NeXT Personal CTA (Clinical Trial Assay) is a patient-specific, tumor-informed device which allows for detection of MRD from cfDNA. By using next generation sequencing technology, whole genome sequencing (WGS) is conducted from DNA derived from patient tumor and normal samples. A tumor informed personalized panel is then constructed that uses only a selection of DNA targets from the WGS by applying bioinformatic filters. The targeted personalized panel is then sequenced using NGS and DNA derived from cfDNA from plasma samples. The data from the cfDNA NGS are then further analyzed using bioinformatics filters to report the MRD status.