Lentigo Maligna: Next-Line Treatment When Imiquimod Therapy Did Not Achieve the Expected Response

This protocol is for patients with lentigo maligna who completed a course of topical Imiquimod as first-line therapy but did not reach the required clinical endpoint — and for whom an alternative treatment modality is now indicated.

Previous Line — Failure Condition

Escalation trigger

The first-line treatment was Imiquimod 5% cream applied topically. The therapeutic target for that course was to achieve visible inflammation of the treated lesion sustained for at least 10–11 weeks — an indicator of adequate immune activation at the site.

When that level of inflammatory response is not achieved within the required timeframe, the first-line course has not met its target, and escalation to a different treatment approach is appropriate.

Next-Line Approach (partial summary)

This protocol uses a radiotherapy-based approach, delivering ionising radiation to the lesion and a defined margin of surrounding skin. The full protocol specifies the applicable technique, field parameters, and scheduling details.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.3390/jcm13092527

Radiotherapy (RT) can be used for the treatment of LM either as primary treatment or as adjuvant therapy in the case of positive margins following excision.
Grenz ray therapy and superficial radiotherapy are the two techniques that can be used.
A total dose of 100 Gy can be safely performed in Grenz ray RT, with a single fraction dose of 10–20 Gy, while in superficial RT, smaller single fractions of 2.0–7 Gy and a lower total dose are recommended (54–60 Gy).
According to the same systematic review, the radiation field should include the visible lesion and a safety margin of at least 10 mm of the surrounding skin, in order to reduce the risk of out-of-field recurrences.

View source ↗