Cervical Stabilization in Patients with Instability Resulting from Osteoradionecrosis with Subsequent Spondylodiscitis After Radiotherapeutic Treatment for Head- and Neck Carcinoma.

High dose of radiation to bone may cause necrosis. Osteoradionecrosis of the cervical vertebrae is a rare adverse event of radiotherapy in patients treated for head and neck cancer. The risk on osteoradionecrosis will increase with doses exceeding 60 Gy. Minimal trauma of the overlying mucosa of the heavily irradiated cervical spine causes subsequent infections or instability may cause neck pain and severe neurological disability. In four patients the cervical spine received up to 100 Gy due to reirradiation. Clinically the patients presented with neck pain. All patients had defects in the pharyngeal posterior wall and cervical instability due to osteoradionecrosis of several cervical vertebrae. Despite optimal conservative treatment the patients developed sensory and motor function loss of the upper extremities. Laminectomies were performed and the cervical spine was stabilized. The pharyngeal posterior wall defects could not be reconstructed. All patients received lifelong antibiotic treatment. Pain and neurological deficits declined after surgery and initiating antibiotics. Eventually all patients could take up their daily activities. Three patients died between 6 months and 2 years after surgery. The cause of death was not related to the osteoradionecrosis. In case of cervical osteoradionecrosis, with secondary infections, stability of the spine should be restored even when the integrity of the pharyngeal posterior wall cannot be restored. Our cases demonstrate that even when an anterior approach is impossible, due to irradiation changed tissue structures of the pharyngeal posterior wall, a combination of lifelong antibiotic treatment and posterior stabilization is a good alternative. The vertebrae affected by osteoradionecrosis and secondary infection can be left in situ. This intervention leads to improvement in quality of life.

Clinical outcome of salvage neck dissections in head and neck cancer in relation to initial treatment, extent of surgery and patient factors.

OBJECTIVE: Salvage surgery has a higher complication rate compared to primary surgical treatment. We evaluated clinical outcome of salvage neck dissections in relation to initial treatment modality, extent of surgery and patient-related factors. DESIGN: Single institution consecutive case series. SETTING: Tertiary Head and Neck Cancer Centre. PARTICIPANTS: In all, 87 patients with head and neck squamous cell carcinoma, who underwent salvage neck dissection after initial radiotherapy (n = 30), radiotherapy with carboplatin/5-fluorouracil (n = 43) or radiotherapy with cetuximab (n = 14). MAIN OUTCOME MEASURES: Incidence of complications, disease-specific survival. RESULTS: Complications occurred in 28% of the patients. Multivariate analysis identified extent of neck dissection as the only independent predictor of surgical complications (P = 0.010). Surgical complication rate was 16% after radiotherapy with systemic treatment, and 47% after radiotherapy alone (P = 0.171). The 5-year disease-specific survival was 55%, independent of complications, initial treatment, extent of surgery and patient-related factors. CONCLUSION: The only predictor for surgical complications was extent of surgery. Survival was not influenced by complications.

Techniques for precision irradiation of the lateral half of the rat cervical spinal cord using 150 MeV protons [corrected].

Techniques for high precision irradiation experiments with protons, to investigate the volume dependence of the tolerance dose of the rat cervical spinal cord are described. In the present study, 50% of the lateral cross section of the spinal cord was irradiated. The diameter of the cross section of this part of the rat spinal cord is at maximum 3.5 mm. Therefore, a dedicated procedure was developed to comply with the needs for a very high positioning accuracy and high spatial resolution dosimetry. By using 150 MeV protons a steep dose gradient (20-80% = 1 mm) in the centre of the spinal cord was achieved. This yields a good dose contrast between the left and right halves of the cord. A home-made digital x-ray imager with a pixel resolution of 0.18 mm/pixel was used for position verification of the spinal cord. A positioning accuracy of 0.09 mm was obtained by using information of multiple pixels. The average position stability during the irradiation was found to be 0.08 mm (1 SD) without significant systematic deviations. Profiles of the dose distribution were measured with a 2D dosimetry system consisting of a scintillating screen and a CCD camera. Dose volume histograms of the whole spinal cord as well as separately of the white and grey matters were calculated using MRI imaging of the cross section of the rat cervical spinal cord. From the irradiation of 20 animals a dose-response curve has been established. MRI showed radiation-induced damage at the high dose side of the spinal cord. Analysis of the preliminary dose-response data shows a significant dose-volume effect. With the described procedure and equipment it is possible to perform high precision irradiations on selected parts of the spinal cord.