Table 1.
Baseline characteristics of the study population (n = 58). Sr-90 was administered between 1999 and 2012, Ru-106 was administered from 2012 onwards.
| Item | Total cases (%) |
Sr-90 cases (%) |
Ru-106 cases (%) |
P value |
|---|---|---|---|---|
| Total | 58 (100) | 32 (100) | 26 (100) | |
| Sex | ||||
| Female | 28 (48) | 17 (53) | 11 (42) | 0.41 |
| Male | 30 (52) | 15 (47) | 15 (58) | |
| Age at diagnosis (years) | ||||
| Mean (SD) | 58.9 (18) | 52.7 (20) | 66.5 (14) | 0.003 |
| Age at diagnosis | ||||
| <60 years | 30 (52) | 19 (59) | 11 (42) | 0.20 |
| ≥60 years | 28 (48) | 13 (41) | 15 (58) | |
| Eye involved | ||||
| Right | 30 (52) | 18 (56) | 12 (46) | 0.44 |
| Left | 28 (48) | 14 (44) | 14 (54) | |
| Location | ||||
| Epibulbar | 58 (100) | 32 (100) | 26 (100) | N.A. |
| Non-epibulbar | 0 (0) | 0 (0) | 0 (0) | |
| cTNM | ||||
| T1 | 57 (98) | 31 (97) | 26 (100) | 1.00 |
| T2 | 1 (2) | 1 (3) | 0 (0) | |
| Thickness (mm) | ||||
| Median (IQR) | 0.9 (0.5–1.5) | 1.0 (0.6–1.7) | 0.8 (0.2–1.3) | 0.14 |
| Largest Basal Diameter (mm) | ||||
| Median (IQR) | 6.0 (5.0–8.0) | 6.0 (4.5–9.0) | 6.0 (5.0–8.0) | 0.93 |
| Tumour pigmentationa | ||||
| Pigmented | 32 (64) | 19 (70) | 13 (57) | 0.31 |
| Non-pigmented/Mixed | 18 (36) | 8 (30) | 10 (43) | |
| PAMb | ||||
| Present | 52 (90) | 30 (94) | 22 (85) | N.A. |
| Absent | 3 (5) | 0 (0) | 3 (12) | |
| Unknown | 3 (5) | 2 (6) | 1 (4) | |
| Timing of treatment | ||||
| Primary CoM | 49 (85) | 25 (78) | 24 (92) | 0.17 |
| Recurrence | 9 (15) | 7 (22) | 2 (8) | |
| Location initial treatmentc | ||||
| LUMC | 20 (34) | 11 (34) | 9 (35) | 0.99 |
| Elsewhere | 38 (66) | 21 (66) | 17 (65) | |
SD standard deviation, PAM primary acquired melanosis, IQR inter-quartile range, cTNM clinical AJCC TNM classification, LUMC Leiden University Medical Center, Sr-90 strontium-90 brachytherapy, Ru-106 ruthenium-106 brachytherapy, N.A. not applicable.
aTumour pigmentation describes the clinical appearance of the conjunctival melanoma (melanin pigment) and was assessed visually and via colour photography [34].
bPAM status was determined histologically.
cInitial treatment for all patients was excision. This procedure was followed by adjuvant brachytherapy as described.