Radiotherapy for the treatment of pituitary adenomas: A dosimetric comparison of three planning techniques.

AIM: Our goal was to compare conformal 3D (C3D) radiotherapy (RT), modulated intensity RT (IMRT), and volumetric modulated arc therapy (VMAT) planning techniques in treating pituitary adenomas. BACKGROUND: RT is important for managing pituitary adenomas. Treatment planning advances allow for higher radiation dosing with less risk of affecting organs at risk (OAR). MATERIALS AND METHODS: We conducted a 5-year retrospective review of patients with pituitary adenoma treated with external beam radiation therapy (C3D with flattening filter, flattening filter-free [FFF], IMRT, and VMAT). We compared dose-volume histogram data. For OARs, we recorded D2%, maximum, and mean doses. For planning target volume (PTV), we registered V95%, V107%, D95%, D98%, D50%, D2%, minimum dose, conformity index (CI), and homogeneity index (HI). RESULTS: Fifty-eight patients with pituitary adenoma were included. Target-volume coverage was acceptable for all techniques. The HI values were 0.06, IMRT; 0.07, VMAT; 0.08, C3D; and 0.09, C3D FFF (p < 0.0001). VMAT and IMRT provided the best target volume conformity (CI, 0.64 and 0.74, respectively; p < 0.0001). VMAT yielded the lowest doses to the optic pathway, lens, and cochlea. The position of the neck in extreme flexion showed that it helps in planning mainly with VMAT by allowing only one arc to be used and achieving the desired conformity, decreasing the treatment time, while allowing greater protection to the organs of risk using C3D, C3DFFF. CONCLUSIONS: Our results confirmed that EBRT in pituitary adenomas using IMRT, VMAT, C3D, C3FFF provide adequate coverage to the target. VMAT with a single arc or incomplete arc had a better compliance with desired dosimetric goals, such as target coverage and normal structures dose constraints, as well as shorter treatment time. Neck extreme flexion may have benefits in treatment planning for better preservation of organs at risk. C3D with extreme neck flexion is an appropriate treatment option when other treatment techniques are not available.

Adyuvant fractionated radiotherapy after resection of intracranial hemangiopericytoma.

AIM: Review of literature and adjuvant treatment in Hemangiopericytoma after complete resection. BACKGROUND: Intracranial hemangiopericytoma (HPC) is an uncommon malignant vascular tumor arising from mesenchymal cells with pericytic differentiation. Surgery remains the mainstay treatment, and adjuvant radiation therapy appears to be appropriate for patients with high grade tumors or incomplete resection. We present our experience and review of the literature. MATERIALS AND METHODS: We describe two cases of intracranial hemangiopericytoma located in the frontal lobe of the CNS. Both patients underwent complete tumor resection followed by adjuvant fractionated radiotherapy and completed treatment without interruptions. RESULTS: A local recurrence was observed in one of these cases and fractionated stereotactic radiotherapy was performed. Both patients are alive and disease has been under control up to date. CONCLUSION: The treatment of choice for intracranial hemangiopericytoma is a complete surgical resection as long as possible. Adjuvant radiotherapy of HPC can result in increased tumor control and should be considered as an effective treatment for patients with high grade or demonstrated residual tumor in the postoperative period. Salvage treatment using limited-field fractionated radiotherapy for local recurrence treatment is considered an acceptable option.