Potential of Proton Therapy to Reduce Acute Hematologic Toxicity in Concurrent Chemoradiation Therapy for Esophageal Cancer

Abstract

PurposeRadiation therapy dose escalation using a simultaneous integrated boost (SIB) is predicted to improve local tumor control in esophageal cancer; however, any increase in acute hematologic toxicity (HT) could limit the predicted improvement in patient outcomes. Proton therapy has been shown to significantly reduce HT in lung cancer patients receiving concurrent chemotherapy. Therefore, we investigated the potential of bone marrow sparing with protons for esophageal tumors.Methods and MaterialsTwenty-one patients with mid-esophageal cancer who had undergone conformal radiation therapy (3D50) were selected. Two surrogates for bone marrow were created by outlining the thoracic bones (bone) and only the body of the thoracic vertebrae (TV) in Eclipse. The percentage of overlap of the TV with the planning treatment volume was recorded for each patient. Additional plans were created retrospectively, including a volumetric modulated arc therapy (VMAT) plan with the same dose as for 3D50; a VMAT SIB plan with a dose prescription of 62.5 Gy to the high-risk subregion within the planning treatment volume; a reoptimized TV-sparing VMAT plan; and a proton therapy plan with the same SIB dose prescription. The bone and TV dose metrics were recorded and compared across all plans and variations with respect to PTV and percentage of overlap for each patient.ResultsThe 3D50 plans showed the highest bone mean dose and TV percentage of volume receiving ≥30 Gy (V30Gy) for each patient. The VMAT plans irradiated a larger bone V10Gy than did the 3D50 plans. The reoptimized VMAT62.5 VT plans showed improved sparing of the TV volume, but only the proton plans showed significant sparing for bone V10Gy and bone mean dose, especially for patients with a larger PTV.ConclusionsThe results of the present study have shown that proton therapy can reduced bone marrow toxicity.

Association of Chemoradiotherapy With Thoracic Vertebral Fractures in Patients With Esophageal Cancer

“…Proton therapy was reported to reduce doses to vertebrae without compromising target coverage in the radiotherapy planning study. 37 The incidence of thoracic vertebral fracture after CRT for esophageal cancer may decrease if the vertebral dose is reduced using the advanced radiotherapy techniques.…”

Predictive value of lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR) in patients with oesophageal cancer undergoing concurrent chemoradiotherapy

“…Studies by Stefania Martini and Francesca Arcadipane et al have demonstrated that volumetric modulated arc therapy (VMAT) is an effective and safe strategy for treatment of patients with advanced oesophageal cancer [6–8]. According to a study by Samantha Warren et al, proton therapy for patients with advanced oesophageal cancer may have lower blood toxicity [9]. Similarly, a retrospective analysis by Mian Xi and Cai Xu et al showed that the metrological advantages of proton therapy play an important role in improving the overall survival of patients with advanced oesophageal cancer [10].…”

Vertebral body irradiation during chemoradiation therapy for esophageal cancer contributes to acute bone marrow toxicity

“…Previously published Efforts to spare the bone marrow in an attempt to reduce rates of HT can have several implications including improving the tolerance of concurrent chemotherapy, lowering the risk of infections, hospitalizations, fatal complications, and potentially impact survival outcomes in esophageal patients undergoing CRT (21)(22)(23)(24). Recent studies have shown that decreases in HT have been observed in esophageal cancer patients receiving proton therapy because of improvement in the distribution of radiation low dose bath (5-15 Gy) compared to IMRT, VMAT, or 3DCRT photon plans (25). Similarly, dosimetric analysis shows that passive scatter proton therapy can decrease HT in stage III NSCLC lung cancer patients, which is statistically correlated with an improvement of TVV 10 by around 30% compared with 3DCRT and IMRT treatment (26,27).…”