Hiroshi Doi1,2, Keisuke Tamari1,3, Ryoong-Jin Oh1, Carsten Nieder4,5. 1. Miyakojima IGRT Clinic, 1-16-22 Miyakojimahondori, 534-0021, Osaka, Miyakojima-ku, Japan. 2. Department of Radiation Oncology, Kindai University Faculty of Medicine, 377-2 Ohno-Higashi, 589-8511, Osaka, Osaka-Sayama, Japan. 3. Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, 565-0871, Osaka, Suita, Japan. 4. Department of Oncology and Palliative Medicine, Nordland Hospital Trust, 8092, Bodø, Norway. cnied@hotmail.com. 5. Department of Clinical Medicine, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway. cnied@hotmail.com.
Abstract
PURPOSE: To provide additional clinical data about the re-irradiation tolerance of the spinal cord. METHODS: This was a retrospective bi-institutional study of patients re-irradiated to the cervical or thoracic spinal cord with minimum follow-up of 6 months. The maximum dose (Dmax) and dose to 0.1cc (D0.1cc) were determined (magnetic resonance imaging [MRI]-defined cord) and expressed as equivalent dose in 2‑Gy fractions (EQD2) with an α/β value of 2 Gy. RESULTS: All 32 patients remained free from radiation myelopathy after a median follow-up of 12 months. Re-irradiation was performed after 6-97 months (median 15). In 22 cases (69%) the re-irradiation spinal cord EQD2 Dmax was higher than that of the first treatment course. Forty-eight of 64 treatment courses employed fraction sizes of 2.5 to 4 Gy to the target volume. The median cumulative spinal cord EQD2 Dmax was 80.7 Gy, minimum 61.12 Gy, maximum 114.79 Gy. The median cumulative spinal cord D0.1cc EQD2 was 76.1 Gy, minimum 61.12 Gy, maximum 95.62 Gy. Besides cumulative dose, other risk factors for myelopathy were present (single-course Dmax EQD2 ≥51 Gy in 9 patients, single-course D0.1cc EQD2 ≥51 Gy in 5 patients). CONCLUSION: Even patients treated to higher cumulative doses than previously recommended, or at a considerable risk of myelopathy according to a published risk score, remained free from this complication, although one must acknowledge the potential for manifestation of damage in patients currently alive, i.e., still at risk. Individualized decisions to re-irradiate after appropriate informed consent are an acceptable strategy, including scenarios where low re-irradiation doses to the spinal cord would compromise target coverage and tumor control probability to an unacceptable degree.
PURPOSE: To provide additional clinical data about the re-irradiation tolerance of the spinal cord. METHODS: This was a retrospective bi-institutional study of patients re-irradiated to the cervical or thoracic spinal cord with minimum follow-up of 6 months. The maximum dose (Dmax) and dose to 0.1cc (D0.1cc) were determined (magnetic resonance imaging [MRI]-defined cord) and expressed as equivalent dose in 2‑Gy fractions (EQD2) with an α/β value of 2 Gy. RESULTS: All 32 patients remained free from radiation myelopathy after a median follow-up of 12 months. Re-irradiation was performed after 6-97 months (median 15). In 22 cases (69%) the re-irradiation spinal cord EQD2 Dmax was higher than that of the first treatment course. Forty-eight of 64 treatment courses employed fraction sizes of 2.5 to 4 Gy to the target volume. The median cumulative spinal cord EQD2 Dmax was 80.7 Gy, minimum 61.12 Gy, maximum 114.79 Gy. The median cumulative spinal cord D0.1cc EQD2 was 76.1 Gy, minimum 61.12 Gy, maximum 95.62 Gy. Besides cumulative dose, other risk factors for myelopathy were present (single-course Dmax EQD2 ≥51 Gy in 9 patients, single-course D0.1cc EQD2 ≥51 Gy in 5 patients). CONCLUSION: Even patients treated to higher cumulative doses than previously recommended, or at a considerable risk of myelopathy according to a published risk score, remained free from this complication, although one must acknowledge the potential for manifestation of damage in patients currently alive, i.e., still at risk. Individualized decisions to re-irradiate after appropriate informed consent are an acceptable strategy, including scenarios where low re-irradiation doses to the spinal cord would compromise target coverage and tumor control probability to an unacceptable degree.
Authors: R Lee MacDonald; Young Lee; Jannie Schasfoort; Hany Soliman; Arjun Sahgal; Mark Ruschin Journal: Int J Radiat Oncol Biol Phys Date: 2019-10-23 Impact factor: 7.038
Authors: Giuseppe Roberto Giammalva; Gianluca Ferini; Fabio Torregrossa; Lara Brunasso; Sofia Musso; Umberto Emanuele Benigno; Rosa Maria Gerardi; Lapo Bonosi; Roberta Costanzo; Federica Paolini; Paolo Palmisciano; Giuseppe Emmanuele Umana; Rina Di Bonaventura; Carmelo Lucio Sturiale; Domenico Gerardo Iacopino; Rosario Maugeri Journal: Life (Basel) Date: 2022-04-12