Nuclear medicine imaging methods of early radiation-induced cardiotoxicity: a ten-year systematic review.

Introduction: Radiotherapy has significantly improved cancer survival rates, but it also comes with certain unavoidable complications. Breast and thoracic irradiation, for instance, can unintentionally expose the heart to radiation, leading to damage at the cellular level within the myocardial structures. Detecting and monitoring radiation-induced heart disease early on is crucial, and several radionuclide imaging techniques have shown promise in this regard. Method: In this 10-year review, we aimed to identify nuclear medicine imaging modalities that can effectively detect early cardiotoxicity following radiation therapy. Through a systematic search on PubMed, we selected nineteen relevant studies based on predefined criteria. Results: The data suggest that incidental irradiation of the heart during breast or thoracic radiotherapy can cause early metabolic and perfusion changes. Nuclear imaging plays a prominent role in detecting these subclinical effects, which could potentially serve as predictors of late cardiac complications. Discussion: However, further studies with larger populations, longer follow-up periods, and specific heart dosimetric data are needed to better understand the relationship between early detection of cardiac abnormalities and radiation-induced heart disease.

Efficacity of Deep Inspiration Breath Hold and Intensity-Modulated Radiotherapy in Preventing Perfusion Defect for Left Sided Breast Cancer (EDIPE): A Prospective Cohort Study Protocol.

Breast radiotherapy can lead to radiation-induced cardiac disease, particularly in left breast cancers. Recent studies have shown that subclinical cardiac lesions, such as myocardial perfusion deficits, may occur early after radiotherapy. The primary method for irradiating breast cancer, known as opposite tangential field radiotherapy, can cause the anterior interventricular coronary artery to receive a high dose of radiation during left breast irradiation. To explore alternative approaches that could reduce the risk of myocardial perfusion defects in patients with left breast cancer, we plan to conduct a prospective single-center study using a combination of deep inspiration breath hold radiotherapy and intensity modulated radiation therapy. The study will use stress and, if necessary, resting myocardial scintigraphy to assess myocardial perfusion. The trial aims to show that reducing the cardiac dose with these techniques can prevent the appearance of early (3-month) and medium-term (6- and 12-month) perfusion disorders.

Advantages of 18F-FDG PET/CT Imaging over Modified Duke Criteria and Clinical Presumption in Patients with Challenging Suspicion of Infective Endocarditis.

According to European Society of Cardiology guidelines (ESC2015) for infective endocarditis (IE) management, modified Duke criteria (mDC) are implemented with a degree of clinical suspicion degree, leading to grades such as "possible" or "rejected" IE despite a persisting high level of clinical suspicion. Herein, we evaluate the 18F-FDG PET/CT diagnostic and therapeutic impact in IE suspicion, with emphasis on possible/rejected IE with a high clinical suspicion. Excluding cases of definite IE diagnosis, 53 patients who underwent 18F-FDG PET/CT for IE suspicion were selected and afterwards classified according to both mDC (possible IE/Duke 1, rejected IE/Duke 0) and clinical suspicion degree (high and low IE suspicion). The final status regarding IE diagnosis (gold standard) was based on the multidisciplinary decision of the Endocarditis Team, including the 'imaging specialist'. PET/CT images of the cardiac area were qualitatively interpreted and the intensity of each focus of extra-physiologic 18F-FDG uptake was evaluated by a maximum standardized uptake value (SUVmax) measurement. Extra-cardiac 18F-FDG PET/CT pathological findings were considered to be a possible embolic event, a possible source of IE, or even a concomitant infection. Based on the Endocarditis Team consensus, final diagnosis of IE was retained in 19 (36%) patients and excluded in 34 (64%). With a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and global accuracy of 79%, 100%, 100%, 89%, and 92%, respectively, PET/CT performed significantly better than mDC (p = 0.003), clinical suspicion degree (p = 0.001), and a combination of both (p = 0.001) for IE diagnosis. In 41 patients with possible/rejected IE but high clinical suspicion, sensitivity, specificity, PPV, NPV, and global accuracies were 78%, 100%, 100%, 85%, and 90%, respectively. Moreover, PET/CT contributed to patient management in 24 out of 53 (45%) cases. 18F-FDG PET/CT represents a valuable diagnostic tool that could be proposed for challenging IE cases with significant differences between mDC and clinical suspicion degree. 18F-FDG PET/CT allows a binary diagnosis (definite or rejected IE) by removing uncertain diagnostic situations, thus improving patient therapeutic management.

Muscle fluorodeoxyglucose uptake assessed by positron emission tomography-computed tomography as a biomarker of inflammatory myopathies disease activity.

OBJECTIVE: To devise a simple PET-CT score for measurement of muscle disease activity in patients with inflammatory myopathies (IMs) and to assess its validity. METHODS: A total of 44 PET-CT examinations in 34 IM patients (performed during cancer screening) and 20 PET-CT examinations in matched controls (investigated for pulmonary nodules with a conclusion of benignity) were analysed. Maximal standardized uptake values (SUVmax) were recorded bilaterally in eight proximal muscles. The muscle SUVmax (mSUVmax) was defined as the average of the 16 muscle SUVmax values, normalized on the liver mean SUV. Reliability, validity and responsiveness were evaluated. RESULTS: The mSUVmax was increased in IM patients compared with controls. This index allowed the identification of patients with high vs low muscle disease activity using the myositis intention to treat activity index as the gold standard. In patients with subsequent examinations, our method showed good accuracy to detect changes in muscle disease activity [area under the curve 0.96 (95% CI 0.84, 1)]. Responsiveness was strong. Interrater reliability was excellent. CONCLUSION: PET-CT, a non-invasive tool useful for cancer screening, is also valuable to measure muscle disease activity and its evolution in IM patients.

Evaluation of Oxalate Osteopathy Secondary to Hyperoxaluria With 18F-FDG PET/CT and 99mTc-HMDP Bone Scan.

We report a case of a 69-year-old woman with primary hyperoxaluria type I, who developed a severe hypercalcemia despite controlled secondary hyperparathyroidism. Bone scintigraphy showed diffuse increased uptake in axial and peripheral skeleton. F-FDG PET/CT showed countless striking hypermetabolic foci, interesting 2 types of lesions (joint calcifications and periosteal resorptions). Bone biopsy demonstrated inflammatory changes around many calcium oxalate crystals; hypercalcemia was then related to oxalate osteopathy. Immunotherapy with denosumab was thus initiated. Eighteen months later, a second PET/CT showed decreased F-FDG uptake, reflecting treatment efficacy on inflammatory reaction secondary to calcium oxalosis skeletal deposits.

A systematic review of palliative bone radiotherapy based on pain relief and retreatment rates.

Palliative radiotherapy has been shown to have effects on Quality of Life during painful bone metastasis. This review aimed to determine equivalence in pain relief (PR) and retreatment rate (RR) using both single and multi-fraction irradiations, based on evaluation of the trial's quality. We performed a systematic review since ICRU 50 Report (1993) to June 2017, then evaluated trials for reproducibility and good methodology criteria. We found five studies that were reproducible in both dose and volume prescription. One study used three-dimensional (3D) treatment planning. Equivalence between single and multi-fraction schedules was demonstrated for PR after 3 months, but a 2-3 time RR appeared after single-fraction schedules, notably in the first year after treatment (primarily during the first four months). Reserving long course therapy for well-preserved patients would allow for better long-term efficacy with lower RR, while altered patients would suffer less from single-fraction treatments. It appears that life expectancy might not be used as a criterion for this choice.

18F-FDG PET/CT for the Diagnosis of Malignant and Infectious Complications After Solid Organ Transplantation.

PURPOSE: Infection and malignancy represent two common complications after solid organ transplantation, which are often characterized by poorly specific clinical symptomatology. Herein, we have evaluated the role of 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) in this clinical setting. METHODS: Fifty-eight consecutive patients who underwent FDG PET/CT after kidney, lung or heart transplantation were included in this retrospective analysis. Twelve patients underwent FDG PET/CT to strengthen or confirm a diagnostic suspicion of malignancies. The remaining 46 patients presented with unexplained inflammatory syndrome, fever of unknown origin (FUO), CMV or EBV seroconversion during post-transplant follow-up without conclusive conventional imaging. FDG PET/CT results were compared to histology or to the finding obtained during a clinical/imaging follow-up period of at least 6 months after PET/CT study. RESULTS: Positive FDG PET/CT results were obtained in 18 (31 %) patients. In the remaining 40 (69 %) cases, FDG PET/CT was negative, showing exclusively a physiological radiotracer distribution. On the basis of a patient-based analysis, FDG PET/CT's sensitivity, specificity, PPV and NPV were respectively 78 %, 90 %, 78 % and 90 %, with a global accuracy of 86 %. FDG PET/CT was true positive in 14 patients with bacterial pneumonias (n = 4), pulmonary fungal infection (n = 1), histoplasmosis (n = 1), cutaneous abscess (n = 1), inflammatory disorder (sacroiliitis) (n = 1), lymphoma (n = 3) and NSCLC (n = 3). On the other hand, FDG PET/CT failed to detect lung bronchoalveolar adenocarcinoma, septicemia, endocarditis and graft-versus-host disease (GVHD), respectively, in four patients. FDG PET/CT contributed to adjusting the patient therapeutic strategy in 40 % of cases. CONCLUSIONS: FDG PET/CT emerges as a valuable technique to manage complications in the post-transplantation period. FDG PET/CT should be considered in patients with severe unexplained inflammatory syndrome or FUO and inconclusive conventional imaging or to discriminate active from silent lesions previously detected by conventional imaging particularly when malignancy is suspected.

Impact of Malignancies in the Early and Late Time Course of Takotsubo Cardiomyopathy.

BACKGROUND: Although the relationship between malignancies and catecholamine-induced myocardial stunning remains largely speculative, it has been suggested that the presence of cancer may lower the threshold for stress stimuli and/or may aggravate cardiac adrenoreceptor sensitivity. We sought to investigate whether associations exist between a previous or current diagnosis of malignancy, diagnostic parameters during hospitalization and death in takotsubo. METHODS AND RESULTS: The 154 takotsubo patients were retrospectively identified between May 2008 and December 2014. Previous history of malignancy was identified in 44 patients (28.5%). Cardiac arrest was present at admission in 13 patients (8.4%). Intra-aortic balloon pump was inserted in 16 patients (10.4%). In patients with malignancy, higher B-type natriuretic peptide (BNP), leukocyte and C-reactive protein (CRP) peaks could be observed during the hospital phase. Initial impairment of left ventricular ejection fraction was negatively related to BNP, leukocyte, and CRP peaks. At a median follow-up of 364 days, all-cause death occurred in 41 patients (26.6%) and cardiac death in 12 patients (7.7%). Multivariate Cox regression analysis identified malignancy (hazard ratio 4.77 (1.02-22.17), leukocyte peak and age as independent predictors of cardiac death. Malignancy (2.62 (1.26-5.44), leukocyte peak (1.05 (1.01-1.08) and initial cardiac arrest (6.68 (2.47-18.01) were identified as independent predictors of overall mortality. CONCLUSIONS: In the present takotsubo patients, the prevalence of malignancy was high and may have affected cardiovascular outcomes through the activation of inflammatory and neurohormonal mechanisms. (Circ J 2016; 80: 2192-2198).

Pathological Laughing: Brain SPECT Findings.

We present the case of a 40-year-old man consulting for uncontrollable episodes of laughing related to emotional lability and not systematically linked to feelings of happiness. Seven months earlier he had presented a pontine ischemic stroke related to an occlusion of the basilar and left vertebral arteries. No epileptic activity or new MRI brain lesions were found. Brain perfusion SPECT performed showed marked hypoperfusion in the right frontal inferior and temporoinsular regions, suggesting a diaschisis phenomenon caused by pontine lesions and highlighted laughing regulation pathways. The patient was successfully treated with a serotonergic reuptake inhibitor, fluoxetine.

18F-FDG PET/CT Findings in a Patient With a Proliferating Trichilemmal Cyst.

Proliferating trichilemmal cyst is considered as a rare tumor that originates in the outer root sheath of hair follicle. Metastatic potential has not been yet fully established. Moreover, histological analysis does not allow precise malignancy prediction. Proliferating trichilemmal cyst glucose metabolism behavior was never previously described. Herein, we report the case of a 62-year-old patient with a left shoulder proliferating trichilemmal cyst showing an intense uptake of ¹8F-FDG on PET/CT examination. ¹8F-FDG PET/CT could be proposed to optimize diagnostic strategy of patients with proliferating trichilemmal cysts.

FDG PET findings of the brain in sudden blindness caused by bilateral central retinal artery occlusion revealing giant cell arteritis.

We report the case of a 73-year-old woman presenting sudden blindness caused by bilateral simultaneous central retinal artery occlusion revealed by ophthalmoscopy. Temporal artery biopsy confirmed the giant cell arteritis. The patient was treated with a systemic steroid without visual recovery. FDG PET/CT was performed 6 months later in the context of persistent inflammatory syndrome. This case shows the close relationship between functional activity and glucose energy metabolism. We observed both bilateral occipital hypometabolism corresponding to loss of functional activity and bilateral temporal (auditory areas) and orbitofrontal hypermetabolism related to compensatory neuronal plasticity.

Importance of inflammation and neurohumoral activation in Takotsubo cardiomyopathy.

BACKGROUND: To gain more insight into the involvement of inflammatory response and neurohumoral activation in Takotsubo cardiomyopathy (TTC), we investigated C-reactive protein (CRP), leukocytes, plasma catecholamines levels, iodine 123 meta-iodobenzylguanidine (123I-mIBG) myocardial uptake, myocardial perfusion (thallium 201 [201Tl] or technetium [Tc] 99m-tetrofosmin myocardial single photon emission computed tomography [SPECT]), and metabolism (fluorine 18-fluorodeoxyglucose positron emission tomography). METHODS AND RESULTS: Inflammatory status and brain natriuretic peptide (BNP) levels in 17 patients with TTC were compared with 14 age-matched patients. In TTC, elevated levels of CRP were evidenced on admission, reaching a peak in the following days (P < .01). CRP levels were correlated to baseline left ventricular ejection fraction (LVEF) and BNP levels (P < .05). Leukocytes were correlated to BNP and noradrenaline levels. Myocardial 123I-mIBG SPECT showed a reduced activity in the midventricle and apex corresponding to 35% +/- 23% of the total myocardial mass, partially reversible at follow-up. An identical pattern was retrieved when assessing myocardial glucose metabolism. At rest, no relevant abnormalities of myocardial perfusion could be evidenced at the subacute phase. CONCLUSION: Inflammatory status in TTC was related to LVEF impairment and to the extent of neurohormonal activation. The hypothesis of a catecholamine-induced myocardial "stunning" is emphasized by the evidence of a reduced 123I-mIBG myocardial activity, impairment of myocardial glucose metabolism, and wall motion kinetic after the same temporospatial distribution.