Emerging Treatments For DIPG
Radiation is currently the standard of care for children with diffuse intrinsic pontine gliomas (DIPGs). There are new and upcoming treatment methods on the rise, some are in the early phases of being used for DIPGs, while others need more clinical trials and studies before being herald as the new standard.
Proton Beam Radiation (PRT)
Proton Beam Radiation is a form of radiation that uses high-energy beams to focus on tumors. It is a newer type of radiation therapy that limits damage to critical structures near the tumor that’s being treated. It also yields fewer long-term side effects than traditional radiation treatments since doctors are able to better control where the proton beams hit.
Proton Beam therapy has limited availability in the United States. So, for DIPG patients the issue becomes finding a center that has a proton beam and getting protocols and a treatment plan set up, which often takes a minimum of four weeks. DIPG patients don’t have that time, so Photon radiation is recommended. With Photon therapy, it is more widely available and treatment protocols can be setup within a week. There are no differences in terms of overall effect between the two.
Convection Enhanced Delivery (CED)
Convection Enhanced Delivery (CED) is a technique of inserting a small catheter directly into the DIPG, the pontine tumor, to deliver drugs. With other delivery methods, typically only 10% of a dose is able to cross the Blood Brain Barrier (BBB). CED is a way to bypass the BBB and deliver drugs at high concentrations into the DIPG tumor.
While CED is a way to administer drugs directly to the tumor, it is not a full treatment plan. Doctors and scientist still need to discover which drug(s) will work best with the CED method.
Intra-arterial is a method that delivers chemotherapy to the DIPG through a small catheter that is inserted into an artery of the brain. This specific technique is used in other types of tumors, especially retinoblastoma, tumors of the eye. More trials and studies are needed on the effectiveness of intra-arterial therapies for DIPG and, like CED, what drug(s) will work best.
Immunotherapy is the technique of harnessing the body’s own immune system to attack and kill tumors. Doing this can cause an immune inflammatory response. For DIPG patients, this can effectively cause inflammation and swelling in the pons that may need to be treated with steroids. The swelling and immune response can be so overwhelming that is can be worse than the tumor and have poor outcomes. Because of this, oncologists need a better understanding of the immune response and how it can be modulated before immunotherapies are used in DIPG and the pediatric population. There are high hopes that within the next few years immunotherapies will be an option for treating DIPG because, in theory, the body’s immune system should be able to bypass the BBB to help fight tumors but the side effects from that are still a very real issue.