Pluvicto presents a much lower risk of radiation damage to healthy cells, because it is not a beam, but a molecule that targets only cells that express PSMA. Here is an excerpt from the Mayo entry about Pluvicto:

Treatments that target PSMA: Radiopharmaceutical treatments can target a protein that's common on prostate cancer cells called prostate-specific membrane antigen. It's also called PSMA. One radiopharmaceutical medicine that works in this way is lutetium Lu-177 vipivotide tetraxetan (Pluvicto). This medicine contains a molecule that finds and sticks to the PSMA on prostate cancer cells. The medicine also contains a radioactive substance. A healthcare professional gives this medicine through a vein. The medicine finds the prostate cancer cells and releases the radiation directly into the cells. It can treat prostate cancer anywhere in the body. PSMA therapy only works if the prostate cancer cells have the PSMA protein. Side effects include dry mouth, dry eyes, nausea and feeling very tired.

Regarding possible damage to other healthy tissue from Pluvicto:
The saliva glands and prostate cancer cell membrane structure "looks" similar through Pluvicto's eyes. It is not uncommon for some of the saliva glads (there are many) to be damaged. This is why dry mouth is a commonly listed side effect. But, not to worry.
I was a Novartis Pharmaceutical clinical trial patient in 2021-22 for what became Pluvitco. The delivery of the product was different than it is now and consisted of two separate infusions. Now, it's one injection. During the trial, the patient would suck on ice chips and hold an ice pack around the throat prior, during and several hours after the procedure. The purpose was to chill the throat resulting in reduced blood flow carrying the Pluvitco to the saliva glands in an attempt to minimize damage. I had some, but minimal change to my saliva output.
Going forward... In 2024, I started another 6 round of Pluvitco. Rare, but true. I'm in-between #4 and #5. This time, it has been determined by the medical professionals the potential saliva gland damage is minimal enough that no chilling to the throat area is being given as standard treatment. For the record, I still do it each time, regardless. I do have reduced saliva from prior to the 2021 trial, but considering I've had 10 treatments (2 to go for me, but only 6 is normal), the dry mouth is minor. I drink liquids more often and would not eat salty potato chips with a drink. So, as I said earlier, don't worry about it. You have bigger issues to worry about. Good luck.