Timing and necessity of staging imaging in clinical stage II cutaneous melanoma: Cost-effectiveness and clinical decision analysis.

BACKGROUND: Preoperative imaging in clinical stage II melanoma is not indicated per National Comprehensive Cancer Network (NCCN) guidelines but remains common in clinical practice. METHODS: Patients presenting with cutaneous clinical stage II melanoma from 2007 to 2019 were retrospectively reviewed. A clinical decision analysis with cost data was designed to understand ideal practice patterns in managing stage II melanoma, with pre-versus selective post-operative imaging as the initial decision node. RESULTS: There were 277 subjects included, and 143 underwent preoperative imaging (49.5%). This changed management (i.e. no surgery) in one patient (0.4%). Overall, 16 patients had additional findings on imaging (5.8%). Upfront surgery with selective postoperative imaging was a more cost-effective strategy than routine performance of preoperative imaging, with savings of $1677 per patient. CONCLUSION: Preoperative imaging is a low yield, costly approach for patients with clinical stage II melanoma with minimal impact on the decision to proceed with surgical management.

A Mechanistically Inspired Halenium Ion Initiated Spiroketalization: Entry to Mono- and Dibromospiroketals.

Employing halenium affinity (HalA) as a guiding tool, the weak nucleophilic character of alkyl ketones was modulated by the templating effect of a tethered 2-tetrahydropyranyl(THP)-protected alcohol towards realizing a bromenium ion initiated spiroketalization cascade. Addition of ethanol aided an early termination of the cascade by scavenging the THP group after the halofunctionalization stage, furnishing monobromospiroketals. Alternatively, exclusion of ethanol from the reaction mixture biased the transient oxocarbenium towards α-deprotonation that precedes a second bromofunctionalization event thus, furnishing dibrominated spiroketals. The regio- and stereoselectivity exploited in the current methodology provides a novel and rapid access to the dibrominated spiroketal motifs exhibited by several natural products.