Measure	Definition	What does this mean?
True positive	Positive surveillance examination followed by diagnosis of ductal carcinoma in situ (DCIS) or invasive breast cancer within a follow-up period	A radiologist finding requires additional work-up; woman diagnosed with a second breast cancer during follow-up
False-positive	Positive surveillance examination with no breast cancer diagnosed by end of follow-up	A radiologist finding requires additional work-up; woman not diagnosed with a second breast cancer during follow-up
False negative	Negative surveillance examination followed by a diagnosis of DCIS or invasive breast cancer by the end of a follow-up period	No radiologist findings require additional work-up, but woman diagnosed with a second breast cancer event during follow-up
True negative	A negative surveillance examination with no diagnosis of breast cancer by the end of a follow-up period	No radiologist findings require additional work-up; woman is not diagnosed with a second breast cancer event during follow-up
Cancer rate	The proportion of women with breast cancer among the entire population receiving surveillance examinations	In the entire population, the percentage of breast cancer both detected and undetected by surveillance
Cancer detection rate	The proportion of women with breast cancer detected by screening among the entire population receiving surveillance examinations	In the entire population, percentage of breast cancer events detected by surveillance imaging
Sensitivity	The proportion of women with a second breast cancer event who have a positive surveillance examination	Percentage of second breast cancer events during follow-up detected by the surveillance examination
Specificity	The proportion of women without a second breast cancer event who have a negative surveillance examination	Percentage of examinations with no second breast cancer event during follow-up that were also negative on the surveillance examination
Positive predictive value (PPV1)	The probability that a woman has a second breast cancer event given that her surveillance examination is positive	Likelihood of a true second breast cancer event in a woman who screens positive with a breast MRI
Positive predictive value (PPV2)	The probability that a women has a second breast cancer event among women recommended to receive a breast biopsy	Likelihood of a true second breast cancer event in a women who screens positive with breast MRI and is recommended to receive a breast biopsy
Positive predictive value (PPV3)	The probability that a woman has a second breast cancer event among women who received a biopsy	Likelihood of a true second breast cancer event in a woman who screens positive with breast MRI and receives a breast biopsy