Jimm Grimm1, John A Vargo2, Panayiotis Mavroidis3, Vitali Moiseenko4, Bahman Emami5, Sheena Jain6, Jimmy J Caudell7, David A Clump2, Diane C Ling8, Shiva Das3, Eduardo G Moros7, Yevgeniy Vinogradskiy9, Jinyu Xue10, Dwight E Heron11. 1. Department of Radiation Oncology, Geisinger Health System, Danville, Pennsylvania; Department of Medical Imaging and Radiation Sciences, Thomas Jefferson University, Philadelphia, Pennsylvania. Electronic address: JimmGrimmJr@yahoo.com. 2. UPMC Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. 3. Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina. 4. Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California. 5. Department of Radiation Oncology, Loyola University, Maywood, Illinois. 6. Bott Cancer Center, Holy Redeemer Hospital, Meadowbrook, Pennsylvania. 7. Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. 8. Department of Radiation Oncology, Keck School of Medicine, University of Southern California, Los Angeles, California. 9. Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado. 10. Department of Radiation Oncology, New York University School of Medicine, New York, New York. 11. Department of Radiation Oncology, Bon Secours Mercy Health System, Youngstown, Ohio.
Abstract
PURPOSE: Dose-volume data for injury to carotid artery and other major vessels in stereotactic body radiation therapy (SBRT)/SABR head and neck reirradiation were reviewed, modeled, and summarized. METHODS AND MATERIALS: A PubMed search of the English-language literature (stereotactic and carotid and radiation) in April 2018 found 238 major vessel maximum point doses in 6 articles that were pooled for logistic modeling. Two subsequent studies with dose-volume major vessel data were modeled separately for comparison. Attempts were made to separate carotid blowout syndrome from other bleeding events (BE) in the analysis, but we acknowledge that all except 1 data set has some element of BE interspersed. RESULTS: Prior radiation therapy (RT) dose was not uniformly reported per patient in the studies included, but a course on the order of conventionally fractionated 70 Gy was considered for the purposes of the analysis (with an approximately ≥6-month estimated interval between prior and subsequent treatment in most cases). Factors likely associated with reduced risk of BE include nonconsecutive daily treatment, lower extent of circumferential tumor involvement around the vessel, and no surgical manipulation before or after SBRT. CONCLUSIONS: Initial data pooling for reirradiation involving the carotid artery resulted in 3 preliminary models compared in this Hypofractionated Treatment Effects in the Clinic (HyTEC) report. More recent experiences with alternating fractionation schedules and additional risk-reduction strategies are also presented. Complications data for the most critical structures such as spinal cord and carotid artery are so limited that they cannot be viewed as strong conclusions of probability of risk, but rather, as a general guideline for consideration. There is a great need for better reporting standards as noted in the High Dose per Fraction, Hypofractionated Treatment Effects in the Clinic introductory paper.
PURPOSE: Dose-volume data for injury to carotid artery and other major vessels in stereotactic body radiation therapy (SBRT)/SABR head and neck reirradiation were reviewed, modeled, and summarized. METHODS AND MATERIALS: A PubMed search of the English-language literature (stereotactic and carotid and radiation) in April 2018 found 238 major vessel maximum point doses in 6 articles that were pooled for logistic modeling. Two subsequent studies with dose-volume major vessel data were modeled separately for comparison. Attempts were made to separate carotid blowout syndrome from other bleeding events (BE) in the analysis, but we acknowledge that all except 1 data set has some element of BE interspersed. RESULTS: Prior radiation therapy (RT) dose was not uniformly reported per patient in the studies included, but a course on the order of conventionally fractionated 70 Gy was considered for the purposes of the analysis (with an approximately ≥6-month estimated interval between prior and subsequent treatment in most cases). Factors likely associated with reduced risk of BE include nonconsecutive daily treatment, lower extent of circumferential tumor involvement around the vessel, and no surgical manipulation before or after SBRT. CONCLUSIONS: Initial data pooling for reirradiation involving the carotid artery resulted in 3 preliminary models compared in this Hypofractionated Treatment Effects in the Clinic (HyTEC) report. More recent experiences with alternating fractionation schedules and additional risk-reduction strategies are also presented. Complications data for the most critical structures such as spinal cord and carotid artery are so limited that they cannot be viewed as strong conclusions of probability of risk, but rather, as a general guideline for consideration. There is a great need for better reporting standards as noted in the High Dose per Fraction, Hypofractionated Treatment Effects in the Clinic introductory paper.