title: Pathological vertebral fracture after stereotactic body radiation therapy for lung metastases. Case report and literature review.
abstract: BACKGROUND
  Stereotactic body radiation therapy (SBRT) is a radiation technique used in patients with oligometastatic lung disease. Lung and chest wall toxicities have been described in the patients but pathological vertebral fracture is an adverse effect no reported in patients treated with SBRT for lung metastases.
  
  
  METHODS
  A 68-year-old woman with the diagnosis of a recurrence of a single lung metastatic nodule of urothelial carcinoma after third line of chemotherapy. The patient received a hypo-fractionated course of SBRT.A 3D-conformal multifield technique was used with six coplanar and one non-coplanar statics beams. A total dose of 48 Gy in three fractions over six days was prescribed to the 95% of the CTV. Ten months after the SBRT procedure, a CT scan showed complete response of the metastatic disease without signs of radiation pneumonitis. However, rib and vertebral bone toxicities were observed with the fracture-collapse of the 7th and 8th vertebral bodies and a fracture of the 7th and 8th left ribs. We report a unique case of pathological vertebral fracture appearing ten months after SBRT for an asymptomatic growing lung metastases of urothelial carcinoma.
  
  
  CONCLUSIONS
  Though SBRT allows for minimization of normal tissue exposure to high radiation doses SBRT tolerance for vertebral bone tissue has been poorly evaluated in patients with lung tumors. Oncologists should be alert to the potential risk of fatal bone toxicity caused by this novel treatment. We recommend BMD testing in all woman over 65 years old with clinical risk factors that could contribute to low BMD. If low BMD is demonstrated, we should carefully restrict the maximum radiation dose in the vertebral body in order to avoid intermediate or low radiation dose to the whole vertebral body.
authors.affiliation: Radiation Oncology Department, University of Navarra Clinic, Pamplona, Spain. mrruiz@unav.es
authors.forename: María Esperanza
authors.initials: ME
authors.lastname: Rodríguez-Ruiz
authors.forename: Iñigo
authors.initials: I
authors.lastname: San Miguel
authors.forename: Ignacio
authors.initials: I
authors.lastname: Gil-Bazo
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Perez-Gracia
authors.forename: Leire
authors.initials: L
authors.lastname: Arbea
authors.forename: Marta
authors.initials: M
authors.lastname: Moreno-Jimenez
authors.forename: Javier
authors.initials: J
authors.lastname: Aristu
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D015519:Bone Density; D016190:Carboplatin / Q000008:administration & dosage; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery; D002574:Cervical Vertebrae / Q000528:radiation effects; D002945:Cisplatin / Q000008:administration & dosage; D003131:Combined Modality Therapy; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D005598:Fractures, Spontaneous / Q000209:etiology*; D005971:Glutamates / Q000008:administration & dosage; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D015663:Osteoporosis, Postmenopausal / Q000150:complications; D000068437:Pemetrexed; D016634:Radiosurgery / Q000009:adverse effects*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D012253:Rib Fractures / Q000209:etiology*; D012272:Ribs / Q000528:radiation effects*; D016103:Spinal Fractures / Q000209:etiology*; D013904:Thoracic Vertebrae / Q000528:radiation effects*; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy; D000093542:Gemcitabine
chemical_list: D005971:Glutamates; D000068437:Pemetrexed; D003841:Deoxycytidine; D006147:Guanine; D016190:Carboplatin; D002945:Cisplatin; D000093542:Gemcitabine