BACKGROUND:
For patients diagnosed with localized kidney cancer, two main options exist to surgically
remove the kidney tumor. During radical nephrectomy (RN), the entire kidney is removed.
During partial nephrectomy (PN), only the tumor is resected, safeguarding the function of
the remaining healthy kidney tissue. This last procedure is preferred, but not always
technically feasible. To resect only the tumor, a balance has to be found in the clamping
approach: clamping the blood supply to the kidney assures bloodless tumor resection, yet
compromises the postoperative renal function due to the temporary ischemia. Tumor
resection without clamping on the other hand, might lead to substantial blood loss. That
is why "selective clamping" (SC) is proposed. In this approach, only those selective
arteries are clamped that perfuse the zone including the tumor. The main drawback of this
strategy is that it is often not clear which arteries should be clamped based on standard
preoperative imaging, while misjudgment can lead to a high-risk surgery with excessive
bleeding or prolonged ischemia time. Therefore, RN is currently recommended when PN is
considered not feasible. Better prediction of individual kidney perfusion will allow to
perform more frequently a PN and thus save healthier kidney tissue. Additionally, it is
difficult for patients to assess their own individual oncological situation based on 2D
CT images.
With this project, the investigators want to offer the surgeon an easy-to-use virtual
planning tool that facilitates the decision-making process regarding the feasibility of
PN and the corresponding optimal clamping strategy. This tool uses virtual 3D models
based on CT scans, to visualize precise information on the different anatomical
structures and perfusion zones. This may also improve patients' understanding of their
own individual situation. The proposed new tool (DIPLANN-tool) for predicting kidney
perfusion zones on a segmented 3D model during robot-assisted partial nephrectomy (RAPN)
for localized renal cancer demonstrated high accuracy when planning selective clamping
(SC) for RAPN. However, the tool's clinical added value still needs to be confirmed.
Therefore, a randomized controlled trial using a study and control group is the preferred
study design.
DESIGN:
A confirmatory, multicentric, unblinded, randomized, controlled, pivotal trial using
parallel group assignment and stratified randomization.
Experimental group: the use of the DIPLANN model + conventional CT imaging for
preoperative planning and perioperative guidance.
Control group: the use of only conventional CT imaging for preoperative planning and
perioperative guidance (= current standard of care).
METHODOLOGY:
Sample size calculation: 235 patients.
Patients will be randomized according to a 1:1 allocation ratio to either the
experimental group (the DIPLANN-tool in combination with conventional CT imaging) or the
control group (conventional CT imaging alone), using permuted block randomization with
blocks of varying size.
Randomization will be stratified on the following variables:
Whether SC is deemed possible according to the DIPLANN-tool in combination with
conventional CT imaging or on conventional CT imaging alone, as assessed by an
independent surgeon (between inclusion and randomization) who will not be not
involved in the RAPN surgical procedure (yes vs no).
Hospital where surgery is performed.
PADUA classification (low (<8) and intermediate (8-9) vs high-risk (>9)). In case of
multiple masses, the mass with the highest individual PADUA classification will be
used.
PRIMARY OBJECTIVE:
To assess if the DIPLANN-tool in combination with conventional CT imaging is superior to
conventional CT imaging alone, with respect to planning and performing as planned a SC
strategy during RAPN, in patients diagnosed with localized kidney cancer who are planned
to undergo renal cancer surgery and in whom SC is deemed possible either according to the
DIPLANN-tool in combination with conventional CT imaging or according to conventional CT
imaging only, as assessed between inclusion and randomization by an independent surgeon.
SECONDARY OBJECTIVES:
To assess if the DIPLANN-tool in combination with conventional CT imaging is
superior to conventional CT imaging alone, with respect to planning and performing
as planned a SC strategy during RAPN, in patients diagnosed with localized kidney
cancer who are planned to undergo renal cancer surgery.
To compare the DIPLANN-tool in combination with conventional CT imaging to
conventional CT imaging alone with respect to: patients' health, patients' insight,
and surgeons' benefits.
ENDPOINTS:
The primary endpoint is planning and performing as planned a SC strategy. Secondary
endpoints include patients' health, patients' insight and surgeons' benefits.
Extended listing of all outcome measures: see below.