A proton treatment room in the Roberts Proton Therapy CEnter Credit: Penn Medicine

Two studies show promise, safety of proton therapy in the brain in children with cancer

2 Oct 2019 News

From improving outcomes in children with brain cancer to lowering the risk of damage to the brainstem in children with central nervous system tumors, a pair of new studies published today add to the growing body of research showing the potential benefits of proton therapy. The first study, published in Pediatric Blood and Cancer, found that very young children who received proton therapy for medulloblastoma had higher rates of overall survival and recurrence free survival compared to patients who received intense chemotherapy without radiotherapy. The second study, published in Acta Oncologica, showed children with central nervous system tumors who received proton therapy with a newer technique called pencil beam scanning experienced a significantly lower rate of brainstem damage than patients treated with older proton techniques. Both studies were led by Christine Hill-Kayser, MD, an associate professor of Radiation Oncology at the Perelman School of Medicine at the University of Pennsylvania, a member of Penn’s Abramson Cancer Center, and a pediatric oncologist in the Cancer Center at Children’s Hospital of Philadelphia (CHOP).

Proton therapy has key differences from traditional photon radiation. Photon radiation typically uses multiple X-ray beams to attack a tumor target but unavoidably deposits radiation in the normal tissues beyond the target, potentially damaging those tissues as the beam exits the body. Proton therapy is an FDA-approved treatment that directs positively charged protons at the tumor, where they deposit the bulk of the radiation dose, with minimal residual radiation delivered beyond the target, potentially reducing side effects and damage to surrounding tissue.

The first study focused on children with newly diagnosed medulloblastoma—a cancer at the base of the skull. Older children—between the ages of four and 18—with the disease generally receive radiation to the entire brain and spine; however, this treatment can be very toxic to the developing brains of very young children—ages four and younger. The youngest children with this disease thus typically receive intense chemotherapy regimens rather than radiation, but they can often relapse, and previous studies have shown the highest risk of relapse is tied to an area called the posterior fossa—the part of the base of the skull where the tumor is primarily located.

Researchers evaluated 14 young children who received proton therapy following surgery and chemotherapy. They found the five-year rate of overall survival was 84 percent, while the rate of recurrence-free survival was 70 percent. Historical data shows both rates are usually only between 30 and 60 percent in very young patients who do not receive radiotherapy.

“Our study, while small, shows promising outcomes when we use proton therapy to target just the area of surgery in these cases as opposed to radiating the whole brain and spinal areas,” said the study’s lead author Amardeep Grewal, MD, chief resident in Radiation Oncology at Penn.

The authors say further research is needed given the small cohort.

The second study deals with a new proton technique called pencil beam scanning (PBS), which is more effective at sparing healthy tissue than older proton techniques such as double scattered or uniform scanning. This study evaluated 166 patients with pediatric central nervous system tumors and found that at 24 months, the rate of patients experiencing brainstem tissue damage from PBS proton therapy is 0.7 percent. This is much lower than rates of serious brainstem toxicity historically reported in the literature after treatment with double scattered proton therapy.

“The effect of proton therapy on the brainstem has been a subject of much debate, but our data show that pencil beam scanning proton therapy does not increase the risk compared to conventional photon techniques,” said the study’s lead author Jennifer Hyatt Vogel, MD, who completed this work while she was a resident at Penn.

The authors say these data warrant further study, especially in high-risk patients and patients who have had prior radiation therapy.

“Regardless of technique, expertise in proton therapy planning and strict adherence to safety constraints is essential, particularly in treatment of tumors near the brainstem,” Hill-Kayser said.

 

Image: Penn Medicine

Source: Medicalxpress.com

Proton therapy for cancer lowers risk of side effects

27 May 2019 News

Proton therapy results in fewer side effects than traditional X-ray radiation therapy for many cancer patients, according to a new study led by Washington University School of Medicine in St. Louis and the Perelman School of Medicine at University of Pennsylvania. Even with reduced side effects, proton therapy resulted in cure rates similar to those of X-ray radiation therapy.

The findings will be presented June 1 by the study’s first author, Brian C. Baumann, MD, a radiation oncologist at Washington University School of Medicine, at the American Society of Clinical Oncology’s annual meeting, in Chicago.

The study is the first major side-by-side comparison of side effects related to proton therapy and X-ray radiation therapy. It included almost 1,500 patients receiving combined chemotherapy and radiation therapy for lung, brain, head and neck, gastrointestinal and gynecologic cancers that had not yet spread to other parts of the body. Such patients receive both radiation and chemotherapy, a treatment regimen that often cures nonmetastatic cancer. But it also causes severe side effects—such as difficulty swallowing, nausea and diarrhea—that reduce quality of life and can, in some cases, require hospitalization.

After controlling for differences between the groups, such as age and additional medical problems, the researchers found that patients receiving proton therapy experienced a two-thirds reduction in the relative risk of severe side effects within 90 days of treatment, compared with patients receiving X-ray radiation therapy. Forty-five of 391 patients receiving proton therapy experienced a severe side effect in the 90-day time frame (11.5 percent). In the X-ray radiation therapy group, 301 of 1,092 patients experienced a severe side effect in the same period (27.6 percent). Patient data on side effects were gathered as the trial was ongoing, rather than after the fact.

“Proton therapy was associated with a substantial reduction in the rates of severe acute side effects—those that cause unplanned hospitalizations or trips to the emergency room—compared with conventional photon, or X-ray, radiation for patients treated with concurrent radiation and chemotherapy,” said Baumann, an assistant professor of radiation oncology at Washington University and an adjunct assistant professor of radiation oncology at Penn. “The opportunity to reduce the risk of severe side effects for patients and thereby improve their quality of life is very exciting to me. While there have been other studies suggesting that proton therapy may have fewer side effects, we were somewhat surprised by the large magnitude of the benefit.”

The researchers focused their study on what are called grade 3 adverse events, which are severe enough to require hospitalization. These can include pain, difficulty swallowing that might result in weight loss, difficulty breathing, and nausea and diarrhea severe enough to cause dehydration.

Sourcemedicalxpress.com

Proton Therapy and Barbecue: My Recipe for Beating Cancer and Being Myself

15 Apr 2019 News

Going through a cancer diagnosis and treatment is so difficult. Thanks to my care team suggesting proton therapy, I never felt like my life became consumed by my lung cancer diagnosis.

The word “barbecue” might make you think of ribs or pulled pork, Kansas City or Memphis-style. But when I hear the word, what I think of is passion and community.

For 10 years, I’ve participated in barbecue competitions throughout Washington state. In fact, I’m a registered member of the Pacific Northwest Barbecue Association (PNWBA), which organizes competitions from Canada to California. I started off as a competitor with my husband, but we quickly grew curious about what makes winning barbecue. It didn’t take long for us to discover how much fun it was to judge!

But when I was diagnosed with a recurrence of lung cancer in 2016, I was afraid that I’d have to give it all up. I can still recall the anxiety and fear I experienced when I learned my cancer had returned. During my first battle with lung cancer, my physicians were able to remove the tumor through surgery. A series of tests showed that surgery wasn’t an option this time around. My thoracic surgeon recommended a treatment I had never heard of: proton radiation therapy. This precise form of radiation targets the cancerous tumor and spares healthy tissues that surround it. For me, that meant protecting my heart, lungs, esophagus, and spinal cord from excess radiation exposure.

Thankfully, life never skipped a beat during treatment. Minimal side effects meant everyday life and my passion for brisket and the community I had become a part of would not need to take a backseat to cancer treatment. When I tell my story to others, many people have never heard of proton therapy and didn’t know that it can be a better alternative to traditional radiation.

Proton therapy isn’t right for every cancer patient but for certain types of cancer, it is an option worth considering. I’m certainly motivated by my positive experience to try to encourage cancer patients to learn about proton therapy and ask their doctors about it.

I felt little more than fatigue throughout my proton therapy treatment. Sessions lasted mere minutes– it took longer to change my clothes! I was at the Seattle Cancer Care Alliance Proton Therapy Center every day for six weeks, so I got to know the doctors, nurses and staff pretty well. They understood what was most important to me and helped me in ways I couldn’t have expected.

One Saturday, I had a proton treatment scheduled in the morning. When I realized that there was a barbecue competition happening nearby that same day, I signed up to judge. Balancing the two was no problem– my team made sure of that! I can proudly say that to date, I’ve judged 45 barbecue competitions, and judging has led to opportunities I could never have imagined.

One of my biggest feats was being named the 2017 PNWBA Judge of the Year along with my husband. It was an accomplishment that I’ll never forget and one that I was proud to celebrate nearly a year after beating cancer. And my husband and I have become master judges!

I doubt anyone would say that cancer treatment is a positive experience. Going through a cancer diagnosis and treatment is so difficult. I just feel grateful to my care team for suggesting proton therapy and then helping me live my best life even during treatment. I never felt like my life became consumed by my lung cancer diagnosis. Thankfully, I was able to remain Melba Fujiura: wife, friend, barbecue enthusiast– and now, cancer survivor.

Source: curetoday.com

Outcomes After Proton Therapy for Treatment of Pediatric High-Risk Neuroblastoma

15 Apr 2019 News

Purpose

Patients with high-risk neuroblastoma (HR-NBL) require radiation to the primary tumor site and sites of persistent metastatic disease. Proton radiation therapy (PRT) may promote organ sparing, but long-term outcomes have not been studied.

Methods and Materials

Sequential patients with HR-NBL received PRT: 2160 cGy (relative biological effectiveness) to primary tumor bed and persistent metastatic sites, with 3600 cGy (relative biological effectiveness) to gross residual disease.

Results

From September 2010 through September 2015, 45 patients with HR-NBL received PRT after systemic therapy, primary tumor resection, and high-dose chemotherapy with stem cell rescue. Median age was 46 months at the time of PRT (range, 10 months to 12 years); 23 patients (51%) were male. Primary tumors were adrenal in 40 (89%); 11 (24%) received boost. Ten metastatic sites in 8 patients were radiated. Double scattered proton beams were used for 19 (42%) patients, in combination with x-rays for 2 (5%). The remaining 26 (58%) received pencil beam scanning, available since January 2013. We observed 97% freedom from primary site recurrence at 3, 4, and 5 years. Overall survival rates were 89%, 80%, and 80% and disease-free survival rates were 77%, 70%, and 70%, at 3, 4, and 5 years, respectively. With median follow-up of 48.7 months from diagnosis (range, 11-90 months) for all patients (57.4 months for those alive), 37 (82%) patients are alive, and 32 (71%) are without evidence of disease. One patient experienced locoregional recurrence; the remaining 12 (27%) experienced relapse at distant, nonradiated sites. Acute toxicities during treatment were mainly grade 1. No patient has experienced World Health Organization grade 3 or 4 long-term renal or hepatic toxicity. Pencil beam scanning plans required less planning time and resources than double scattered plans.

Conclusions

We observe excellent outcomes in patients treated with PRT for HR-NBL from 2010 through 2015, with 82% of patients alive and 97% free of primary site recurrence. No patient has experienced long-term renal or liver toxicity. This treatment maximizes normal tissue preservation and is appropriate for this patient population.

Source: Sciencedirect.com

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