Proton Therapy Hypofractionation for Prostate Cancer

An effective option that reduces the length of radiation treatment in a young patient with early-stage prostate cancer

By Karen Godette, MD, Medical Director of Radiation Oncology, Emory University Hospital Midtown, Winship radiation oncologist

Patient Profile

A 48-year-old man from a neighboring state was monitored with serial PSAs by his local physician because of family history, including his father’s diagnosis at an early age. In 2019, a rising PSA that had reached 3.9 prompted a prostate biopsy that detected a Gleason score of 6 (3 + 3) in multiple cores. This meant low risk but high volume. His urologist recommended radical prostatectomy, but a family friend in Atlanta urged him to follow-up with the Emory Proton Therapy Center.

Many Resources -- All at Emory Proton Therapy Center

Evaluation at the proton center included review of his MRI that showed his cancer confined to the prostate. Patients with prostate cancer have various radiation as well as surgical options. All of these choices were reviewed with the patient. He wanted proton therapy, which was determined to be an appropriate approach for this patient, given the early stage of his cancer and his relative youth and potential life expectancy. Studies show increased benefits of proton radiation for such patients, including decreased bowel and bladder toxicity and a reduced chance of second malignancies due to radiation exposure.

The patient returned to the Emory Proton Therapy Center for the insertion of three fiducial markers in the prostate. These metal objects, about the size of a grain of rice, enable the radiation oncologist to perform image-guided radiation to assure precision targeting of the prostate while decreasing healthy tissue exposure. During the same session, done under local anesthesia, the patient also had a SpaceOAR® hydrogel rectal spacer placed between the prostate and rectum. The spacer moves the rectum some distance from the prostate, further decreasing the amount of radiation to the rectum (by three months after therapy, the hydrogel spacer is absorbed; however the markers remain in place).

During the following week, the patient’s treatment was planned in detail. He underwent a CT scan and MRI while in the position he would assume during treatment. Molds were made for his legs and feet to ensure he would stay in the same position during each treatment. In addition to the internal fiducial markers, the skin of his abdomen and sides were marked as reference points and covered with tape so he could shower or swim.

Proton Therapy Precision and Power in Shorter Time

He began treatment two weeks later. Because of the early stage of his cancer, his radiation oncologist was able to use hypofractionated doses in which the total dose of radiation is divided into larger dosages given over a shorter period of time. What would have required 43 sessions over eight and a half weeks was reduced to 28 sessions over five and a half weeks.

On the first day of treatment, a cone beam CT scan was performed. This new technology, available at centers like Emory Proton Therapy Center, can show the fiducial markers, bones, soft tissue and internal anatomy. At each treatment session, a new image is taken of the pelvis, and this image is overlaid with the planned field, allowing the team to consistently direct the powerful beams in the most precise manner.

Comparative images of proton therapy (left) with minimal radiation to surrounding tissues compared to photon therapy (right).Comparative images of proton therapy (left) with minimal radiation to surrounding tissues compared to photon therapy (right).

Before each treatment, the patient was asked to drink water to fill his bladder and, ideally, to have an empty rectum. Each session required no more than 20-30 minutes in the treatment room. Treatments took place Monday through Friday. While away from home for treatment, he telecommuted and continued his exercise regimen. On weekends, he returned home to resume normal activities with his family and friends. Toward the end of his treatment, in the fourth week, he experienced some increased urinary frequency and urgency. These side effects were neither severe nor unexpected and improved markedly with Flomax. Mild redness of the skin was treated topically.

Reduced Long-Term Side Effects

In January 2020, the patient returned to Emory for his first month follow up visit. He reported feeling well, with decreased nocturia. His energy was back to normal. He resumed a more intense exercise regimen and his endurance was almost back to normal. Erectile function had not been affected by the proton treatment and remained unchanged. All side effects had largely subsided. He will continue to return at three-month intervals, during which his PSA will be retested, and all results sent to his local physician.

Expertise in Proton Therapy for Your Patient

As the only proton therapy center in the state of Georgia, we specialize in the most advanced radiation technologies and treatments for patients with specific cancers. We are an integral part of Winship Cancer Institute of Emory University, a National Cancer Institute-Designated Comprehensive Cancer Center. Together, our teams of world-renowned experts deliver the most effective treatments and achieve the best outcomes for your patients.

To refer a patient, call 1-833-3PROTON (377-6866) or complete a referral form at
emoryhealthcare.org/protonreferral.

Emory Proton Therapy Center is committed to the continued health and safety of all patients. During this time, we are taking all necessary precautions to screen for coronavirus (COVID-19) and to prevent its potential spread. We continue to monitor the evolving COVID-19 pandemic and are working with experts throughout Emory Healthcare to keep your patients safe. For the most up-to-date information for our referring partners, click here.