Stereotactic Radiosurgery as a Salvage Treatment for Recurrent Skull Base Adenoid Cystic Carcinoma

Abstract

Twelve patients (15 lesions) with recurrent skull base adenoid cystic carcinoma (ACC) were treated by Gamma Knife stereotactic radiosurgery (SRS). The tumor volume ranged from 2 to 103 ml (median 15 ml). Treatment was prescribed at the 40–60% isodose line and ranged from 10 to 18 Gy (median: 13.0 Gy). The median follow-up period was 18 months (range 3–55). Six patients were alive and 6 dead at the end of the follow-up period. Only 1 patient died from local tumor recurrence. Ten among 15 tumors treated by SRS decreased in size until the end of the follow-up period or the patients’ death. Three remained unchanged in size. Two tumors initially regressed but then increased in size. In selected patients with recurrent skull base ACC, SRS can be considered as a salvage treatment with good local control.

Stereotactic Radiation for Palliation of Skull Base Recurrences of Salivary Gland Carcinomas: Implications for Tumor Targeting

“…In addition to marginal failures, we also observed two cases of "skip" lesions along the meninges, with one of these patients having leptomeningeal involvement in the spinal cord (►Table 2, patients 1 and 2). These skip lesions contributed to mortality in at least one of our patients and may correlate with the deaths from "distant intracranial disease" reported by Mori et al 9 Since infield failures were approximately one-third of all local failures in this study, dose de-escalation is not a viable option for these patients.…”

“…8,9 From a patient comfort viewpoint, which is of increased importance in a palliative setting, a hypofractionated SRT approach may be most suitable as it avoids both placement of a headframe and repeated trips to the treatment facility. We observed a 65% radiographic response rate (complete or partial response) compared with 62% reported by Lee et al 8 and 80% reported in the adenoid cystic carcinoma series by Mori et al 9 In our study, there were patients within all the three treatment group types who eventually failed locally, and we did not have enough statistical power to discriminate between the three fractionation schedules. One area of concern from our results is the large rate of marginal failures along meningeal surfaces after stereotactic radiation, a finding that has not been previously reported.…”

Long-term follow-up of stereotactic radiosurgery for head and neck malignancies

“…Similarly, a study from Japan examining 12 patients with recurrent adenoid cystic carcinoma at the skull base reported crude local control rates of 10 of 12 patients with a median overall survival of 18 months. However, there was no discussion of late effects …”

“…However, there was no discussion of late effects. 4 Stereotactic radiosurgery has been studied extensively in the primary treatment of nasopharyngeal cancers. Multiple retrospective studies have demonstrated improved local control ranging from 93% to 100% at 3 years for stereotactic radiosurgery boost after radical EBRT (series had doses ranging from 64.8-66 Gy) with concurrent chemotherapy.…”

Stereotactic Radiosurgery and Stereotactic Radiotherapy for Malignant Skull Base Tumors

“…We have hitherto reported the results of SRS/SRT for various malignant extra-axial skull base tumors [3][4][5][6][7][8][9][10][11][12][13]. They were summarized with additional data on SRS/SRT of skull-base involvement of head and neck carcinomas.…”