With regional lymph node metastasis what is the progression?

From the following summary what should I expect going forward other than Androgen Deprivation Therapy (ADT)?

SUMMARY

2020-06 Prostatectomy

Pathology:
Gleason 4+3
T3
Positive surgical margins
Perineural nerve invasion
Invasive carcinoma (cancer in surrounding healthy tissue)

2021-04 Salvage radiation therapy (SRT) started
2021-06 Salvage radiation therapy ended
2024-07 Undetectable PSA end of SRT to here
2024-09 PSA at 0.02
2025-04 PSA at 0.03
2025-07 PSA at 0.03

I was told that the cancer is probably in the lymph nodes at this stage. With such low PSA levels, it would appear to me to be oligometastatic.

Other than Androgen Deprivation Therapy (ADT), what should I expect going forward? Are low PSA levels like 0.03 typical of the start of metastatic progression? Any other context someone might give would be appreciated. I have read that the 5-year survival rate for regional lymph node involvement is 100%.

Regards,

Aaron