Proton therapy, a major frontier in current medicine, is also a major advance in the field of radiation therapy for tumors.
After entering the body, protons deposit most of their energy at the end of the range, and by adjusting the sharp dose peaks, they can accurately cover the entire tumor target area at a specific depth to kill the tumor, while the surrounding normal tissue is irradiated to a very low level.
Proton radiotherapy is characterized by strong penetrating properties, good dose distribution, high local dose, low backscatter, and small penumbra, and has great dose distribution superiority for treating tumors in adjacent vital tissues and organs.
Simply put, the dose advantage of proton therapy is more precise, more accurate, and with fewer side effects.
What is the value of proton radiotherapy in the treatment of lung cancer?
While proton radiotherapy has dosimetric advantages that are unmatched by photon radiotherapy, proton gas pedals are technically complex, expensive, and still under development, and are currently concentrated in medical research centers in Europe and the United States.
In 2016, a phase II clinical study published at the MD Anderson Cancer Center compared the efficacy and adverse effects of proton radiotherapy with photon radiotherapy in patients with stage III lung cancer. The results suggested that there was no significant difference in lesion local control rates and side effects between the use of intensity-modulated photon therapy (IMRT) and 3-dimensional proton therapy (3DPT).
A number of clinical studies are currently exploring the use of protons in lung cancer, including the phase III randomized controlled study of proton-modulated radiotherapy versus photon-modulated radiotherapy, RTOG1308, proton macrofractionated radiotherapy, photon radiotherapy + proton local push irradiation, and proton-synchronized radiotherapy for stage III lung cancer, which will hopefully provide more evidence-based evidence for the clinical use of proton radiotherapy in lung cancer. We hope to provide more evidence-based medical evidence for the clinical use of proton radiotherapy in lung cancer.
Who can be considered for lung cancer patients?
Who can be considered for proton radiotherapy?
Because proton radiotherapy is expensive and the available clinical evidence does not yet suggest that proton radiotherapy is superior to photon radiotherapy, proton therapy is not yet routinely recommended as a clinical treatment. Proton radiotherapy can be considered under the guidance of a physician in the following situations:
(1) Tumors adjacent to vital tissues and organs;
(2) Re-course radiotherapy after tumor recurrence;
(3) enrollment in clinical studies.
What are the adverse effects of proton therapy?
Proton radiotherapy irradiates the same sites as photon radiotherapy, so the clinical adverse effects are similar to those of photon radiotherapy. Patients may experience systemic reactions such as fatigue and anorexia, local skin pigmentation, desquamation, radiation pneumonia, pulmonary fibrosis, radiation esophagitis, radiation heart damage, and radiation nerve damage. However, these conditions, with aggressive symptomatic management by physicians, can usually be alleviated and are rarely life-threatening.
Because of the dosimetric advantages of proton radiotherapy, some retrospective studies suggest a reduced incidence of these adverse effects compared with photon radiotherapy.
However, the proton therapy technique is not yet mature, for example, it is strongly influenced by the degree of respiratory motion, making it necessary for physicians to enlarge the margins during treatment to take into account the degree of motion, which leads to some decrease in accuracy. In the currently published phase II prospective clinical study, the toxic side effects of proton radiotherapy were similar to conventional radiotherapy and were not significantly reduced as expected.
Doctors and patients are looking forward to the publication of results from ongoing clinical studies that will give us more insight into the world of proton therapy and take full advantage of the benefits of proton to bring better and safer treatment to patients.
Co-reviewed by: Guangdong Provincial People’s Hospital Guangdong Provincial Lung Cancer Institute Dr. Pan Yao, Chief Physician Dr. Chen Zhiyong Dr. Zhang Jiatao