Purposeful irradiation of the epidural space to enhance local control without compromising cord sparing in spine radiosurgery † .

Autor: Jensen PJ; Department of Radiation Oncology, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC, USA., Torok JA; Department of Radiation Oncology, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC, USA., Goodwin CR; Department of Radiation Oncology, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC, USA.; Department of Neurosurgery, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC 27710 USA., Floyd SR; Department of Radiation Oncology, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC, USA., Wu Q; Department of Radiation Oncology, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC, USA., Wu QJ; Department of Radiation Oncology, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC, USA., Kirkpatrick JP; Department of Radiation Oncology, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC, USA.; Department of Neurosurgery, The Duke Center for Brain and Spine Metastasis, Duke Cancer Institute, Durham, NC 27710 USA.
Jazyk: angličtina
Zdroj: Journal of radiosurgery and SBRT [J Radiosurg SBRT] 2022; Vol. 8 (1), pp. 21-26.
Abstrakt: Purpose: The epidural space is a frequent site of cancer recurrence after spine stereotactic radiosurgery (SSRS). This may be due to microscopic disease in the epidural space which is underdosed to obey strict spinal cord dose constraints. We hypothesized that the epidural space could be purposefully irradiated to prescription dose levels, potentially reducing the risk of recurrence in the epidural space without increasing toxicity.
Methods and Materials: SSRS clinical treatment plans with spinal cord contours, spinal planning target volumes (PTV spine ), and delivered dose distributions were retrospectively identified. An epidural space PTV (PTV epidural ) was contoured to avoid the spinal cord and focus on regions near the PTV spine . Clinical plan constraints included PTV spine constraints (D 95% and D 5% , based on prescription dose) and spinal cord constraints (D max < 1300 cGy, D10% < 1000 cGy). Plans were revised with three prescriptions of 1800, 2000 and 2400 cGy in two sets, with one set of revisions (supplemented plans) designed to additionally target the PTV epidural by optimizing PTV epidural D 95% in addition to meeting every clinical plan constraint. Clinical and revised plans were compared according to their PTV epidural DVH distributions, and D 95% distributions.
Results: Seventeen SSRS plans meeting the above criteria were identified. Supplemented plans had higher doses to the epidural low-dose regions at all prescription levels. Epidural PTV D 95% values for the supplemented plans were all statistically significantly different from the values of the base plans (p < 10 -4 ). The epidural PTV D 95% increases depended on the initial prescription, increasing from 11.52 to 16.90 Gy, 12.23 to 18.85 Gy, and 13.87 to 19.54 Gy for target prescriptions of 1800, 2000 and 2400 cGy, respectively.
Conclusions: Purposefully targeting the epidural space in SSRS may increase control in the epidural space without significantly increasing the risk of spinal cord toxicity. A clinical trial of this approach should be considered.
Competing Interests: Authors’ disclosure of potential conflicts of interest The authors have nothing to disclose.
(© 2022 Old City Publishing, Inc.)
Databáze: MEDLINE
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