Year : 2013 | Volume
: 29 | Issue : 1 | Page : 81--82
In-situ frozen sections in robotic prostatectomy: An approach to reduce positive surgical margin rates
Praveen Kumar Pandey
Praveen Kumar Pandey
|How to cite this article:|
Pandey PK. In-situ frozen sections in robotic prostatectomy: An approach to reduce positive surgical margin rates.Indian J Urol 2013;29:81-82
|How to cite this URL:|
Pandey PK. In-situ frozen sections in robotic prostatectomy: An approach to reduce positive surgical margin rates. Indian J Urol [serial online] 2013 [cited 2020 Jan 23 ];29:81-82
Available from: http://www.indianjurol.com/text.asp?2013/29/1/81/109998
In this study, all patients undergoing a modified "curtain"-type nerve-sparing robotic-assisted laparoscopic prostatectomy (RALP) between May 2007 and September 2009 formed the base population for the analyses (n = 970). These cases were then stratified by those undergoing intraoperative frozen section (IFS) (n = 177). After specimen removal, the prostatic fossa was routinely examined for macroscopic evidence of prostatic tissue. In situations where there was concern for a positive surgical margin (PSM) or possible capsular incision, corresponding tissue was removed from the in situ neurovascular bundles (NVBs) or the urethral margin, and not the prostate specimen itself. If carcinoma or benign glands were identified on the IFS, further tissue was resected from that area until the IFS was negative, reproducing the technique of Mohs micrographic surgery.
A PSM in the prostatectomy specimen was defined as tumor cells present at the inked margin. In cases of positive margins on prostate specimen, the location of IFS was compared with the corresponding area on the prostate specimen. The IFS was considered to be "matched" if PSM was at a corresponding location. Otherwise, or in cases of multifocal PSMs on the prostate specimen without the corresponding IFS from all locations of PSMs, the IFS was considered to be 'unmatched'. The margin status for the purpose of analysis was considered negative if the last IFS specimen taken from a 'matched' margin was negative. The margin was considered positive if the IFS were 'unmatched' or the last IFS remained positive. A second analysis was performed with margin status being defined as the margin on the permanent prostatectomy specimen, regardless of the presence or absence of tumor in the IFS specimen.
Overall PSM rates were 7% in the IFS group, compared to 18% in non-IFS cases (P = 0.001). Six patients were converted from a positive to negative margin by the use of IFS. There was a concordance rate of 98% between the frozen section and the permanent section. Overall, 11 patients (6%) had IFS specimens positive for carcinoma. Four of these patients had biochemical recurrence (BCR) requiring adjuvant treatment. Twenty-five additional patients (14%) had benign prostatic tissue identified in the frozen section. Only one of these patients (4%) experienced BCR. Eight patients (5%) experienced BCR at a median follow-up of 11 months.
On follow-up at 6 weeks and then every 3 months for the first year after surgery, continence and potency outcomes were similar between the two groups. Serum PSA measurements were obtained at the same intervals. However, patients undergoing IFS were observed to have a longer mean operative time.
The indications for RALP are essentially the same as that for open surgery. Patients with clinical stage ≤ T2 prostate cancer without any either clinical or radiographic evidence of metastasis should be considered for RALP. Absolute contraindications are the same as those for any other minimal invasive procedure.
The three-dimensional (3D) magnification and ability to duplicate movements without transmission of hand tremors are chief advantages of this novel innovation. Hence, RALP is expected to improve functional results without compromising the oncological outcomes.  In recent times, PSM rates are used as an index to evaluate the oncological efficacy of RALP.
Although PSM rates are already lower in patients treated by RALP as compared to RRP, , efforts are under way to reduce them even further. The use of IFS in RALP is one of such endeavours. It has been described in radical retro pubic prostatectomy by Hartwig Huland's and in RALP by Mani Menon et al. IFS analysis in laparoscopic retro pubic prostatectomy predicts permanent apical section status with accuracy >90%. 
The impact of IFS analysis in nerve sparing RALP should be evaluated in terms of disease-free quality of life, i.e. no BCR. The evidence for BCR-free survival for RALP is limited and still not mature enough. Some patients with PSM do not develop BCR, which in turn may be due to the false-positive margin rate. IFS are more likely to reflect the true margin status. The main therapeutic significance of performing systematic IFS is converting PSM cases to a residual cancer-free status and thus preventing BCR. It promises a high possibility of resecting additional tissue from matched areas of suspicion. The longer time taken in performing this meticulous procedure is well supported by less likely chances of BCR.
In conclusion, systematic IFS during nerve sparing RALP can reliably predict the final surgical margin status in patients and thus reduce the chances of BCR as compared to those cases where it is not applied.
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