Synergism between radiotherapy and vascular risk factors in the accelerated development of atherosclerosis: a report of three cases

Radiation-induced lower-limb arteriopathy: report of 4 cases and systematic literature review

INTRODUCTION

Radiation-induced arteriopathy (RIA) is a rare complication but may become more common due to the increased use of radiotherapy and the prolonged survival of patients. There is still a lack of evidence concerning treatment options. The aim of this study is to review reported cases of lower-limb RIA in order to provide guidelines for management.

EVIDENCE ACQUISITION

We reported 4 cases treated for lower limb RIA and performed a systematic literature review without time limitation in the Medline database using the MeSh tems "iliac artery/radiation effects" OR "femoral artery/radiation effects." Main outcomes of interest were radiation dose, time before symptoms, symptoms, involved vessels, treatment and outcome.

EVIDENCE SYNTHESIS

Twenty-five studies were included, reporting a total of 43 patients. Median time between irradiation and symptoms was 12 years (range: 9 days-49 years), with a median irradiation dose of 40Gy. Clinical presentation was claudication in 18 patients (52%), critical limb threatening ischemia (CLTI) in 4 patients (11%), acute limb ischemia (ALI) in 3 patients (9%) and hemorrhage in 6 patients (17%), the remaining 4 patients were asymptomatic (11%). Vessels involved were iliac arteries in 65% of the cases, femoropopliteal arteries in 28% of cases and concomitant supra and infrainguinal vessels in 7% of the cases. Claudication was mostly treated by open surgery (62%). Treatment of CLTI included primary amputation (50%), open surgery (25%) or endovascular surgery (25%). ALI was treated medically (33%), by open surgery (33%) or in situ thrombolysis (33%). Hemorrhagic cases or pulsatile masses were mostly treated by open surgery (66%). Follow-up was reported in 26 patients (67%), with mean follow-up of 12 months (range: 2 weeks - 5 years). During follow-up, 16% of these patients presented a recurrence of symptoms, and 8% required a reintervention.

CONCLUSIONS

There seems to be no evidence for open versus endovascular treatment, but close and long-term follow-up is needed in these patients due to the possible late presentation and recurrence of symptoms after treatment.

Dose to the penile bulb and individual patient anatomy are predictive of erectile dysfunction in men treated with 125I low dose rate brachytherapy for localized prostate cancer

Background: To evaluate the occurrence of erectile dysfunction at 3 years (3yED) after prostate brachytherapy (BT) and to predict 3yED after treatment based on patients and treatments characteristics. Material and methods: From September 2007 to July 2015, 117 men with mild or no ED [International Index of Erectile Function (IIEF-5) > 16] underwent ¹²⁵Iodine real-time ultrasound-guided low-dose rate BT to a total dose of 160 Gy for low-risk or favorable intermediate-risk prostate adenocarcinoma, and were followed prospectively during 3 years. Median age was 63 years (51-79). The post-implant dosimetric parameters on the postoperative computer tomography were derived from the dose-volume histogram of the prostate and the penile bulb (PB), crura, neurovascular bundles (NVBs) and internal pudendal arteries (IPAs). Potential clinical confounding factors were collected. Additionally, anatomical indexes reflecting the prostate anatomical location within the pelvis were studied. These variables were compared between patients with and without 3yED. 3yED was defined as an IIEF-5 score change to the lower category between baseline, with or without medication. Results: The 3yED rate was 59% (62% maintained an IIEF-5 > 16). On multivariate analysis, prostate D90% (p > .5) and pretreatment characteristics including age (p > .5), pre-implant potency (p > .5), diabetes (p = .08) and high cardiovascular risk rates (p = .1) did not influence the occurrence of 3yED. Only the PB dose especially the D10% > 51 Gy was associated with 3yED (p = .005). Conversely, dose to the crura, IPAs or NVBs did not seem to impact the erectile function. The prostate position, especially the apex location varied significantly between potent and impotent patients and 3yED was significantly associated with close position of the prostate apex to PB (p = .008). Conclusion: The most predictive factor of 3yED was the dose to the PB. This may be explained by variation in individual patients' anatomy and this could allow for the development of better strategies to prevent ED.

Cardiovascular complications after radiotherapy

Over the past decades, effective cancer therapies have resulted in a significant improvement in the survival rates for a number of cancers and an increase in the number of cancer survivors. Radiation therapy is widely used in the treatment of cancer, and it can induce various cardiotoxicities that differ considerably from chemotherapy-induced cardiotoxicity. They occur primarily as late radiation-induced complications, several years from the end of anticancer treatment and present as coronary artery disease, heart failure, pericardial disease, valvular heart disease and arrhythmias. Patients who recovered from cancer disease suffer from cardiac complications of anticancer treatment, it affects the quality of their lives and life expectancy, especially if the diagnosis is delayed. These patients may present distinct symptoms of cardiac injury, resulting from radiation-induced neurotoxicity and altered pain perception, which makes diagnosis difficult. This review highlights the need for a screening programme for patients who have undergone radiation therapy and which will subsequently have a potentially profound impact on morbidity and mortality.

Short and long term radiation induced cardiovascular disease in patients with cancer

Radiation-induced cardiovascular disease is well described as a late effect in cancer patients treated with radiation therapy. Advancements in surgery, radiotherapy, and chemotherapy have led to an increasing number of cancer survivors with resultant long-term side effects related to their cancer treatments. In this review, we describe the short- and long-term cardiovascular consequences of mediastinal radiotherapy and discuss the optimal cardiovascular assessments and diagnostic tools in asymptomatic and symptomatic patients.

Accelerated development of mesenteric and renal artery calcific atherosclerosis following radiotherapy for testicular cancer

We present a case of a 61-year-old male presenting with post-prandial epigastric pain and marked weight loss. Investigation revealed calcific atherosclerosis of the abdominal aorta, coeliac axis, superior mesenteric (SMA) and renal arteries. He had undergone radiotherapy for testicular teratoma 34 years previously. Percutaneous mesenteric revascularization by primary stenting of the SMA proved successful. Radiotherapy for intra-abdominal malignancy has the potential to induce both acute and chronic enteritis and an accelerated atherosclerotic process in the arteries within the field of beam.

Arterial occlusive disease complicating radiation therapy of cervical cancer

Radiation-induced arterial disease is caused by significant atherosclerosis in the circumjacent vessels being irradiated. Even though this has been recognized as survival of cancer patients treated with radiotherapy improves, it is a problem that is often under-reported. We present a case of chronic thromboembolic occlusion of right common iliac artery in a 53-year-old woman who was treated with radiation therapy for cervical cancer 13 years ago. We initially performed percutaneous transluminal angioplasty with thrombolytic therapy, but had to cease thrombolytic therapy due to upper gastrointestinal bleeding of Dieulafoy's lesion, nevertheless, achieved good results after revascularization by Fogarty embolectomy.

Fatal ischemic enteritis with hemorrhage--a late complication of treated Wilms tumor

A 35-year-old man with a history of childhood Wilms tumor successfully treated with radiotherapy, chemotherapy, and surgery, collapsed and died unexpectedly in hospital following admission for abdominal pain. At autopsy, there was ischemic necrosis of the small intestine with altered blood within the stomach and small intestine. Within the upper abdominal aorta, there was patchy confluent calcific atherosclerosis with extension into the proximal superior mesenteric artery which was occluded by thrombus. Death was attributed to ischemic enteritis of the small intestine caused by mesenteric artery thrombosis complicated by gastrointestinal hemorrhage with aspiration. Localization of atherosclerosis to the radiation field with no significant atherosclerosis elsewhere and the young age of the decedent were supportive of radiation-induced atherogenesis. Geographically, localized atherosclerosis at autopsy in a tumor survivor should raise the possibility of a treatment-related side effect that may directly contribute to death many years after the original therapeutic intervention.

Radiation dose to the internal pudendal arteries from permanent-seed prostate brachytherapy as determined by time-of-flight MR angiography

PURPOSE

To determine the feasibility of time-of-flight magnetic resonance (MR) angiography to visualize the internal pudendal arteries (IPAs) in potent men undergoing permanent-seed prostate brachytherapy and to calculate the radiation dose received by these arteries.

METHODS AND MATERIALS

Prostate brachytherapy is performed at the University Health Network/Princess Margaret Hospital by use of transrectal ultrasound (TRUS) preplanning and preloaded needles. All patients received (125)I, with a mean seed activity of 0.32 mCi/seed (0.41 U). Postplan evaluation is performed at 1 month by magnetic resonance-computed tomography fusion. Twenty consecutive potent men had time-of-flight MR angiography as part of their postplan evaluation.

RESULTS

The mean V100 was 96.5%, and the mean D90 was171.5 Gy. The IPAs were easily visualized for 18 of the 20 men. The mean peak dose received by the IPA was 17 Gy. The highest peak dose received by any patient was 38.2 Gy, with only 1 other patient receiving a peak dose greater than 30 Gy. Eleven of 18 had a measurable portion of at least 1 IPA that received 10% of the prescribed dose (V10 = 14.5 Gy). Only 2 patients had nonzero values for V25. The distal third of the IPA received the highest dose for 16 of the 18 patients.

CONCLUSIONS

The IPAs can be well visualized in the majority of potent men by use of time-of-flight MR angiography 1 month after brachytherapy. The IPAs receive a low but calculable dose from permanent-seed (125)I brachytherapy. Further research is needed to determine if this outcome has any correlation with subsequent potency.

Long-term risk of cardiovascular disease in 5-year survivors of testicular cancer

PURPOSE

To evaluate the long-term risk of cardiovascular disease (CVD) in survivors of testicular cancer (TC).

PATIENTS AND METHODS

We compared CVD incidence in 2,512 5-year survivors of TC, who were treated between 1965 and 1995, with general population rates. Treatment effects on CVD risk were quantified in multivariate Cox regression analysis.

RESULTS

After a median follow-up of 18.4 years, 694 cardiovascular events occurred, including 141 acute myocardial infarctions (MIs). The standardized incidence ratio (SIR) for coronary heart disease was 1.17 (95% CI, 1.04 to 1.31), with 14 excess cases per 10,000 person-years. The SIR for MI was significantly increased in nonseminoma survivors with attained ages of less than 45 (SIR = 2.06) and 45 to 54 years (SIR = 1.86) but significantly decreased for survivors with attained ages of 55 years or older (SIR = 0.53). In Cox analysis, mediastinal irradiation was associated with a 3.7-fold (95% CI, 2.2- to 6.2-fold) increased MI risk compared with surgery alone, whereas infradiaphragmatic irradiation was not associated with an increased MI risk. Cisplatin, vinblastine, and bleomycin (PVB) chemotherapy (CT) was associated with a 1.9-fold (95% CI, 1.7- to 2.0-fold) increased MI risk, and bleomycin, etoposide, and cisplatin (BEP) CT was associated with a 1.5-fold (95% CI, 1.0- to 2.2-fold) increased CVD risk and was not associated with increased MI risk (hazard ratio = 1.2; 95% CI, 0.7 to 2.1). Recent smoking was associated with a 2.6-fold (95% CI, 1.8- to 3.9-fold) increased MI risk.

CONCLUSION

Nonseminomatous TC survivors experience a moderately increased MI risk at young ages. Physicians should be aware of excess CVD risk associated with mediastinal radiotherapy, PVB CT, and recent smoking. Intervention in modifiable cardiovascular risk factors is especially important in TC survivors. Whether BEP treatment increases CVD risk should be evaluated after more prolonged follow-up.

Increased carotid wall thickening after radiotherapy on the neck

Patients treated for head and neck tumours with local radiotherapy (RT) on the neck harbour an increased risk of stroke. This may be due to accelerated atherosclerotic changes within the RT-field; however, the real impact of local RT on the carotid artery remains debatable. The aim of the present study was to assess the difference in carotid wall thickness (intima-media thickness) in 42 unilaterally irradiated parotid tumour patients by performing B-mode ultrasonography. A mean difference in intima-media thickness (IMT) of the irradiated compared with the non-irradiated carotid artery of 0.30 mm (P=0.031) was found. A significant correlation was established with a longer post-RT interval (P=0.008). RT on the neck is associated with increased thickening of carotid IMT. Screening and treatment of additional cerebrovascular risk factors which contribute to further IMT thickening and stroke development is recommended, especially in radiotherapy patients with a favourable prognosis.

Detection of radiation-accelerated atherosclerosis of the carotid artery by panoramic radiography

BACKGROUND

The authors review the pathophysiology, epidemiology, course of disease, dental findings and dental treatment of patients who developed atherosclerosis of the carotid artery after having received therapeutic radiation to the neck for squamous-cell carcinoma of the oral cavity, pharynx or larynx; salivary gland tumors; and lymphomas involving the cervical lymph nodes.

TYPE OF STUDIES REVIEWED

The authors conducted a MEDLINE search for 1997 through 2002 using the key terms "radiation therapy," "carotid artery" "atherosclerosis," "cancer" and "dentistry." The articles selected for further review included those published in English in peer-reviewed journals, with preference given to articles reporting randomized, controlled trials.

RESULTS

Recent advances in the delivery of radiation therapy to malignancies of the head and neck have resulted in the prolonged survival of increasing numbers of patients. However, the therapy has been implicated as causing atherosclerotic lesions in the cervical component of the carotid artery, which predisposes patients to an increased risk of developing stroke. Panoramic radiography can identify some of these lesions before they can cause a stroke. Radiation-induced atherosclerosis is common, with approximately 40 percent of patients developing hemodynamically significant carotid artery plaques within 10 years of having received irradiation.

CLINICAL IMPLICATIONS

Dentists treating patients who have received therapeutic radiation to the neck should examine the patients' panoramic radiographs for evidence of atheromalike calcifications, which appear 1.5 to 2.5 centimeters posterior and inferior to the angle of the mandible. Patients with evidence of such lesions should be referred to their physician for an ultrasound examination of their carotid arteries.