Advice
Clinical and technical evidence
Clinical and technical evidence
A literature search was carried out for this briefing in accordance with the interim process and methods statement. This briefing includes the most relevant or best available published evidence relating to the clinical effectiveness of the technology. Further information about how the evidence for this briefing was selected is available on request by contacting mibs@nice.org.uk.
Published evidence
This briefing summarises 5 studies: 2 retrospective, comparative observational studies (Kroes et al. 2016a; Kroes et al. 2016b); 2 prospective, non-comparative observational studies (Brabrand et al. 2004; Krombach et al. 2000); and 1 case report (Varro et al. 2004). The studies include a total of 151 patients, excluding any identified overlapping cohorts, of whom 100 had a SimpliCT-guided procedure.
Table 1 summarises the clinical evidence as well as strengths and limitations of the studies. The table does not include the case report by Varro et al. (2004); this reported on a patient having CT‑guided percutaneous radiofrequency ablation of 2 kidney tumours in a single centre in the US, and has limited relevance to the population in the scope of this briefing.
Overall assessment of the evidence
The evidence base for the SimpliCT is currently limited in quantity and quality.
The identified studies report limited technical outcomes, such as accuracy of needle placement and how laser guidance affects imaging time and total procedure time. A reduction in patient and operator radiation doses is implied but not quantified.
No studies have reported comparative clinical-effectiveness outcomes from adding laser-guided needle placement to non-vascular puncture procedures in interventional radiology.
The reported technical outcomes are relevant to the NHS care pathway.
Table 1 Summary of selected studies
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Study size, design and location |
n=51 Retrospective, comparative observational study in a single centre in the Netherlands. |
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Intervention and comparator(s) |
15 prospective CBCT‑guided biopsies with laser navigation by SimpliCT in the intervention arm and 36 retrospective records of CBCT‑guided biopsies using freehand technique alone in the comparator arm. |
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Key outcomes |
Biopsies using the standard freehand technique took more fluoroscopy time (and hence more radiation exposure to patient and operator) to guide the needle onto the target, compared with those under SimpliCT laser guidance. Comparing these results, the fluoroscopy times were significantly lower (p<0.001) in the SimpliCT group. Conversely, overall procedure times were shorter for freehand biopsies. |
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Strengths and limitations |
Prospective cases in the intervention arm (7 thoracic and 8 abdominal biopsies) were compared against historical controls without any propensity matching. Inter-operator variability was eliminated and intra-operator variability was minimised in the intervention arm, because a single interventional radiologist with 4 years' experience of CBCT‑guided needle interventions conducted all of the SimpliCT cases. Retrospective freehand controls were selected on the basis of being 'easier'; defined as a target size larger than 20 mm in diameter and a procedure time shorter than 35 minutes (16 thoracic and 20 abdominal biopsies). These were inherently dissimilar to the prospective SimpliCT cases, which is likely to have impacted on the relative effect on fluoroscopy and overall procedure times. The retrospective freehand procedures were conducted by 2 interventional radiologists, potentially adding inter- and intra-operator variability to the comparator results. This research was part-funded by NeoRad. |
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Study size, design and location |
n=32 Retrospective, comparative observational study in a single centre in the Netherlands. |
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Intervention and comparator(s) |
17 retrospective records of CBCT‑guided radiofrequency ablations of osteoid osteoma with laser navigation by SimpliCT in the intervention arm and 15 retrospective records of CBCT‑guided ablations using freehand technique alone in the comparator arm. Subgroup analysis of 18 cases where procedures were assessed to have had a similar degree of difficulty (10 with SimpliCT guidance and 8 with freehand technique). |
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Key outcomes |
For the whole patient cohort, adding SimpliCT laser guidance to the CBCT‑guided radiofrequency ablation procedure resulted in a significant reduction in fluoroscopy time (p=0.004). Although overall procedure times were also shorter with SimpliCT, this difference was not statistically significant (p=0.355). These fluoroscopy and overall procedure time outcomes were replicated in the subgroup analysis. Retrospective radiation dose area product data from the imaging system were analysed, but the authors were unable to draw any comparative conclusions from the results, primarily owing to the heterogeneity in the patient populations and too many unknown operational variables. |
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Strengths and limitations |
Although attempts were made to define a subgroup based on position and size of the osteoid osteoma and comparative difficulty of the retrospective cases, the matching process between intervention and comparator arms was flawed, because the laser-guided cases were conducted in a significantly younger (p=0.011) and lower BMI (p=0.006) population. The retrospective procedures were conducted by 3 interventional radiologists, all with 5 or more years of experience in radiofrequency ablation of osteoid osteoma, potentially adding inter- and intra-operator variability to the results. This procedure involved guiding a drill into the bone (rather than a needle) before inserting the ablation catheter. The results from this study are therefore not considered generalisable to straight needle puncture procedures in soft tissue. This research was part-funded by NeoRad. |
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Study size, design and location |
n=67 Prospective, non-comparative, non-randomised, multicentre study in Norway, Germany and Sweden. Adults (excluding any pregnant women) consecutively included those needing CT‑guided biopsy or cytology (n=49), neurolysis (n=8), aspiration (n=4), drainage (n=4) and others (n=2). The procedures were done by 8 radiologists at 4 centres. |
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Intervention and comparator(s) |
Prospective CT‑guided puncture procedures with laser navigation by SimpliCT in the intervention arm. No comparator arm. |
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Key outcomes |
The target was hit in 65 out of 67 patients and in 55 of these, the target was hit with first pass of the needle. In 87.0% of the punctures, the difference between planned and target angle achieved was less than 3°. In 69.8% of the patients, the target was hit within 15 minutes of the initial localising scan. Subjective operator scores found the SimpliCT both useful and easy to use. |
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Strengths and limitations |
Consecutive patients were enrolled, reducing the likelihood of selection bias. The heterogeneity of the case mix in this study is also likely to reflect 'real world' practice, making the study generalisable to the broad population in scope of this briefing. As a multicentre study, the results will be affected by both inter- and intra-operator variability. Caution: the 8 neurolysis patients in this study are the same as those patients reported by Krombach et al. (2000). |
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Study size, design and location |
n=8 Prospective, non-comparative observational study in a single centre in Germany. |
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Intervention and comparator(s) |
8 patients undergoing 9 CT‑guided nerve blocks with laser navigation by SimpliCT in the intervention arm. No comparator arm. |
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Key outcomes |
All 9 nerve blocks were successful on the first needle pass and without complication. The mean difference between planned and actual needle angle was 1.4° (0 to 4°). The mean time between planning the puncture and completion of the needle placement was 8.4 minutes (5 to 17 minutes), while the overall procedure time was 30 to 40 minutes on average. Subjective operator opinion found the SimpliCT both easy to handle and useful for the procedure. |
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Strengths and limitations |
This study was conducted using a prototype of the commercial SimpliCT system. However, the technical specifications of the prototype appear to match those of the commercial SimpliCT system, therefore this study is considered generalisable to the intervention in scope of this briefing. An unspecified number of operators conducted the procedures in this study, therefore the results will be affected by both inter- and intra-operator variability. The population in this study is limited to nerve blocks, which is just 1 of the indications in scope of the intervention. |
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Abbreviation: CBCT, cone-beam CT. |
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