Lateral skull base malignancies

Lateral Skull Base Lesions: Our Experience of 15 Years

To analyse and report various aspects of lateral skull base surgery by describing the incidence and demographic variables, diagnostic and management challenges, surgical choices along with complications and their management and the long term morbidity and survival outcomes in our experience of 15 years. Retrospective review of complete records of all cases operated for lateral skull base tumors at a tertiary care teaching institution in India between timespan of 15 years from 2003 to 2018 was undertaken. 53 cases were selected and analysed. Those having follow up of less than 6 months were excluded. Outcomes were assessed in terms of incidence of types of tumors, benign or malignant, age and sex variation of the patients, staging status at presentation, status of facial and other lower cranial nerves pre-operatively, surgical techniques with complications if any, recurrences and survival. Of 35 benign tumors, tympanojugular paragangliomas were most common. Average age for these was 53 years with 19 females and 14 males. All were non-functional. Tinnitus and hearing loss were most common presentations. Class B2 and C1 tumors were most commonly encountered and the ITF A approach was most commonly used. Hearing loss and Facial palsy were commonest complication post-operatively. There were 2 recurrences. 18 malignancies were observed. Most were stage IV at presentation. Otorrhea and otalgia were most common presenting symptoms followed by hearing loss. 5 year survival was 55%. Successful treatment of lateral skull base lesions requires a multimodality therapy with team approach. Surgical resection is the primary management choice with variable approaches. ICA status related to the tumor is the most important consideration. Malignancies require more aggressive treatment for obtaining clear margins along with pre/post-op chemoradiation. Good results with acceptable complications can be obtained even with advanced tumors.

Stereotactic ablative radiosurgery for locally advanced or recurrent skull base malignancies with prior external beam radiation therapy

PURPOSE

Stereotactic ablative radiotherapy (SABR) is an attractive modality to treat malignancies invading the skull base as it can deliver a highly conformal dose with minimal toxicity. However, variation exists in the prescribed dose and fractionation. The purpose of our study is to examine the local control, survival, and toxicities in SABR for the treatment of previously irradiated malignant skull base tumors.

MATERIALS AND METHODS

A total of 31 patients and 40 locally advanced or recurrent head and neck malignancies involving the skull base treated with a common SABR regimen, which delivers a radiation dose of 44 Gy in 5 fractions from January 1st, 2004 to December 31st, 2013, were retrospectively reviewed. The local control rate (LC), progression-free survival rate, overall survival (OS) rate, and toxicities were reported.

RESULTS

The median follow-up time of all patients was 11.4 months (range: 0.6-67.2 months). The median tumor volume was 27 cm(3) (range: 2.4-205 cm(3)). All patients received prior external beam radiation therapy with a median radiation dose of 64 Gy (range: 24-75.6 Gy) delivered in 12-42 fractions. Twenty patients had surgeries prior to SABR. Nineteen patients received chemotherapy. Specifically, eight patients received concurrent cetuximab (Erbitux™) with SABR. The median time-to-progression (TTP) was 3.3 months (range: 0-16.9 months). For the 29 patients (93.5%) who died, the median time from the end of first SABR to death was 10.3 months (range: 0.5-41.4 months). The estimated 1-year OS rate was 35%. The estimated 2-year OS rate was 12%. Treatment was well-tolerated without grade 4 or 5 treatment-related toxicities.

CONCLUSION

Stereotactic ablative radiotherapy has been shown to achieve low toxicities in locally advanced or recurrent, previously irradiated head and neck malignancies invading the skull base.

Conjugated polymer dots for ultra-stable full-color fluorescence patterning

Stable full-color fluorescence patterning are achieved by multicolor polymer-dot inks. The fluorescent patterns show extraordinary stability upon various treatments, offering a superior combination of bright fluorescence, excellent photostability, chemical resistance, and eco-friendship.

Temporal bone malignancies

Primary temporal bone tumors are rare. Suspicious lesions of the ear canal should be biopsied for diagnosis. Surgical resection to achieve negative margins is the mainstay of treatment. Small tumors can be treated with lateral temporal bone resection. Parotidectomy and neck dissection are added for disease extension and proper staging. Higher staged tumors generally require subtotal temporal bone resection or total temporal bone resection. Adjuvant postoperative radiotherapy has shown improved survival for some patients. Chemotherapy has an emerging role for advanced stage disease. Evaluation and management by a multidisciplinary team are the best approach for patients with these tumors.

The oncology of otology

OBJECTIVES/HYPOTHESIS

To describe the population of patients with malignancy affecting the ear canal and temporal bone.

STUDY DESIGN

Retrospective review.

METHODS

The charts of 157 patients with temporal bone cancer were reviewed for clinical outcomes.

RESULTS

Between 1999 and 2009, 157 patients underwent temporal bone surgery for cancer involving the ear canal (n = 25), external ear with ear canal involvement (n = 26), periauricular skin (n = 40), parotid gland (n = 40), temporal bone (n = 13), and lateral skull base (n = 13). All surgeries involved one or more otologic approaches: mastoidectomy (28.0%), lateral temporal bone resection (TBR) (59.2%), subtotal TBR (2.5%), total TBR (3.2%), transtemporal approach (TTA) to the jugular foramen (8.2%), TTA to the middle fossa (5.7%), and TTA to the infratemporal fossa (3.2%). Cancers of the cartilaginous ear canal were managed with wide local excision of canal skin and cartilage in nine patients (5.7%). A combination of approaches was performed in 32 patients (20.4%). The 5-year overall survival rate was 58.0%. Patients whose disease was limited to the ear canal had significantly better overall survival than did patients who had skull base primaries (P = .02989), periauricular skin cancer (P = .00138), or temporal bone tumors (P = .02598). Patients with parotid tumors also had better overall survival than did those with periauricular skin tumors (P = .02357).

CONCLUSIONS

Otologic surgery plays an important role in managing cancers that involve the ear canal, temporal bone, or lateral skull base. The specialty of otologic oncology is emerging as a defined area of practice.

Parotid and temporal bone resection for skull base malignancies: outcome

We reviewed the outcome of and determined prognostic factors for patients undergoing combined lateral skull base resection for advanced lateral skull base malignancies. We performed a retrospective, single-institution case series in an academic tertiary care hospital. Seventy-nine patients with combined temporal bone resection and parotidectomy for advanced lateral skull base malignancy were included. Main outcome measures were overall survival and disease-free survival. The mean follow-up time was 18.3 months, with an overall survival of 64.5 months and disease-free survival of 42.6 months. Disease-free survival was 36.2 months for skin tumors, 42.7 months for salivary glands tumors, and 8.5 months for tumors of mesenchymal origin. Log-rank tests for prognostic indicators demonstrated that temporal bone erosion on computed tomography (CT) scan (p = 0.009) and histology (p = 0.045) were statistically significant predictors of poor outcome. Subtotal resection of the facial nerve and positive lymph nodes were associated with poor outcome in tumors arising from skin. Advanced malignancies of the lateral skull base are best managed using a combined lateral temporal bone resection and parotidectomy, with a 50% disease-specific survival of 32 months. Malignant mesenchymal tumors as well as presence of temporal bone erosion on preoperative CT scan are associated with poor prognosis.

Outcomes following temporal bone resection

OBJECTIVES/HYPOTHESIS

To evaluate survival outcomes in patients undergoing temporal bone resection.

STUDY DESIGN

Retrospective review.

METHODS

From 2002 to 2009 a total of 65 patients underwent temporal bone resection for epithelial (n = 47) and salivary (n = 18) skull base malignancies. Tumor characteristics, defect reconstruction, and postoperative course were assessed. Outcomes measured included disease-free survival and cancer recurrence.

RESULTS

The majority of patients presented with recurrent (65%), advanced stage (94%), cutaneous (72%), and squamous cell carcinoma (57%). Thirty-nine patients had perineural invasion (60%) and required facial nerve resection; 16 (25%) had intracranial extension. Local (n = 6), regional (n = 2), or free flap (n = 46) reconstruction was required in 80% of patients. Free flap donor sites included the anterolateral thigh (31%), radial forearm free flap (19%), rectus (35%), and latissimus (4%). The average hospital stay was 4.9 days (range, 1-28 days). The overall complication rate was 15% and included stroke (n = 4), cerebrospinal fluid leak (n = 2), hematoma formation (n = 1), infection (n = 1), flap loss (n = 1), and postoperative myocardial infarction (n = 1). A total of 22 patients (34%) developed cancer recurrence during the follow-up period (median, 10 months), 17 (77%) of whom presented with recurrent disease at the time of temporal bone resection. Two-year disease-free survival was 68%, and 5-year disease-free survival was 50%.

CONCLUSIONS

Aggressive surgical resection and reconstruction is recommended for primary and recurrent skull base malignancies with acceptable morbidity and improved disease-free survival.

Management of lateral skull base tumours

Lateral skull base tumours arise from overlying skin, parotid, temporal bone, mandible, muscle or the vasculature and they spread in midst of important neurovascular structures. This makes their diagnosis and management challenging. These tumours are primarily dealt with surgery which can be extensive, functionally disabling and cosmetically disfiguring. Tumour biology, involvement of the internal carotid artery and cranial nerves play key roles in management of these tumours. This review will focus on management of common tumours afflicting the lateral skull base.

Treatment of malignant tumors of the skull base with multi-session radiosurgery

OBJECTIVE

Malignant tumors that involve the skull base pose significant challenges to the clinician because of the proximity of critical neurovascular structures and limited effectiveness of surgical resection without major morbidity. The purpose of this study was to evaluate the efficacy and safety of multi-session radiosurgery in patients with malignancies of the skull base.

METHODS

Clinical and radiographic data for 37 patients treated with image-guided, multi-session radiosurgery between January 2002 and December 2007 were reviewed retrospectively. Lesions were classified according to involvement with the bones of the base of the skull and proximity to the cranial nerves.

RESULTS

Our cohort consisted of 37 patients. Six patients with follow-up periods less than four weeks were eliminated from statistical consideration, thus leaving the data from 31 patients to be analyzed. The median follow-up was 37 weeks. Ten patients (32%) were alive at the end of the follow-up period. At last follow-up, or the time of death from systemic disease, tumor regression or stable local disease was observed in 23 lesions, representing an overall tumor control rate of 74%. For the remainder of lesions, the median time to progression was 24 weeks. The median progression-free survival was 230 weeks. The median overall survival was 39 weeks. In the absence of tumor progression, there were no cranial nerve, brainstem or vascular complications referable specifically to CyberKnife radiosurgery.

CONCLUSION

Our experience suggests that multi-session radiosurgery for the treatment of malignant skull base tumors is comparable to other radiosurgical techniques in progression-free survival, local tumor control, and adverse effects.

Long-term outcome following radical temporal bone resection for lateral skull base malignancies: a neurosurgical perspective

OBJECT

Primary temporal bone malignancy is a rare form of tumor for which the therapeutic strategy remains controversial. In this study, the authors reviewed their experience with radical temporal bone resection (TBR) of such lesions and analyzed the long-term results to provide treatment recommendations.

METHODS

Between 1994 and 2006, 17 patients (10 men and 7 women) underwent total or subtotal TBR for primary temporal bone malignancies. Tumors were graded according to the University of Pittsburgh system. The effects of surgical margins and tumor extensions on patient survival were analyzed using the Kaplan-Meier method.

RESULTS

All tumors, except 1, were graded T4 (most advanced). Subtotal TBR was performed in 14 patients, and total TBR was performed in 3. The surgical margin was tumor negative in 10 patients and tumor positive in 7. For large tumors extending into the infratemporal fossa or encroaching on the jugular foramen, orbitozygomatic (3 patients) and posterior transjugular (4 patients) approaches were combined with the standard approach, and en bloc resection with a negative margin was achieved in all cases but 1. The follow-up time ranged from 0.3-11.6 years (mean 3.3 years). The 5-year recurrence-free and disease-specific survival rates were 67.5 and 60.1%, respectively. When a negative surgical margin was achieved, the survival rates improved to 100 and 89%, respectively.

CONCLUSIONS

The neurosurgical skull base technique could improve the probability of en bloc resection with a tumor-free margin for extensive temporal bone malignancies, which would cure a subset of patients. The active participation of neurosurgeons would improve patient care in this field.