A method of providing a peptide receptor radiotherapy (PRRT) treatment recommendation for a subject having a neuroendocrine tumor, the method comprising: determining the expression level of 12 biomarkers from a test sample from the subject by contacting the test sample with a plurality of agents specific to detect the expression of the 12 biomarkers, wherein the 12 biomarkers consist of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2, PLD3, NAP1L1, NOL3, TECPR2, and ALG9; normalizing the expression level of each of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2, PLD3, NAP1L1, NOL3, and TECPR2 to the expression level of ALG9, thereby obtaining a normalized expression level of each of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2, PLD3, NAP1L1, NOL3, and TECPR2; summing the normalized expression level of each of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2 PLD3, NAP1L1, NOL3, and TECPR2, thereby obtaining a summated expression level; determining a first score, wherein the first score is 1 when the summated expression level is equal to or greater than a first predetermined cutoff value, or the first score is 0 when the summated expression level is below the first predetermined cutoff value; determining a second score based on the histological grade of the NET, wherein the second score is 1 when the NET is designated high grade, or the second score is 0 when the NET is designated low grade; calculating a third score based on the following equation: Third Score = 39.22787 - 40.80341 * (First Score) - 18.441 * (Second Score); and providing a recommendation that the NET will respond to PRRT when the third score is equal to or less than a second predetermined cutoff value, or providing a recommendation that the NET will not respond to PRRT when the third score is above the second predetermined cutoff value. determining the expression level of 12 biomarkers from a test sample from the subject by contacting the test sample with a plurality of agents specific to detect the expression of the 12 biomarkers, wherein the 12 biomarkers consist of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2, PLD3, NAP1L1, NOL3, TECPR2, and ALG9; normalizing the expression level of each of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2, PLD3, NAP1L1, NOL3, and TECPR2 to the expression level of ALG9, thereby obtaining a normalized expression level of each of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2, PLD3, NAP1L1, NOL3, and TECPR2; summing the normalized expression level of each of ARAF1, BRAF, KRAS, RAF-1, ATP6V1H, OAZ2, PANK2 PLD3, NAP1L1, NOL3, and TECPR2, thereby obtaining a summated expression level; determining a first score, wherein the first score is 1 when the summated expression level is equal to or greater than a first predetermined cutoff value, or the first score is 0 when the summated expression level is below the first predetermined cutoff value; determining a second score based on the histological grade of the NET, wherein the second score is 1 when the NET is designated high grade, or the second score is 0 when the NET is designated low grade; calculating a third score based on the following equation: Third Score = 39.22787 - 40.80341 * (First Score) - 18.441 * (Second Score); and providing a recommendation that the NET will respond to PRRT when the third score is equal to or less than a second predetermined cutoff value, or providing a recommendation that the NET will not respond to PRRT when the third score is above the second predetermined cutoff value.