PROMISE is a molecular imaging TNM staging system which is proposed to facilitate reporting and study design of prostate cancer molecular imaging [
79,
80]. Under this system, local disease is categorized into T stages, ranging from miT0 (no local tumor) to miT4 (tumor invades structures other than seminal vesicles) [
79]. Regional nodal disease is assigned N stages, ranging from miN0 (no regional lymph nodes) to miN2 (multiple pelvic nodal regions affected) [
79]. Metastatic disease is classified with an M stage, which spans from miM0 (no distant metastases) to miM1 (distant metastases), further categorized as diss (disseminated), dmi (diffuse marrow involvement), oligo (oligiometastatic), and uni (unifocal) [
79]. PSMA uptake levels are assessed using a visual scoring system based on the mean uptake in the blood pool, liver, and parotid gland, and the results are reported as 0, 1, 2, or 3, indicating no, low, intermediate, or high PSMA expression, respectively [
79]. The recently introduced PROMISE V2 [
80] comes with two hierarchical levels of assessment including an updated TNM staging schema and reporting of PSMA expression score which is now integrated with PRIMARY score [
80]. PRIMARY score is a five-point scoring system, validated for detection of clinically significant prostate cancer in biopsy naïve patients [
62]. PROMISE V2 has new recommendations for reporting sequential studies, lesion distribution and tumor volume assessment. These new changes facilitate use of specific PSMA response criteria such as PSMA PET Progression criteria (PPP) which focuses on a single lesion or Response Evaluation Criteria in PSMA-PET/CT (RECIP) which mostly focuses on total tumor volume in patients with extensive disease [
62].
Prostate-specific Membrane Antigen-Reporting and Data System (PSMA-RADS) is a proposed reporting and data system with ultimate goal of establishing a uniform and structured reporting system for PSMA-targeted PET studies [
81]. This framework assigns a PSMA-RADS value of 1–5 to both individual lesions and the overall scan. A value of 1 indicates a normal scan or a known benign lesion based on pathological examination or pathognomonic imaging. A value of 2 suggests a likely benign lesion, although biopsy results may be unavailable, or imaging findings may not be pathognomonic. Category 3 is multifaceted and includes lesions that are indeterminate for prostate cancer or suspicious for a non-prostate malignancy. A value of 4 indicates a likely prostate cancer, while 5 signifies almost certain prostate cancer with a classic imaging appearance [
81]. The aim of this framework is to reflect the level of confidence of the clinician in presence of prostate cancer and clarify the need for further workup. Different categories of PSMA-RADS specifically category 3 which is reflects more equivocal findings, has been validated in recent studies [
82‐
84].