Stereotactic radiosurgery XVI: a treatment for previously irradiated pituitary adenomas.
Swords FM, Allan CA, Plowman PN, Sibtain A, Evanson J, Chew SL, Grossman AB, Besser GM, Monson JP.
Department of Endocrinology, St. Bartholomew's and The Royal London School of Medicine, London EC1A 7BE, United Kingdom.
We report the use of stereotactic radiosurgery delivered through an adapted linear accelerator [stereotactic multiple arc radiation therapy (SMART)] for pituitary adenomas not cured by conventional therapy. All 21 patients had undergone conventional radiotherapy (45-50 Gy); 18 had also undergone prior surgery. This cohort comprised 13 patients with somatotrope adenomas, four with corticotrope adenomas, one with a lactotrope adenoma, and three with nonfunctioning pituitary adenomas (median follow-up: 33 months, range: 3-72 months). SMART has proven effective, safe, and rapidly acting. We observed an accelerated reduction in GH and IGF-I levels in acromegaly, with normalization of GH and IGF-I levels in 58%. Mean GH fell from 21.1 mU/liter to 7.9 mU/liter (7 ng/ml to 2.6 ng/ml, P < 0.01, median 25 months) faster than our predicted fall to 50% at 2 yr with conventional radiotherapy. Mean IGF-I fell from 624 ng/ml to 384 ng/ml (P < 0.001). Tumor growth was controlled in two of three nonfunctioning pituitary adenomas, and three of four corticotrope adenomas. There were no adverse effects from SMART. Notably there have been no visual sequelae or further loss of anterior pituitary function in this heavily pretreated group. Our data indicate that SMART is an effective complementary therapy for pituitary adenomas that have displayed a suboptimal response to conventional therapy including external irradiation.
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PMID: 14602770 [PubMed - indexed for MEDLINE]
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Stereotactic radiosurgery as an alternative to fractionated radiotherapy for patients with recurrent or residual nonfunctioning pituitary adenomas.
Pollock BE, Carpenter PC.
Department of Neurological Surgery, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
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OBJECTIVE: To evaluate tumor control rates and complications after stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas. METHODS: Between 1992 and 2000, 33 patients underwent radiosurgery for treatment of nonfunctioning pituitary adenomas. Thirty-two patients (97%) had undergone one or more previous tumor resections. Twenty-two patients (67%) had enlarging tumors before radiosurgery. The median tumor margin dose was 16 Gy (range, 12-20 Gy). The median follow-up period after radiosurgery was 43 months (range, 16-106 mo). RESULTS: Tumor size decreased for 16 patients, remained unchanged for 16 patients, and increased for 1 patient. The actuarial tumor growth control rates at 2 and 5 years after radiosurgery were 97%. No patient demonstrated any decline in visual function. Five of 18 patients (28%) with anterior pituitary function before radiosurgery developed new deficits, at a median of 24 months after radiosurgery. The actuarial risks of developing new anterior pituitary deficits were 18 and 41% at 2 and 5 years, respectively. No patient developed diabetes insipidus. CONCLUSION: Stereotactic radiosurgery safely provides a high tumor control rate for patients with recurrent or residual nonfunctioning pituitary adenomas. However, despite encouraging early results, more long-term information is needed to determine whether radiosurgery is associated with lower risks of new endocrine deficits and radiation-induced neoplasms, compared with fractionated radiotherapy.
PMID: 14580275 [PubMed - indexed for MEDLINE]
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A study on the radiation tolerance of the optic nerves and chiasm after stereotactic radiosurgery.
Stafford SL, Pollock BE, Leavitt JA, Foote RL, Brown PD, Link MJ, Gorman DA, Schomberg PJ.
Division of Radiation Oncology, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
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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.
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PMID: 12654424 [PubMed - indexed for MEDLINE]
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Late bilateral temporal lobe necrosis after conventional radiotherapy.
Hoshi M, Hayashi T, Kagami H, Murase I, Nakatsukasa M.
Department of Neurosurgery, Saiseikai Utsunomiya Hospital, Utsunomiya, Tochigi, Japan.
A 63-year-old woman presented with radionecrosis in the bilateral temporal lobes manifesting as dementia about 30 years after undergoing conventional radiotherapy for pituitary adenoma. Computed tomography and magnetic resonance (MR) imaging showed edema and cystic lesions in both temporal lobes. The mass in the left temporal lobe was excised. MR imaging 12 days after surgery showed reduced edema. Her dementia had improved. Radionecrosis usually occurs between several months and a few years after radiotherapy. The incidence of radionecrosis is estimated as 5%, but may be higher with longer follow-up periods. Clinical reports have suggested that larger total doses of radiation are associated with earlier onset of delayed necrosis and the fractional dose is the most significant factor causing cerebral radionecrosis. Radionecrosis can occur long after conventional radiotherapy or stereotactic radiosurgery using a linac-based system or a gamma knife unit.
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PMID: 12760503 [PubMed - indexed for MEDLINE]
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The role of gamma knife radiosurgery in the management of pituitary adenomas.
Thoren M, Hoybye C, Grenback E, Degerblad M, Rahn T, Hulting AL.
Department of Endocrinology and Diabetology, Karolinska Hospital and Institute, Stockholm, Sweden.
No treatment modality has been entirely successful in the management of pituitary adenomas. Although most patients with pituitary microadenomas can be cured by transsphenoidal surgery, the results are less satisfactory in macroadenomas in particular with suprasellar and/or parasellar extension. Additional treatment is then called for. Conventional fractional radiotherapy can often control tumour growth but is limited to 45-50 Gy with a very slow reduction in elevated pituitary hormones and a high incidence of pituitary insufficiency. Stereotactic radiosurgery allows the delivery of radiation with high precision to the target with low doses to the surrounding tissues permitting higher radiation doses. Gamma knife radiosurgery using photon energy with gamma beams from multiple cobalt 60 radiation sources is now used in many centers. It can be carried out in an outpatient setting with one single treatment. A more rapid normalization of pituitary hormone hypersecretion than with conventional radiation can be achieved as well as arrest of tumour growth and reduction of tumour mass. We therefore consider gamma knife radiosurgery as a valuable compliment to pituitary surgery. Long-term prospective studies are needed to evaluate the frequency of pituitary insufficiency in patients where the target area is determined with stereotactic magnetic resonance imaging (MRI).
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PMID: 11761436 [PubMed - indexed for MEDLINE]
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Fractionated stereotactically guided radiotherapy and radiosurgery in the treatment of functional and nonfunctional adenomas of the pituitary gland.
Milker-Zabel S, Debus J, Thilmann C, Schlegel W, Wannenmacher M.
Department of Clinical Radiology, Radiation Therapy, University of Heidelberg, Heidelberg, Germany.
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PURPOSE: We evaluated survival rates and side effects after fractionated stereotactically guided radiotherapy (SCRT) and radiosurgery in patients with pituitary adenoma. METHODS AND MATERIALS: 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. RESULTS: 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. CONCLUSION: Stereotactically guided radiotherapy is effective and safe in the treatment of pituitary adenomas to improve local control and reduce hormonal overproduction.
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PMID: 11483339 [PubMed - indexed for MEDLINE]
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Stereotactic radiosurgery for pituitary adenoma invading the cavernous sinus.
Shin M, Kurita H, Sasaki T, Tago M, Morita A, Ueki K, Kirino T.
Department of Neurosurgery, The University of Tokyo Hospital, Japan.
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OBJECT: The purpose of this study is to determine the efficacy of gamma knife radiosurgery (GKS) treatment of pituitary adenomas that have invaded the cavernous sinus. METHODS: Sixteen patients were treated with GKS: three with nonfunctional adenomas and 13 with hormone-secreting (seven growth hormone [GH] and six adrenocorticotropic hormone [ACTH]) adenomas. More than 16 Gy and 30 Gy were delivered to the tumor margin for nonfunctioning tumors and functioning tumors, respectively, keeping the dose to the optic pathways below 10 Gy. The median follow up was 3 years. Tumor growth control was achieved in all cases. In GH-producing tumors, four of six cases evaluated were endocrinologically normalized (serum GH < 10 mIU/L, somatomedin C < 450 ng/ml), and the remaining two cases also showed a steady decrease in the GH and somatomedin level. In ACTH-producing tumors, three of six cases were endocrinologically normalized (24-hour urinary-free cortisol < 90 mg/day), two were unchanged, and one showed hormonal recurrence 3 years after radiosurgery. Notably, there were no cases of permanent hypopituitarism or visual symptoms caused by radiosurgery. CONCLUSIONS: The authors data indicate that GKS can be a safe salvage therapy for invading pituitary adenomas, with effectiveness equivalent to conventional radiation therapy but with less risk of causing radiation-induced injury to the surrounding structures.
PMID: 11143249 [PubMed - indexed for MEDLINE]
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The efficacy of conventional radiation therapy in the management of pituitary adenoma.
Sasaki R, Murakami M, Okamoto Y, Kono K, Yoden E, Nakajima T, Nabeshima S, Kuroda Y.
Department of Radiology, Tenri Hospital, Nara, Japan.
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PURPOSE: To evaluate the efficacy of conventional radiotherapy for reducing tumor size and endocrine hypersecretion of pituitary adenomas. METHODS AND MATERIALS: We reviewed the records of 91 patients with pituitary adenoma, who were first treated between 1969 and 1994 and had been followed for more than 2 years (median, 8.2 years.) Of these patients, 86 had received postoperative radiotherapy, and 5 had received radiotherapy alone. The median total dose was 51 Gy. Clinical symptoms related to mass effects or endocrine hypersecretion were assessed. The efficacy of radiotherapy was evaluated before treatment and during the follow-up period (1-14 years; median, 3 years) by estimating tumor size on computed tomography or magnetic resonance imaging in 56 patients, as well as by endocrine testing in the 22 patients who had secreting adenomas. Local control rate, prognostic factors, and side effects were analyzed. RESULTS: Mass-effect symptoms improved in 72% and 79% of patients who had such symptoms due to nonsecreting adenomas and secreting adenomas, respectively. Symptoms of endocrine hypersecretion abated in 67% of patients who had such symptoms. Excessive hormone levels normalized in 74% of patients who showed endocrine hypersecretions. The greatest size reduction was seen 3 years after the completion of radiotherapy (24% CR, 62% PR, 12% NC, and 3% PD in nonsecreting adenomas, and 32% CR, 36% PR, 27% NC, and 5% PD in secreting adenomas). Three patients with secreting adenomas (2 with prolactinoma and 1 with Cushing's disease) showed a mismatch between reduction in tumor size and normalization of endocrine hypersecretion. The 10-year local control rates were 98%, 85%, 83%, and 67% for nonsecreting adenoma, growth-hormone-secreting adenoma, prolactinoma, and Cushing's disease, respectively. Univariate analyses showed that disease type and radiation field size were significant prognostic factors. Brain necrosis occurred in 1 patient who received a 60-Gy dose of irradiation. CONCLUSION: We conclude that conventional external radiotherapy with 50 Gy is safe and sufficient to control pituitary adenoma. Careful observation is required in the management of secreting adenomas because the effects on tumor size and endocrine hypersecretion may be mismatched in some secreting adenomas.
PMID: 10889388 [PubMed - indexed for MEDLINE]
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Stereotactic conformal radiotherapy for pituitary adenomas: technique and preliminary experience.
Jalali R, Brada M, Perks JR, Warrington AP, Traish D, Burchell L, McNair H, Thomas DG, Robinson S, Johnston DG.
Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Trust, London, UK.
OBJECTIVE: Stereotactic conformal radiotherapy (SCRT) is a high precision technique of fractionated radiotherapy which ensures accurate delivery of radiation with reduction in the volume of normal tissue irradiated as compared to conventional external beam radiotherapy. We describe the technique and preliminary experience of SCRT in patients with residual and recurrent pituitary adenomas. PATIENTS AND METHODS: Between February 1995 and March 1999, 22 patients (mean age: 45.3, range: 20-67 years) with residual or recurrent pituitary adenomas (13 nonfunctioning, nine secretory) were treated with SCRT. All were immobilized in a relocatable Gill-Thomas-Cosman (GTC) frame and tumour was localized on a postcontrast planning computerized tomography (CT) and MRI scan. The gross tumour volume (GTV) and the critical structures were outlined on contiguous 2-3 mm separated slices. A margin of 5 mm (12 patients) to 10 mm (10 patients) was grown around GTV in three-dimensions (3-D) to generate the planning target volume (PTV). The treatment was delivered by three (five patients) and four (17 patients) maximally separated conformal fixed fields with each field conformed to the shape of the tumour using customized lead alloy blocks (19 patients) or multileaf collimator (three patients). The patients were treated on a 6-MV linear accelerator to a dose of 45 Gy in 25 fractions (18 patients) and 50 Gy in 30 fractions (four patients). RESULTS: The technique of SCRT has become a part of the routine work of the radiotherapy department. The treatment was well tolerated with minimal acute toxicity. One patient developed transient quadrantanopia 2 weeks after treatment with full recovery after a short course of corticosteroids. One patient had a transient visual deterioration 7 months after treatment due to cystic degeneration of the tumour which fully recovered following surgical decompression. Nine of the 15 patients presenting with visual impairment had improvement after treatment and the visual status remained stable in all others. One patient with acromegaly and one with a prolactinoma achieved normalization of elevated hormonal abnormality four and 10 months after SCRT, respectively. The remaining seven patients with a secretory adenoma had declining hormone levels at last follow-up. Newly initiated hormone replacement therapy was required in five patients. At a median follow-up of 9 months (range 1-44 months), the 1 and 2 year actuarial progression free and overall survival were 100%. CONCLUSION: Stereotactic conformal radiotherapy is a high precision technique suitable for the treatment of pituitary adenomas requiring radiotherapy. Preliminary results suggest effective tumour control and low toxicity within the range expected for conventional external beam radiotherapy. While the technique is of potential benefit in reducing the volume of normal brain irradiated, the advantages in terms of sustained tumour control and reduced toxicity over conventional radiotherapy need to be demonstrated in long-term prospective studies.
PMID: 10848873 [PubMed - indexed for MEDLINE]
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Postoperative radiation therapy for pituitary adenoma.
Isobe K, Ohta M, Yasuda' S, Uno T, Hara R, Machida N, Saeki N, Yamaura A, Shigematsu N, Ito H.
Department of Radiology, Chiba University, School of Medicine, Japan.
BACKGROUND: We evaluated the efficacy of postoperative radiation therapy (RT), prognostic factors for local control probability, dose response relationship and treatment sequelae in 75 patients with pituitary adenoma. MATERIALS AND METHODS: A total dose of 48-60 Gy (median: 50 Gy) was delivered with a conventional fractionation schedule after surgery. Of 75 patients, 55 (73%) were followed for more than 5 years and 27 (36%) were followed for more than 10 years with a median of 95 months. RESULTS: Five- and 10-year local control probabilities were 87.1% and 85.0%, respectively. Univariate analysis revealed that age (p = 0.007), tumor volume smaller than 30 cm3 (p = 0.018) and the absence of prolactin secretion (p = 0.003) were significantly favorable prognostic factors for local control probability. After multivariate analysis combining these 3 factors, tumor volume smaller than 30 cm3 (p = 0.017) and age (p = 0.039) were statistically significant. Patients with prolactinoma greater than 30 cm3 showed particularly poor local control rates. No significant improvement of the local control rate was detected with increasing total irradiation doses between 48 and 60 Gy (p = 0.29). The most common side effect was hypopituitarism, and there were no severe sequelae such as optic neuropathy or brain necrosis. CONCLUSION: Except with prolactinoma, the dose of postoperative RT for pituitary adenoma should not exceed 50 Gy. Large prolactinoma, however, was very difficult to control with the irradiation doses between 50 and 60 Gy, and would be good candidates for stereotactic radiosurgery or stereotactic radiation therapy.
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PMID: 11083077 [PubMed - indexed for MEDLINE]
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Octreotide may act as a radioprotective agent in acromegaly.
Landolt AM, Haller D, Lomax N, Scheib S, Schubiger O, Siegfried J, Wellis G.
Neurosurgery Section, Klinik im Park, Zurich, Switzerland.
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Clinical experience shows that an increasing number of patients undergoing radiation treatment for recurring acromegaly or acromegaly persisting after surgery are treated with octreotide. We, therefore, performed a follow-up study of patients undergoing stereotactic radiosurgery (Gamma Knife) to determine whether this medication has an influence on the ultimate result of radiation therapy in either a positive or negative sense. It has been suggested that the combination of radiation with antisecretory drugs may increase the effectiveness of radiation. A follow-up study of 31 patients suffering from recurrent acromegaly and acromegaly persisting after surgery, and who had been treated with stereotactic radiosurgery, showed that patients treated with octreotide at the time of radiation application simultaneously reached a normal level of growth hormone and insulin-like growth factor-I only after a significantly longer interval than patients who did not receive the drug. The two groups of patients did not demonstrate significant differences in the main clinical findings (age, sex, target volume, radiation dose, baseline growth hormone, and baseline insulin-like growth factor-I).
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PMID: 10720077 [PubMed - indexed for MEDLINE]
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Comment in:
Fractionated stereotactic radiotherapy (FSRT) for optic glioma.
Debus J, Kocagoncu KO, Hoss A, Wenz F, Wannenmacher M.
Department of Clinical Radiology, University of Heidelberg, Germany.
PURPOSE: To determine efficacy and toxicity of fractionated stereotactic radiotherapy (FSRT) in patients with optic glioma. METHODS AND MATERIALS: Ten patients suffering from optic glioma were treated by FSRT between December 1990 and December 1995 at the German Cancer Research Center (DKFZ) in Heidelberg. Eight patients were treated for progressive recurrent tumor following partial tumor resection and 2 patients were treated postoperatively. Dose distributions were calculated by a 3D treatment planning system (Voxelplan, Heidelberg). Patients were treated with a noninvasive repeatable stereotactic fixation system using a manually driven midsize multileaf collimator attached to a linear accelerator. We applied a median prescribed total dose to the isocenter of 52.4 Gy with a median daily fraction size of 1.8 Gy. RESULTS: All patients treated by definitive radiotherapy remained free from local tumor progression during the follow-up period (range 12-72 months) except the 1 patient treated for recurrence after previous radiotherapy. A complete remission was achieved in 3 patients with subsequent improvement of visual acuity. None of the patients with locally controlled tumor experienced any further impairment of vision. One patient developed new ACTH deficiency. No other clinically significant late effects attributable to radiotherapy were observed. CONCLUSION: FSRT permits treatment of optic glioma with excellent tumor control and without clinically relevant morbidity. Compared to conventional techniques there is the potential of sparing the pituitary gland in chiasmatic lesions.
PMID: 10760415 [PubMed - indexed for MEDLINE]
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Radiotherapy for nonfunctional pituitary adenoma: analysis of long-term tumor control.
Breen P, Flickinger JC, Kondziolka D, Martinez AJ.
Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pennsylvania, USA.
OBJECT: The authors studied outcomes in patients who had undergone radiotherapy for nonfunctional pituitary adenoma to assess long-term tumor control and to identify factors affecting tumor control such as higher radiation doses, improved imaging, and histological characteristics of the tumor. METHODS: In this retrospective study, the authors evaluated 120 patients who received radiotherapy for nonfunctional pituitary adenomas between 1960 and 1991. The median follow-up period was 9 years (range 1 month-32 years). Radiation doses varied between 37.6 and 65.6 Gy (median 46.7 Gy). Tumors progressed in 15 of the 120 patients by 1 to 25 years after radiotherapy. Actuarial tumor control rates at 10, 20, and 30 years were 87.5+/-3.6%, 77.6+/-6.3%, and 64.7+/-12.9%, respectively. Tumor progression after radiotherapy occurred significantly more often (p=0.0397) in patients with oncocytoma than in patients with nononcocytic null cell adenoma. No other factors correlated significantly with tumor control. One case of optic and oculomotor neuropathy developed 4.5 years after a maximum dose of 50 Gy in 25 fractions. Radiation-induced neoplasms (meningioma and glioblastoma multiforme) developed at a rate of 2.7% at 10 and 30 years. CONCLUSIONS: The oncocytic variant of null cell pituitary adenoma appears less sensitive to control by radiotherapy than nononcocytic undifferentiated cell adenoma. A follow-up period extending beyond 20 years is needed adequately to assess the efficacy of radiotherapy for tumor control. Doses of 40 or 45 Gy in 20 or 25 fractions, respectively, appear optimal.
PMID: 9833818 [PubMed - indexed for MEDLINE]
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Initial clinical results of LINAC-based stereotactic radiosurgery and stereotactic radiotherapy for pituitary adenomas.
Mitsumori M, Shrieve DC, Alexander E 3rd, Kaiser UB, Richardson GE, Black PM, Loeffler JS.
The Brain Tumor Center of the Brigham and Women's Hospital, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.
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.
PMID: 9806517 [PubMed - indexed for MEDLINE]
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Multiple radiation-induced intracranial lesions after treatment for pituitary adenoma. Case report.
Alexander MJ, DeSalles AA, Tomiyasu U.
Division of Neurosurgery, University of California at Los Angeles Medical Center, 90095-6901, USA.
This 53-year-old man presented with a syncopal episode 31 years after undergoing craniotomy and external-beam radiation for a pituitary macroadenoma. A gadolinium-enhanced magnetic resonance (MR) image of the brain demonstrated a 2.5-cm enhancing mass in the right caudate region that had not been seen on previous studies. A stereotactically guided biopsy procedure was performed to obtain specimens from the mass, which were consistent with ependymoma. The MR image also revealed two additional lesions that appeared to be within the radiation fields: a right temporal meningioma and a left frontal cavernous malformation. A review of the literature found three previous reports in which ependymomas presented after radiation therapy.
Publication Types:
- Case Reports
- Review
- Review of Reported Cases
PMID: 9420081 [PubMed - indexed for MEDLINE]
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