Figure 1:
Figure 2:
Stratification of overall survival (OS) groups at 2 years resulting from multivariate analysis (3)_
| Class I | Treatment interval > 2 years, in patients submitted to surgery | 2 years OS of 62% |
| Class II | Treatment interval > 2 years, in patients not submitted to surgery or interval < 2 years, without organ dysfunction | 2 years OS of 40% |
| Class III | Interval between treatments < 2 years, with organ dysfunction | 2 years OS of 17% |
Toxicity grading differences between first and second irradiation_
| Toxicity grade | Timing, % (n) | Time between irradiations (months), median (IQR) | |
|---|---|---|---|
| After first irradiation | After re-irradiation | ||
| Dermatitis | |||
| 1 | 59.0 (23) | 59.0 (23) | 21.0 (47) |
| 2 | 33.3 (13) | 30.8 (12) | 31.0 (41) |
| 3 | 7.7 (3) | 10.3 (4) | 24.5 (19) |
| Mucositis | |||
| 0 | 35.9 (14) | 33.3 (13) | 20.0 (14) |
| 1 | 17.9 (7) | 35.9 (14) | 26.0 (47) |
| 2 | 33.3 (13) | 12.8 (5) | 39.0 (109) |
| 3 | 12.8 (5) | 17.9 (7) | 24.0 (89) |
| Xerostomia | |||
| 0 | 23.1 (9) | 5.1 (2) | 34.0 |
| 1 | 46.2 (18) | 76.9 (30) | 21.0 (36) |
| 2 | 30.8 (12) | 17.9 (7) | 27.0 (92) |
| Dysphagia | |||
| 0 | 33.3 (13) | 20.5 (8) | 26.0 (117) |
| 1 | 17.9 (7) | 35.9 (14) | 23.0 (46) |
| 2 | 17.9 (7) | 15.4 (6) | 21.0 (25) |
| 3 | 30.8 (12) | 28.2 (11) | 16.0 (35) |
Univariate logistic regression of predictors for severe toxicity after first and second irradiations_
| Variables | After first irradiation | After re-irradiation | ||
|---|---|---|---|---|
| RR (CI 95%) | P-value | RR (CI 95%) | P-value | |
| Location (reference: oropharynx) | ||||
| Oral cavity | 0.93 (0.11–7.82) | .949 | - | - |
| Nasopharynx | 4.20 (0.33–53.1) | .268 | 0.24 (0.02–3.01) | .268 |
| Larynx | 0.70 (0.13–3.68) | .268 | 0.51 (0.10–2.59) | .416 |
| Hypopharynx | 0.93 (0.11–7.82) | .949 | 0.48 (0.06–4.00) | .494 |
| ECOG status (reference: 0) | ||||
| 1 | 5,08 (0,48–54,03) | .178 | 1.40 (0.35–5.54) | .632 |
| 2 | - | - | 3.60 (0.32–40.23) | .298 |
| CT cycles (per each cycle) | 1.27 (0.74–2.17) | .383 | 0.97 (0.51–1.84) | .933 |
| Dose of RT (per each Gy) | 0.98 (0.84–1.14) | .780 | 1.06 (0.98–1.13) | .134 |
| Concurrent chemotherapy | 3.90 (0.96–15.82) | .057 | 1.25 (0.28–5.59) | .770 |
Disease features at first and second radiotherapy irradiation_
| Variable | Timing, % (n) | |
|---|---|---|
| At first irradiation | At re-irradiation | |
| Location | ||
| Oropharynx | 30.8 (12) | |
| Oral cavity | 12.8 (5) | |
| Nasopharynx | 10.3 (4) | |
| Larynx | 30.8 (12) | |
| Hypopharynx | 12.8 (5) | |
| Others | 2.6 (1) | |
| ECOG Performance status | ||
| 0 | 89.7 (35) | 56.4 (22) |
| 1 | 10.3 (4) | 33.3 (13) |
| 2 | 0.0 (0) | 10.3 (4) |
| T-stage | ||
| T0 | 5.1 (2) | 20.5. (8) |
| T1 | 33.3 (13) | 5.1 (2) |
| T2 | 15.4 (6) | 23.1 (9) |
| T3 | 17.9 (7) | 12.8 (5) |
| T4 | 28.2 (11) | 38.5 (15) |
| N-stage | ||
| N0 | 41.0 (16) | 53.8 (21) |
| N1 | 23.1 (9) | 15.4 (6) |
| N2 | 28.2 (11) | 20.5 (8) |
| N3 | 7.7 (3) | 10.3 (4) |
| M-stage | ||
| M0 | 100.0 (39) | 94.9 (37) |
| M1 | 0.0 (0) | 5.1 (2) |
| Clinical stage | ||
| I | 20.5 (8) | 5.1 (2) |
| II | 12.8 (5) | 15.4 (6) |
| III | 15.4 (6) | 15.4 (6) |
| IV | 51.3 (20) | 64.1 (25) |
| CT cycles, median (IQR) | 2.0 (2) | 0.0 (0) |
| Dose of RT (Gy), median (IQR) | 70.0 (4.0) | 60.0 (16) |
| Concurrent chemotherapy | 56.4 (22) | 23.1 (9) |
Concurrent chemotherapy (cCT) and toxicity grading following first and second irradiation_
| Toxicity grade | After first irradiation | After re-irradiation | ||
|---|---|---|---|---|
| cCT | Without cCT | cCT | Without cCT | |
| Dermatitis | ||||
| 1 | 50.0 (11) | 70.6 (12) | 44.4 (4) | 63.3 (19) |
| 2 | 40.9 (9) | 23.5 (4) | 44.4 (4) | 26.7 (8) |
| 3 | 9.1 (2) | 5.9 (1) | 11.1 (1) | 10.0 (3) |
| Mucositis | ||||
| 0 | 27.3 (6) | 47.1 (8) | 22.2 (2) | 36.7 (11) |
| 1 | 18.2 (4) | 17.6 (3) | 33.3 (3) | 36.7 (11) |
| 2 | 36.4 (8) | 29.4 (5) | 22.2 (2) | 10.0 (3) |
| 3 | 18.2 (4) | 5.9 (1) | 22.2 (2) | 16.7 (5) |
| Xerostomia | ||||
| 0 | 13.6 (3) | 35.3 (6) | 0.0 (0) | 6.7 (2) |
| 1 | 50.0 (11) | 41.2 (7) | 77.8 (7) | 76.7 (23) |
| 2 | 36.4 (8) | 23.5 (4) | 22.2 (2) | 16.7 (5) |
| Dysphagia | ||||
| 0 | 22.7 (5)a | 47.1 (8)a | 22.2 (2) | 20.0 (6) |
| 1 | 9.1 (2)a | 29.4 (5)a | 33.3 (3) | 36.7 (11) |
| 2 | 27.3 (6)a | 5.9 (1)a | 22.2 (2) | 13.3 (4) |
| 3 | 40.9 (9)a | 17.6 (3)a | 22.2 (2) | 30.0 (9) |