The 'urn' portal; an alternative to the 'mantle' portal in the chemoradiotherapy management of paediatric Hodgkin's disease.

The experience of St Bartholomew's Hospital with a less than full mantle radiation field in the treatment of 31 children with clinically staged Hodgkin's disease is reported over a ten year period (1977-1987). The major indication for this portal was initial bulk, or residual disease after chemotherapy. Primary treatment consisted of radiotherapy alone (two children) or in combination with chemotherapy (29 children). An 'Urn' radiation portal has been used to encompass mediastinal and neck nodes, but with the aim of reducing radiation doses to lung, breast, axilla, lateral end of clavicle and humeral head. More recently, a further modification has employed partial heart shielding when anthracyclines have been part of the chemotherapy schedule. The majority have received 35 Gy in 20 fractions over 4 weeks with 4-6 Mv photons, and no child received in excess of 35 Gy to the mediastinum. An overall 5-year actuarial survival of 85% was achieved, and a 5-year relapse-free survival of 77%. Seven relapses and five deaths have been reported, all of which occurred in children who presented with nodular sclerosing histology. Six children relapsed within the radiation portals, and one with systemic disease alone. Only a single child relapsed in the unirradiated axilla, and this simultaneously with cervical, mediastinal and paraortic nodes. To date no second malignancies have been reported.