Operating rooms (ORs) are simultaneously the largest cost center and greatest source of revenues for most hospitals. Due to significant uncertainty in surgery durations, scheduling of ORs can be very challenging. Longer than average surgery durations result in late starts not only for the next surgery in the schedule, but potentially for the rest of the surgeries in the day as well. Late starts also result in direct costs associated with overtime staffing when the last surgery of the day finishes later than the scheduled shift end time. In this article we describe a stochastic optimization model and some practical heuristics for computing OR schedules that hedge against the uncertainty in surgery durations. We focus on the simultaneous effects of sequencing surgeries and scheduling start times. We show that a simple sequencing rule based on surgery duration variance can be used to generate substantial reductions in total surgeon and OR team waiting, OR idling, and overtime costs. We illustrate this with results of a case study that uses real data to compare actual schedules at a particular hospital to those recommended by our model.
Objective
To construct a postoperative nomogram to estimate the risk of local recurrence for patients with desmoid tumors.
Background
The standard management of desmoid tumors is resection, but many recur locally. Other options include observation or novel chemotherapeutics, but little guidance exists on selecting treatment.
Methods
Patients undergoing resection during 1982-2011 for primary or locally recurrent desmoids were identified from a single-institution prospective database. Cox regression analysis was used to assess risk factors and to create a recurrence nomogram, which was validated using an international, multi-institutional dataset.
Results
Desmoids were treated surgically in 495 patients (median follow-up 60 months). Of 439 patients undergoing complete gross resection, 100 (23%) had recurrence. Five-year local recurrence–free survival (LRFS) was 69%. Eight patients died of disease, all after R2 resection. Adjuvant radiation was not associated with improved LRFS. In multivariate analysis, factors associated with recurrence were extremity location, young age, and large tumor size, but not margin. Abdominal wall tumors had the best outcome (5-year LRFS 91%). Age, site, and size were used to construct a nomogram with concordance index 0.703 in internal validation and 0.659 in external validation. Integration of additional variables (R1 margin, gender, depth, and primary vs. recurrent presentation) did not importantly improve concordance (internal concordance index 0.707).
Conclusions
A postoperative nomogram including only size, site, and age predicts local recurrence and can aid in counseling patients. Systemic therapies may be appropriate for young patients with large, extremity desmoids, but surgery alone is curative for most abdominal wall lesions.
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