Table 2. Select clinical comparisons of PBT vs. IMRT for patients with esophagus cancer.
| Author (year) | Study design | No. patients | Technique comparison | Dose (Gy)/No. fractions | Efficacy, PBT (IMRT) | Toxicity, PBT (IMRT) | Post-op complications, PBT (IMRT) |
|---|---|---|---|---|---|---|---|
| Lin et al. (2012) | Retrospective cohort | 62 | PS-PBT | 50.4/28 | OS3: 52%; RFS3: 41%; DMFS3: 67%; LRC3: 57% | G2+ pneumonitis: 3%; mortality: 3% | Pulmonary: 7%; cardiac: 8%; anastomotic leak: 7%; wound: 3% |
| Ishikawa et al. (2015) | Retrospective cohort | 40 | PS-PBT | 60/30 | OS2: 75%; LRC2: 66%; CSS2: 77% | G3+ pulmonary: 0%; G3+ cardiac: 0% | – |
| Xi et al. (2017) | Retrospective cohort | 343 | PBS-PBT/PS-PBT; IMRT | 50.4/28 | OS5: 42% (32%)*; PFS5: 35% (20%)*; DMFS5: 65% (50%)* | G3+: 38% (45%) | – |
| Lin et al. (2017) | Multi-institutional retrospective cohort | 580 | PBS-PBT/PS-PBT; IMRT; 3DCRT | 50.4/28 | – | – | Pulmonary: 16% (24%)*; cardiac: 12% (12%); wound: 5% (14%)*; GI: 19% (23%); hospital stay: 9 [12] days* |
| Lin et al. (2019) | Prospective randomized phase IIb trial | 105 | PS-PBT/PBS-PBT; IMRT | 50.4/28 | – | TTB: 26.5 (40.2)* | POCS: 2.4 (19.2)* |
*, indicates statistically significant improvements with PBT compared to photon-based technique. PBT, proton beam therapy; IMRT, intensity modulated radiotherapy; PS-PBT, passively scattered proton beam therapy; PBS-PBT, pencil beam scanning proton beam therapy; 3DCRT, 3-dimensional conformal radiotherapy; GI, gastrointestinal, OS, overall survival; LRC, locoregional control; CSS, cancer-specific survival, G, grade; PFS, progression-free survival; DMFS, distant metastasis free survival; TTB, total toxicity burden, POCS, post-operative complication severity score.