Small-field fractionated radiotherapy with or without stereotactic boost for vestibular schwannoma

PURPOSE

To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas.

METHODS AND MATERIALS

Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SB. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).dash;p >

RESULTS

Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively.

CONCLUSIONS

Small-field fractionated radiotherapy with or without SB provides excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results.

Use of saline-filled tissue expanders to protect the small bowel from radiation

Over the past 7 years, 58 saline-filled tissues expanders (TEs) have been temporarily placed in 57 patients. The indications for TE placement were: small bowel exclusion from external-beam radiation therapy (N = 25), interstitial RT (N = 16), or both (N = 13) when there was insufficient omentum to provide adequate exclusion. Of the 57 patients, 24 had primary tumors (4 colon, 4 endometrial, and 11 rectal cancer; 3 sarcomas, 1 schwannoma; and 1 vaginal cancer). The remaining 33 patients (58%) had recurrent cancers (3 anal, 8 colon, and 16 rectal cancers; and 6 sarcomas), of whom 26 (79%) had received prior RT. Of the 58 TEs, 15 were placed superior to the iliac vessels and 43 were placed in the pelvis. Complications included post-withdrawal enterocutaneous fistulae in four patients, TE deflation in three patients, and TE extrusion in one patient. Improvements in TE design and removal techniques have reduced the incidence of these complications. When no native tissue is available for small bowel exclusion, the saline-filled TE is a safe, effective substitute.

Primary malignant schwannoma involving simultaneously the right Gasserian ganglion and the distal part of the right mandibular nerve. Case report

A 66-year-old man presented to our Department with trigeminal neuralgia of the third division of the right trigeminal nerve. He also complained of some difficulty in mastication because of a tumour mass in the right lower jaw. A brain CT scan, X-rays of the lower jaw and viscerocranium CT scan revealed a malignant schwannoma of the right Gasserian ganglion involving simultaneously the distal end of the right mandibular nerve. The patient was operated on and has undergone a course of external irradiation. Seven years later, he is living a normal life. The value of the preoperative diagnosis of this extremely rare pathology is discussed because it seems that this tumour is radiosensitive.

Benign schwannoma surrounding and obstructing the ureteropelvic junction. First case report

With a varied presentation and a difficult preoperative diagnosis, schwannoma accounts for only a small percentage of retroperitoneal tumors. Moreover, malignant schwannoma of the adrenal gland, kidney and renal pelvis has previously been described. We report the first case of benign schwannoma causing obstruction by external compression of the ureteropelvic junction. A case report of a male patient who complained of a 3-month history of dull lumbar pain on the right side is reported. Using intravenous pyelogram, sonography and computed tomography a benign tumor of the retroperitoneum was suspected. Upon exploration, the suspected diagnosis of the tumor's retroperitoneal origin was confirmed. After the histological and immunohistochemical studies the diagnosis was verified. The diagnosis, treatment and histological features of benign schwannoma are discussed. A brief review of the literature is also included.

Malignant schwannoma of the breast

Malignant schwannoma (MS) is a tumor of the Schwann or nerve sheath cells, most frequently occurring in the lower and upper extremities, trunk and head region. We report the third known case of MS of the breast, which occurred in a 27-year-old woman. The palpable tumor, about 1.2 cm in diameter, was localized in the upper inner quadrant of the right breast. After ultrasonography, mammography and fine needle aspiration cytology, the tumor was removed surgically.

Von Recklinghausen's disease associated with a primary malignant schwannoma of the breast

A case of a primary malignant schwannoma of the breast is reported. This case and the review of the literature illustrate the problems of diagnosing and treating this rare malignancy.

Fractionated radiation therapy in the treatment of stage III and IV cerebello-pontine angle neurinomas: long-term results in 24 cases

PURPOSE

To reevaluate long-term results of fractionated radiation therapy (RT) in a previously published series of cerebello-pontine angle neurinomas (CPA).

METHODS AND MATERIALS

From January 1986 to May 1992, 24 patients with Stage III and IV CPA neurinomas were treated with external fractionated RT; 7 patients had phacomatosis. One patient was irradiated on both sides and indications for radiotherapy were as follows: (a) poor general condition or old age contraindicating surgery, 14 cases; (b) hearing preservation in bilateral neurinomas after contralateral tumor removal, 5 cases; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 4 cases; (d) nonsurgical relapse, 2 cases. Most patients were irradiated with 9 MV photons. A three- to four-field technique with coned-down portals was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 51 Gy (1.80 Gy/fraction).

RESULTS

Median follow-up from RT was 60 months (7 to 84); five patients died, two with progressive disease. Two patients underwent total tumor removal after RT (one stable and one growing tumor). On the whole, tumor shrinkage was observed in 9 patients (36%), stable disease in 13 (52%), and tumor progression in 3. Hearing was maintained in 3 out of 5 hearing patients with phacomatosis.

CONCLUSION

Fractionated RT appears to be an effective and well-tolerated treatment for Stage III and IV CPA neurinomas. Hearing can be preserved for a long time.

Treatment of extensive malignant schwannoma of the mandibular nerve

This article describes a rare malignant schwannoma invading the left mandible in a 42-year-old man. The clinical presentation, inconclusive radiographic findings, and light microscopic histology are included. The appropriate surgical treatment could be determined only intraoperatively when frozen sections provided the exact tumor margins. The patient subsequently received adjuvant treatment by brachytherapy.

Intradural tumors of the cauda equina: a single institution review of clinical characteristics

A retrospective review of 106 cases of intradural tumors of the cauda equina are presented, subdivided into 5 groups according to their histological characteristics. For each group the clinical course and long-term postoperative results were analyzed: it emerged that differential diagnosis between neurinomas, meningiomas or non-tumoral lesions is not possible based on clinical findings alone and that neuroradiological diagnosis is more accurate when MRI is employed. Long-term prognosis was always favorable with the exception of the group of ependymomas. Nevertheless, early diagnosis in the latter group of tumors gives excellent results because prognosis is apparently directly correlated to the length of preoperative clinical history.

[Imitation of ovarian malignant tumor by malignant schwannoma]

A case is reported of a 78-year old female with a malignant retroperitoneal schwannoma. The diagnosis of schwannoma is often delayed because of the absence of early clinical signs. Clinical examination and computed tomography indicated an ovarian tumour. IVP demonstrated retroperitoneal involvement. Biopsy of a pelvic wall tumour at laparotomy yielded a positive histology for malignant schwannoma. Due to the extensive size and infiltration of the tumour it was deemed inoperable and the patient recommended a trial of radiotherapy. The patient had no manifestation of von Recklinghausen's disease.

Primary spinal malignant schwannoma

Malignant schwannomas are uncommon primary tumours of nerve sheath origin. They are rarely found within the spine and spinal canal, and little is known about their management in this unusual location. We describe the presentation of three patients with primary spinal malignant schwannomas and discuss the surgical management.

Fractionated stereotactically guided radiotherapy of head and neck tumors: a report on clinical use of a new system in 195 cases

Between November 1988 and December 1992, 195 patients with tumors of the head and neck (low grade gliomas, meningiomas, neurinomas, chordomas and miscellaneous) were treated with a newly developed stereotactical system for fractionated, conformal, high-precision radiotherapy. The overall preparation time, including head mask production for fixation, CT, MRI, 3-D treatment planning and stereotactical localisation could be reduced to 4-5 h per patient. The use of MR in the target definition was increased to a mean of about 60%. The medial follow-up time is 22 months. Three different patient groups were selected according to pretreatment. Patients with full high-precision radiotherapy survived in 95% of cases, patients with boost treatment in 86% and patients with preirradiated recurrent disease in 64%. Meningiomas as the largest histology group (n = 62) showed partial response in 27% and complete response in 10% of cases. Progression occurred in two patients. All patients are alive. Acute side-effects were minimal and of the order of 10%, no late complications occurred despite tumor doses ranging up to 72 Gy. High-precision radiotherapy as it is performed in Heidelberg can be regarded as an effective, reliable and tolerable system for selected tumors of the head and neck.

Fractionated radiation therapy in the treatment of stage III and IV cerebello-pontine angle neurinomas: preliminary results in 20 cases

From January 1986 to March 1989, 20 patients with stage III and IV cerebello-pontine angle neurinomas were treated with external fractionated radiation therapy; seven patients had phacomatosis. Indications for radiation therapy were as follows: (a) poor general condition or old age contraindicating surgery, 10 patients; (b) hearing preservation in bilateral neurinomas after contralateral tumor removal, 5 patients; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 4 patients; (d) non-surgical relapse, 1 patient. Most patients were irradiated with a 9 MV linear accelerator. A 3 to 4-field technique with 5 x 5 cm portals was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 5140 cGy (180 cGy/fraction). Median follow-up from radiation therapy was 30 months (7 to 46); 4 patients died, 2 with progressive disease. Two patients underwent total tumor removal after radiation therapy (1 stable and 1 growing tumor). On the whole, 14 tumors remained stable, 3 decreased in size, and 3 progressed. CT scan or NMR tumor changes consistent with partial tumor necrosis appeared in four cases. Hearing preservation was obtained in 3/5 hearing patients with phacomatosis. When surgery is not indicated or incomplete, fractionated radiation therapy appears to be an effective and well-tolerated treatment for stage III and IV neurinomas. Hearing can be preserved.

Malignant "triton" tumor in the thyroid--a case report

This report presents a very rare case of a malignant "Triton" tumor developing in the thyroid. Although malignant "Triton" tumors have often been known to develop in cases of neurofibromatosis, Von Recklinghausen's disease, this patient showed no clinical evidence of that disease. Total thyroidectomy including left standard radical neck dissection was followed by postoperative irradiation to the neck. Despite this, local and distant metastases developed four months after treatment and the recurrent foci did not respond to chemotherapy or irradiation. The clinical course of this case mimicked that of anaplastic carcinoma of the thyroid and interestingly, a minimal lesion of papillary adenocarcinoma was found to exist concurrently in the thyroid gland of this patient.

[Post pneumonectomy empyema with bronchopleural fistula--a successful management using pedicled intercostal muscle flap on an atypical mycobacteriosis following the irradiation]

A 48-year-old woman underwent a right pneumonectomy for advanced mycobacterial disease (M. avium Complex), which followed the postoperative radiotherapy against a malignant schwannoma of the right lower chest wall treated seven years ago. On the 13th postoperative day, re-suture of the bronchial stump was performed urgently because of early bronchopleural fistula development. On the heels of that, reclosure of the bronchial fistula with coverage of the stump by parietal pleural flap was performed on the forty-first post operative day. On the 110th day, however, open drainage with thoracoplasty was performed because development of insidious aspergillous empyema was detected. Since then, local instillation of amphotellisin B, with an oral administration of antifungus drug was started. After succeeding to control the mycotic infection, reclosure of the bronchofistula, covered with pedicled intercostal muscle flap were performed on the 280th postoperative day and extraperiostal air-plombage for reducing empyema cavity. Postoperative course was uneventful and the patient was discharged one year later. With respect to pathogenetic relationship between radiation pneumonitis and feasibility of infection to atypical mycobacteria, preoperative radiotherapy and concurrence of postoperative bronchofistula, and some problems on management of empyema bronchofistula were briefly discussed.

Intranodal myofibroblastoma presenting in the submandibular region: evidence of a broader clinical and histological spectrum

Intranodal myofibroblastoma is an uncommon benign mesenchymal tumour of lymph nodes which was first described in May 1989. All the cases described to date have presented exclusively in the groin, a feature which has been regarded as distinctive. Two new cases are presented herein, both of which arose in the submandibular region of middle-aged females. Both lesions showed histological features marginally different from the cases originally described, which may reflect their different anatomical location. Immunohistochemical staining revealed positivity for muscle-specific actin (HHF 35), as previously described, and ultrastructural examination in one case confirmed the presence of myofibroblasts. The data presented suggest that this distinctive lesion has a broader clinicopathological spectrum than previously realised.

Therapy of malignant schwannomas: usefulness of an integrated radiologic. Surgical therapy

A series of 30 patients with malignant schwannomas, who underwent diagnostic and therapeutic treatment at the Istituto Nazionale Tumori of Milan, is presented. Twenty-five of the patients have been followed for at least 3 years. Paravertebral regions were the most frequent sites of primary localizations of the malignant schwannomas. Computerized tomography, echography, nuclear magnetic resonance and arteriography are very important for a radio-diagnostic study. Arteriography is very useful for the diagnosis of malignancy and recurrence of such tumors. Three years after an integrated radiologic-surgical treatment, 14 of 25 patients (56%) were free of disease. Such a percentage is higher than other series of patients who prevalently underwent only surgery. Two patients who did not undergo grossly radical surgery were free of disease 3 years after radiotherapy. The dose of ionizing radiation sufficient for a good possibility of cure is about 52 Gy or higher.

Surgical treatment of intracavernous neoplasms: a four-year experience

Forty-two patients with neoplasms involving the cavernous sinus had operations between 1983 and 1987. The lesions included 25 benign tumors (e.g., meningioma, neurilemoma) and 17 malignant tumors (e.g., chondrosarcoma, adenoid cystic carcinoma). The cavernous sinus was entered by inferior, anterolateral, or medial extradural approaches or by superior or lateral intradural approaches. The intracavernous internal carotid artery was managed by dissecting tumor away from it or by occlusion and excision with or without direct vein graft reconstruction, based on the results of a preoperative balloon occlusion test. Cranial nerves III, IV, V, and VI usually were dissected from tumor, but in 3 cases of tumor invasion, the excised nerve segment was reconstructed by direct suture or with a sural nerve interposition graft. Twenty-one of the benign tumors and 8 of the malignant tumors were excised totally and the remainder subtotally. On follow-up ranging from 3 to 48 months, one subtotally excised meningioma recurred and was treated with re-excision and adjuvant radiation therapy. Two "totally" excised malignant tumors recurred outside the cavernous sinus at the margins of excision. There was no operative mortality or permanent cerebral morbidity. Postoperatively, the ocular and neurological function of most patients was similar to the preoperative status; in some, it was significantly improved. Thirteen additional patients with intracavernous neoplasms also were evaluated during the same period and followed without operation. The early follow-up information regarding these patients is provided.

[Successful combination therapy of a metastatic Triton tumor in a 5-year-old boy]

A 5-year-old boy with a metastatic Triton tumor was treated with resection, local irradiation and an additional combination chemotherapy including Ifosfamide. One year after completion of the treatment the boy is now without a tumor and in excellent condition.

Effective preoperative irradiation of highly vascular cerebellopontine angle neurinomas

Three cases of large cerebellopontine angle neurinoma with marked vascularity and tumor staining on the angiogram were treated with effective preoperative irradiation. The radiotherapy was given before the second operation in two cases and before the first operation in the other case. Irradiation doses administered with a linear accelerator were 2.34 to 3.0 Gy for 3 to 3.5 weeks, and radical operations were done 1.5 to 2 months after irradiation. After the irradiation, vertebral angiography showed moderate to marked decrease of the hypervascular capsular stain and disappearance of the early draining vein. Computed tomographic scan showed enlargement of the central necrotic area within the heterogeneously enhanced tumor, which was unchanged in size. Radical operations, which had been impossible because of uncontrollable massive bleeding, were successful without any intraoperative bleeding after radiotherapy. Postirradiation radiological findings corresponded well with those of histopathological examination, which showed decrease in cellularity and in vascularity and diffuse coagulation necrosis around the collapsed tumoral vessels as radiation effects. Preoperative irradiation of the hypervascular neurinoma was though to facilitate radical surgery by abolishing or diminishing the risk of intraoperative bleeding.

Radiation therapy for the treatment of non-eight nerve intracranial neurilemmoma

The records of 19 patients treated for intracranial neurilemmomas, other than of the eighth nerve, at the University of California, San Francisco from 1945 through 1983 were reviewed. One patient who died within 30 days following surgery was excluded from the analysis. The 5th and the 9/10/11th nerve complex were the most common sites of tumor origin. Patients were classified by the extent of surgical resection: total (90-99% resection, NTR), subtotal (less than 90% resection, STR) and biopsy. Five patients had total excision of their tumor without post-operative irradiation and none had recurred. One of the 2 patients who had STR and did not receive post-operative irradiation recurred, while 2 of the 3 patients who received post-operative irradiation following STR recurred. One of the 2 patients who had NTR and did not receive post-operative irradiation recurred, while 1 of the 3 patients who received post-operative irradiation following NTR recurred. Two patients were treated with post-operative irradiation following biopsy and one recurred. One patient was treated with planned preoperative irradiation to reduce tumor vascularity, followed by total resection. Because of the small number of patients, no firm conclusion regarding the efficacy of irradiation for non-eighth nerve intracranial neurilemmoma can be made.

Tumors of the peripheral nervous system

Most nerve tumors (benign and malignant) do not arise from the nerves per se, but from the supporting cells; tumors arising from the cells of Schwann are termed schwannoma or neurilemmoma-benign or malignant. Surgical extirpation is the most effective treatment for these tumors. Radiation therapy can offer significant palliation and prolongation of life, but no cures have been observed. Benign tumors can be treated by local surgical extirpation; malignant tumors must be radically resected, including major amputation where indicated. Neurofibromatosis (von Recklinghausen's disease) is a genetic error of metabolism with a proclivity to produce multiple neurofibromas and, in about 10% of the patients, malignant neurilemmomas. Of 100 patients with malignant neurilemmomas treated by the author, 74 were considered determinate; among them, the 10-year "cure" rate was 32%. Patients with von Recklinghausen's disease had almost as good a 10-year survival rate as those with solitary malignant schwannoma (30% vs. 39%).

Brachytherapy of recurrent tumors of the skull base and spine with iodine-125 sources

Thirteen patients with recurrent, previously irradiated tumors of the skull base or spine were reirradiated with 125I sources implanted interstitially using microsurgical or stereotactic techniques. Patients harbored difficult, end-stage recurrences of chordoma, meningioma, malignant meningioma, fibrosarcoma, invasive pituitary adenoma, and malignant schwannoma. In two other patients with malignant meningioma, the dose of external radiation was augmented by implanting 125I sources during the initial operation for excision of the lesion or at a separate surgical procedure after conventional teletherapy. Microsurgical implantation of 125I sources into basal tumors was limited by the difficulties inherent in operating in this region; it is not possible to visualize the entire tumor that requires implantation. Three of five chordomas stabilized or regressed; these patients probably benefited from the procedure. Two patients with recurrent malignant meningiomas had long term remission after interstitial brachytherapy. Interstitial 125I brachytherapy for recurrent tumors at the base of skull or adjacent to the spine can be more successful only if more aggressive surgical exposures of these regions are attempted. Implantation of sources for a "boost" dose, either microsurgically during the initial surgical resection of the lesion before conventional teletherapy or stereotactically after conventional teletherapy, may be a valuable adjunct to external irradiation for the control of potentially devastating tumors (such as chordomas and malignant meningiomas) before they recur with the severe consequences seen in the patients reported here.