Giuseppe Minniti

Fractionated stereotactic conformal radiotherapy for secreting and nonsecreting pituitary adenomas

Objective  To assess the medium‐term outcome in a cohort of patients with residual or recurrent pituitary adenoma treated with fractionated stereotactic conformal radiotherapy (SCRT).

The long‐term efficacy of conventional radiotherapy in patients with GH‐secreting pituitary adenomas

Objective  To assess the long‐term efficacy and safety of conventional radiotherapy (RT) in the control of acromegaly according to recent stringent criteria of cure.

Fractionated stereotactic radiotherapy for skull base tumors: analysis of treatment accuracy using a stereotactic mask fixation system

BackgroundTo assess the accuracy of fractionated stereotactic radiotherapy (FSRT) using a stereotactic mask fixation system.Patients and MethodsSixteen patients treated with FSRT were involved in the study. A commercial stereotactic mask fixation system (BrainLAB AG) was used for patient immobilization. Serial CT scans obtained before and during FSRT were used to assess the accuracy of patient immobilization by comparing the isocenter position. Daily portal imaging were acquired to establish day to day patient position variation. Displacement errors along the different directions were calculated as combination of systematic and random errors.ResultsThe mean isocenter displacements based on localization and verification CT imaging were 0.1 mm (SD 0.3 mm) in the lateral direction, 0.1 mm (SD 0.4 mm) in the anteroposterior, and 0.3 mm (SD 0.4 mm) in craniocaudal direction. The mean 3D displacement was 0.5 mm (SD 0.4 mm), being maximum 1.4 mm. No significant differences were found during the treatment (P = 0.4). The overall isocenter displacement as calculated by 456 anterior and lateral portal images were 0.3 mm (SD 0.9 mm) in the mediolateral direction, -0.2 mm (SD 1 mm) in the anteroposterior direction, and 0.2 mm (SD 1.1 mm) in the craniocaudal direction. The largest displacement of 2.7 mm was seen in the cranio-caudal direction, with 95% of displacements < 2 mm in any direction.ConclusionsThe results indicate that the setup error of the presented mask system evaluated by CT verification scans and portal imaging are minimal. Reproducibility of the isocenter position is in the best range of positioning reproducibility reported for other stereotactic systems.

Radiotherapy and radiosurgery for benign skull base meningiomas

Meningiomas located in the region of the base of skull are difficult to access. Complex combined surgical approaches are more likely to achieve complete tumor removal, but frequently at a cost of treatment related high morbidity. Local control following subtotal excision of benign meningiomas can be improved with conventional fractionated external beam radiation therapy with a reported 5-year progression-free survival up to 95%. New radiation techniques, including stereotactic radiosurgery (SRS), fractionated stereotactic radiotherapy (FSRT), and intensity-modulated radiotherapy (IMRT) have been developed as a more accurate technique of irradiation with more precise tumor localization, and consequently a reduction in the volume of normal brain irradiated to high radiation doses. SRS achieves a high tumour control rate in the range of 85-97% at 5 years, although it should be recommended only for tumors less than 3 cm away more than 3 mm from the optic pathway because of high risk of long-term neurological deficits. Fractionated RT delivered as FSRT, IMRT and protons is useful for larger and irregularly or complex-shaped skull base meningiomas close to critical structures not suitable for single-fraction SRS. The reported results indicate a high tumour control rate in the range of 85-100% at 5 years with a low risk of significant incidence of long-term toxicity. Because of the long natural history of benign meningiomas, larger series and longer follow-up are necessary to compare results and toxicity of different techniques.

Echocardiographic evidence for a direct effect of GH/IGF-I hypersecretion on cardiac mass and function in young acromegalics

The interpretation of echocardiographic abnormalities in acromegalic patients is complicated by non‐specific age‐related diseases, many of which are commoner in acromegaly. We have therefore investigated the cause‐effect relationship between GH/IGF‐I hypersecretion and precocious cardiovascular abnormalities in a series of young acromegalic patients.

Multidose Stereotactic Radiosurgery (9 Gy × 3) of the Postoperative Resection Cavity for Treatment of Large Brain Metastases

PURPOSE To evaluate the clinical outcomes with linear accelerator-based multidose stereotactic radiosurgery (SRS) to large postoperative resection cavities in patients with large brain metastases. METHODS AND MATERIALS Between March 2005 to May 2012, 101 patients with a single brain metastasis were treated with surgery and multidose SRS (9 Gy × 3) for large resection cavities (>3 cm). The target volume was the resection cavity with the inclusion of a 2-mm margin. The median cavity volume was 17.5 cm(3) (range, 12.6-35.7 cm(3)). The primary endpoint was local control. Secondary endpoints were survival and distant failure rates, cause of death, performance measurements, and toxicity of treatment. RESULTS With a median follow-up of 16 months (range, 6-44 months), the 1-year and 2-year actuarial survival rates were 69% and 34%, respectively. The 1-year and 2-year local control rates were 93% and 84%, with respective incidences of new distant brain metastases of 50% and 66%. Local control was similar for radiosensitive (non-small cell lung cancer and breast cancer) and radioresistant (melanoma and renal cell cancer) brain metastases. On multivariate Cox analysis stable extracranial disease, breast cancer histology, and Karnofsky performance status >70 were associated with significant survival benefit. Brain radionecrosis occurred in 9 patients (9%), being symptomatic in 5 patients (5%). CONCLUSIONS Adjuvant multidose SRS to resection cavity represents an effective treatment option that achieves excellent local control and defers the use of whole-brain radiation therapy in selected patients with large brain metastases.

Marked improvement in cardiovascular function after successful transsphenoidal surgery in acromegalic patients

OBJECTIVE Transsphenoidal surgery results in biochemical remission of acromegaly in 45–80% of patients; however, few studies have addressed the impact of transsphenoidal surgery on cardiovascular function in acromegalic patients. The aim of this prospective study was to investigate the effects of postoperative GH/IGF‐I normalization on echocardiographic parameters and blood pressure (BP) in a series of patients with active acromegaly.

Radiotherapy for nonfunctioning pituitary adenomas: from conventional to modern stereotactic radiation techniques

The initial management of nonfunctioning pituitary macroadenomas (NFAs) is usually surgery; however, a significant proportion of NFAs may require further treatment. Radiotherapy is currently used in patients with residual tumour and achieves excellent long-term control, but there are concerns about potential late toxicity. Stereotactic radiotherapy, both in the form of radiosurgery or fractionated stereotactic radiotherapy, has been developed as a more accurate technique of irradiation with more precise tumour localization and consequently a reduction in the volume of normal tissue, particularly the brain, irradiated to high radiation doses. A review of the literature suggests that new radiation techniques offer safe and effective treatment for recurrent or residual pituitary adenomas; however longer follow-up is necessary to confirm the excellent tumour control and the potential reduction of long-term radiation toxicity. Currently, radiotherapy has an important role in patients with residual or progressive disease after surgery. Patients with small or no residual tumours after surgery may generally continue on a policy of surveillance without immediate irradiation, in order to avoid the potential toxicity of treatment.

The role of fractionated radiotherapy and radiosurgery in the management of patients with craniopharyngioma.

The optimal management of craniopharyngiomas remains controversial. The first-line treatment usually consists of surgical resection. Complete tumor removal provides a high rate of long-term control; however, aggressive surgery is associated with significant incidence of complications. Radiotherapy (RT) is currently used in patients after limited surgery and achieves excellent long-term tumor control. Stereotactic radiotherapy, both in the form of radiosurgery (RS) or fractionated stereotactic radiotherapy (FSRT), has been developed as a more accurate technique of irradiation with more precise tumor localization and consequently a reduction in the volume of normal brain irradiated to high radiation doses. We provide a review of published data on outcome of conventional fractionated RT and modern radiation techniques. FSRT is a suitable treatment technique for all sizes of craniopharyngiomas, and efficacy is comparable to conventional RT. Single-fraction stereotactic radiosurgery is usually delivered to small tumors away from critical structures. Longer follow-up is necessary to confirm the excellent tumor control and the potential reduction of long-term radiation toxicity.

EANO guidelines for the diagnosis and treatment of meningiomas

Although meningiomas are the most common intracranial tumours, the level of evidence to provide recommendations for the diagnosis and treatment of meningiomas is low compared with other tumours such as high-grade gliomas. The meningioma task force of the European Association of Neuro-Oncology (EANO) assessed the scientific literature and composed a framework of the best possible evidence-based recommendations for health professionals. The provisional diagnosis of meningioma is mainly made by MRI. Definitive diagnosis, including histological classification, grading, and molecular profiling, requires a surgical procedure to obtain tumour tissue. Therefore, in many elderly patients, observation is the best therapeutic option. If therapy is deemed necessary, the standard treatment is gross total surgical resection including the involved dura. As an alternative, radiosurgery can be done for small tumours, or fractionated radiotherapy in large or previously treated tumours. Treatment concepts combining surgery and radiosurgery or fractionated radiotherapy, which enable treatment of the complete tumour volume with low morbidity, are being developed. Pharmacotherapy for meningiomas has remained largely experimental. However, antiangiogenic drugs, peptide receptor radionuclide therapy, and targeted agents are promising candidates for future pharmacological approaches to treat refractory meningiomas across all WHO grades.