The success of evolutionary algorithms (EAs) depends crucially on finding suitable parameter settings. Doing this by hand is a very time consuming job without the guarantee to finally find satisfactory parameters. Of course, there exist various kinds of parameter control techniques, but not for parameter tuning. The Design of Experiment (DoE) paradigm offers a way of retrieving optimal parameter settings. It is still a tedious task, but it is known to be a robust and well tested suite, which can be beneficial for giving reason to parameter choices besides human experience. In this paper we analyse evolution strategies (ES) and particle swarm optimisation (PSO) with and without optimal parameters gathered with DoE. Reasonable improvements have been observed for the two ES variants.
Background
Percutaneous cervical cordotomy (PCC) is a nerve-destructive procedure for severe unilateral cancer pain related to mesothelioma and other cancers.
Aims
Prospective case series of patients undergoing percutaneous cordotomy for cancer pain.
Methods
Prospective data collection for consecutive patients who underwent percutaneous cordotomy through a joint pain/palliative care clinic at a large regional pain centre in the Northwest between 2/2008 and 6/2011. Patients were assessed 1 day prior, 2 days post procedure as well as 4 weeks postprocedure. Average and maximum pain scores on a numerical rating scale (NRS) ranging from 0 to 10 of pain 24 h prior and 48 h and 28 days post procedure, the global impression of change scale, morphine equivalent 24 h prior to and percentage reduction after procedure and side effects from procedure were recorded.
Results
39 patients underwent PCS. Most common diagnoses were mesothelioma (19 patients) and bronchial carcinoma (10 patients). 29 patients had chest wall pain. Mean pain max score 24 h prior to procedure was 8.5 (SD 1.7) and 1 (SD 2.1) and 2 (SD 3.1) 48 h and 28 days post. Average pain score was 6.5 (SD 1.8), 0.85 (SD 2.1) and 1.9 (SD 2.98). Morphine equivalent dose median 140 mg prior to procedure and 50% reduction post procedure. Nine patients felt very much better, 23 patients much better on global impression of change scale 2 days post procedure. No patient had irreversible side effects from procedure.
Conclusion
PCS is a highly effective procedure for unilateral refractory cancer pain due to mesothelioma and other cancers in well selected palliative patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.