A cost-effectiveness analysis of sentinel lymph node detection in vulvar cancer by preoperative lymphoscintigraphy versus intraoperative detection alone.

OBJECTIVE: To determine cost-effectiveness of preoperative lymphoscintigraphy (LSG) for detection of inguinofemoral sentinel lymph nodes (SLN). METHOD: We compared the use of preoperative LSG prior to SLN excision versus omission of preoperative LSG. The two outcomes were death or survival. Costs associated with the procedure were determined by CPT code and published estimates. Cost analysis was performed using Treeage software, and incremental cost-effectiveness ratios (ICERs) were calculated. The measure of effectiveness was incremental survival benefit. ICER thresholds for considering LSG to be cost-effective were based on the value of a statistical life (VSL). RESULTS: Using a baseline probability of 0.93 for finding SLN with LSG, our model estimated LSG costs were $2783.84 with 84.7% survival. Our model then estimated the cost and survival without LSG by varying the SLN detection rate. Survival was equivalent when probability of SLN detection without LSG was 0.93. If detection without LSG was >0.93, not performing LSG was the dominant strategy. Costs were equal when probability of finding SLN without LSG was 0.6. For any SLN detection without LSG below 0.6, performing LSG was the dominant strategy. Formal cost-effectiveness analysis was performed using ICERs for probabilities from 0.60 to 0.93. In this range, costs were higher with LSG, but survival was improved. As long as the incremental detection with LSG was at least 1.05% to 1.47% higher, LSG was cost-effective with ICERs below the VSL. CONCLUSION: In our model, LSG is cost-effective as long as it increases detection of SLN by at least 1.05-1.47%.

Cost analysis of sentinel lymph node biopsy in melanoma.

INTRODUCTION AND OBJECTIVE: Sentinel lymph node biopsy (SLNB) is the most useful tool for node staging in melanoma. SLNB facilitates selective dissection of lymph nodes, that is, the performance of lymphadenectomy only in patients with sentinel nodes positive for metastasis. Our aim was to assess the cost of SLNB, given that this procedure has become the standard of care for patients with melanoma and must be performed whenever patients are to be enrolled in clinical trials. Furthermore, the literature on the economic impact of SLNB in Spain is scarce. METHOD: From 2007 to 2010, we prospectively collected data for 100 patients undergoing SLNB followed by transhilar bivalving and multiple-level sectioning of the node for histology. Our estimation of the cost of the technique was based on official pricing and fee schedules for the Spanish region of Murcia. RESULTS: The rate of node-positive cases in our series was 20%, and the mean number of nodes biopsied was 1.96; 44% of the patients in the series had thin melanomas. The total cost was estimated at between €9486.57 and €10471.29. Histopathology accounted for a considerable portion of the cost (€5769.36). DISCUSSION: The cost of SLNB is high, consistent with amounts described for a US setting. Optimal use of SLNB will come with the increasingly appropriate selection of patients who should undergo the procedure and the standardization of a protocol for histopathologic evaluation that is both sensitive and easy to perform.

Sentinel lymph node status in vulval cancer: systematic reviews of test accuracy and decision-analytic model-based economic evaluation.

BACKGROUND: Vulval cancer causes 3-5% of all gynaecological malignancies and requires surgical removal and inguinofemoral lymphadenectomy (IFL). Complications affect > 50% of patients, including groin wound infection, lymphoedema and cellulitis. A sentinel lymph node (SLN) is the first groin node with the highest probability of malignancy. SLN biopsy would be useful if it could accurately identify patients in whom cancer has spread to the groin, without removing all groin nodes. SLNs can be identified by isosulfan blue dye and/or technetium-99 ((99m)Tc) radioactive tracer during lymphoscintigraphy. The blue dye/(99m)Tc procedure only detects SLN, not metastases - this requires histological examination, which can include ultrastaging and staining with conventional haematoxylin and eosin (H&E) or immunohistochemistry. OBJECTIVES: To determine the test accuracy and cost-effectiveness of the SLN biopsy with (99m)Tc and/or blue dye compared with IFL or clinical follow-up for test negatives in vulval cancer, through systematic reviews and economic evaluation. DATA SOURCES: Standard medical databases, including MEDLINE, EMBASE, Science Citation Index and The Cochrane Library, medical search gateways, reference lists of review articles and included studies were searched to January 2011. METHODS: For accuracy and effectiveness, standard methods were used and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches were to January 2011, with no language restrictions. Meta-analyses were carried out with Meta-Disc version 1.4 (Javier Zamora, Madrid, Spain) for accuracy; none was appropriate for effectiveness. The economic evaluation from a NHS perspective used a decision-tree model in DATA TreeAge Pro Healthcare 2001 (TreeAge Software, Inc., Williamstown, MA, USA). Six options (blue dye with H&E, blue dye with ultrastaging, (99m)Tc with H&E, (99m)Tc with ultrastaging, blue dye/(99m)Tc with H&E, blue dye/(99m)Tc with ultrastaging) were compared with IFL. Deterministic and probabilistic sensitivity analyses were conducted. RESULTS: For accuracy, of the 26 included studies, most evaluated (99m)Tc/blue dye combined. Four studies had clinical follow-up only for test negatives and five had clinical follow-up for all and IFL for test negatives. Numbers with no SLN found were difficult to distinguish from those with negative SLN biopsies. The largest group of 11 studies using (99m)Tc/blue dye, ultrastaging and immunohistochemistry had a pooled sensitivity of 95.6% [95% confidence interval (CI) 91.5% to 98.1%] and a specificity of 100% (95% CI 99.0% to 100%). Mean SLN detection rates were 94.6% for (99m)Tc, 68.7% for blue dye and 97.7% for both. One study measured global health status quality of life (QoL) and found no difference between SLN biopsy and IFL. One patient preference evaluation showed that 66% preferred IFL rather than a 5% false-negative rate from SLN biopsy. For effectiveness, of 14,038 references, one randomised controlled trial, three case-control studies and 13 case series were found. Approximately 50% died from vulval cancer and 50% from other causes during follow-ups. Recurrences were in the ratio of approximately 4 : 2 : 1 vulval, groin and distant, with more recurrences in node-positive patients. No studies reported QoL. For cost per death averted, IFL was less costly and more effective than strategies using SLN biopsy. For morbidity-free survival and long-term morbidity-free survival, (99m)Tc with ultrastaging was most cost-effective. Strategies with blue dye only and H&E only were never cost-effective. The incremental cost-effectiveness ratio for (99m)Tc with ultrastaging compared with IFL was £4300 per case of morbidity-free survival and £7100 per long-term morbidity-free survival. LIMITATIONS: The main limitations of this study include the lack of good-quality evidence on accuracy, effectiveness and QoL. A large project such as this takes time to publish, so the most recent studies are not included. CONCLUSIONS: A sensitive and specific combined metastatic SLN detection test and information on generic QoL in vulval cancer is urgently required. FUNDING: The National Institute for Health Research Health Technology Assessment programme.