Impact of Dose on Local Failure Rates After Image-Guided Reirradiation of Recurrent Paraspinal Metastases

• Published in: International journal of radiation oncology, biology, physics Vol. 81; no. 3; pp. 819 - 826
• Main Authors: Damast, Shari, M.D, Wright, Jean, M.D, Bilsky, Mark, M.D, Hsu, Meier, M.S, Zhang, Zhigang, Ph.D, Lovelock, Michael, Ph.D, Cox, Brett, M.D, Zatcky, Joan, N.P, Yamada, Yoshiya, M.D
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-11-2011; Elsevier
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Biological and medical sciences; BODY; CENTRAL NERVOUS SYSTEM; Decompression, Surgical; DISEASES; Diseases of the nervous system; Diseases of the osteoarticular system. Orthopedic treatment; DOSES; FAILURES; Female; Follow-Up Studies; HAZARDS; Hematology, Oncology and Palliative Medicine; HISTOLOGY; Humans; Image-guided radiation therapy; Male; Medical sciences; MEDICINE; METASTASES; Middle Aged; Neoplasm Recurrence, Local - radiotherapy; NEOPLASMS; NERVOUS SYSTEM; NUCLEAR MEDICINE; ORGANS; Paraspinal tumors; RADIATION DOSES; RADIOLOGY; RADIOLOGY AND NUCLEAR MEDICINE; Radiosurgery; RADIOTHERAPY; Radiotherapy Dosage; Radiotherapy, Image-Guided; Radiotherapy, Intensity-Modulated - adverse effects; Radiotherapy, Intensity-Modulated - methods; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Reirradiation; Retreatment - methods; SKELETON; SPINAL CORD; Spinal cord metastases; Spinal Neoplasms - pathology; Spinal Neoplasms - radiotherapy; Spinal Neoplasms - secondary; Spinal Neoplasms - surgery; SURGERY; THERAPY; Treatment Failure; Tumor Burden; VERTEBRAE; Young Adult; Image-guided radiation therapy; Reirradiation; Paraspinal tumors; Spinal cord metastases; Radiosurgery; Human; Relapse; Spine; Diseases of the osteoarticular system; Spine disease; Malignant tumor; Metastasis; Guidance; Myelopathy; Radiation dose; Intensity modulated radiotherapy; Treatment; Central nervous system disease; Complication; Medical imagery; Spinal cord disease; Cancer
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2010.06.013

Purpose To examine the impact of dose on local failure (LF) rates in the re-treatment of recurrent paraspinal metastases with image-guided intensity-modulated radiotherapy (IG-IMRT). Methods and Materials The records of patients with in-field recurrence after previous spine radiation (median dose, 30 Gy) who received salvage IG-IMRT with either five 4-Gy (20-Gy group, n = 42) or five 6-Gy (30-Gy group, n = 55) daily fractions between January 2003 and August 2008 were reviewed. Institutional practice was 20 Gy before April 2006, when it changed to 30 Gy. A total of 47 cases (48%) were treated adjuvantly, after surgery to decompress epidural disease. LF after IG-IMRT was defined radiographically. Results The median follow-up was 12.1 months (range, 0.2–63.6 months). The 1-year cumulative incidences of LF after 20 Gy and 30 Gy IG-IMRT were 45% and 26%, respectively ( p = 0.04). Of all treatment characteristics examined (20-Gy vs. 30-Gy dose group, dose to 95% of the planned and gross target volume, tumor size, histology, receipt of surgery, and interval between first and second radiation), only dose group had a significant impact on actuarial LF incidence ( p = 0.04; unadjusted HR, 0.51; 95% CI, 0.27–0.96). There was no incidence of myelopathy. Conclusions A significant decrease in LF after IG-IMRT with five 6-Gy fractions compared with five 4-Gy fractions was observed without increased risk of myelopathy. Until prospective data comparing stereotactic hypofractionated and single-fraction regimens become available, when reirradiating recurrent paraspinal metastases with IG-IMRT, administration of five 6-Gy daily fractions is reasonable.