Limits...
Beyond penile cancer, is there a role for sentinel node biopsy in urological malignancies?

View Article: PubMed Central - PubMed

ABSTRACT

This review aims to discuss the current state-of-the-art of sentinel node (SN) mapping in urological malignancies. The principles and methodological aspects of lymphatic mapping and SN biopsy in urological malignancies are reviewed. Literature search was restricted to English language. The references of the retrieved articles were examined to identify additional articles. The review also includes meta-analyses published in the past 5 years. SN biopsy for penile cancer is recommended by the European Association of Urology as the preferred staging tool for clinically node-negative patients with at least T1G2 tumours (level of evidence 2a, Grade B). The feasibility of SN biopsy in prostate cancer has been repeatedly demonstrated and its potential value is increasingly being recognised. However, conclusive prospective clinical data as well as consensus on methodology and patient selection are still lacking. For bladder, renal and testicular cancer, only few studies have been published, and concerns around high false-negative rates remain. Throughout the years, the uro-oncological field has portrayed a pivotal role in the development of the SN concept. Recent advances such as hybrid tracers and novel intraoperative detection tools such as fluorescence and portable gamma imaging will hopefully encourage prospectively designed clinical trials which can further substantiate the potential of the SN approach in becoming an integral part of staging in urological malignancies beyond penile cancer.

No MeSH data available.


Related in: MedlinePlus

Sentinel node in renal-cell carcinoma. Following needle insertion under ultrasound guidance (a, b) 99mTc-nanocolloid is administered into the tumour (c). Transversal SPECT/CT (d) shows a paracaval sentinel node, which is removed by means of laparoscopy assisted with a portable gamma camera (e)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5037151&req=5

Fig5: Sentinel node in renal-cell carcinoma. Following needle insertion under ultrasound guidance (a, b) 99mTc-nanocolloid is administered into the tumour (c). Transversal SPECT/CT (d) shows a paracaval sentinel node, which is removed by means of laparoscopy assisted with a portable gamma camera (e)

Mentions: After its initial feasibility was shown in porcine models by Bernie et al., the first pilot study exploring SN biopsy for RCC in humans was published by Bex et al. in 2010 [129, 130]. 99mTc-nanocolloid was injected percutaneously into the renal tumour (<10 cm = cT1a/b-cT2a) guided by ultrasound or CT, followed by lymphoscintigraphy and SPECT/CT. The use of a portable gamma camera may assist tracer injection and help to modify/repeat the injection procedure in case radioactivity is detected outside the tumour and the kidney (Fig. 5). This approach led to successful SN identification in six of eight patients. Following a similar protocol, Sherif et al. detected 32 SNs in 10 of 11 patients in 2011 [126]. In a later follow-up study from Bex et al. expanding the cohort to 20 patients SN visualisation was possible in 70 % of cases. 2 of 20 patients had SNs outside the retroperitoneal region [131]. The absence of lymphatic drainage on imaging in 30 % of patients is of concern, in relation to a potential clinical application of this technique. This may be caused by lack of drainage of the radiocolloid through lymphatic vessels. Alternatively, the radiocolloid may have drained directly into the thoracic duct without any interposition of a lymph node, as has been proposed in a cadaver study by Assouad [132] and visualised in a recent study using SPECT/CT [133]. Intraoperative detection of SNs in RCC has been performed during open, and laparoscopic procedures and is generally carried out guided by a gamma-probe. Patent blue is not frequently used because of its limited contribution [126]. In the published series by Bex et al., one patient had two tumour-positive SNs at histopathology. The fact that all other excised lymph nodes during retroperitoneal lymph node dissection were tumour negative confirms the feasibility of SN procedure in RCC patients, although more extensive research is needed to further substantiate the diagnostic and therapeutic value of renal SN biopsy. Until then (extended) lymph node dissection still remains the management of choice in clinically node-positive patients without distant metastases [116].Fig. 5


Beyond penile cancer, is there a role for sentinel node biopsy in urological malignancies?
Sentinel node in renal-cell carcinoma. Following needle insertion under ultrasound guidance (a, b) 99mTc-nanocolloid is administered into the tumour (c). Transversal SPECT/CT (d) shows a paracaval sentinel node, which is removed by means of laparoscopy assisted with a portable gamma camera (e)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037151&req=5

Fig5: Sentinel node in renal-cell carcinoma. Following needle insertion under ultrasound guidance (a, b) 99mTc-nanocolloid is administered into the tumour (c). Transversal SPECT/CT (d) shows a paracaval sentinel node, which is removed by means of laparoscopy assisted with a portable gamma camera (e)
Mentions: After its initial feasibility was shown in porcine models by Bernie et al., the first pilot study exploring SN biopsy for RCC in humans was published by Bex et al. in 2010 [129, 130]. 99mTc-nanocolloid was injected percutaneously into the renal tumour (<10 cm = cT1a/b-cT2a) guided by ultrasound or CT, followed by lymphoscintigraphy and SPECT/CT. The use of a portable gamma camera may assist tracer injection and help to modify/repeat the injection procedure in case radioactivity is detected outside the tumour and the kidney (Fig. 5). This approach led to successful SN identification in six of eight patients. Following a similar protocol, Sherif et al. detected 32 SNs in 10 of 11 patients in 2011 [126]. In a later follow-up study from Bex et al. expanding the cohort to 20 patients SN visualisation was possible in 70 % of cases. 2 of 20 patients had SNs outside the retroperitoneal region [131]. The absence of lymphatic drainage on imaging in 30 % of patients is of concern, in relation to a potential clinical application of this technique. This may be caused by lack of drainage of the radiocolloid through lymphatic vessels. Alternatively, the radiocolloid may have drained directly into the thoracic duct without any interposition of a lymph node, as has been proposed in a cadaver study by Assouad [132] and visualised in a recent study using SPECT/CT [133]. Intraoperative detection of SNs in RCC has been performed during open, and laparoscopic procedures and is generally carried out guided by a gamma-probe. Patent blue is not frequently used because of its limited contribution [126]. In the published series by Bex et al., one patient had two tumour-positive SNs at histopathology. The fact that all other excised lymph nodes during retroperitoneal lymph node dissection were tumour negative confirms the feasibility of SN procedure in RCC patients, although more extensive research is needed to further substantiate the diagnostic and therapeutic value of renal SN biopsy. Until then (extended) lymph node dissection still remains the management of choice in clinically node-positive patients without distant metastases [116].Fig. 5

View Article: PubMed Central - PubMed

ABSTRACT

This review aims to discuss the current state-of-the-art of sentinel node (SN) mapping in urological malignancies. The principles and methodological aspects of lymphatic mapping and SN biopsy in urological malignancies are reviewed. Literature search was restricted to English language. The references of the retrieved articles were examined to identify additional articles. The review also includes meta-analyses published in the past 5&nbsp;years. SN biopsy for penile cancer is recommended by the European Association of Urology as the preferred staging tool for clinically node-negative patients with at least T1G2 tumours (level of evidence 2a, Grade B). The feasibility of SN biopsy in prostate cancer has been repeatedly demonstrated and its potential value is increasingly being recognised. However, conclusive prospective clinical data as well as consensus on methodology and patient selection are still lacking. For bladder, renal and testicular cancer, only few studies have been published, and concerns around high false-negative rates remain. Throughout the years, the uro-oncological field has portrayed a pivotal role in the development of the SN concept. Recent advances such as hybrid tracers and novel intraoperative detection tools such as fluorescence and portable gamma imaging will hopefully encourage prospectively designed clinical trials which can further substantiate the potential of the SN approach in becoming an integral part of staging in urological malignancies beyond penile cancer.

No MeSH data available.


Related in: MedlinePlus