Table 2.
Select studies of clinical outcomes comparing proton beam therapy vs. x-ray therapy for esophageal cancer.
| Author | No. of patients(RT modality) | Study type | Treatment intent | Follow-up time | Survival | Toxicity or QOL outcomes |
|---|---|---|---|---|---|---|
| Makishima et al. (11) | 44 (19 XRT, 25 PBT) |
Retrospective cohort | Definitive | NR | N/A | Grade 2+ pulmonary: XRT 18.2%, PBT 0%; Grade 2+ cardiac: XRT 52.6%, PBT 4.0%. |
| Xi et al. (13) | 343 (211 IMRT, 132 PBT) |
Retrospective cohort | Definitive | 65.1 months | 5-year OS: IMRT 31.6% vs. PBT 41.4% (p = 0.011); 5-year PFS: IMRT 20.4% vs. PBT 34.9% (p = 0.001); 5-year DMFS: IMRT 48.6% vs. PBT 64.9% (p = 0.031) |
Grade 3–4: IMRT 45.0% vs. PBT 37.9% (p = 0.192); Grade 5: IMRT 1.9% vs. PBT 0.8% (p = 0.653). |
| Lin et al. (19) | 580 (214 3DCRT, 255 IMRT, 111 PBT) |
Retrospective cohort | Neoadjuvant | NR | N/A | Pulmonary complications: 3DCRT 39.5% vs. IMRT 24.3% vs. PBT 16.2% (p < 0.001); Cardiac complications: 3DCRT 27.4% vs. IMRT 11.7% vs. PBT 11.7% (p < 0.001); Wound complications: 3DCRT 15.3% vs. IMRT 14.1% vs. PBT 4.5% (p = 0.014); Mean LOS: 3DCRT 13.2d vs. IMRT 11.6d vs. PBT 9.3d (p < 0.0001). |
| Garant et al. (20) | 128 (63 XRT, 62 IMPT) | Prospective registry | Definitive and Neoadjuvant | NR | NR | FACT-E PRO: less mean decline in PRO scores in PBT vs. XRT (−12.7 vs. −20.6, p = 0.026). |
| Routman et al. (21) | 144 (65 XRT, 79 PBT) |
Retrospective cohort | Definitive and Neoadjuvant | NR | N/A | G4L: XRT 56% vs. PBT 22% (p < 0.01). |
| Davuluri et al. (22) | 504 (317 IMRT, 187 PBT) | Retrospective cohort | Definitive and Neoadjuvant | 32.1 months | Median OS with or without G4L: 2.8 years vs. 5.0 years (p = 0.027); Median PFS with or without G4L: 1.1 years vs. 5.4 years (p < 0.001) |
G4L: IMRT: 33% vs. PBT 15.5% (p < 0.001). |
| Lin et al. (23) | 107 (61 IMRT, 46 PBT) |
Prospective phase 2 randomized | Definitive and Neoadjuvant | 44.1 months | 3-year OS: IMRT 50.8% vs. PBT 51.2% (p = 0.60); 5-year PFS: IMRT 44.5% vs. PBT 44.5% (p = 0.70) |
Mean TTB: IMRT (39.9; 95% highest posterior density interval, 26.2–54.9) vs. PBT (17.4; 10.5–25.0); Mean POC score: IMRT (19.1; 7.3–32.3) vs. PBT (2.5; 0.3–5.2). |
3DCRT, three-dimensional conformal radiation therapy; IMRT, intensity modulated radiation therapy; PBT, proton beam therapy; IMPT, intensity-modulated proton therapy; NR, not reported; OR, odds ratio; XRT, X-ray (photon) radiation therapy; LOS, length of hospital stay; OS, overall survival; PFS, progression-free survival; DMFS, distant metastatic-free survival; G4L, grade 4 lymphopenia; FACT-E PRO, Functional Assessment of Cancer Therapy-Esophagus Patient Reported Outcomes; TTB, total toxicity burden; POC, postoperative complication.