Vaginal rhabdomyosarcoma (embryonal type) in childhood and adolescence: what to do when first-line chemotherapy did not achieve complete remission

This protocol applies to children and adolescents with vaginal rhabdomyosarcoma of embryonal histological type whose first-line multimodal treatment — centred on systemic chemotherapy — did not produce the complete remission required to conclude that line.

Patient Population

Childhood and adolescent patients with vaginal rhabdomyosarcoma, embryonal type. Rhabdomyosarcoma accounts for the majority of malignant vaginal tumours in this age group and is highly chemosensitive, which is why a multimodal strategy beginning with systemic chemotherapy is the standard first-line approach.

First-Line Failure Condition — Why This Protocol Is Needed

The first-line approach — neoadjuvant and adjuvant combination chemotherapy including an alkylating agent, adapted to risk factors — targets complete remission confirmed by negative pelvic MRI and negative vaginoscopy with biopsies of any suspicious areas, assessed after 3 and 6 courses. When this endpoint is not reached — whether by stable or progressive disease — the next step is required.

Next-Line Approach (Partial Overview)

The protocol that follows is centred on local therapy adapted to tumour response and histological type, with brachytherapy as the preferred modality for the primary tumour in most cases. The full scope of interventions — determined by the extent and location of residual disease — is defined in the complete protocol.

Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1016/j.radonc.2023.109662

The main histological types are RMS (70%) and GCT/YST (27%); clear cell carcinoma is less common (3%).

RMS and YST are highly chemosensitive. Therefore, a multimodal strategy starting with systemic chemotherapy should be always considered in the first line.

Brachytherapy is preferred over EBRT for treatment of the primary tumour. A total dose of 50–60 Gy EQD2 is prescribed.

In case of stable or progressive disease after 3 courses, second line chemotherapy should be proposed [IV, A].

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