Fractionated stereotactically guided radiotherapy and radiosurgery in the treatment of functional and nonfunctional adenomas of the pituitary gland

We evaluated survival rates and side effects after fractionated stereotactically guided radiotherapy (SCRT) and radiosurgery in patients with pituitary adenoma.

Between 1989 and 1998, 68 patients were treated with FSRT (n = 63) or radiosurgery (n = 5) for pituitary adenomas. Twenty-six had functional and 42 had nonfunctional adenomas. Follow-up included CT/MRI, endocrinologic, and ophthalmologic examinations. Mean follow-up was 38.7 months. Seven patients received radiotherapy as primary treatment and 39 patients received it postoperatively for residual disease. Twenty-two patients were treated for recurrent disease after surgery. Mean total dose was 52.2 Gy for SCRT, and 15 Gy for radiosurgery.

Overall local tumor control was 93% (60/65 patients). Forty-three patients had stable disease based on CT/MRI, while 15 had a reduction of tumor volume. After FSRT, 26% with a functional adenoma had a complete remission and 19% had a reduction of hormonal overproduction after 34 months’ mean. Two patients with STH-secreting adenomas had an endocrinologic recurrence, one with an ACTH-secreting adenoma radiologic recurrence, within 54 months. Reduction of visual acuity was seen in 4 patients and partial hypopituitarism in 3 patients. None of the patients developed brain radionecrosis or radiation-induced gliomas.

Stereotactically guided radiotherapy is effective and safe in the treatment of pituitary adenomas to improve local control and reduce hormonal overproduction.     

KX2-361: a novel orally bioavailable small molecule dual Src/tubulin inhibitor that provides long term survival in a murine model of glioblastoma

Stereotactic radiosurgery (SRS) is frequently used for Cushing’s disease (CD) after failed pituitary surgery. Management of patients with persistent CD after failed SRS is complex, as the alternative therapeutic options harbor significant risks. The outcomes of repeat pituitary radiosurgery, however, have not been described. We sought to determine the outcomes of repeat SRS in patients with CD. We pooled data from five institutions participating in the International Gamma Knife Research Foundation for patients with recurrent or persistent CD?≥?12 months after initial SRS. Patients were included in the study if they had ≥?6 months endocrine follow-up after repeat SRS. Twenty patients were included in the study. Repeat single-session SRS was performed 1.3–9.7 years after initial SRS. Median endocrine follow-up was 6.6 years (1.4–19.1 years). Median margin dose was 20 Gy (range 10.8–35 Gy). Endocrine remission after second SRS was noted in 12 patients (60%), with a median time to remission of 6 months (range 2–64 months). Biochemical recurrence occurred in two patients (17%) after initial remission. Overall, the cumulative rates of durable endocrine remission at 5 and 10 years were 47 and 53%, respectively. Two patients (10%) experienced adverse radiation effects, including transient visual loss and permanent diplopia. Repeat SRS achieves lasting biochemical remission in approximately half of patients with CD refractory to both prior microsurgery and SRS. Because of the morbidity of refractory or recurrent CD, repeat SRS should be considered for carefully selected patients with hypercortisolism confirmed one or more years after initial SRS.     

Overall and progression-free survival and visual and endocrine outcomes for patients with parasellar lesions treated with intensity-modulated stereotactic radiosurgery

Linear accelerator single-fraction radiosurgery (SRS) for skull base lesions is usually delivered with dynamic conformal arcs (DCAs), but intensity-modulated radiosurgery (IMRS) is another option when SRS dose is limited by proximity of the optic nerve and chiasm. We review the long-term outcome of patients treated with IMRS for parasellar lesions. Fourteen patients with parasellar lesions were treated with IMRS when standard DCA radiosurgery was limited by optic nerve tolerance. Prospective patient data included endocrine function, visual acuity and field testing, nonoptic nerve cranial neuropathy, and overall survival. In addition, tumor control on serial magnetic resonance imaging is reported as progression-free survival (PFS). Six patients with cavernous sinus meningiomas and eight with recurrent pituitary adenomas were treated. Three of the pituitary tumors were hormonally active (two with Cushing disease, one with acromegaly). The median patient age was 50 years (range 24–70 years). Median follow-up was 54 months. Average tumor treatment volume was 4.99 ml (average dose 16 Gy, average of 10 IMRS fields). Tumor control was achieved in 11 of 14 (79%) patients. Median PFS has not been reached in our patient population. Thirteen patients are alive (one died of an unrelated cancer). No patients developed new endocrinological, ophthalmological, or cranial nerve deficits. IMRS allows for treatment of parasellar lesions when standard DCA SRS is limited by optic nerve tolerance. Although our follow-up period was relatively short and the number of patients was small, it appears that this can be accomplished with a high tumor control rate and survival without new endocrinopathies, optic neuropathies, or other complications in patients who have failed other therapies.     

Gamma knife radiosurgery for patients with nonfunctioning pituitary adenomas: results from a 15-year experience

PURPOSE: To evaluate the efficacy and complications of stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas (NFA). METHODS AND MATERIALS: This was a retrospective review of 62 patients with NFA undergoing radiosurgery between 1992 and 2004, of whom 59 (95%) underwent prior tumor resection. The median treatment volume was 4.0 cm(3) (range, 0.8-12.9). The median treatment dose to the tumor margin was 16 Gy (range, 11-20). The median maximum point dose to the optic apparatus was 9.5 Gy (range, 5.0-12.6). The median follow-up period after radiosurgery was 64 months (range, 23-161). RESULTS: Tumor size decreased for 37 patients (60%) and remained unchanged for 23 patients (37%). Two patients (3%) had tumor growth outside the prescribed treatment volume and required additional treatment (fractionated radiation therapy, n = 1; repeat radiosurgery, n = 1). Tumor growth control was 95% at 3 and 7 years after radiosurgery. Eleven (27%) of 41 patients with normal (n = 30) or partial (n = 11) anterior pituitary function before radiosurgery developed new deficits at a median of 24 months after radiosurgery. The risk of developing new anterior pituitary deficits at 5 years was 32%. The 5-year risk of developing new anterior pituitary deficits was 18% for patients with a tumor volume of < or = 4.0 cm(3) compared with 58% for patients with a tumor volume >4.0 cm(3) (risk ratio = 4.5; 95% confidence interval = 1.3-14.9, p = 0.02). No patient had a decline in visual function. CONCLUSIONS: Stereotactic radiosurgery is effective in the management of patients with residual or recurrent NFA, although longer follow-up is needed to evaluate long-term outcomes. The primary complication is hypopituitarism, and the risk of developing new anterior pituitary deficits correlates with the size of the irradiated tumor.     

Clinical results of 24 pituitary macroadenomas with linac-based stereotactic radiosurgery

Purpose: To determine the impact of stereotactic radiosurgery (SRS) on the clinical course, hormonal status, and follow-up CT/MRI scan of pituitary macroadenomas.Methods and Materials: From July 1988 to March 1996, 24 pituitary macroadenomas had been treated using 6 MV linear accelerator based SRS. They consisted of 11 (45.8%) prolactinomas, 2 (8.3%) growth hormone (GH)-secreting tumors, 1 (4.2%) Cushing’s disease, 8 (33.3%) nonsecreting (nonfunctioning: NF) tumors, and 2 (8.3%) mixed prolactin-growth hormone (PRL-GH)-secreting tumors (M:F = 12:12; aged 21–61 years). Postoperative irradiation was performed in all cases except for the instance of Cushing’s disease. The prescribed dose to tumor center varied from 10 to 27 Gy (mean 21.1 Gy) using a collimator size of 0.5 to 2.5 cm. The follow-up duration ranged from 13 to 89 months (mean 49.2 months). Results from these patients were compared to our results using conventional radiation.Results: Visual acuity and field defect were improved or became normal in 19 (79.2%) cases. Four (16.7%) remained unchanged after the treatment. One (4.1%) progressed 6 years after SRS and subsequently had repeat surgery with conventional boost irradiation. Of the 13 (46.4%) prolactinomas, including two mixed PRL-GH secreting tumors, 11 (84.1%) revealed normal hormonal levels within 1 year after SRS. In contrast, it took 2 years to become normal after conventional radiation therapy. In four GH-secreting tumors including two mixed PRL-GH secreting tumors, SRS and conventional methods showed similar responses. On follow-up imagings of the 21 patients, the mass was completely resolved in 4 (16.7%), including 3 PRLs and one NF, decreased in 11 (45.8%), and unchanged in 5 (16.7%) with central necrosis or cysts. One (4.2%) progressed and was reoperated 6 years after treatment. The complications related to SRS were comparable to those from conventional method.Conclusion: Radiosurgery can be used effectively in patients with pituitary adenoma. In this study, a more rapid hormonal and clinical response was achieved with radiosurgery than with conventional pituitary irradiation treatment.     

Stereotactic radiosurgery for patients with ACTH-producing pituitary adenomas after prior adrenalectomy

PURPOSE: To review the results of stereotactic radiosurgery for patients with adrenocorticotropic hormone (ACTH)-producing pituitary adenomas after bilateral adrenalectomy. METHODS AND MATERIALS: Eleven patients with ACTH-producing pituitary adenomas after bilateral adrenalectomy underwent radiosurgery between 1990 and 1999. Nine patients had documented tumor growth, hyperpigmentation, and elevated ACTH levels (median 920 ng/mL) at the time of radiosurgery. Five of these patients had tumor enlargement despite prior fractionated radiotherapy (median dose 50 Gy). Two patients were treated prophylactically within 1 month of their adrenalectomies to prevent future tumor growth. The median follow-up was 37 months (range 22-74). RESULTS: Tumor growth control was achieved in 9 patients (82%); 2 patients had had continued tumor growth after radiosurgery. The ACTH levels decreased a median of 66% (range -99% to +27%); 4 patients had normal ACTH levels. Three patients had radiation-related complications, including diplopia (n = 2), ipsilateral blindness (n = 1), testosterone/growth hormone deficiency (n = 1), and asymptomatic temporal lobe radiation necrosis (n = 1): all had received prior radiotherapy. One patient who had undergone three prior resections and radiotherapy died 59 months after radiosurgery despite two additional attempts at tumor resection. CONCLUSION: Although our experience is limited, it appears that radiosurgery provides tumor control for most patients with ACTH-producing pituitary adenomas who have undergone bilateral adrenalectomy.     

The impact of whole-brain radiation therapy on the long-term control and morbidity of patients surviving more than one year after gamma knife radiosurgery for brain metastases

PURPOSE: To better analyze how whole-brain radiotherapy (WBXRT) affects long-term tumor control and toxicity from the initial stereotactic radiosurgery (SRS) for brain metastases, we studied these outcomes in patients who had survived at least 1 year from SRS. METHODS AND MATERIALS: We evaluated the results of gamma knife radiosurgery for 160 brain metastases in 110 patients who were followed for a median of 18 months (range, 12-122 months) after SRS. Eighty-two patients had a solitary brain metastasis and 28 patients had multiple metastases. Seventy patients (116 tumors) were treated with initial radiosurgery and WBXRT, whereas 40 patients (44 lesions) initially received radiosurgery alone. Median treatment volume was 1.9 cc in the entire group, 2.3 cc in the WBXRT group, and 1.6 cc in the SRS alone group. Median tumor dose was 16 Gy (range, 12-21 Gy). RESULTS: At 1, 3, and 5 years, local tumor control was 84.1% +/- 5.5%, 68.6% +/- 8.7%, and 68.6% +/- 8.7% with SRS alone compared with 93.1% +/- 2.4%, 87.7% +/- 4.9%, and 65.7% +/- 10.2%. with concurrent WBXRT and SRS (p = 0.0228, univariate). We found that WBXRT improved local control in patient subsets tumor volume > or =2 cc, peripheral dose < or =16 Gy, single metastases, nonradioresistant tumors, and lung cancer metastases (p = 0.0069, 0.0080, 0.0083, 0.0184, and 0.0348). Distal intracranial failure developed at 1, 3, and 5 years in 26.0% +/- 7.1%, 74.5% +/- 9.4%, and 74.5% +/- 9.4% with SRS alone compared with 20.7% +/- 4.9%, 49.0% +/- 8.7%, and 61.8% +/- 12.8% with concurrent WBXRT and SRS (p = 0.0657). We found a trend for improved distal intracranial control with WBXRT for only nonradioresistant tumors (p = 0.054). Postradiosurgery complications developed in 2.8% +/- 1.2% and 10.7% +/- 3.5% at 1 and 3-5 years and was unaffected by WBXRT (p = 0.7721). WBXRT did not improve survival in the entire series (p = 0.5027) or in any subsets. CONCLUSIONS: In this retrospective study of 1-year survivors of SRS for brain metastases, the addition of concurrent WBXRT to SRS was associated with an improved local control rate in patient subsets with tumor volume > or =2 cc, peripheral dose < or =16 Gy, single metastases, nonradioresistant tumors, and specifically lung cancer metastases. A trend was noted for improved distal intracranial control for patients having nonradioresistant tumors. Distant intracranial relapse >1 year posttreatment is a significant problem with or without initial WBXRT.     

Stereotactic radiosurgery for intracranial chondrosarcoma

To assess outcomes after stereotactic radiosurgery (SRS) for chondrosarcomas of the skull base, we reviewed 22 patients with cranial base chondrosarcomas who underwent SRS between 1987 and 2009. The median patient age was 42 years (range, 15-75). The median SRS target volume was 8.0 cc (range, 0.9-28.2) and median margin dose was 15.0 Gy (range, 10.5-20). 15 patients (68 %) underwent one or more tumor resections and 3 of these patients also had fractionated radiation therapy. At a median follow-up of 75 months after SRS, seven patients died due to tumor progression. The actuarial overall survival after SRS for the entire group of chondrosarcoma patients was 95, 76, 70 and 56 % at 1, 3, 5 and 10 years, respectively. Factors associated with longer survival after SRS included patient age >40 years, a shorter interval (<6 months) between diagnosis and SRS, and either no or a single prior resection. Treated tumor control rates were 91, 72, 72 and 54 % at 1, 3, 5 and 10 years, respectively. Factors associated with longer progression-free survival after SRS included patient age >40 years and no prior RT. Symptomatic adverse radiation effects occurred in two patients (10 %). Stereotactic radiosurgery may provide a benefit to patients as either a primary or adjuvant therapy. The ability to achieve tumor control in patients with chondrosarcoma is likely to be enhanced by earlier timing of SRS after diagnosis and multimodal management, beginning with resection when feasible followed by early SRS for progressive residual tumor.     

The Efficacy of Stereotactic Radiosurgery in the Management of Intracranial Ependymoma

OBJECTIVE: A retrospective analysis was performed to determine the outcome of patients with intracranial ependymoma treated with stereotactic radiosurgery (SRS). METHODS: Nine ependymoma patients have been treated with SRS (four with linear accelerator and five with Gamma Knife) since 1990. Two patients had WHO grade III tumors, and the remaining seven had WHO grade II tumors. Eight of nine patients received external beam radiation therapy at some point prior to radiosurgery to a total median dose of 54 Gy. The radiosurgery dose ranged from 14 to 20 Gy. RESULTS: The median follow-up was 28 months. The median age of patients at diagnosis was 35 years. Four patients developed progressive disease following radiosurgery, and two patients have died of progressive disease. The 3-year relapse-free survival was 55.6%. The 3-year overall survival was 71.1%. Patients treated with radiosurgery as a component of initial treatment (generally as a boost following external beam) had an improved relapse-free survival (100%) compared to those treated with radiosurgery to salvage an external beam local failure (20%). CONCLUSION: SRS is an effective treatment for intracranial ependymoma. Further clinical trials are warranted incorporating radiosurgery as a component of initial management in selected ependymoma patients.     

Hypofractionated stereotactic radiosurgery for pituitary metastases

Pituitary metastases (PMs) are uncommon, representing only 1% of pituitary lesions. The diagnosis of PMs can be challenging and an optimal management remains to be determined. Here, we present a pilot clinical study on the efficacy and safety of hypofractionated stereotactic radiosurgery (SRS) with an optimized dosimetric plan in treating PMs. Between June 2013 and December 2014, seven consecutive patients (4 men and 3 women; median age 62 years) had been diagnosed with PMs based on their characteristic clinical and radiological features and subsequently treated using hypofractionated SRS. Primary cancers originated from the lung (n?=?5) or the breast (n?=?2). All patients presented with diabetes insipidus (DI). Anterior pituitary and visual dysfunction were combined in 4 and 3 patients, respectively. On magnetic resonance imaging (MRI), PMs involved the pituitary stalk and/or the posterior lobe in all patients. SRS of a cumulative marginal dose 31 Gy with dose-volume constraints for the optic apparatus was delivered in 5 daily fractions. As results, tumor was locally controlled in all patients with substantial responses on MRI (including complete remission in 4 patients). The median survival time was 14 months (range, 6–24 months) after SRS. DI and visual dysfunction improved in all patients, although anterior pituitary dysfunction did not recover. No patients experienced any deterioration in visual, pituitary, or other cranial nerve functions. These results suggest a promising role of hypofractionated SRS in treating PMs in terms of both tumor control and functional outcomes.     

A study on the radiation tolerance of the optic nerves and chiasm after stereotactic radiosurgery

PURPOSE: To evaluate the risk of clinically significant radiation optic neuropathy (RON) for patients having stereotactic radiosurgery of benign tumors adjacent to the optic apparatus. METHODS AND MATERIALS: We reviewed the dose plans and clinical outcomes of 218 gamma knife procedures (215 patients) for tumors of the sellar and parasellar region (meningiomas, n = 122; pituitary adenomas, n = 89; craniopharyngiomas, n = 7 patients). Previous surgery or radiation therapy was performed in 156 (66%) and 24 (11%) patients, respectively. Median follow-up was 40 months (range 4-115). RESULTS: The median maximum radiation dose to the optic nerve was 10 Gy (range 0.4-16.0). Four patients (1.9%) developed RON at a median of 48 months after radiosurgery. All had prior surgery, and 3 of 4 had external beam radiotherapy (EBRT) in their management either before (n = 2) or adjuvantly (n = 1). The risk of developing a clinically significant RON was 1.1% for patients receiving 12 Gy or less. Patients receiving prior or concurrent EBRT had a greater risk of developing RON after radiosurgery (p = 0.004). CONCLUSION: RON occurred in less than 2% of our patients, despite the majority (73%) receiving more than 8 Gy to a short segment of the optic apparatus. Knowledge of the dose tolerance of these structures permits physicians to be more aggressive in treating patients with sellar or parasellar tumors, especially those with hormone-producing pituitary adenomas that appear to require higher doses to achieve biochemical remission.     

Initial clinical results of linac-based stereotactic radiosurgery and stereotactic radiotherapy for pituitary adenomas

Purpose: To retrospectively evaluate the initial clinical results of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) for pituitary adenomas with regard to tumor and hormonal control and adverse effects of the treatment.Subjects and Methods: Forty-eight patients with pituitary adenoma who underwent SRS or SRT between September 1989 and September 1995 were analyzed. Of these, 18 received SRS and 30 received SRT. The median tumor volumes were 1.9 cm³ for SRS and 5.7 cm³ for SRT. Eleven of the SRS and 18 of the SRT patients were hormonally active at the time of the initial diagnosis. Four of the SRS and none of the SRT patients had a history of prior radiation therapy. Both SRS and SRT were performed using a dedicated stereotactic 6-MV linear accelerator (LINAC). The dose and normalization used for the SRS varied from 1000 cGy at 85% of the isodose line to 1500 cGy at 65% of the isodose line. For SRT patients, a total dose of 4500 cGy at 90% or 95% of the isodose line was delivered in 25 fractions of 180 cGy daily doses.Results: Disease control—The three year tumor control rate was 91.1% (100% for SRS and 85.3% for SRT). Normalization of the hormonal abnormality was achieved in 47% of the 48 patients (33% for SRS and 54% for SRT). The average time required for normalization was 8.5 months for SRS and 18 months for SRT. Adverse effects—The 3-year rate of freedom from central nervous system adverse effects was 89.7% (72.2% for SRS and 100% for SRT). Three patients who received SRS for a tumor in the cavernous sinus developed a ring enhancement in the temporal lobe as shown by follow-up magnetic resonance imaging. Two of these cases were irreversible and were considered to be radiation necrosis. None of the 48 patients developed new neurocognitive or visual disorders attributable to the irradiation. The incidence of endocrinological adverse effects were similar in the two groups, resulting in 3-year rates of freedom from newly initiated hormonal replacement of 78.4% (77.1% for SRS and 79.9% for SRT).Conclusion: Considering the relatively high incidence of morbidity observed in the SRS group, we recommend SRT as the primary method of radiation therapy for pituitary tumors. When treating a lesion in the cavernous sinus with SRS, special attention should be paid to dose distribution in the adjacent brain parenchyma. Longer follow-up is necessary before drawing any conclusions about the advantages of these techniques over conventional external beam radiation therapy.     

Stereotactic radiosurgery for cavernous sinus hemangiomas

We performed this retrospective study to analyze the outcome of patients with cavernous sinus hemangioma (CSH) after stereotactic radiosurgery (SRS). We analyzed 19 patients with CSHs who were treated with SRS between 1998 and 2011. The median age of the patients was 50 years (range, 35–73 years), and 16 (84.2 %) of the patients were female. SRS was performed as a primary treatment for 18 patients and to treat a residual lesion after surgical resection in one patient. Nine (47.4 %) patients had cranial neuropathies in 14 cranial nerves before SRS, whereas five (26.3 %) patients were initially asymptomatic. The mean volume of the CSHs was 6.1 ± 7.2 cm³ (range, 0.3–32.3 cm³), and the median marginal dose at the 50 % isodose line was 14.5 Gy (range, 11.5–16.0 Gy). The mean follow-up period was 37 months (range, 12–85 months). At the last follow-up, the lesion volume had decreased in all patients. The average tumor volume had decreased to 26 % (range, 0–70 %) of the initial volume at the last follow-up MRI. The first follow-up MRI, performed 6.1 ± 1.0 months after the SRS, showed that the tumor volume had decreased to 41 % (range, 0–88 %) of the initial volume. All 14 of the cranial neuropathies observed before SRS had improved, with complete remission in 12 (85.7 %) cranial nerves and partial remission in two (14.3 %). There were no radiation-induced neuropathies or complications during the follow-up period. SRS appears to be an effective and safe treatment modality for the management of CSHs.     

立体定向放射外科治疗鼻咽癌的初步应用

目的探讨立体定向放射外科（ＳＲＳ）在鼻咽癌治疗中应用的可行性及价值。方法１９９６年８月至１９９７年１２月用Ｘ－刀治疗鼻咽癌１３例,其中初治者６例,复发者７例。初治者结合外照射７０～７５Ｇｙ,Ｘ－刀靶区周边剂量为１７～２２．５Ｇｙ（中位剂量１８Ｇｙ）。复发者中行外照射加Ｘ－刀３例,Ｘ－刀多次治疗４例,其中行２次者３例,４次者１例。靶区周边剂量为１８～３０Ｇｙ（中位剂量２４Ｇｙ）。结果初治者局控率为８３．３％（５／６）。复发者局控率为７１．４％（５／７）。初治者全部存活,中位生存期１１个月。复发者存活２例,死亡５例,中位生存期７个月。结论ＳＲＳ为提高鼻咽癌治疗的局控率,降低后期并发症发生率提供了安全有效的途径。确切评价ＳＲＳ在鼻咽癌治疗中的作用尚需累积更多的病例资料,进行较长期的观察研究。     

Gamma Knife robotic microradiosurgery of pituitary adenomas invading the cavernous sinus: treatment concept and results in 89 cases

The objective of the present retrospective study was evaluation of results of “robotic microradiosurgery” of pituitary adenomas invading the cavernous sinus. Eighty-nine patients with such tumors underwent management using Leksell Gamma Knife model C with automatic positioning system. There were 77 residual and 12 recurrent neoplasms. The applied radiosurgical treatment plan was based on the use of multiple isocenters, mainly of smaller size, which were positioned compactly within the border of the lesion with resultant improved dose homogeneity, increased average dose within the target, and sharp dose fall outside the treated volume. The marginal dose varied from 12 to 25 Gy (mean, 18.2 Gy) in non-functional pituitary adenomas (43 cases), and from 12 to 35 Gy (mean, 25.2 Gy) in hormone-secreting ones (46 cases). The length of follow-up after treatment ranged from 24 to 76 months (mean, 36 months). Control of the tumor growth was attained in 86 cases (97%), whereas actual shrinkage of the lesion was marked in 57 cases (64%). In 18 out of 46 secreting neoplasms (39%), normalization of the excess of the pituitary hormone production was noted after radiosurgery. Treatment-associated morbidity was limited to transitory cranial nerve palsy in two patients (2%). No patient with either non-functional or hormone secreting tumor exhibited new pituitary hormone deficit after treatment. In conclusion, highly precise microanatomy-based Gamma Knife robotic microradiosurgery provides an opportunity for effective management of pituitary adenomas invading the cavernous sinus with preservation of the adjacent functionally important neuronal structures.     

Long-term outcome of stereotactic radiosurgery (SRS) in patients with acoustic neuromas

PURPOSE: To evaluate the effectiveness and long-term outcome of stereotactic radiosurgery (SRS) for acoustic neuromas (AN). PATIENTS AND METHODS: Between 1990 and 2001, we treated 26 patients with 27 AN with SRS. Two patients suffered from neurofibromatosis type 2. Before SRS, a subtotal or total resection had been performed in 3 and in 5 patients, respectively. For SRS, a median single dose of 13 Gy/80% isodose was applied. RESULTS: The overall actuarial 5-year and 10-year tumor control probability in all patients was 91%. Two patients developed tumor progression after SRS at 36 and 48 months. Nineteen patients (73%) were at risk of treatment-related facial nerve toxicity; of these, 1 patient developed a complete facial nerve palsy after SRS (5%). A total of 93% of the lesions treated were at risk of radiation-induced trigeminal neuralgia. Two patients (8%) developed mild dysesthesia of the trigeminal nerve after SRS. The hearing preservation rate in patients with useful hearing before SRS was 55% at 9 years. CONCLUSION: Stereotactic radiosurgery results in good local control rates of AN and the risk of cranial nerve toxicities is acceptable. As toxicity is lower with fractionated stereotactic radiotherapy, SRS should be reserved for smaller lesions.     

Stereotactic radiosurgery and fractionated stereotactic radiotherapy: comparison of efficacy and toxicity in 260 patients with brain metastases

We retrospectively evaluated and compared the efficacy and the toxicity profile of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for the treatment of patients with brain metastases (BM). Between 2000 and 2009, 260 patients with 1-3 BM were treated using either SRS (median dose 20 Gy; n = 138) or two different FSRT dose concepts: 7 × 5 Gy (n = 61) or 10 × 4 Gy (n = 61). The median survival for SRS, 7 × 5 Gy and 10 × 4 Gy was 8, 7 and 10 months (p = 0.575), respectively, and the overall survival (OS) was 9 months. Follow-up imaging data were available in 214 of the 260 patients. The 1-year local progression-free survival (LPFS) was 73, 75 and 71 %, respectively (p = 0.191). After a mean follow-up of 28 months (range: 2.1-77 months), the rate of complete remission, partial remission, stable disease and progressive disease were 29, 40, 21 and 10 %, respectively. On multivariate analysis, RPA class I was associated with better OS and regional progression-free survival (both p < 0.001). SRS was associated with a higher toxicity rate (grade I-III) compared to the 7 × 5 Gy and 10 × 4 Gy groups (14 vs. 6 vs. 2 %, respectively; p = 0.01). Although FSRT was used for large lesions and/or lesions near critical structures, the LPFS was comparable to SRS. Importantly, FSRT presented low toxicity and appears to be an effective and safe treatment for BM not amenable to SRS. The 10 × 4 Gy fractionation scheme warrants further investigation due to its efficacy and safe toxicity profile.     

垂体腺瘤的立体定向放射治疗

目的评估伽玛刀立体定向放射治疗对垂体腺瘤的治疗效果。方法对２９２例垂体腺瘤患者,用１．５Ｔ磁共振和γｐｌａｎ计算机联网定位,Ｌｅｋｓｅｌ伽玛刀实施放射外科手术。肿瘤直径３．８～５１．１ｍｍ,平均１６．３ｍｍ,照射剂量９～３５Ｇｙ,平均２１．６Ｇｙ。结果本组病例随访１２～３４个月,平均２１个月,获随访２０４例。肿瘤消失３９例（１９．１％）,缩小１５６例（７６．４％）;激素值恢复正常１４例（１１．８％）,较术前下降９４例（７９．６％）;临床症状改善１９０例（９３．１％）,９例症状加重,３例肿瘤增大,２例开颅手术,１例死亡。结论伽玛刀是治疗垂体腺瘤安全、有效的一种方法,但要严格掌握适应证,对Ⅲ级以上肿瘤应首选手术治疗,γ刀治疗后有可能加重垂体低功能状态,诱发垂体危象。