Table 2

Key questions regarding the use of NB-UVB for generalised vitiligo13

QuestionStrategy tested in the HI-Light Vitiligo Trial
1What is the optimal weekly frequency of NB-UVB treatment?HI-Light Trial: every other day (3–4 times weekly).
Rationale: this is the most commonly used treatment regimen in the UK.
2With regard to initial dosing, which strategy should ideally be employed?HI-Light Trial: all participants started on the same low dose, 0.05 J/cm2.
Rationale: MED test was carried out before treatment, but only to identify any undiagnosed cases of photosensitivity. Starting at a fixed low dose to minimise the risk of symptomatic erythema was felt to be safer for home delivery of NB-UVB.
3At subsequent treatments, what increments should be used for dose escalation in the absence of perceptible erythema?HI-Light Trial: 10% dosing increase after each treatment not followed by erythema.
Rationale: this reflects typical clinical practice in UK phototherapy services
4What is the maximum acceptable dose to be given in a single treatment?HI-Light Trial: maximum dose in the trial is 2.81 J/cm2.
Rationale: this reflects typical clinical practice in UK phototherapy services.
5What is the ideal practice for dose adjustment following symptomatic erythema?HI-Light Trial: patient self-adjustment for grades 1 and 2 erythema (according to flow chart in patient handbook) and investigator adjusted dosing for grades 3 and 4.
Rationale: the upwards and downwards dosing used in the trial reflects the clinical practice of most UK phototherapy services.
6How should the protocol be adjusted for missed doses?HI-Light Trial: varies in function of number of missed treatments. 1 or 2 missed: go back one step on treatment schedule; 3 missed: go back two steps on treatment schedule; 4–6 missed: 50% of last dose; 6+ missed restart treatment schedule from beginning.
Rationale: this conservative approach ensures that participants who have missed a lot of doses are not at risk of symptomatic erythema when they restart treatment.
7How should a ‘course’ of NB-UVB therapy be defined? (ie, At what interval should further exposure be reassessed?) Not directly applicable within the scope of the trial.
8What is the maximum number of exposures allowable for patients with vitiligo given the potential risk of carcinogenesis with NB-UVB? Not directly applicable within the scope of the trial. Participants in the trial will only be treating limited areas of skin and the total number of treatments will be less than the current maximum recommended number of treatments.
9Should dosing strategies differ when treating children with vitiligo?HI-Light Trial: children are treated in the same way as adults. Parents are given the choice of what patches they are comfortable treating, and may opt out of treating sensitive areas if they wish to do so.
Rationale: the home-based treatment is more flexible than hospital-based full-body treatment, so it is possible for children to be treated in the same way as adults.
10Should shielding of sensitive structures (eyelids, areolas and genitals) be a universal requirement, or is it safe to expose these areas if affected by vitiligo?HI-Light Trial: the trial excludes treatment of vitiligo in the genital region. Other sensitive areas can be treated if they are affected by vitiligo, but will not otherwise be exposed to NB-UVB due to the localised nature of treatment using a hand-held device. If treating the eyes, patients are advised to seek assistance from someone else so that they can keep their eyes closed during treatment, thus reducing the risk of accidental exposure during treatment.
11What is the most accurate definition of treatment unresponsiveness?HI-Light Trial: treatment response is assessed in terms of its onset; unresponsiveness would be defined by patient report of ’stayed the same' or ’got worse' in response to the question, ‘Compared with the start of the study, has there been a change in the vitiligo patch?' Participants are encouraged to continue treatment for as long as they are happy to do so. The trial may provide useful data on when and how to define treatment unresponsiveness.
12How frequently should patients with vitiligo undergo surveillance following completion of a NB-UVB treatment protocol for both signs of relapse and adverse events? Is there a role for phototherapy in maintenance following repigmentation?HI-Light Trial: long-term treatment response is being assessed 3-monthly for 1 year following completion of NB-UVB treatment. The trial has not been designed to evaluate the use of intermittent treatment for maintenance of response.
Rationale: patients are particularly interested in how long treatment response might last and this is now a core outcome domain for vitiligo clinical trials.
  • MED, minimum erythema dose; NB-UVB, narrowband ultraviolet B-light