 The study is split into four cohorts, with a minimum of 1-5 patients expected to be enrolled annually in each cohort, and a total of approximately 10 subjects expected for each cohort. The cohorts are defined by the type of tumor and by scenarios when our measurements will be made relative to the patients standard therapies: 1 intraoral tumors with planned resection and adjuvant radiation therapy; 2 cutaneous malignant tumors receiving surgical resection only, receiving radiation therapy only, or receiving both surgical resection and adjuvant radiation therapy; 3 breast tumor receiving radiation therapy following surgery; and 4 other tumors receiving radiation therapy. The diagnosis for patients in all cases assumes that an eligible tumor or the postsurgical area receiving radiation occurs within approximately one-half centimeter of the surface, as determined by physical exam or imaging if available. All potentially eligible subjects are approached by their treating physician; those who agree to be contacted and are subsequently consented are assigned to the cohort for which they qualify. There is no randomization and no stratification within the cohorts. 