2.3.3. SUVmax of Malignant Lesions (P-T)

In P-T patients, an increase of tracer accumulation was also observed in bone metastases, but these data were not statistically significant (*p* = 0.068).

#### *2.4. Gleason Score*

The LPR showed a clear differentiation depending on the primary histological starting situation, which is expressed by the evaluation system for determining the aggressiveness of PCa. According to previous studies, PCa with a Gleason score (GS) of 7b (4 + 3) has a significantly worse prognosis than PCa with a GS of 7a (3 + 4). For this reason, 7a is classified as grade group 2 and 7b is classified as grade group 3, although they belong to the same group of intermediate-risk PCa. In our study, 11% of the PSMA-positive subgroup P-P was previously categorized as low-risk PCa (GS < 7) with grade 1 according to the International Society of Urological Pathology (ISUP) and intermediate-risk with grade 2 (GS 7a), whereas a categorization of PCa grade 3 to grade 5 (GS 7b, 8 and >8; intermediate up to high-risk) was found in 89% (Table 4) [3,16,17]. By comparison of the LNM-LPR of grade group 1 to 2 PCa-patients (GS ≤ 7a) with that of grade group 3 to 5 (GS ≥7b), a statistically significant difference (*p* = 0.029) was noted (12% vs. 88% respectively) (Table 4).


**Table 4.** Gleason score in relation to [68Ga]Ga-PSMA-11 PET/CT LPR P-P.

Abbreviations: GS, Gleason score; *n*, number of patients; *p* < 0.05 is considered significant; *r*, Pearson correlation coefficient.

When comparing grade 1 to 2 PCa patients (GS ≤ 7a) with grade 3 to 5 PCa patients (GS ≥ 7b) in the subgroup P-I, we evaluated an LNM-LPR in 10% for grade 1 to 2 and in 80% for grade 3 to 5. In the subgroup P-T, all PSMA-avid LNM belong to grade group 3 to 5 (GS ≥ 7b). However, these results were not statistically significant.
