Testosterone check after Radiation and lupron

I am 73 and am ( was ) in good shape. Worked our pretty hard 6 days/ wk. for over 40 years. I had been on TRT for approx.18 months with a T level between 490 and 510 the past year. I was diagnosed with prostate cancer via a prostate biopsy in Feb. of '20. Prostate biopsy had 1 positive out of 12. It was a 3+3 Gleason score of 6. I had a 16 week Lupron injection on April 14th and started 39 radiation treatments on June 10. I had a 12 week Lupron injection on Aug. 4 and the last radiation treatment of Aug.5. My nuclear bone scan, Prostate MRI, Spine MRI and Pelvis/Abdomen CT scan were all negative. I just had my first follow up blood work last week. My PSA was 20 and it is now .2. My medical oncologist gave me orders for my next PSA in 6 months and said that my next Lupron ( 12 week ) shot on Oct. 27 will be the last one. He originally indicated I would be on Lupron for 18 months but this will just get me to 40 weeks. ( fine with me ) My question concerns the fact that he told me he doesn't believe there is any need to check my testosterone level. I thought that was the key reason for the Lupron injections. Has anyone else gone through this process without knowing what your testosterone level has become?