Extended remission of a recurrent median nerve malignant peripheral nerve sheath tumor after multimodal treatment. Case report.

Malignant peripheral nerve sheath tumors (MPNSTs) are difficult to control despite aggressive treatment. In this report the authors describe the treatment and follow-up review of a patient with neurofibromatosis Type I who harbored a recurrent median nerve MPNST. The man underwent preoperative intraarterial and intravenous chemotherapy followed by additional surgery for gross-total removal and postoperative radiotherapy. Two courses of preoperative intraarterial cisplatin and intravenous Adriamycin produced significant tumor shrinkage. Gross-total removal of the remaining tumor without amputation of the arm was followed by fractionated radiotherapy (total minimum tumor dose 6485 cGy, maximal dose 6575 cGy). The patient is alive 9.5 years after treatment without evidence of tumor recurrence and with only focal median nerve functional deficits. A review of the patient's treatment is warranted to provide a description of a regimen that may be useful in the treatment of similar patients in the future.

Safety and efficacy of tiered limited-dose gamma knife stereotactic radiosurgery for unilateral acoustic neuroma.

Stereotactic radiosurgery has become a more widely employed modality of treatment for acoustic neuromas, but controversy still arises regarding the safety and efficacy of the technique. In general, radiation doses have been reduced over time. Since beginning treatments of acoustic neuromas with the Gamma Knife at the University of Miami/Jackson Memorial Medical Center in 1994, a dose regimen was adopted by the first author employing limited doses selected on the basis of tumor size with the anterior and medial regions of the prescription isodose surface kept just inside the gadolinium-enhanced limit of the tumor, in order to protect the facial nerve and brainstem. The records of patients treated for unilateral tumors were retrospectively reviewed. Fifty-two patients, aged 23-83 years, were treated with peripheral tumor doses of 10-14 Gy at the 45-70% isodoses. No patient developed new facial weakness or sensory loss; 3 patients had minor transient facial twitching within a few months of treatment. Of 34 patients followed more than 1 year (range 14-100 months, mean 43.4 months, median 37 months), 17 tumors reduced in size, 16 remained unchanged, and 1 increased in size. One patient, who had radiosurgery as planned postoperative adjuvant treatment after partial resection of a large tumor, developed an enlarging peritumoral arachnoid cyst that required surgical resection 79 months after radiosurgery. Patients with good pretreatment hearing retained approximately the same subjective level of hearing. Very good control of unilateral acoustic neuroma has been achieved by a limited-dose scheme that produces minimal complications, but due to the frequently indolent course of these tumors, continued long-term monitoring will be necessary.