The value of computerized tomography in delineating suprasellar extension of pituitary adenoma for radiotherapeutic management

Radiotherapy plays a major role in the management of pituitary adenomas, either as a surgical adjunct or as the primary form of treatment. Small field precision techniques are utilized. The ability to employ limited field therapy and produce local control rates of 80--90% demands precise tumor localization. The extrasellar extension of pituitary adenomas has classically been demonstrated on angiographic and pneumoencephalographic examinations. Direct superior extension is accurately delineated by these examinations; lateral extension, however, is not and the total anterior-posterior extent of the tumor may be underestimated. The addition of computerized tomography significantly increases the information available in the assessment of tumor extension and the subsequent accuracy of treatment planning for radiotherapeutic purposes.