Table 1.
Patient Characteristics.
| Characteristic | Distribution, n (%) |
|---|---|
| Gender | |
| Male | 20 (54.1) |
| Female | 17 (45.9) |
| Age, years | |
| Median (range) | 72 (52-92) |
| <70 | 17 (45.9) |
| ≥70 | 20 (54.1) |
| ECOG PS | |
| 0 | 31 (83.8) |
| 1 | 6 (16.2) |
| Histology | |
| Adenocarcinoma | 37 (100) |
| Tumor location | |
| Head | 23 (62.2) |
| Body/tail | 14 (37.8) |
| Tumor size,a cm | |
| Median (range) | 3.6 (2.0-7.3) |
| <4 | 23 (54.1) |
| ≥4 | 14 (37.8) |
| T classification | |
| T3 | 5 (13.5) |
| T4 | 32 (86.5) |
| N classification | |
| N0 | 34 (91.9) |
| N1 | 3 (8.1) |
| Pretreatment CA 19-9 level, U/mL | |
| Median (range) | 35.2 (2.0-1707) |
| ≤37 | 20 (54.1) |
| >37 | 17 (45.9) |
| Induction chemotherapyb | |
| No | 29 (78.4) |
| Yes | 8 (21.6) |
| Pre-SIB-PBT CA 19-9 level, U/mL | |
| Median (range) | 34.0 (2.0-1707) |
| ≤37 | 21 (56.8) |
| >37 | 16 (43.2) |
| Concurrent chemotherapyc | |
| No | 6 (16.2) |
| Yes | 31 (83.8) |
| Post-SIB-PBT CA 19-9 level, U/mL | |
| Median (range) | 24.3 (2.0-705) |
| ≤37 | 21 (56.8) |
| >37 | 16 (43.2) |
| Post-SIB-PBT surgeryd | |
| No | 35 (94.6) |
| Yes | 2 (5.4) |
| Maintenance chemotherapye | |
| No | 13 (35.1) |
| Yes | 24 (64.9) |
Abbreviations: ECOG PS, Eastern Cooperative Oncology Group performance status; CA 19-9, carbohydrate antigen 19-9; SIB-PBT, simultaneous integrated boost-proton beam therapy.
a Maximum diameter of the primary tumor.
b 5-Flurouracil (5-FU), irinotecan, plus oxaloplatin (FOLFINOX; n = 4), gemcitabine plus erlotinib (GT; n = 3), and gemcitabine plus cisplatin (GP; n = 1).
c Capectabine (n = 29) and 5-FU (n = 2).
d Pylorus-preserving pancreaticoduodenectomy (n = 1) and distal pancreatectomy (n = 1).
e Gemcitabine (n = 9), GT (n = 9), tegafur/gemeracil/oteracil (TS-1; n = 2), FOLFINOX (n = 2), gemcitabine plus nab-paclitaxel (n = 1), and capecitabine (n = 1).