Sentinel lymph node diagnostic in prostate carcinoma: Part I: Technique and clinical evaluation

A Multicentre Clinical Trial Evaluating a Drop-in Gamma Probe for Minimally Invasive Sentinel Lymph Node Dissection in Prostate Cancer

BACKGROUND

This study evaluated the safety and performance of a drop-in gamma probe for prostate cancer (PCa) sentinel lymph node biopsy (SeLNB) in a prospective, open-label, multicentre, single-arm clinical trial.

OBJECTIVE

The main objective was to determine the sentinel lymph node (SeLN) detection rate with the drop-in gamma probe system. The secondary objectives were overall performance and safety.

DESIGN, SETTING, AND PARTICIPANTS

At three European centres, patients received an ultrasound-guided systemic and tumour-targeted injection of [99mTc]Tc-nanocolloid followed by planar lymphoscintigraphy and/or single-photon emission computerised tomography. The next day, manual laparoscopic or robot-assisted radical prostatectomy was performed, including SeLN dissection (SeLND) and extended pelvic lymph node dissection (ePLND).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

SeLNs were detected with the drop-in probe and a rigid laparoscopic gamma probe (RLGP). The primary endpoint of the study was the SeLND rate defined as the percentage of patients with at least one SeLN detected in vivo by the drop-in probe. The secondary endpoints included diagnostic performance, ease of SeLN detection, number of SeLNs detected, and safety. The first two patients at each site (six in total) were used for familiarisation.

RESULTS AND LIMITATIONS

A total of 27 patients were included in the main analysis. SENSEI successfully detected at least one SeLN in all 27 patients, resulting in a detection rate of 100% (95% confidence interval 87.2-100%). The total number of SeLNs identified with SENSEI was 85 (median three SeLNs per patient, range 1-6); of these 85 SeLNs, 12 were located outside of the ePLND template. In the nine patients in whom the RLGP was used, SENSEI detected two SeLNs that could not be detected with the RLGP due to manoeuvrability restrictions. Ten of the 27 patients were pN1; four patients had a false-negative SeLNB. No adverse events or complications were related to the use of the drop-in probe.

CONCLUSIONS

The study demonstrated that the drop-in gamma probe meets the performance and safety requirements for SeLNB in PCa. The device provided improved manoeuvrability and SeLN detection compared with the conventional RLGP.

PATIENT SUMMARY

A novel device was tested for detecting sentinel lymph nodes during minimally invasive surgery for prostate cancer. In this first evaluation, the performance and safety of the device were evaluated positively.

Sentinel node biopsy and lymphatic mapping in penile and prostate cancer

BACKGROUND

Nodal metastases are linked to poor outcome in men with penile or prostate cancer. Early detection and resection are important for staging and for the prognosis. However, lymphadenectomy is associated with morbidity and may miss metastases when performed solely on the basis of anatomical templates.

METHODS

In this article we describe the technique and benefits of sentinel node biopsy (SNB) and provide a review of the literature.

RESULTS

Dynamic sentinel node techniques using both radioactive and optical (hybrid) tracers have been proven effective in penile cancer. For prostate cancer, SNB added to extended nodal dissection may further tailor dissection to the highly variable lymphatic drainage patterns in the pelvis. The sensitivity of SNB was found to be superior to conventional imaging methods; however, false-negative SNB procedures can occur and a complementary extensive lymphadenectomy is required to remove additional positive nodes that were not detected in the SNB template.

CONCLUSION

SNB is a standard method for early detection of nodal metastases in penile cancer and provides superior diagnostic accuracy to conventional imaging modalities in prostate cancer.

Sentinel node mapping in the prostate cancer

Aim: Sentinel node (SN) biopsy is becoming a standard procedure in the management of several malignancies. Several groups have evaluated the feasibility and value of this procedure in prostate cancer patients. In the current meta-analysis, we comprehensively and quantitatively summarized the results of these studies. Methods: Several databases including Medline, SCOPUS, Google Scholar, Ovid, Springer, and Science direct were systematically searched for the relevant studies regarding SL biopsy in the prostate cancer (“prostate” AND “sentinel” as search keywords). The outcomes of interest were sensitivity and detection rate of the procedure. Results: For detection rate and sensitivity 21 and 16 studies met the criteria of inclusion respectively. Pooled detection rate was 93.8% (95% CI 89–96.6%). Cochrane Q value was 216.077 (I2 = 89.81% and p < 0.001). Pooled sensitivity was 94% (95% CI 91–96%). Cochrane Q value was 14.12 (I2 = 0.0 and p = 0.516). Conclusion: SL biopsy can prevent unnecessary pelvic lymph node dissection in prostate cancer patients. This procedure is feasible with low false negative rate and high detection rate.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.

Detection Rate and Operating Time Required for γ Probe-Guided Sentinel Lymph Node Resection after Injection of Technetium-99m Nanocolloid into the Prostate with and without Preoperative Imaging

OBJECTIVE

To investigate the usefulness of presurgical image fusion of three-dimensional single photon emission computed tomography (SPECT) with computed tomography/magnetic resonance imaging (CT/MRI) for detecting primary prostatic lymphatic landing sites (sentinel lymph nodes [SLNs]) using an intraoperative gamma probe in patients undergoing radical prostatectomy for organ-confined prostate cancer after intraprostatic (99m)Tc-nanocolloid injection.

METHODS

In 15 patients the surgeon was unaware of the preoperative SPECT/CT/MRI fusion imaging results. In 21 patients the surgeon was supported by the preoperative SPECT/CT/MRI images. Selective SLN resection was followed by an extended backup pelvic lymph node dissection (PLND) and radical prostatectomy.

RESULTS

In the group of 15 patients (gamma probe-guided SLN search only) presurgical SPECT/CT/MRI identified 137 SLNs (median of 10/patient; range: 2-19) and a total of 135 SLNs (median of 8/patient; range: 2-20) were detected intraoperatively (detection rate 98.5%). In the group of 21 patients with the surgeon knowing the preoperative SPECT/CT/MRI findings, 189 (median of 9/patient; range: 3-20) of the 190 imaged SLNs (median of 8/patient, range: 2-19) were found intraoperatively (detection rate 99.5%). Median operating time for sentinel lymphadenectomy using gamma probe only was 100 min (range: 40-130) versus 70 min (range: 20-140) for the SPECT/CT/MRI-supported resection (p=0.025). A median of 9 SLNs per patient (range: 2-19) was confirmed histologically.

CONCLUSIONS

Preoperative SPECT/CT/MRI is highly reliable to detect nonmetastatic sentinel nodes of the prostate. The operating time for SPECT/CT/MRI-supported SLN resection is significantly reduced compared to SLN resection guided by gamma probe alone. Both procedures take significantly longer than routine extended PLND.

Is pelvic lymph node dissection necessary in patients with a serum PSA<10ng/ml undergoing radical prostatectomy for prostate cancer?

OBJECTIVE

Controversy persists concerning the role of pelvic lymph node dissection (PLND) in patients with preoperative PSA values <10ng/ml undergoing treatment for prostate cancer with a curative intent. The aim of this study was to determine the incidence of lymph node metastasis in this subgroup of patients.

METHODS

Patients with clinically localized prostate cancer and a serum PSA<10ng/ml, without neoadjuvant hormonal or radiotherapy, with negative staging examinations who underwent radical retropubic prostatectomy with bilateral extended PLND and with >/=10 lymph nodes detected by the pathologist in the surgical specimen, were included in the study.

RESULTS

A total of 231 patients with a median serum PSA of 6.7ng/ml (range 0.4-9.98) and a median age of 62 years (range 44-76) were evaluated. A median of 20 (range 10-72) nodes were removed per patient. Positive nodes were found in 26 of 231 patients (11%), the majority of which (81%) had a Gleason score >/=7 in the surgical specimen. Of the patients with a Gleason score >/=7 in the prostatectomy specimen 25% had positive nodes, whereas only 3% with a Gleason score </=6 were node positive.

CONCLUSIONS

The incidence of positive nodes in patients with clinically localized prostate cancer, a serum PSA<10ng/ml and a Gleason score >/=7 in the prostatectomy specimen was 25% after extended PLND. It seems that in this patient group extended PLND, including removal of nodes along the internal iliac vessels, is warranted.

Sentinel lymph node biopsy progress in surgical treatment of cancer

BACKGROUND

Forty-three years after the first description of the sentinel lymph node technique in malignant tumours of the parotid by Gould, sentinel lymph node biopsy (SNLB) has become a precious tool in the treatment of solid tumours.

METHODS

In the following review we give a synopsis of the fundamentals of the sentinel lymph node concept and then proceed to an overview of recent advances of SNLB in gastrointestinal cancers.

RESULTS

In some tumour entities, SNLB has been shown to reflect reliably the lymph node status of the tumour-draining lymph node basin. In melanoma and breast cancer, it became a widely accepted element of the routine surgical management of these malignant diseases. In gastrointestinal tumours, the technique is currently under intense investigation. First reports on its application in other solid tumours, such as non-small cell lung cancer, thyroid carcinoma, oropharyngeal carcinoma, vulvar carcinoma, and Merckel cell carcinoma of the skin, were published more recently.

CONCLUSION

SNLB has become an important component of diagnosis and treatment of solid tumours. A growing number of publications on SNLB in gastrointestinal cancer documents the interest of many investigators in the application of this technique in this tumour entity. As long as imaging techniques like 18FDG PET or other molecular imaging techniques are limited by their spatial resolution, SNLB remains the technique of choice for lympho-nodal staging.