Table 6.
Dosimetric comparison and late toxicity of proton beam therapy
| Authors (year) | Patients | Assessment strategy | Result |
|---|---|---|---|
| Harrabi et al.,201623) | 74 (LGG) | 3D-CRT vs. PBT (RO; Optic nerve, Inner ear, Optic chiasm, Thalamus, Brain, Brain stem, etc) | PBT reduced the dose to risk organs (DVH analysis) |
| Merchant et al., 200816) | 40 (OPG/CR/MB /EP = 10/10/10/10) | Photon vs. PBT (RO; Brain, Hypothalamus, Cochlea) | PBT reduced the dose to risk organs not adjacent to tumor. Functional preservation was expected (DVH analysis). |
| Brodin et al., 201192) | 10 (MB) | 3D-CRT vs. IMPT Evaluate second cancer risk | IMPT plans compared favorably to photon radiotherapy (DVH analysis) |
| Zhang et al., 201444) | 17 (MB) | Photon vs. Proton Evaluate risk of second cancer and cardiac mortality | PBT significantly reduced the risk of second cancer and cardiac mortality (DVH analysis) |
| Cochran et al., 200843) | 39 (MB) | Photon vs. Proton Evaluate dose to the lens | PBT significantly reduced the dose to the lens (DVH analysis) |
| Brodin et al., 201438) | 17 (MB) | 3D-CRT vs. IMRT vs. Proton Evaluate the dose of Hippocampus | PBT significantly reduced the dose to the hippocampus (DVH analysis) |
| Howell et al., 201245) | 18 (MB) | Photon vs. Proton (RO; Liver, Heart, Lung, Thyroid, Kidney, Esophagus) | PBT reduced the dose to risk organs (DVH analysis) |
| Kuhlthan et al., 201293) | 142 (MB/PNET 50, EP 31, LGG 20, other 41) | Evaluate health-related quality of life (HRQoL) after PBT | CSI and chemotherapy were negatively correlated with HRQoL Comparison was not performed between photon and proton |
| Yock et al., 201637) | 59 (MB) | Evaluate late toxicity after PBT (CSI 23.4 GyE, boost dose 54.0 GyE) | 3-year incidence of Grade 3–4 hearing loss was 12% 5-year incidence rate of any neuroendocrine deficit was 55% Comparison was not performed between photon and proton |
| Pulsifer et al., 201539) | 60 (28 CSI, 32 partial brain) | Evaluate full scale IQ, verbal comprehension, perceptual reasoning, working memory | Comparison was not performed between photon and proton |
| Eaton et al., 201636) | 77 (MB) | Proton vs. Photon Evaluate endocrine outcome | proton vs photon; hypothyroidism 23% vs 69%, Sex hormone deficiency 3% vs 19%, any endocrine replacement therapy 55% vs 78%. PBT may reduce the risk of some endocrine abnormalities. |
| Moeller et al., 201140) | 23 (MB) | Evaluate early ototoxicity after PBT | 1-year grade 3 or 4 ototoxicity rate was 5% Comparison was not performed between photon and proton |
| Giantsoudi et al., 201541) | 111 (MB) | Evaluate incidence of CNS injury after PBT | 5-year incidence of grade 3 or more CNS injury was 2.7% Comparison was not performed between photon and proton |
| Min et al., 201442) | 12 (MB) | Evaluate alopecia after PBT | Permanent alopecia was associated with dose to the skin. |
| Indelicato et al., 201491) | 313 (EP 73, CR 68, LGG 66, MB 38, Other 68) | Evaluate pediatric brain stem toxicity after PBT (received 50.4 GyE or more to the brain stem) | 2-year incident of grade 3 or more brain stem toxicity was 2.1% Comparison was not performed between photon and proton |
| Park et al., 201576) | 17 (GCT) | Proton vs. IMRT (RO; brain, hippocampus, pituitary gland) | PBT significantly reduced the dose to risk organs except for the pituitary gland. (DVH analysis) |
| Beltran et al., 201284) | 14 (CR) | Proton vs. IMRT (RO; brain, cochlea, chiasm, hippocampus, optic nerve, brain stem, body) | PBT significantly reduced the dose to brain and body (DVH analysis) |
| Boehling et al., 201285) | 10 (CR) | IMPT vs. IMRT (RO; Hippocampus, carotid, brain stem, brain) | PBT reduced the dose to a variety of risk organs (DVH analysis) |
CR: craniopharyngioma, CSI: craniospinal irradiation, DVH analysis: non-clinical data: only in theory, EP: ependymoma, GCT: germ cell tumor, IMPT: intensity-modulated proton therapy, LGG: low grade glioma, MB: medulloblastoma, OPG: optic pathway glioma, RO: risk organ.