a Areas in which the VMAT / IMRT plans will deliver more dose to organs at risk or the body compartment. b Areas in which the proton plan delivers more dose to organs at risk or the body compartment compared to the VMAT / IMRT plant
“Proton therapy for mediastinal lymphoma reduces significantly the dose to organs at risk and the integral body dose. It might lead to reduced late toxicities and secondary malignancies. This is especially important for children and young adults. It should be considered for both sexes, as both male and female patients benefit from the unique features of particle irradiation. Whenever proton for mediastinal lymphoma is not available or technical not feasible the alternative photon concepts have to be chosen carefully. Depending on the used technique certain organs at risk, i.e. the breasts in young females, can be spared with higher priority. However, with all photon techniques that comes at the cost of higher doses to the other organs at risk. If available, proton therapy should be the standard pattern of care for mediastinal lymphoma for young adults below 30 years of age, no matter if male or female.”
S. Lautenschlaeger, G. Iancu, V. Flatten, K. Baumann, M. Thiemer, C. Dumke, K. Zink, H. Hauswald, D. Vordermark, C. Mauz-Körholz, R. Engenhart-Cabillic & F. Eberle Radiation Oncology volume 14, Article number: 157 (2019)
Everett AS, Hoppe BS, Louis D, McDonald AM, Morris CM, Mendenhall NP, Li Z, Flampouri S,
Comparison of Techniques for Involved-Site Radiation Therapy in Patients with Lower Mediastinal Lymphoma, Practical Radiation Oncology (2019), doi: https://doi.org/10.1016/ j.prro.2019.05.009.
In this study, various radiation techniques and doses to Organs At Risk (OARs) are compared to determine the optimal treatment technique in patients with lower mediastinal lymphoma involvement.
In patients with lower mediastinal lymphoma, radiation delivery is particularly challenging because of the proximity of the target to critical structures, such as the heart and its substructures, lungs, breast, and esophagus. Therefore, PT has been increasingly used in patients with mediastinal lymphoma given its ability to improve dose conformity and decrease radiation to normal tissues while providing equivalent target coverage
Patients with lower mediastinal lymphoma (LML) benefit dosimetrically from proton therapy (PT) compared with intensity-modulated radiotherapy (IMRT). The added dosimetric benefit of deep-inspiration breath-hold (DIBH) is unknown; therefore, we evaluated IMRT versus PT and free-breathing (FB) versus DIBH among patients with LML.
Proton therapy significantly decreased the dose to critical structures (heart, lungs, esophagus, thyroid, and non-target body), specifically in patients with mediastinal lymphomas. Therefore, when PT is available and the patient has lower mediastinal involvement, PT should be considered to maximally reduce the dose to nearby normal structures and decrease the risk of late toxicity associated with LM lymphoma radiation treatment.
CONCLUSION Among patients with lower mediastinal lymphoma involvement, PT significantly reduces radiation to the lung, heart, esophagus, thyroid, and non-target body compared with IMRT.
PT can provide a significant benefit over IMRT techniques and should be considered in patients with lower mediastinal lymphoma involvement.
Figure 2. Colorwash dose distribution for a representative patient showing (A) free-breathing intensity-modulated radiation therapy, (B) free-breathing proton therapy, (C) deep inspiration breath-hold intensity-modulated radiation therapy, and (D) deep-inspiration breath-hold proton therapy. Image borrowed with permission from Hoppe BS, Mendenhall NP, Louis D, et al. Comparing Breath Hold and Free Breathing during Intensity-Modulated Radiation Therapy and Proton Therapy in Patients with Mediastinal Hodgkin Lymphoma. International Journal of Particle Therapy. 2017;3(4):492-496. 10.14338/ijpt-17-000
