The Click-On gamma probe, a second-generation tethered robotic gamma probe that improves dexterity and surgical decision-making.

PURPOSE: Decision-making and dexterity, features that become increasingly relevant in (robot-assisted) minimally invasive surgery, are considered key components in improving the surgical accuracy. Recently, DROP-IN gamma probes were introduced to facilitate radioguided robotic surgery. We now studied if robotic DROP-IN radioguidance can be further improved using tethered Click-On designs that integrate gamma detection onto the robotic instruments themselves. METHODS: Using computer-assisted drawing software, 3D printing and precision machining, we created a Click-On probe containing two press-fit connections and an additional grasping moiety for a ProGrasp instrument combined with fiducials that could be video tracked using the Firefly laparoscope. Using a dexterity phantom, the duration of the specific tasks and the path traveled could be compared between use of the Click-On or DROP-IN probe. To study the impact on surgical decision-making, we performed a blinded study, in porcine models, wherein surgeons had to identify a hidden 57Co-source using either palpation or Click-On radioguidance. RESULTS: When assembled onto a ProGrasp instrument, while preserving grasping function and rotational freedom, the fully functional prototype could be inserted through a 12-mm trocar. In dexterity assessments, the Click-On provided a 40% reduction in movements compared to the DROP-IN, which converted into a reduction in time, path length, and increase in straightness index. Radioguidance also improved decision-making; task-completion rate increased by 60%, procedural time was reduced, and movements became more focused. CONCLUSION: The Click-On gamma probe provides a step toward full integration of radioguidance in minimal invasive surgery. The value of this concept was underlined by its impact on surgical dexterity and decision-making.

Correction to: Cost Effectiveness of Cladribine Tablets for the Treatment of Relapsing-Remitting Multiple Sclerosis in The Netherlands.

The second author's name should be "Maria De Francesco" rather than "Maria de Fransesco".

Cost Effectiveness of Cladribine Tablets for the Treatment of Relapsing-Remitting Multiple Sclerosis in The Netherlands.

BACKGROUND: Cladribine tablets have recently become available in The Netherlands for patients with relapsing-remitting multiple sclerosis (RRMS) as a disease-modifying agent that reduces the frequency and severity of relapses and delays disability progression. OBJECTIVE: The aim of this study was to evaluate the cost effectiveness of cladribine tablets, compared with alternative options, in the treatment of RRMS patients with high disease activity (HDA) and patients with rapidly evolving severe (RES) MS in The Netherlands. METHODS: A Markov model was developed simulating the costs and effects of RRMS treatment. For HDA, alemtuzumab and fingolimod were used as comparators; natalizumab was used for the RES subpopulation. The analysis included a societal perspective and a value-of-information (VOI) analysis. RESULTS: For the HDA subpopulation, treatment with cladribine tablets was the cost-effective (dominant) strategy compared with alemtuzumab and fingolimod, with 50.9% and 98.2%, respectively, probability of being cost effective at a threshold of €50,000/QALY gained and a net monetary benefit (NMB) of €10,866 and €151,115, respectively. For the RES subpopulation, treatment with cladribine tablets dominated treatment with natalizumab, with 94.1% probability of being cost effective at a threshold of €50,000/QALY gained and an NMB of €122,986. Note that these outcomes are driven by the lower costs of cladribine tablets. Efficacy differences were small, very uncertain, and likely not clinically meaningful. The probabilistic sensitivity analyses showed significant overlap in the credible intervals for total lifetime QALY outcomes and costs of cladribine tablets and all relevant comparators. The population-level VOI amounted to €19,295,441. CONCLUSIONS: The base-case analysis shows that treatment of RRMS with cladribine tablets is cost effective versus alemtuzumab and fingolimod in HDA patients, and cost effective versus natalizumab in RES patients, at a threshold of €50,000. Driven by the lower costs, cladribine tablets were cost effective (dominant) in all base-case analyses. However, given that outcomes are based on indirect comparisons and post hoc subgroup analysis, as well as the uncertainty surrounding the outcomes, the results presented in this paper should be interpreted with caution.

Do self-statements enhance the effectiveness of virtual reality exposure therapy? A comparative evaluation in acrophobia.

There is a clear need for more detailed analysis of the role of cognitive self-statements in virtual reality exposure therapy (VRET). To date, no research on this topic has been done. The primary aim of this study was to investigate whether coping self-statements would enhance the effectiveness of VRET. In a randomized crossover design, 26 patients with acrophobia (DSM-IV diagnosis of specific phobia) were randomly assigned to two sessions of VRET followed by two sessions of VRET plus coping self-statements, or the other way around: first two sessions of VRET plus coping self-statements followed by two sessions of VRET. Results showed that VRET, regardless of addition of coping self-statements, decreased anxiety of heights, decreased avoidance of height situations, and improved attitudes towards heights. However, at 6-month follow-up, most gains during treatment were not fully retained.

Virtual reality exposure therapy of anxiety disorders: a review.

Virtual reality exposure therapy (VRET) is an altered form of behavioral therapy and may be a possible alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse patients in a computer-generated virtual environment. Research on this type of treatment for anxiety disorders is discussed in this article, and the mediating and moderating variables that influence VR treatment effectiveness as well. Evidence is found that VRET is effective for participants with fear of heights and of flying. For other phobias, research to date is not conclusive. More randomized clinical trials in which VRET is compared with standard exposure are required. Furthermore, studies are needed in which VRET is not just a component of the treatment package evaluated, but in which VRET should be assessed as a stand-alone treatment.

Virtual reality treatment versus exposure in vivo: a comparative evaluation in acrophobia.

The aim of the present study was to evaluate the effectiveness of low-budget virtual reality (VR) exposure versus exposure in vivo in a between-group design in 33 patients suffering from acrophobia. The virtual environments used in treatment were exactly copied from the real environments used in the exposure in vivo program. VR exposure was found to be as effective as exposure in vivo on anxiety and avoidance as measured with the Acrophobia Questionnaire (AQ), the Attitude Towards Heights Questionnaire (ATHQ) and the Behavioral Avoidance Test (BAT). Results were maintained up to six months follow-up. The present study shows that VR exposure can be effective with relatively cheap hardware and software on stand-alone computers currently on the market. Further studies into the effectiveness of VR exposure are recommended in other clinical groups as agoraphobics and social phobics and studies in which VR exposure is compared with more emerging virtual worlds as presented in CAVE-type systems.

Research on presence in virtual reality: a survey.

Virtual Reality (VR) is starting to be used in psychological therapy around the world. However, a thorough understanding of the reason why VR is effective and what effect it has on the human psyche is still missing. Most research on this subject is related to the concept of presence. This paper gives an up-to-date overview of research in this diverse field. It starts with the most prevailing definitions and theories on presence, most of which attribute special roles for the mental process of attention and for mental models of the virtual space. A review of the phenomena thought to be effected by presence shows that there is still a strong need for research on this subject because little conclusive evidence exists regarding the relationship between presence and phenoma such as emotional responses to virtual stimuli. An investigation shows there has been substantial research for developing methods for measuring presence and research regarding factors that contribute to presence. Knowledge of these contributing factors can play a vital role in development of new VR applications, but key knowledge elements in this area are still missing.