Kassel, Maxwell

In this work, we have developed a robust daily quality assurance (QA) system for pencil-beam scanning (PBS) dosimetry. A novel phantom and multi-PTV PBS plan were used in conjunction with the Sun Nuclear Daily QA3 multichamber detector array to verify output, range, and spot position. The sensitivity to detect change in these parameters with our designed tests was determined empirically. Associated tolerance levels were established based on these sensitivities and guidelines published in recent American Association of Physics in Medicine (AAPM) task group reports. The output has remained within the 3% tolerance and the range was within ±1mm. Spot position has remained within ±2mm. This daily QA procedure is quick and efficient with the time required for setup and delivery at less than 10 minutes.

Reports of a suspected cancer cluster can be frightening for any community. The source of a cancer cluster is often the primary community concern, but it is inherently difficult to link a cluster with any specific environmental agent. This thesis focuses on aspects of cancer clusters such as the official cancer cluster definition and investigation guidelines given by the Centers for Disease Control and Prevention. It explores “Cancer Clusters in the USA: What do the last twenty years of state and federal investigations tell us?” [1], an article which reviewed publicly available cancer cluster investigation reports from 1990 to 2012, and uses a similar methodology to review investigation reports from 2012 to 2016 in the interest of providing more modern data regarding cancer cluster reports.