Is a cxr necessary for general anesthesia for TURP surgery?

Perhaps. generally depends upon the patient age and medical history.
Surgery Risks. Yes. The older one gets the more likelihood there can be deadly consequences with anesthesia. The goal is to get an all clear before surgery or to at least identify common risk factors so plans can be put in place in case something goes wrong during surgery.
CXR is rarely needed. The concept of getting a bunch of labs/cxr/ekg preop has been retired. Unless there is a specific indication (pulmonary symptoms), most informed anesthesiologists would not order a cxr.
See below. For an anesthesiologist a chest x-ray is usually required due to a patient's history, not as a routine. Some surgeons order these as routine. If you are concerned about the procedure please talk to your provider.
Maybe. Clinical characteristics to consider include smoking, recent upper respiratory infection, copd, and cardiac disease. extremes of age, smoking, stable copd, stable cardiac diseaseextremes of age, smoking, stable copd, stable cardiac disease, or resolved recent upper respiratory infection should be considered unequivocal indications for chest radiography.