A 6 year old MC DSH presented on 17/2/22 to discuss radiation therapy for a recently diagnosed thymoma.
As part of routine staging for MCT the patient had a whole body CT scan done on 8/3/22. A large thoracic mass was noted (6x12cm) with vascular invasion and bilateral pleural effusion. 200mls chylous effusion was removed at the time.
Diagnostics and Treatment Options
FNA of the mediastinal mass was done along with aspirates of the spleen and liver. Cytology on the spleen and liver were unremarkable and aspirate of the mediastinal mass was consistent with thymoma on flow cytometry. Prednisolone 7.5mg was started once daily. The patient had a difficult anaesthesia and recovery.
Given the anaesthetic risk, cytoreduction with a dose of vincristine was recommended with intent to follow on with stereotactic radiation therapy. Baseline chest radiographs were obtained on 25/3/22 and a first dose of vincristine was administered. The patient presented for follow up chest radiographs on 29/3/22 which showed a moderate tumour reduction and was deemed stable to proceed to GA for CT simulation and radiation planning. SRT was initiated the following day and 3 consecutive 8Gy doses were administered between 30/3/22 and 1/4/22
The patient did well throughout RT and presented one month later for recheck thoracic radiographs which showed a clinical remission of the mediastinal mass. A follow up CT scan was done on 10/8/22 and cross sectional imaging showed a persistent but markedly smaller cranial mediastinal mass. Adjuvant chemotherapy was declined but prednisolone was continued at 2.5mg daily. On 7/12/22, the patient presented with leukotrichia over lateral thorax in RT field. On 20/3/23 another CT scan (1 year post RT) was done and showed stable disease compared to 4 months post SRT. The patient was last seen on 24/7/23 (16 months post SRT) and was in clinical remission on thoracic radiographs with no reported concerns.
The patient completed a second course of radiation on the 28th September 2023 18 months after the initial course.