Emergency SBRT to trachea and carina for adenoid cystic carcinoma of the trachea with partial airway obstruction
Santosh K. Prusty, Amrit Neupane, Rambha Pandey, Seema Sharma, Karan Madan, Madhavi Tripathy, Ipsita Pati, Subhash Gupta and Haresh K P
Primary tumours of the trachea are rare accounting for 0·1–0·4% of malignant diseases (1). These patients generally report with signs and symptoms of upper airway obstruction which includes dyspnoea, wheeze, stridor, haemoptysis. Tumours do not cause symptoms until they occlude 50–75% of the luminal diameter or until the trachea has narrowed to less than 8 mm, and once the lumen is less than 5 mm dyspnea occurs even at rest (2,3). Primary ACC is typically indolent and slow-growing, which is treated by surgery. With high rate of PNI, coupled with perineural tumor spread and a propensity for hematogenous dissemination make distant metastasis the most common pattern of treatment failure in ACC, often occurring without locoregional recurrence (4). Approximately 30–40% of ACC patients will develop distant metastasis within 10–15 years following curative-intent treatment, with most common site being lungs (5). Role of SBRT in oncology has evolved significantly over past decade, especially while delivering ablative dose to lung, brain and spine metastasis by sparing major organs at risk (OARs) (6,7). In this case we explored the utility of SBRT in palliative setting while delivering radiation to an anecdotal “no fly zone” (NFZ) which anatomically correspond to carina. To best of our knowledge it’s the first case of its kind.
Keywords: emergency SBRT, adenoid cystic carcinoma, airway obstruction