Jason Sheehan

Summary

Affiliation: University of Virginia
Country: USA

Publications

  1. doi request reprint Identification of knowledge gaps in neurosurgery using a validated self-assessment examination: differences between general and spinal neurosurgeons
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA Electronic address
    World Neurosurg 80:e27-31. 2013
  2. doi request reprint External beam radiation therapy and stereotactic radiosurgery for pituitary adenomas
    Jason P Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, VA 22908, USA
    Neurosurg Clin N Am 23:571-86. 2012
  3. doi request reprint Gamma Knife surgery for the management of glomus tumors: a multicenter study
    Jason P Sheehan
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 117:246-54. 2012
  4. pmc Clinical practice of image-guided spine radiosurgery--results from an international research consortium
    Matthias Guckenberger
    Department of Radiation Oncology, University Hospital Wuerzburg, Wuerzburg, Germany
    Radiat Oncol 6:172. 2011
  5. doi request reprint Radiosurgery for intracranial hemangiopericytomas: outcomes after initial and repeat Gamma Knife surgery
    Claire Olson
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 112:133-9. 2010
  6. doi request reprint Gamma knife radiosurgery for resectable brain metastasis
    Zhiyuan Xu
    Department of Neurological Surgery, University of Virginia, Charlottesville, VA
    World Neurosurg 80:351-8. 2013
  7. doi request reprint Trans-sodium crocetinate enhancing survival and glioma response on magnetic resonance imaging to radiation and temozolomide
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA
    J Neurosurg 113:234-9. 2010
  8. doi request reprint Impact of triple-negative phenotype on prognosis of patients with breast cancer brain metastases
    Zhiyuan Xu
    Department of Neurosurgery, University of Virginia, Charlottesville, VA 22908, USA
    Int J Radiat Oncol Biol Phys 84:612-8. 2012
  9. ncbi request reprint Radiosurgery for patients with recurrent small cell lung carcinoma metastatic to the brain: outcomes and prognostic factors
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia 22908, USA
    J Neurosurg 102:247-54. 2005
  10. ncbi request reprint Repeat γ knife surgery for incompletely obliterated cerebral arteriovenous malformations
    Chun Po Yen
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health Sciences System, Charlottesville, Virginia 22908, USA
    Neurosurgery 67:55-64; discussion 64. 2010

Collaborators

Detail Information

Publications52

  1. doi request reprint Identification of knowledge gaps in neurosurgery using a validated self-assessment examination: differences between general and spinal neurosurgeons
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA Electronic address
    World Neurosurg 80:e27-31. 2013
    ..This study examines the gaps in knowledge of spinal neurosurgeons and general neurosurgeons taking SANS...
  2. doi request reprint External beam radiation therapy and stereotactic radiosurgery for pituitary adenomas
    Jason P Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, VA 22908, USA
    Neurosurg Clin N Am 23:571-86. 2012
    ..Specific techniques are discussed. In addition, indications and outcomes, including complications, are detailed...
  3. doi request reprint Gamma Knife surgery for the management of glomus tumors: a multicenter study
    Jason P Sheehan
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 117:246-54. 2012
    ..Stereotactic radiosurgery has gained an increasing role in the management of glomus tumors. The authors of this study examine the outcomes after radiosurgery in a large, multicenter patient population...
  4. pmc Clinical practice of image-guided spine radiosurgery--results from an international research consortium
    Matthias Guckenberger
    Department of Radiation Oncology, University Hospital Wuerzburg, Wuerzburg, Germany
    Radiat Oncol 6:172. 2011
    ..However, the methods of spine radiosurgery have not been standardized. This article describes the results of a survey about the methods of spine radiosurgery at five international institutions...
  5. doi request reprint Radiosurgery for intracranial hemangiopericytomas: outcomes after initial and repeat Gamma Knife surgery
    Claire Olson
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 112:133-9. 2010
    ..The purpose of this study was to evaluate the role of Gamma Knife surgery (GKS) in the management of intracranial hemangiopericytomas...
  6. doi request reprint Gamma knife radiosurgery for resectable brain metastasis
    Zhiyuan Xu
    Department of Neurological Surgery, University of Virginia, Charlottesville, VA
    World Neurosurg 80:351-8. 2013
    ..We evaluate the use of gamma knife radiosurgery (GKS) for resectable non-small cell lung cancer (NSCLC) brain metastases located <3 cm away from the outer cortical surface...
  7. doi request reprint Trans-sodium crocetinate enhancing survival and glioma response on magnetic resonance imaging to radiation and temozolomide
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA
    J Neurosurg 113:234-9. 2010
    ..The authors examined whether this improvement in intratumor oxygenation translates to a therapeutic advantage when delivering standard adjuvant treatment to GBs...
  8. doi request reprint Impact of triple-negative phenotype on prognosis of patients with breast cancer brain metastases
    Zhiyuan Xu
    Department of Neurosurgery, University of Virginia, Charlottesville, VA 22908, USA
    Int J Radiat Oncol Biol Phys 84:612-8. 2012
    ..To elucidate survival times and identify potential prognostic factors in patients with triple-negative (TN) phenotype who harbored brain metastases arising from breast cancer and who underwent stereotactic radiosurgery (SRS)...
  9. ncbi request reprint Radiosurgery for patients with recurrent small cell lung carcinoma metastatic to the brain: outcomes and prognostic factors
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia 22908, USA
    J Neurosurg 102:247-54. 2005
    ....
  10. ncbi request reprint Repeat γ knife surgery for incompletely obliterated cerebral arteriovenous malformations
    Chun Po Yen
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health Sciences System, Charlottesville, Virginia 22908, USA
    Neurosurgery 67:55-64; discussion 64. 2010
    ..The causes of failure after an initial Gamma procedure were studied, along with imaging and clinical outcomes, in a series of 140 patients with cerebral arteriovenous malformations (AVMs) treated with repeat Gamma Knife surgery (GKS)...
  11. doi request reprint Gamma knife surgery of pediatric gliomas
    David Weintraub
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA 22908, USA
    J Neurosurg Pediatr 10:471-7. 2012
    ..Gamma Knife surgery may be beneficial in the treatment of these tumors...
  12. doi request reprint Stereotactic radiosurgery for chordoma: a report from the North American Gamma Knife Consortium
    Hideyuki Kano
    Department of Neurological Surgery, and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
    Neurosurgery 68:379-89. 2011
    ..Although considered slow-growing, low-grade malignancies, chordomas are locally aggressive and destructive tumors with high recurrence rates...
  13. ncbi request reprint Gamma knife surgery for brain metastases from lung cancer
    Hung Chuan Pan
    Lars Leksell Center of Gamma Surgery, Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia 22908, USA
    J Neurosurg 102:128-33. 2005
    ..The authors conducted a study to evaluate the safety and efficacy of gamma knife surgery (GKS) for the treatment of brain metastases from lung cancer...
  14. ncbi request reprint Gamma knife surgery for focal brainstem gliomas
    Chun Po Yen
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 106:8-17. 2007
    ..In the present study the authors assess clinical and imaging results in 20 patients who harbored focal brainstem gliomas treated with GKS between 1990 and 2001...
  15. ncbi request reprint Gamma knife radiosurgery for medically and surgically refractory prolactinomas
    Nader Pouratian
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA
    Neurosurgery 59:255-66; discussion 255-66. 2006
    ..Patients who are refractory to medical and/or surgical therapy may be treated with GKRS. We characterize the efficacy of GKRS for medically and surgically refractory prolactinomas...
  16. doi request reprint Minimally invasive treatment of intracerebral hemorrhage with magnetic resonance-guided focused ultrasound
    Stephen J Monteith
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 118:1035-45. 2013
    ....
  17. doi request reprint Interfraction and intrafraction performance of the Gamma Knife Extend system for patient positioning and immobilization
    David Schlesinger
    Department of Radiation Oncology, University of Virginia Health System, Charlottesville, Virginia 22908 0742, USA
    J Neurosurg 117:217-24. 2012
    ....
  18. ncbi request reprint Gamma knife surgery for neurocytoma
    Chun Po Yen
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 107:7-12. 2007
    ..In this study, the authors present their experience using Gamma Knife surgery (GKS) in the treatment of these tumors...
  19. ncbi request reprint Outcomes of Gamma Knife surgery for craniopharyngiomas
    Zhiyuan Xu
    Department of Neurological Surgery, Lars Leksell Gamma Knife Center, University of Virginia Health System, Charlottesville, VA 22908, USA
    J Neurooncol 104:305-13. 2011
    ..5 Gy related to a longer in-field PFS. GKS may offer reasonable control of recurrent or residual craniopharyngiomas. There was a consistent correlation between absence of VFD at the time of GKS and in-field PFS...
  20. doi request reprint The role of Gamma Knife surgery in the treatment of skull base chordomas
    Kasandra Dassoulas
    Department of Neurological Surgery, University of Virginia, Health Sciences Center, Box 800 212, Charlottesville, VA 22908, USA
    J Neurooncol 94:243-8. 2009
    ..GKS affords a reasonable rate of local tumor control in patients with recurrent or residual chordomas. However further long-term follow-up would be necessary to exclude the possibility of late recurrences...
  21. ncbi request reprint Stereotactic radiosurgery for acromegaly
    Cheng Chia Lee
    Departments of Neurological Surgery C C L, M L V, Z X, C P Y, D S, B D, J S, Radiation Oncology J S, and Medicine M L V, University of Virginia, Charlottesville, Virginia 22908 and Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital C C L, and School of Medicine, National Yang Ming University C C L, Taipei, Taiwan 11217, Republic of China
    J Clin Endocrinol Metab 99:1273-81. 2014
    ..The role of stereotactic radiosurgery (SRS) in acromegaly is being assessed...
  22. ncbi request reprint Identification of knowledge gaps in neurosurgery through analysis of responses to the Self-Assessment in Neurological Surgery (SANS)
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA Electronic address
    World Neurosurg 81:229-33. 2014
    ..To examine the gaps in knowledge of neurosurgeons responding to the Self-Assessment in Neurological Surgery (SANS)...
  23. doi request reprint Gamma Knife surgery for the treatment of 5 to 15 metastases to the brain: clinical article
    David J Salvetti
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia 22908, USA
    J Neurosurg 118:1250-7. 2013
    ..The number of studies detailing the use of GKS for 5 or more brain metastases, however, remains minimal. The aim of the current retrospective study was to elucidate the utility of GKS in patients with 5-15 brain metastases...
  24. doi request reprint Long-term outcomes after Gamma Knife radiosurgery for patients with a nonfunctioning pituitary adenoma
    Rupa Gopalan
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA
    Neurosurgery 69:284-93. 2011
    ..Nonfunctioning pituitary adenomas recur after microsurgery. Gamma Knife radiosurgery (GKRS) has been used to treat recurrent adenomas...
  25. ncbi request reprint Gamma knife surgery for metastatic brainstem tumors
    Chun Po Yen
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 105:213-9. 2006
    ..The authors review imaging and clinical outcomes in patients with metastatic brainstem tumors treated using Gamma Knife surgery (GKS)...
  26. ncbi request reprint Gamma knife surgery for trigeminal schwannoma
    Jason Sheehan
    Lars Leksell Gamma Knife Center, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 106:839-45. 2007
    ..In this article the authors evaluate the radiological and clinical outcomes in a series of patients in whom Gamma Knife surgery (GKS) was used to treat trigeminal schwannomas...
  27. ncbi request reprint Subtotal obliteration of cerebral arteriovenous malformations after gamma knife surgery
    Chun Po Yen
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 106:361-9. 2007
    ..The aim of this study was to determine the risk of hemorrhage for patients with subtotal obliteration of AVMs...
  28. ncbi request reprint Pathological findings following radiosurgery of pituitary adenomas
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, VA 22908, USA
    Prog Neurol Surg 20:172-9. 2007
    ..Further study must be performed to determine the histological changes that accompany the frequently beneficial effects of radiosurgery in recurrent or residual pituitary adenomas...
  29. ncbi request reprint Gamma knife surgery for glomus jugulare tumors: an intermediate report on efficacy and safety
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia 22908, USA
    J Neurosurg 102:241-6. 2005
    ..Despite these therapies, tumor control can be difficult to achieve particularly without undo risk of patient morbidity or mortality. The authors examine the safety and efficacy of gamma knife surgery (GKS) for glomus jugulare tumors...
  30. ncbi request reprint Effect of trans sodium crocetinate on brain tumor oxygenation. Laboratory investigation
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA
    J Neurosurg 111:226-9. 2009
    ..Trans sodium crocetinate (TSC) has been shown to be a radiosensitizer. The goal of this research was to elucidate the underlying mechanism of TSC's radiosensitizing effect...
  31. ncbi request reprint Gamma knife surgery for trigeminal neuralgia: outcomes and prognostic factors
    Jason Sheehan
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 102:434-41. 2005
    ..Gamma knife surgery (GKS) has been used as an alternative, minimally invasive treatment in TN. In the present study, the authors evaluated the long-term results of GKS in the treatment of TN...
  32. ncbi request reprint Shielding strategies for Gamma Knife surgery of pituitary adenomas
    David Schlesinger
    Lars Leksell Gamma Knife Center, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 105:241-8. 2006
    ..The relative performances of two plugging strategies commonly used for pituitary adenoma dose plans were evaluated in terms of factors that influence dose plan quality...
  33. doi request reprint Temozolomide-induced inhibition of pituitary adenoma cells
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA
    J Neurosurg 114:354-8. 2011
    ..The effectiveness of temozolomide in terms of growth suppression and decreased hormonal production is evaluated...
  34. ncbi request reprint Gamma surgery in the treatment of nonsecretory pituitary macroadenoma
    Vincenzo Mingione
    Department of Neurological Surgery, Lars Leksell Center for Gamma Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 104:876-83. 2006
    ..The authors report on a retrospective analysis of the imaging and clinical outcomes following gamma surgery in 100 patients with nonsecretory pituitary macroadenoma...
  35. ncbi request reprint The expanding role of neurosurgeons in the management of brain metastases
    Jason Sheehan
    Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
    Surg Neurol 62:32-40; discussion 40-1. 2004
    ..Median survival after surgery and radiation typically ranged from 5 to 11 months...
  36. ncbi request reprint Development of a posterior fossa cavernous malformation associated with bilateral venous anomalies: case report
    Jason Sheehan
    Department of Neurological Surgery, Center for Image Guided Surgery, University of Pittsburgh Medical Center, Presbyterian Hospital, USA
    J Neuroimaging 12:371-3. 2002
    ..Furthermore, the detailed MRI permitted radiosurgical treatment of these CMs. The occurrence of de novo CMs adjacent to VAs on future imaging studies in other patients may help confirm the etiology of at least a subset of CMs...
  37. doi request reprint Stereotactic radiosurgery of brain metastasis from melanoma
    Edward M Marchan
    Department of Neurosurgery, University of Virginia, Charlottesville, VA 22908, USA
    Prog Neurol Surg 25:176-89. 2012
    ..However, it appears likely that radiosurgery will play an expanded role in the overall management of these patients...
  38. ncbi request reprint Radiosurgery for dural arteriovenous fistulas
    Christopher J Koebbe
    Department of Neurological Surgery, Center for Image Guided Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
    Surg Neurol 64:392-8; discussion 398-9. 2005
    ..Recent studies have demonstrated promising results when radiosurgery is used for DAVFs. We retrospectively analyzed our patients with DAVFs who received stereotactic radiosurgery with or without embolization...
  39. doi request reprint Recurrent astroblastoma treated with gamma knife radiosurgery
    David Weintraub
    Department of Neurological Surgery, University of Virginia, PO Box 800212, Charlottesville, VA 22908, USA
    J Neurooncol 103:751-4. 2011
    ..While surgical resection of low grade astroblastomas can be curative, Gamma Knife radiosurgery may be beneficial in cases where gross total resection is not feasible...
  40. doi request reprint Helical tomotherapy simultaneous integrated boost provides a dosimetric advantage in the treatment of primary intracranial tumors
    Joseph M Baisden
    Department of Radiation Oncology, University of Virginia, Charlottesville, VA 22908, USA
    Neurol Res 33:820-4. 2011
    ....
  41. ncbi request reprint Gamma knife surgery-induced meningioma. Report of two cases and review of the literature
    Jason Sheehan
    Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 105:325-9. 2006
    ..These cases and the few others detailed in the literature emphasize the need for long-term neurosurgical follow-up review in patients after radiosurgery...
  42. ncbi request reprint Assessment of imaging studies used with radiosurgery: a volumetric algorithm and an estimation of its error. Technical note
    John W Snell
    Lars Leksell Gamma Knife Center, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 104:157-62. 2006
    ..Through the application of this volumetric methodology and a greater understanding of the error associated with it, neurosurgeons can better perform radiosurgery and assess its outcome...
  43. doi request reprint Optimal imaging of in vitro clot sonothrombolysis by MR-guided focused ultrasound
    Christopher Durst
    Department of Radiology, University of Virginia, Charlottesville, VA, USA
    J Neuroimaging 23:187-91. 2013
    ..Therefore, the purpose of this study was to evaluate the optimum imaging sequence for sonothrombolysis...
  44. doi request reprint Use of trans sodium crocetinate for sensitizing glioblastoma multiforme to radiation: laboratory investigation
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, VA 22908, USA
    J Neurosurg 108:972-8. 2008
    ..Trans sodium crocetinate (TSC) has been shown to increase oxygen diffusion in the brain and elevate the partial brain oxygen level. The goal of this study was to evaluate the radiosensitizing effects of TSC on GBM tumors...
  45. doi request reprint Glossopharyngeal neuralgia treated with gamma knife radiosurgery
    Brian J Williams
    Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia, USA
    World Neurosurg 73:413-7. 2010
    ..We report a case of glosspharyngeal neuralgia treated effectively with gamma knife radiosurgery, review the literature, and discuss the rationale supporting dose and target selection...
  46. doi request reprint Gamma Knife surgery for the treatment of patients with asymptomatic meningiomas
    David J Salvetti
    Department of Neurological Surgery, University of Virginia, Charlottesville, VA 22908, USA
    J Neurosurg 119:487-93. 2013
    ..However, little research has been performed to determine whether Gamma Knife surgery (GKS) can alter the rate of symptom development in such patients...
  47. doi request reprint Potential intracranial applications of magnetic resonance-guided focused ultrasound surgery
    Stephen Monteith
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    J Neurosurg 118:215-21. 2013
    ..In this review, the authors examine the current intracranial applications under investigation and explore other potential uses for MRgFUS in the intracranial space based on their initial cadaveric studies...
  48. doi request reprint Helical tomotherapy-based STAT stereotactic body radiation therapy: Dosimetric evaluation for a real-time SBRT treatment planning and delivery program
    Neal Dunlap
    Department of Radiation Oncology, University of Virginia, Charlottesville, 22908, USA
    Med Dosim 35:312-9. 2010
    ....
  49. ncbi request reprint Late cyst formation following gamma knife surgery of arteriovenous malformations
    Hung Chuan Pan
    Lars Leksell Center of Gamma Knife Surgery, Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia 22908, USA
    J Neurosurg 102:124-7. 2005
    ..One hundred five cases were lost to follow-up study. The Cox regression method was used to analyze the factors related to cyst formation...
  50. ncbi request reprint Potentiation of neurite outgrowth and reduction of apoptosis by immunosuppressive agents: implications for neuronal injury and transplantation
    Jason Sheehan
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA
    Neurosurg Focus 20:E9. 2006
    ..In this study, the authors evaluate the effect of immunosuppressive medications on neurite outgrowth and cell survival after a pharmacologically induced injury...
  51. ncbi request reprint Radiosurgery for treatment of recurrent intracranial hemangiopericytomas
    Jason Sheehan
    Department of Neurological Surgery, Center for Image Guided Neurosurgery, University of Pittsburgh Medical Center, Pennsylvania, USA
    Neurosurgery 51:905-10; discussion 910-1. 2002
    ..The purpose of this retrospective, single-institution review was to evaluate the efficacy and role of stereotactic radiosurgery in the management of recurrent hemangiopericytomas...
  52. doi request reprint A rare intraosseous arteriovenous malformation of the spine
    Robert G Louis
    Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22903, USA
    J Neurosurg Spine 15:336-9. 2011
    ..On review of the literature, the authors found this case to be the second intraosseous spinal AVM, and the first in a patient whose clinical presentation was consistent with that of a mass lesion of the bone...