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James Mason,

M.D., M.P.H.

Radiation Oncologist

5 (113 Ratings)
Biography photo
Location
City of Hope Wildomar Radiation Oncology
36450 Inland Valley Drive, Suite 101
Wildomar, CA 92595
Specialties
Radiation Oncology
Education
Medical school:

M.D., Wayne State University, Detroit, MI

Residency:

Radiation Oncology - Wayne State University, Detroit, MI

Academic Appointments
  • Assistant Clinical Professor, Department of Radiation Oncology
About Me

James Mason, MD, MPH, brings more than 25 years of experience in radiation oncology to his role at City of Hope® Wildomar, one of our Southern California radiation oncology clinics. Dr. Mason has received extensive training in state-of-the-art precision radiation therapies, including high-dose and low-dose brachytherapy, intensity-modulated radiation therapy, stereotactic radiosurgery, prostate brachytherapy, 3-D conformal radiation therapy and the Mammosite system. 

Dr. Mason earned his medical degree from Wayne State University in Detroit, where he also completed his internship and residency. He later obtained a master’s degree in public health fro Harvard University. Before relocating to Southern California, Dr. Mason practiced for several years at the renowned Cleveland Clinic.

Patient reviews
The patient ratings and comments on this page are obtained from an external Press Ganey® outpatient survey provided to all eligible City of Hope patients within one to two weeks of their treatment occurrence. Raw data from the answers to the survey questions about our physicians are calculated by Press Ganey into a one- to five- star rating. In the spirit of transparency, all patient comments are posted as written by the patient, whether they are positive or negative. We only exclude comments if they are deemed to be slanderous or libelous, contain profanity or vulgar language, or do not relate to the patient's experience with the doctor involved. As a result, the comments are the views and opinions of the patients surveyed and are not endorsed by, and may not necessarily reflect the opinion of, City of Hope.
Apr 18, 2026
5.0
"If it is definitely a very good clinic they do a good job"
Apr 18, 2026
5.0
"Dr Mason is very good at explaining the problem in detail and how to fix the disease"
Apr 17, 2026
5.0
"It was a very positive experience in every respect. Beautiful facility and really professional staff"
Apr 17, 2026
5.0
"Dr. Mason's obvious expertise put me at ease and he took extra time to clearly explain my upcoming treatment plan. He was exceedingly kind, compassionate and knowledgeable about my specific case."
Apr 16, 2026
5.0
"The staff that's there and those who have gone they're all respectful to each other and they make me feel like family"
Apr 16, 2026
5.0
"Awesome Dr. Mason that's why he's the doctor number one to me and I seen quite a few keep up the good work Dr. Mason"
Apr 7, 2026
5.0
"A pleasure to work with."
Apr 3, 2026
5.0
"I've yet to receive treatment due to the fact my appointment was a consultation"
Mar 27, 2026
5.0
"Thank you for taking all care in the way and position of giving me radiation."
Feb 20, 2026
5.0
"[...] City of Hope provides exceptional care"
Feb 17, 2026
5.0
"Dr Mason had obviously prepared for this appointment and provided me with all necessary information for me to proceed with finding a medical oncologist to take over my case at this time."
Feb 13, 2026
5.0
"Outstanding care provider."
Feb 13, 2026
5.0
"Very good customer service coordination."
Dec 31, 2025
5.0
"What I seen in my experience the balance and caring that the whole staff seems to have mastered I'd like to wish your staff to continue with the excellence"
Dec 31, 2025
5.0
"The experience was one of a kind I would do it all over again if it was my first wonderful outstanding experience kind considerate staff communicators which I adore having teamwork makes the dream work"
Dec 18, 2025
5.0
"[...] I love everything about this place and the people there [...]"
Dec 12, 2025
5.0
"I felt supported, important."
Oct 10, 2025
5.0
"All the staff did very well attending my needs"
Oct 8, 2025
5.0
"[...] Dr. Mason was invaluable; he took all the time necessary to answer my questions. I would highly recommend him. [...]"
Aug 24, 2025
5.0
"My husband and I have raved about City of Hope in Wildomar, CA to many people we have met with similar issues."
Jul 25, 2025
5.0
"Thorough explanations"
Jul 4, 2025
5.0
"Dr. Mason answered all my questions and concerns. Very nice man"
Jul 3, 2025
5.0
"I am completely satisfied with the care and help I received at this facility!"
Jul 1, 2025
5.0
"Dr Mason and nurse [...] are the best team I have ever had"
Jun 25, 2025
5.0
"Good communication and attention"
Jun 24, 2025
5.0
"Dr Mason was wonderful! I wish he was my PCP/Oncologist. Very kind, knowledgeable, helpful. Explained the risk vs the benefits of re-radiating the area of recurrence."