impact of PLND on biochemical recurrence and PCa survival is unclear yet. Selection of patients may benefit from extended PLND but the challenge remains to identify them accurately. Only prospective randomized study would answer the precise role of PLND in high-risk pelvis confined PCa patients.

Interventional nuclear medicine: a focus on radioguided intervention and surgery

Within interventional nuclear medicine (iNM) a prominent role is allocated for the sub-discipline of radioguided surgery. Unique for this discipline is the fact that an increasing number of clinical indications (e.g. lymphatic mapping, local tumor demarcation and/or tumor receptor targeted applications) have been adopted into routine care. The clinical integration is further strengthened by technical innovations in chemistry and engineering that enhance the translational potential of radioguided procedures in iNM. Together, these features not only ensure ongoing expansion of iNM but also warrant a lasting clinical impact for the sub-discipline of radioguided surgery.

Recent advances in nuclear and hybrid detection modalities for image-guided surgery

Introduction: Radioguided surgery is an ever-evolving part of nuclear medicine. In fact, this nuclear medicine sub-discipline actively bridges non-invasive molecular imaging with surgical care. Next to relying on the availability of radio- and bimodal-tracers, the success of radioguided surgery is for a large part dependent on the imaging modalities and imaging concepts available for the surgical setting. With this review, we have aimed to provide a comprehensive update of the most recent advances in the field. Areas covered: We have made an attempt to cover all aspects of radioguided surgery: 1) the use of radioisotopes that emit γ, β+, and/or β- radiation, 2) hardware developments ranging from probes to 2D cameras and even the use of advanced 3D interventional imaging solutions, and 3) multiplexing solutions such as dual-isotope detection or combined radionuclear and optical detection. Expert opinion: Technical refinements in the field of radioguided surgery should continue to focus on supporting its implementation in the increasingly complex minimally invasive surgical setting, e.g. by accommodating robot-assisted laparoscopic surgery. In addition, hybrid concepts that integrate the use of radioisotopes with other image-guided surgery modalities such as fluorescence or ultrasound are likely to expand in the future.

Selective biopsy of the sentinel node in cancer of cervix: Experience in validation phase

BACKGROUND AND OBJECTIVE

Sentinel lymph node biopsy (SLNB) was created to reduce the morbidity associated with pelvic lymphadenectomy in the early stages of cervical cancer (CC), preserving its prognostic information. The goal is to assess the diagnostic validity of SLNB in CC in initial stages (IA1 with lymphovascular infiltration (LVI) +, IA2, IB1 and IIA1), thus avoiding unnecessary lymphadenectomies in many of the cases.

MATERIAL AND METHOD

From January 2012 to April 2017, 23 patients with initial stages of CC were included in a cross-sectional study to evaluate the effectiveness of the SLNB in CC with a mixed technique of cervical injection of ^99mTc-nanocolloid of albumin and methylene blue, using combined planar lymphoscintigraphy with multimodality SPECT/CT image and subsequent removal of the sentinel node (SN) by laparoscopy.

RESULTS

The detection rate of SLNB with the mixed technique was 95.65%, with a negative predictive value (NPV) of 95.45% and sensitivity (S) of 100% in the case of bilateral drainage. The mean of excised SN was 3 (range 1-5). The bilateral detection rate in laparoscopy was 85.35%. The concordance between SPECT/CT and laparoscopy for the number and bilaterality of the SN using the Pearson coefficient was r = 0.727 and r = 0.833, respectively; p = 0.01. We only found one SN with a deferred result of micrometástasis and one false negative was detected.

CONCLUSIONS

SLNB in CC using a mixed technique has a high detection and bilateral drainage rate, but S is still low if we include cases of unilateral drainage. A greater number of cases and the development of intraoperative ultrastaging could increase the S of the technique and to reduce the number of false negatives.

First experience with a new technique: Portable gamma camera usage for sentinel lymph node identification in a patient with breast cancer

The newest development in sentinel lymph node imaging is portable gamma probe imaging. In this case report, results of all SLN detection methods were analyzed. The patient was imaged using a large field-of-view gamma camera with additional blue dye administration and intraoperative localization of sentinel lymph node using both gamma probe and portable gamma camera was performed. In this case report, the value of additional portable gamma camera imaging was analyzed.

SPECT-CT and intraoperative portable gamma-camera detection protocol for sentinel lymph node biopsy in oral cavity squamous cell carcinoma

OBJECTIVE

The aim of this study was to evaluate a multimodality approach to sentinel lymph node biopsy (SLNB) detection with lymphoscintigraphy and single-photon emission computed tomography (SPECT)/computed tomography (CT). When combined with intraoperative imaging by a portable gamma camera (PGC), improved SLNB accuracy and detection rate may result.

MATERIAL AND METHODS

A total of 42 patients selected for SLNB in node-negative T1 and T2 oral squamous cell carcinoma were retrospectively analyzed. The detection protocol consisted of preoperative lymphoscintigraphy and SPECT/CT performed the day before surgery. Intraoperative sentinel lymph node (SLN) detection was done with the aid of a PGC in association with hand-held gamma probe.

RESULTS

All SLN detected in the preoperative study could be harvested except for one case. A total of 131 SLN were resected. This number was higher than the SLN depicted on lymphoscintigraphy (119 SLNs) and SPECT/CT (123 SLNs). Sublingual SLNs were observed in two cases (4.76%). These SLNs were detected by SPECT/CT but not by lymphoscintigraphy. Five (3.8%) additional SLNs not previously visualized on lymphoscintigraphy or on SPECT/CT were detected intraoperatively with the aid of the PGC. Positive SLNs were detected in eight cases (19%). Micrometastases were detected in five cases (62%) and macrometastases in three cases (38%).

CONCLUSION

The SLNB detection protocol described contributes to more accurate study and detection.

The value of early SPECT/CT and hand-held γ-camera in radio-guided surgery: a case of a hard-to-locate parathyroid adenoma

A patient with primary hyperparathyroidism underwent radio-guided surgery by means of a γ-probe and a hand-held γ-camera. Before surgery, a parathyroid double-phase planar scintigraphy and an early SPECT/CT with 99mTc-MIBI were performed and suggested an ectopic parathyroid adenoma with early washout. The hand-held γ-camera was very useful for the localization of a parathyroid adenoma, which could not be found with the probe probably due to its faint uptake and to a high blood pool activity because it was localized next to the great vessels. Besides, it demonstrated the complete extirpation of the parathyroid tissue.

The Utility of Intraoperative Handheld Gamma Camera for Detection of Sentinel Lymph Nodes in Melanoma

Accurate identification of the sentinel lymph node (SLN) is an important prognostic factor for melanoma. In a minority of cases drainage to interval nodal basins, such as the epitrochlear region, are possible. Intraoperative handheld gamma cameras have been used to detect SLNs which are located in different anatomical localizations. In this case we report the utility of an intraoperative handheld gamma camera in the localization of epitrochlear drainage of distal upper extremity melanoma and its impact on surgical procedure.