Dr. Sheldon is a board-certified radiation oncologist who treats a wide variety of cancers, including head and neck cancers, lung cancer, breast cancer, esophageal cancer, pancreatic cancer, rectal cancer, skin cancer, brain tumors, and prostate cancer.  He has extensive experience in radioactive seed implants (brachytherapy) for prostate cancer, having done over 2000 procedures.

He has access to state-of-the-art equipment at Cooley Dickinson Hospital with a Varian TrueBeam linear accelerator, which allows for a variety of radiation treatments including: IMRT, VMAT, image-guided radiotherapy, 4D radiotherapy to account for respiratory motion and tumor motion, deep-inspiration breathhold technique, stereotactic body radiotherapy (SBRT), and stereotactic ablative radiotherapy (SABR).

He advocates for patient engagement and patient empowerment as patients consider their treatment options.

He collaborates in a multidisciplinary team approach with cancer and surgical specialists in Boston and elsewhere, so that patients may conveniently receive radiation therapy closer to their home in Western Massachusetts, while still accessing surgical expertise at distant hospital as needed.

He has access to the latest genomic profiling tests of tumor tissue samples, so that the cancer's genetic fingerprint can be determined, and a treatment regimen can be customized and personalized for the patient accordingly.

He practiced in Kansas City, Missouri for 22 years prior to relocating to Western Massachusetts in 2019 and joining the top-rated Mass General Cancer Center network of care.