Radiation Oncology/Toxicity/Carotid artery

Carotid Artery Radiation Toxicity Cavernous Sinus Meningioma Mayo Clinic, 2005 PMID 16029803 -- "Results of stereotactic radiosurgery for patients with imaging defined cavernous sinus meningiomas." (Pollock BE, Int J Radiat Oncol Biol Phys. 2005 Aug 1;62(5):1427-31.) In text authors note they documented 4 cases of internal carotid stenosis (cavernous sinus meningioma n=2, pituitary adenoma n=2) at their institution; however, they don't say how many patients were treated. In this series, there were 49 cavernous sinus meningiomas reported, with mean margin dose 15.9 Gy Marseille, 2000 (France)(1992-1998) PMID 11143266 -- "Gamma knife radiosurgery in the management of cavernous sinus meningiomas." (Roche PH, J Neurosurg. 2000 Dec;93 Suppl 3:68-73.) Retrospective. 80 patients, 50 primary and 30 adjuvant. Mean prescription dose 28 Gy, with median peripheral isodose 50%. One temporary intracavernous carotid artery occlusion at 3 months. Estimated carotid dose was 36 Gy Head & Neck Carotid Artery Blowout Syndrome Complication of aggressive management of H&N cancer Typically presents as significant, difficult to control oronasal bleeding Predisposing factors: RT, radical surgery and surgical complications (flap necrosis, wound infections, pharyngocutaneous fistula), persistent/recurrent tumor Results from destruction or damage to vessel adventitia Most occur in the petrous segment of internal carotid artery, possibly due to associated osteonecrosis after high dose RT Mean dose in Taipei series of patients who developed it was 73 Gy (range 54-110) Latency varies between <1 year to >20 years Management of bleeding can be via endovascular approaches Taipei 2008 (1997-2006) PMID 18164999 -- "Radiation carotid blowout syndrome in nasopharyngeal carcinoma: Angiographic features and endovascular management." (Luo CB, Otolaryngol Head Neck Surg. 2008 Jan;138(1):86-91.) Retrospective. 14 patients with nasopharyngeal carcinoma with 15 carotid blowout syndromes, initially treated by RT alone. All presented with oronasal bleeding. Location was internal carotid (n=10), external carotid (n=4), or common carotid (n=1) RT info: mean dose 73 Gy (54 - 110 Gy); mean latency 33 months (8 - 70 months) Management: Endovascular embolization. 2006 PMID 16538509 -- "Radiation acute carotid blowout syndromes of the ascending pharyngeal and internal carotid arteries in nasopharyngeal carcinoma." (Luo CB, Eur Arch Otorhinolaryngol. 2006 Jul;263(7):644-6. Epub 2006 Mar 15.) Case report. NPC patient with radiation-induced acute carotid blowout syndrome in cervical internal carotid artery Carotid Artery Stenosis After RT, carotid narrowing occurs in ~50% of vessels receiving >40 Gy Multiple other studies document accelerated atherosclerotic disease Duplex ultrasound screening may be warranted Carotid-sparing IMRT feasible for T1-2 glottic cancer, but long-term disease control and carotid outcomes not yet available PMID 19679406 Mayo Clinic; 2005 (1974-1999) PMID 16169673 -- "A historical prospective cohort study of carotid artery stenosis after radiotherapy for head and neck malignancies." (Brown PD, Int J Radiat Oncol Biol Phys. 2005 Dec 1;63(5):1361-7. Epub 2005 Sep 19.) Retrospective. 44 H&N patients treated with unilater RT. Bilateral carotid duplex ultrasound screening performed Outcome: Significant stenosis RT-side 18% vs. contralateral 7% (NS), events increased with time Conclusion: Ultrasound carotid artery screening should be considered Fort Lewis, WA; 2004 PMID 15135672 -- "Focused high-risk population screening for carotid arterial stenosis after radiation therapy for head and neck cancer." (Steele SR, Am J Surg. 2004 May;187(5):594-8.) Retrospective. 40 patients treated with high dose (>55 Gy, mean 64 Gy) H&N RT. Mean F/U 10 years Outcome: Significant carotid artery stenosis 40%; no difference in terms of age, RT dose, tobacco, time from RT, or comorbidities. Unilateral complete occlusion 15%. CVA in 8% Conclusion: Prevalence of carotid artery disease is clinical significant, and warrants aggressive screening Prince of Wales Hospital; 2001 (Hong Kong) PMID 11745291 -- "Incidence of carotid stenosis in nasopharyngeal carcinoma patients after radiotherapy." (Lam WW, Cancer. 2001 Nov 1;92(9):2357-63.) Retrospective. 71 carotid arteries examined with Doppler U/S in nasopharyngeal patients after RT. Compared with control group of 51 newly diagnosed NPC patients Outcome: Arterial stenosis RT group 79% vs. pre-RT group 22% (SS); significant stenosis (>50%) only in post-RT group 51% Conclusion: RT can cause significant carotid stenosis Queen Mary Hospital; 1999 PMID 10587192 -- "Irradiation-induced extracranial carotid stenosis in patients with head and neck malignancies." (Cheng SW, Am J Surg. 1999 Oct;178(4):323-8.) Comparative cross-sectional study. Duplex U/S 240 patients with H&N EBRT. Mean interval 6 years after RT Outcome: Significant (>70%) ICA/CCA disease in 12% Predictors for significant narrowing: age (>60), cerebrovascular symptoms, RT interval (>5 years), location (nasopharynx or larynx) Conclusion: Significant risk of carotid stenosis after RT; recommend routine ultrasound screening VA Washington DC; 1999 (1993-1998) PMID 10587388 -- "Accelerated carotid artery disease after high-dose head and neck radiotherapy: is there a role for routine carotid duplex surveillance?" (Carmody BJ, J Vasc Surg. 1999 Dec;30(6):1045-51.) Case control. 23 patients with RT and 46 age-matched controls. Mean RT dose 60.6 Gy. Average interval to screening 6.5 years Outcome: Advanced carotid disease RT group 22% vs. control 4% (SS); 16/23 RT patients underwent 2nd U/S and had further progression Conclusion: High dose RT significant risk factor for accelerated atherosclerosis, may warrant routine ultrasound screening Seoul; 1994 PMID 8040432 -- "MRI of carotid angiopathy after therapeutic radiation." (Chung TS, J Comput Assist Tomogr. 1994 Jul-Aug;18(4):533-8.) Retrospective. 16 patients, pre and post RT (>40 Gy) MRI scans reviewed blindly by 2 readers Outcome: Interval narrowing of carotid artery lumen (common, internal, or external) seen in 56%; difference in lumen was statistically significant. 3/16 patients had new critical stenosis; 7/16 patients had diffuse obliteration of carotid planes Conclusion: Incidence of accelerated atherosclerosis after RT may be greater than expected Breast Cancer MD Anderson; 2008 PMID 18000801 -- "Prospective analysis of carotid artery flow in breast cancer patients treated with supraclavicular irradiation 8 or more years previously: no increase in ipsilateral carotid stenosis after radiation noted." (Woodward WA, Cancer. 2008 Jan 15;112(2):268-73.) Retrospective. 46 breast cancer patients, adjuvant RT to SCV. Median dose 50 Gy. Bilateral Doppler ultrasound of carotid artery. Minimum F/U 8 years, median F/U 14.6 years Outcome: asymptomatic carotid stenosis 9%, but only 2% (1 patient) irradiated carotid artery only, 2% (1 patient) had bilateral, and 4% (2 patients) had contralateral stenosis. No difference between sides on peak systolic flow Conclusion: No evidence of late, clinically relevant carotid artery stenosis