Experience certainly improves technical skill at RALP


There has been a lot of media noise about a poster presented at the Genitourinary Cancer Symposium. The poster supposedly suggests that it takes 1,600 robot-assisted procedures (RALP) to be really good at this form of surgery. It has been extensively discussed in a report on Bloomberg.com (just as an example).

Now there is no doubt whatsoever that the more dedicated the surgeon, the greater the basic skill s/he brings to the operating room, and the more procedures s/he does, the better the outcomes will be over time. So it is hardly surprising to find that extensive experience will improve the quality of outcomes that specific surgeons can attain.

What did the study by Sooriakumaran et al. actually show?

The authors carried out a retrospective study of 3,794 patients who were given a RALP by three specific surgeons between January 2003 and September 2009. They calculated the mean overall rates of positive surgical margins (PSMs) and the mean overall surgical operating time (OT) for each of the three surgeons at intervals of 50 RALPs per surgeon.

They were able to show that:

  • Rates of  PSMs for all patients demonstrated improvements that continued with greater surgeon experience.
  • For these three surgeons, it required > 1,600 cases to get a PSM rate of < 10 percent.
  • When only pT3 patients were evaluated, the learning curve started to plateau after 1,000-1,500 cases.
  • Mean OT plateaued after 750 cases but started to rise again with further surgical experience.

The authors conclude only that the learning curve for RALP is not as short as previously thought, and that a large number of cases are needed to get PSM rates and OTs to a minimum. They further point out the obvious corrollary that RALP should be performed by high volume surgeons in order to optimize patient outcomes.

The “New” Prostate Cancer InfoLink would point out, however, that there are other data suggesting that some surgeons have a very low incidence of PSMs with a much lower degree of experience. Are these surgeons naturally more skilled? Do they have better eyesight that allows them to better identify potentially cancerous tissue?

We have no idea how many surgeons have actually carried out > 1,600 RALPs, but it can’t be very many. We would also point out that speed is not necessarily a good quality when it comes to carrying out RALPs. It is interesting that, as these three surgeons carried out more operations, they actually realized that they needed to slow down in order to get the highest quality outcomes.

5 Responses

  1. Did they own their own robotic machines? I say that jokingly, as I’ve heard (from my own surgeon) that they are in competition for machine time with surgeons performing other types of surgery.

    In fact, one of the surgeons in the group practice I went to left because he couldn’t get enough time slots at the medical center where I had my surgery.

    I thought QOL meant more than speed and PSMs? In my case, it means resuming continence faster than standard surgery and also the ED aspect. It’s discouraging that the >1,600 surgeries could become the benchmark when a lot of other variables are involved.

    When I had my RALP a few months ago, the surgery time was increased due to my large prostate (99 g) that deformed the bladder at the neck. Otherwise it would have been done in ~ 1.5 to 2 hours.

    I would (and did) definitely recommend a prospective RALP patient ask the direct question of his surgeon: “How many RALPs have you done?”

    It’s your body and your right to know. I’ve read elsewhere that a surgeon gets a good skill level on the Da Vinci after ~ 400 procedures.

  2. I’m wondering if there is any way of separating out the contributions of increased surgical skill versus improved ability to select patients who are unlikely to have positive margins. It’s possible that knowledge about likelihood of positive margins has improved significantly over the course of time that it takes to do 1,600 RALPs, or since 2003 when the first patients were treated in this study. Is that so? Any thoughts on this issue?

    Perhaps looking at open RP studies would throw light on this.

    It would also be useful to have a better handle on the significance of a positive margin rate of <10% versus, let's say, 11% or 15%, in this series. In other words, if it took only 300 patients to reach 11% (admittedly improbable, but used as a test thought), then the extra experience would not look as impressive as it would if it took, say, 1,500 patients to reach 11%.

    I'm also curious about how varying risk may have influenced the statistics. Were all the patients "low risk"? Usually we do not think of stage T3 patients being eligible for RPs; can anyone confirm that only cT1 to cT2 patients were eligible, but that the T3 resulted from the pathology found at surgery (therefore, pT3)? I'm surprised the risk level was not stated in the abstract.

  3. People are massively over-interpreting the data from this poster. All that it really shows is that it takes time and dedication for most surgeons to learn to do RALP really well. This is not surprising. It is true of any complex surgical procedure. These three surgeons were among the earliest to start doing RALPs. The technology has improved since they started; their skill levels have improved; etc. My understanding at this time is that the reference to T3 patients is indeed a reference to pT3 disease and not cT3 disease.

  4. Correct me if I’m wrong, but I thought PSM wasn’t actually correlated with any measurable adverse consequence (higher PSA nadir, higher PSA velocity, mortality, etc.).

  5. The presence of PSMs in general is not well correlated with any specific form of clinical outcome. However, the presence of a PSM in an individual patient does represent a risk for disease progression.

    In that individual patient, the size, location, and Gleason score of tissue in the PSM may make a specific PSM more “risky.”

    This is a complex issue which is still not well defined. However, the ability to ensure that there is no PSM to begin with is clearly an objective of any high quality surgeon.

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