The Caudate Lobe: The Blind Spot in Radioembolization or an Overlooked Opportunity?

Purpose

The caudate lobe (CL) is impartial to the functional left and right hemi-liver and has outspoken inter-individual differences in arterial vascularization. Unfortunately, this complexity is not specifically taken into account during radioembolization treatment (RE), potentially resulting in under- or overtreatment of the CL. The objective of this study was to evaluate the CL coverage in RE and determine the detection rate of the CL arteries on CT angiography during work-up.

Methods

In all consecutive patients who underwent RE treatment between May 2012–January 2015, ^99mTc-MAA SPECT/CT and posttreatment scans (⁹⁰Y-bremsstrahlung SPECT/CT, ⁹⁰Y-PET/CT, or ¹⁶⁶Ho-SPECT/CT) were reviewed for activity in the CL. Pretreatment CT angiographies were reviewed for the visibility of the CL arteries.

Results

Eighty-two patients were treated. In 32/82 (39 %) the CL was involved. In 6/32 (19 %) patients, no activity was seen on the posttreatment scan in the CL, whereas in 40/50 (80 %) patients without CL tumor involvement, the CL was treated. ^99mTc-MAA SPECT/CT and final posttreatment scans were discordant in 16/78 (21 %). ^99mTc-MAA SPECT/CT had a positive and negative predictive value of 94 % and 46 %, respectively, for activity in the CL after RE. In untreated CLs, significant hypertrophy was observed with a median volume increase of 33 % (p = 0.02). CL arteries were seldom visible on the pretreatment CT; the identification rate was 12–17 %.

Conclusion

Currently in RE treatments, targeting or sparing of the CL is highly erratic and independent of tumor involvement. Intentional treatment or bypassing of the CL seems worthwhile to either improve tumor coverage or enhance the functional liver remnant.

     

Perfusion CT best predicts outcome after radioembolization of liver metastases: a comparison of radionuclide and CT imaging techniques

Objective

To determine the best predictor for the response to and survival with transarterial radioembolisation (RE) with ⁹⁰yttrium microspheres in patients with liver metastases.

Methods

Forty consecutive patients with liver metastases undergoing RE were evaluated with multiphase CT, perfusion CT and ^99mTc-MAA SPECT. Arterial perfusion (AP) from perfusion CT, HU values from the arterial (aHU) and portal venous phase (pvHU) CT, and ^99mTc-MAA uptake ratio of metastases were determined. Morphologic response was evaluated after 4 months and available in 30 patients. One-year survival was calculated with Kaplan-Meier curves.

Results

We found significant differences between responders and non-responders for AP (P?<?0.001) and aHU (P?=?0.001) of metastases, while no differences were found for pvHU (P?=?0.07) and the ^99mTc-MAA uptake ratio (P?=?0.40). AP had a significantly higher specificity than aHU (P?=?0.003) for determining responders to RE. Patients with an AP >20 ml/100 ml/min had a significantly (P?=?0.01) higher 1-year survival, whereas an aHU value >55 HU did not discriminate survival (P?=?0.12). The Cox proportional hazard model revealed AP as the only significant (P?=?0.02) independent predictor of survival.

Conclusion

Compared to arterial and portal venous enhancement and the ^99mTc-MAA uptake ratio of liver metastases, the AP from perfusion CT is the best predictor of morphologic response to and 1-year survival with RE.

Key Points

? Perfusion CT allows for calculation of the liver arterial perfusion. ? Arterial perfusion of liver metastases differs between responders and non-responders to RE. ? Arterial perfusion can be used to select patients responding to RE.     

99mTc-MAA overestimates the absorbed dose to the lungs in radioembolization: a quantitative evaluation in patients treated with 166Ho-microspheres

Purpose

Radiation pneumonitis is a rare but serious complication of radioembolic therapy of liver tumours. Estimation of the mean absorbed dose to the lungs based on pretreatment diagnostic ^99mTc-macroaggregated albumin (^99mTc-MAA) imaging should prevent this, with administered activities adjusted accordingly. The accuracy of ^99mTc-MAA-based lung absorbed dose estimates was evaluated and compared to absorbed dose estimates based on pretreatment diagnostic ¹⁶⁶Ho-microsphere imaging and to the actual lung absorbed doses after ¹⁶⁶Ho radioembolization.

Methods

This prospective clinical study included 14 patients with chemorefractory, unresectable liver metastases treated with ¹⁶⁶Ho radioembolization. ^99mTc-MAA-based and ¹⁶⁶Ho-microsphere-based estimation of lung absorbed doses was performed on pretreatment diagnostic planar scintigraphic and SPECT/CT images. The clinical analysis was preceded by an anthropomorphic torso phantom study with simulated lung shunt fractions of 0 to 30 % to determine the accuracy of the image-based lung absorbed dose estimates after ¹⁶⁶Ho radioembolization.

Results

In the phantom study, ¹⁶⁶Ho SPECT/CT-based lung absorbed dose estimates were more accurate (absolute error range 0.1 to ?4.4 Gy) than ¹⁶⁶Ho planar scintigraphy-based lung absorbed dose estimates (absolute error range 9.5 to 12.1 Gy). Clinically, the actual median lung absorbed dose was 0.02 Gy (range 0.0 to 0.7 Gy) based on posttreatment ¹⁶⁶Ho-microsphere SPECT/CT imaging. Lung absorbed doses estimated on the basis of pretreatment diagnostic ¹⁶⁶Ho-microsphere SPECT/CT imaging (median 0.02 Gy, range 0.0 to 0.4 Gy) were significantly better predictors of the actual lung absorbed doses than doses estimated on the basis of ¹⁶⁶Ho-microsphere planar scintigraphy (median 10.4 Gy, range 4.0 to 17.3 Gy; p?99mTc-MAA SPECT/CT imaging (median 2.5 Gy, range 1.2 to 12.3 Gy; p?99mTc-MAA planar scintigraphy (median 5.5 Gy, range 2.3 to 18.2 Gy; p?Conclusion In clinical practice, lung absorbed doses are significantly overestimated by pretreatment diagnostic ^99mTc-MAA imaging. Pretreatment diagnostic ¹⁶⁶Ho-microsphere SPECT/CT imaging accurately predicts lung absorbed doses after ¹⁶⁶Ho radioembolization.     

Assessment of hepatic functional regeneration after hepatectomy using 99mTc-GSA SPECT/CT fused imaging

Background

The liver itself regenerates after hepatectomy but little is known about how much hepatic function recovers during the regeneration. The liver uptake value (LUV), calculated from Tc-99m-labeled galactosyl-human-serum-albumin (^99mTc-GSA) SPECT/CT fused images, is reliable and useful for evaluating hepatic function. In this study, we evaluated the clinical usefulness of LUV for estimating hepatic functional regeneration after hepatectomy.

Methods

We enrolled 95 patients who had undergone ^99mTc-GSA SPECT/CT tests before/on days 30 and 90 after hepatectomy. We determined the LUV from the ^99mTc-GSA SPECT/CT images and calculated the %LUV (postoperative LUV/preoperative LUV × 100). Based on surgical procedures and histopathological damage, we divided the study population into patients with severe (n = 12) or non-severe fibrosis (n = 33) who had undergone minor hepatectomy, and patients with severe (n = 14) or non-severe fibrosis (n = 36) having major hepatectomy. On the 90th post-hepatectomy day, five patients manifested liver failure; in these patients, we analyzed the co-relation between liver failure and the results of the liver function tests performed on day 30 after surgery.

Results

Although the %LUV reached 95.4 ± 12.2 % in 30 days, in patients with severe fibrosis after major hepatectomy it remained below 90 %. Patients having low %LUV (<75 %) and high serum bilirubin (>2.0 mg/dl) at 30 days showed a relative risk of liver failure of 12.0 and 4.5 (p < 0.001 and p < 0.001), respectively.

Conclusions

Although the %LUV recovered to about 95 % in all patients within 30 days after the hepatectomy, in patients with severe fibrosis having major hepatectomy, the process of recovery was delayed. The %LUV corresponded to the quality of the liver function which emerged in a later post-hepatectomy phase.     

Feasibility of temporary protective embolization of normal liver tissue using degradable starch microspheres during radioembolization of liver tumours

Purpose

To describe a new approach to protect nontarget healthy liver tissue using degradable starch microspheres (DSM) as a short-term embolizate during radioembolization of liver tumours with ⁹⁰Y microspheres.

Methods

Between December 2011 and July 2012 radioembolization was performed in 54 patients. Five of these patients (three women, two men; mean age 67 years) underwent protective temporary embolization using DSM (EmboCept® S) of normal liver tissue that could not be excluded from the area treated by radioembolization through catheter repositioning. Clinical symptoms, laboratory findings, preinterventional imaging, and ^99mTc-MAA and bremsstrahlung SPECT/CT, as well as baseline and follow-up imaging with ¹⁸F-FDG PET/CT and MRI, were evaluated in relation to the technical and clinical success of the protective embolization.

Results

Temporary embolization of arteries supplying normal liver tissue using DSM was technically successful in all five patients. ^99mTc-MAA SPECT/CT performed in the first two patients after DSM injection showed no increased pulmonary shunting compared to the MAA test injection without DSM. Bremsstrahlung SPECT/CT after radioembolization demonstrated satisfactory irradiation of the tumour and successful protection of normal liver tissue. There were only mild hepatotoxic effects (grade 1) on laboratory follow-up examinations, and no adverse events associated with DSM embolization or radioembolization were recorded.

Conclusion

Temporary embolization with DSM before radioembolization is feasible and can effectively protect areas of normal liver tissue from irradiation and avoid permanent embolization if other methods such as catheter repositioning are not possible due to the location of the metastases.     

Performance of 18F-FDG PET/CT as a postoperative surveillance imaging modality for asymptomatic advanced gastric cancer patients

Objective

The purpose of this study was to investigate the diagnostic performance of postoperative fluorine-18 fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) as a surveillance modality for advanced gastric cancer patients who were asymptomatic and negative by conventional follow-up.

Methods

We retrospectively collected 46 advanced gastric cancer patients who received approximately 1-year-postoperative ¹⁸F-FDG PET/CT surveillance following curative resection (mean age 60.6 ± 11.5 years). ¹⁸F-FDG PET/CT was interpreted by nuclear medicine physicians who were blind to the clinical information. Final confirmation was determined by clinical follow-up using tumor markers, conventional CT scan, upper gastrointestinal endoscopy and with/without subsequent histopathologic diagnosis.

Results

Four patients developed recurrence (8.7 %; 1 local and 3 distant recurrences). For local recurrence, ¹⁸F-FDG PET/CT found four hypermetabolic lesions and one was local recurrence. For distant recurrence, seven hypermetabolic lesions were found in six patients and true-positive was three lesions. False-positive cases were mainly turned out to be physiologic small bowel uptake. Regardless of the recurrence site, the sensitivity, specificity, positive predictive value and negative predictive value of ¹⁸F-FDG PET/CT were 100 % (4/4, 95 % confidence interval (CI) 39.6–100 %), 88.1 % (37/42, 95 % CI 73.6–95.5 %), 44.4 % (4/9, 95 % CI 15.3–77.3 %) and 100 % (37/37, 95 % CI 88.3–100 %), respectively in the patient-based analysis.

Conclusion

Our study showed good specificity of postoperative surveillance ¹⁸F-FDG PET/CT for detecting recurrence. Careful caution should be made for interpreting some false-positive hypermetabolic lesions in postoperative ¹⁸F-FDG PET/CT, especially at the local anastomosis site.     

18F-Fluorocholine PET/CT for localization of hyperfunctioning parathyroid tissue in primary hyperparathyroidism: a pilot study

Purpose

Primary hyperparathyroidism is a common endocrine disorder which is diagnosed biochemically and for which therapy is surgical. A prerequisite for minimally invasive surgery, which minimizes morbidity and cost, is accurate localization of the involved gland(s). The aim of this study was to evaluate the usefulness of ¹⁸F-fluorocholine PET/CT for preoperative localization of hyperfunctioning parathyroid tissue.

Methods

¹⁸F-Fluorocholine PET/CT and conventional parathyroid scintigraphic imaging consisting of ^99mTc-sestaMIBI SPECT/CT, ^99mTc-sestaMIBI dual-phase imaging and ^99mTc-sestaMIBI/pertechnetate subtraction imaging were performed in 24 patients. The diagnostic performance of the imaging methods was compared against histology as the gold standard and postoperative serum Ca²⁺ and iPTH values.

Results

The sensitivity and specificity of ¹⁸F-fluorocholine PET/CT were 92 % and 100 %, respectively, in contrast to 49 % and 100 %, 46 % and 100 %, and 44 % and 100 % for ^99mTc-sestaMIBI SPECT/CT, ^99mTc-sestaMIBI/pertechnetate subtraction imaging and ^99mTc-sestaMIBI dual-phase imaging, respectively. Combined conventional scintigraphic imaging had a sensitivity and specificity of 64 % and 100 %, respectively. The performance of ¹⁸F-fluorocholine PET/CT was superior particularly in patients with multiple lesions or hyperplasia.

Conclusion

¹⁸F-Fluorocholine PET/CT appears to be a promising, effective imaging method for localization of hyperfunctioning parathyroid tissue.     

Contrast between hypervascularized liver lesions and hepatic parenchyma: early dynamic PET versus contrast-enhanced CT

Objectives

To detect hypervascularized liver lesions, early dynamic (ED) ¹⁸F-FDG PET may be an alternative when contrast-enhanced (CE) imaging is infeasible. This retrospective pilot analysis compared contrast between such lesions and liver parenchyma, an important objective image quality variable, in ED PET versus CE CT.

Materials and methods

Twenty-eight hypervascularized liver lesions detected by CE CT [21 (75 %) hepatocellular carcinomas; mean (range) diameter 4.9 ± 3.5 (1–14) cm] in 20 patients were scanned with ED PET. Using regions of interest, maximum and mean lesional and parenchymal signals at baseline, arterial and venous phases were calculated for ED PET and CE CT.

Results

Lesional/parenchymal signal ratio was significantly higher (P < 0.005) with ED PET versus CE CT at the arterial phase and similar between the methods at the venous phase.

Conclusion

In liver imaging, ED PET generates greater lesional–parenchymal contrast during the arterial phase than does CE CT; these observations should be formally, prospectively evaluated.     

Diagnostic Value of 68Ga-DOTATATE PET/CT in Liver Metastases of Neuroendocrine Tumours of Unknown Origin

Purpose

In neuroendocrine liver metastases of unknown primary, a multimodality approach is usually adopted and consists of transabdominal ultrasound, endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine techniques, endoscopy and exploratory surgery. The purpose of the study is to evaluate the diagnostic value of ⁶⁸Ga-DOTATATE positron emission tomography (PET)/CT as part of a multimodality approach in neuroendocrine liver metastases of unknown primary.

Materials and Methods

Six patients (M:F?=?5:1, age range 28–56 years) with immunohistochemically proven neuroendocrine liver metastases but inconclusive initial CT work-up were retrospectively analysed. Clinical finding, histopathology, comparative imaging and follow-up were used to validate the results when ethically justified.

Results

⁶⁸Ga-DOTATATE PET/CT identified the primary tumour in five out of six (83.3 %) patients: pancreas (n?=?4) and stomach (n?=?1). Out of three patients with indeterminate primary on initial CT, two patients were confirmed by ⁶⁸Ga-DOTATATE PET/CT. Absence of uptake in indeterminate primary of one patient was later confirmed negative by histopathology. In another three patients with undetected primary on initial CT, primary site was demonstrated in all patients with unsuspected metastases in two patients on ⁶⁸Ga-DOTATATE PET/ CT. No further work-up was done to confirm the primary in patients with distant metastases. Change of management was observed in three out of six (50 %) patients.

Conclusion

Our small study indicates that ⁶⁸Ga-DOTATATE PET/CT is a promising diagnostic option in the multimodality approach to neuroendocrine liver metastases of unknown primary origin.     

Usefulness of 99mTc-pertechnetate whole body scan with neck and chest SPECT/CT for detection of post-surgical thyroid remnant and metastasis in differentiated thyroid cancer patients

Objective

The aim of the study was to evaluate the usefulness of ^99mTc-pertechnetate whole body scan (WBS) with neck and chest SPECT/CT for detection of post-surgical thyroid remnant and metastasis in differentiated thyroid cancer (DTC) patients.

Methods

Fifty-six post total thyroidectomy patients were included. All patients were prospectively imaged with ^99mTc-pertechnetate WBS with neck and chest SPECT/CT before ¹³¹I ablation. The post-ablative ¹³¹I WBS with SPECT/CT was performed at 5–7 days after receiving ¹³¹I. Both scans were directly compared to determine the concordance of sites and number of remnant and metastasis.

Results

Overall per-patient analysis, the percentage of concordance between two scans was 96.4 %. In thyroid bed, lymph node, lung and bone subgroups, the percentage of concordance between two scans was 96.4, 92.9, 98.2 and 100 %, respectively. All of them show good correlation with unweighted kappa between 0.7 and 1. Overall per-lesion analysis, the percentage of concordance between two scans was 84 %. In thyroid bed, lymph node, lung and bone subgroups, the percentage of concordance between two scans was 89.5, 55, 82.6 and 50 %, respectively.

Conclusions

Pre-ablative pertechnetate WBS with neck and chest SPECT/CT has good correlation for the detection of post-surgical thyroid remnant, cervical node and discrete lung nodule metastasis as compared to ¹³¹I WBS with SPECT/CT per-patient basis. Because ¹³¹I therapeutic activity is desired base on metastatic site and less concerning about the number of lesions, pre-ablative ^99mTc-pertechnetate WBS with SPECT/CT was a good alternative tool to avoid radioiodine stunning in post-surgical DTC patients.     

N-butyl Cyanoacrylate Glue Embolization of Arterial Networks to Facilitate Hepatic Arterial Skeletonization before Radioembolization

Purpose

Avoidance of nontarget microsphere deposition via hepatoenteric anastomoses is essential to the safety of yttrium-90 radioembolization (RE). The hepatic hilar arterial network may remain partially patent after coil embolization of major arteries, resulting in persistent risk. We retrospectively reviewed cases where n-butyl cyanoacrylate (n-BCA) glue embolization was used to facilitate endovascular hepatic arterial skeletonization before RE.

Methods

A total of 543 RE procedures performed between June 2004 and March 2012 were reviewed, and 10 were identified where n-BCA was used to embolize hepatoenteric anastomoses. Arterial anatomy, prior coil embolization, and technical details were recorded. Outcomes were reviewed to identify subsequent complications of n-BCA embolization or nontarget RE.

Results

The rate of complete technical success was 80 % and partial success 20 %, with one nontarget embolization complication resulting in a minor change in treatment plan. No evidence of gastrointestinal or biliary ischemia or infarction was identified, and no microsphere-related gastroduodenal ulcerations or other evidence of nontarget RE were seen. Median volume of n-BCA used was <0.1 ml.

Conclusion

n-BCA glue embolization is useful to eliminate hepatoenteric networks that may result in nontarget RE, especially in those that persist after coil embolization of major vessels such as the gastroduodenal and right gastric arteries.     

68Ga-DOTATATE PET/CT in the evaluation of patients with neuroendocrine metastatic carcinoma of unknown origin

Objective

There is little evidence regarding the role of ⁶⁸Ga-DOTATATE PET/CT for the identification of primary tumors in patients with metastatic neuroendocrine carcinoma of unknown primary. The aim of this study is to assess the value of this technique in the mentioned clinical scenario.

Methods

We retrospectively studied twenty-nine patients (mean age 59.5 ± 10.6 years; female 17) with pathologically proven neuroendocrine metastases. In all cases conventional imaging was negative for primary tumor identification. ⁶⁸Ga-DOTATATE PET/CT was performed with a mean dose of 104.2 ± 18.8 MBq, using a 64-slice PET/CT with time-of-flight correction. A team of an experienced radiologist and a nuclear medicine physician evaluated the images. The maximum SUV (SUVm) was measured in all abnormal foci. Histopathology (when available) and/or clinical follow-up with correlative imaging was considered as reference standard.

Results

⁶⁸Ga-DOTATATE PET/CT identified the primary tumor in 17/29 (59 %) patients in the following locations: pancreas (n = 7), ileum (n = 7), duodenum (n = 1), colon (n = 1) and stomach (n = 1). In this population a significant correlation was found between SUVm of primary tumor and metastases (r = 0.815, P < 0.0001). Furthermore, additional sites of unsuspected metastases were demonstrated in 9 patients of this group and in 6 patients in whom no primary tumor was localized, mainly in lymph nodes and mesentery. Pathology confirmation was obtained in 7 patients who underwent surgery, whereas in the remaining 10 patients, correlative imaging and follow-up confirmed primary tumor localization.

Conclusions

⁶⁸Ga-DOTATATE PET/CT is a clinically useful imaging technique for the localization of primary tumors in patients with neuroendocrine metastatic carcinoma of unknown origin with the potential of having a significant impact in patient management and therapy planning.     

The role of metabolic tumor volume and total lesion glycolysis on 18F-FDG PET/CT in the prognosis of epithelial ovarian cancer

Purpose

This study assessed the prognostic value of pre-operative 2-[¹⁸F] fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) volumetric parameters, including metabolic tumor volume (MTV) and total lesion glycolysis (TLG), in patients with epithelial ovarian cancer.

Methods

A total of 175 patients with epithelial ovarian cancer who underwent ¹⁸?F-FDG PET/CT and subsequent cytoreductive surgery were retrospectively enrolled. Maximum standardized uptake value (SUVmax) on ¹⁸F-FDG PET/CT was measured for all patients. Because nine patients showed low tumor-to-background uptake ratios, MTV and TLG were measured in 166 patients. Univariate and multivariate analyses were performed to evaluate the prognostic significance of SUVmax, MTV, TLG, and clinicopathological factors for disease progression-free survival.

Results

Disease progressed in 78 (44.6 %) of the 175 patients, and the 2-year disease progression-free survival rate was 57.5 %. Univariate analysis showed that tumor stage, histopathological type, presence of regional lymph node metastasis, residual tumor after cytoreductive surgery, pre-operative serum carbohydrate antigen 125 (CA125) level, SUVmax, MTV, and TLG were significant prognostic factors (p?100.0).

Conclusion

Along with tumor stage, TLG is an independent prognostic factor for disease progression after cytoreductive surgery in patients with epithelial ovarian cancer. By combining tumor stage and TLG, one can further stratify the risk of disease progression for patients undergoing cytoreductive surgery.     

Pretherapy metabolic tumour volume is an independent predictor of outcome in patients with diffuse large B-cell lymphoma

Purpose

We investigated the prognostic value of total metabolic tumour volume (TMTV) in diffuse large B-cell lymphoma (DLBCL).

Methods

TMTV was measured in 114 patients with newly diagnosed DLBCL who underwent ¹⁸F-FDG PET/CT at baseline before immunochemotherapy. TMTV was computed by summing the volumes of all lymphomatous lesions after applying the local SUVmax threshold of 41 % using semiautomatic software. Prognostic value was assessed by Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS).

Results

Median follow-up was 39 months. Average pretherapy TMTV was 509?±?568 cm³. The 3-year estimates of PFS were 77 % in the low metabolic burden group (TMTV ≤550 cm³) and 60 % in the high metabolic burden group (TMTV >550 cm³, p?=?0.04), and prediction of OS was even better (87 % vs. 60 %, p?=?0.0003). Cox regression showed independence of TMTV for OS prediction (p?=?0.002) compared with other pretherapy indices of tumour burden, such as tumour bulk and the International Prognostic Index.

Conclusion

Pretherapy TMTV is an independent predictor of outcome in patients with DLBCL.     

Radioembolisation with 90Y-labelled resin microspheres in the treatment of liver metastasis from breast cancer

Objectives

Metastatic breast cancer is a heterogeneous disease, commonly affecting the liver. We report our experience with ⁹⁰Y radioembolisation (RE) and its effects on the survival of patients with treatment-refractory breast cancer liver metastases.

Methods

A total of 77 female patients affected by breast cancer were accepted into our department for RE. Inclusion criteria were inoperable and chemotherapy-refractory hepatic metastases, acceptable performance status, sufficient residual liver, no significant hepato-pulmonary shunts. Patients were divided in two groups: group 1 (29 patients) included those with Eastern Cooperative Oncology Group (ECOG) score 0, liver involvement (0–25 %) and no extrahepatic disease (EHD); group 2 (23 patient) included patients with ECOG score 1–2, liver involvement (26–50 %) and evidence of EHD.

Results

A total of 25 patients were considered ineligible. The median age of the remaining 52 patients was 57.5 years. The median overall survival was 11.5 months and better in those whose performance status and liver function were preserved (14.3 versus 8.2 months). According to Response Evaluation Criteria in Solid Tumor (RECIST), partial response (PR) was achieved in 29 patients (56 %), stable disease (SD) was achieved in a further 18 patients (35 %) and 5 patients showed progressive disease (PD) (10 %).

Discussion

⁹⁰Y RE is effective in the treatment of liver metastases from breast cancer. We demonstrated a relevant survival and encouragingly high response rate in patients with treatment-refractory disease.

Key Points

? Interventional radiological techniques are increasingly used for metastatic disease in the liver. ? ⁹⁰ Y radioembolisation (RE) seems effective for treating hepatic metastases from breast cancer. ? RE is safe and well tolerated when performance status and liver function are preserved.     

Pulmonary veno-occlusive disease: the role of CT

Objective

The authors sought to evaluate the diagnostic accuracy of high-resolution computed tomography (HRCT) in the detection of pulmonary veno-occlusive disease (PVOD) in patients with pre-capillary pulmonary arterial hypertension (PAH) of unknown aetiology, and to identify the role of CT in diagnosis and therapy.

Materials and methods

The CT scans of 96 patients were retrospectively reviewed and assessed for specific HRCT findings: ground-glass opacities, septal lines and mediastinal lymph nodal enlargement (short diameter ≥1 cm). According to the HRCT findings, patients were divided into PVOD-suspicious and not PVOD-suspicious. Subsequently, a clinical-instrumental evaluation was performed, and the response to therapy and histopathological reports were evaluated.

Results

Radiological evaluation based on HRCT findings revealed 29 patients as PVOD-suspicious and 67 as not PVOD-suspicious. The final diagnosis was PVOD in 22 patients and idiopathic PAH in 74 patients. The CT scan showed 95.5 % sensitivity, 89 % specificity, 72.5 % positive predictive value, and 98.5 % negative predictive value, with a diagnostic accuracy of 90.5 % in identifying patients with PVOD.

Conclusions

Chest CT can be considered a screening test in the assessment of patients with PAH of unknown aetiology, and the radiologist can help the clinician to identify patients with CT findings that make PVOD highly probable.     

Comparison of the prognostic values of 68Ga-DOTANOC PET/CT and 18F-FDG PET/CT in patients with well-differentiated neuroendocrine tumor

Purpose

To determine the prognostic value of ⁶⁸Ga-DOTANOC PET/CT in patients with well-differentiated neuroendocrine tumor (NET), and to compare the prognostic value with that of ¹⁸F-FDG PET/CT and other conventional clinicopathological prognostic factors.

Methods

Data from 37 consecutive patients (age 46.6?±?13.5 years, 51 % men) with well-differentiated NET who underwent ⁶⁸Ga-DOTANOC PET/CT and ¹⁸F-FDG PET/CT were analyzed. All patients underwent a baseline visit with laboratory and radiological examinations. Clinical and imaging follow-up was performed in all patients. Progression-free survival (PFS) was measured from the date of the first PET/CT scan to the first documentation of progression of disease.

Results

⁶⁸Ga-DOTANOC PET/CT was positive in 37 of the 37 patients and ¹⁸F-FDG PET/CT was positive in 21. During follow-up 10 patients (27 %) showed progression of disease and 27 (73 %) showed no progression (24 stable disease, 3 partial response). The median follow-up was 25 months (range 2 – 52 months). Among the variables evaluated none was significantly different between the progressive disease and nonprogressive disease groups, with only SUVmax on ⁶⁸Ga-DOTANOC PET/CT being borderline significant (P?=?0.073). In the univariate analysis for PFS outcome, SUVmax on ⁶⁸Ga-DOTANOC PET/CT (HR 0.122, 95 % CI 0.019 – 0.779; P?=?0.026) and histopathological tumor grade (HR 4.238, 95 % CI 1.058 – 16.976; P?=?0.041) were found to be associated with PFS. Other factors including age, sex, primary site, Ki-67 index, TNM stage, ¹⁸F-FDG PET/CT status (positive/negative), SUVmax on ¹⁸F-FDG PET/CT and type of treatment were not significant. In multivariable analysis, only SUVmax on ⁶⁸Ga-DOTANOC PET/CT was found to be an independent positive predictor of PFS (HR 0.122, 95 % CI 0.019 – 0.779; P?=?0.026).

Conclusion

SUVmax measured on ⁶⁸Ga-DOTANOC PET/CT is an independent, positive prognostic factor in patients with well-differentiated NET and is superior to SUVmax on ¹⁸F-FDG PET/CT and conventional clinicopathological factors for predicting PFS.     

Assessment of aortitis by semiquantitative analysis of 180-min 18F-FDG PET/CT acquisition images

Purpose

The aim of this study was to evaluate the contribution of semiquantitative analysis of 180-min ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT images for the assessment of aortitis in cases of suspected large vessel vasculitis (LVV) and to establish a threshold index for application in the clinical setting.

Methods

This prospective study included 43 patients (mean age 67.5?±?12.9?years) with suspicion of LVV (25 with a final diagnosis of aortitis). ¹⁸F-FDG PET/CT scan was acquired 180 min after injection of 7 MBq/kg of ¹⁸F-FDG. A semiquantitative analysis was performed calculating the aortic wall maximum standardized uptake value (SUV_max) (T), the lumen SUV_max (B) and the target to background ratio (TBR). These results were also compared with those obtained in a control population.

Results

The mean aortic wall SUV_max was 2.00?±?0.62 for patients with aortitis and 1.45?±?0.31 for patients without aortitis (p?p?max (0.997 vs 0.871). The highest sensitivity and specificity was obtained for a TBR of 1.34 (sensitivity 100 %, specificity 94.4 %).

Conclusion

Semiquantitative analysis of PET/CT images acquired 180 min after ¹⁸F-FDG injection and the TBR index of 1.34 show very high accuracy and, therefore, are strongly recommended for the diagnosis of aortitis in the clinical setting.     

Right ventricular 18F-FDG uptake is an important indicator for cardiac involvement in patients with suspected cardiac sarcoidosis

Purpose

Cardiac sarcoidosis is most commonly found in the left ventricular (LV) free wall. Presence in the right ventricle (RV) is less common but might be useful for detecting cardiac involvement of sarcoidosis. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET has been used to detect LV regions with cardiac sarcoidosis. However, the same has not been done for RV involvement. The aims of the current study were to evaluate RV ¹⁸F-FDG uptake and its relationship to the distribution of LV wall ¹⁸F-FDG-positive segments in the LV, and to evaluate whether patients with positive RV ¹⁸F-FDG uptake met the 1993 diagnostic criteria of the Japanese Ministry of Health and Welfare (JMHW) guidelines regarding sarcoidosis with suspected cardiac involvement.

Method

Fifty-nine biopsy-proven extra-cardiac sarcoidosis patients (age 56.1 ± 14.7 years) with suspected cardiac involvement based on abnormal electrocardiography or echocardiography findings underwent fasting ¹⁸F-FDG PET or PET/CT. The LV wall was divided into 17 segments and RV uptake was also evaluated.

Result

Among 59 patients, 35 (59.3 %) showed some abnormal ¹⁸F-FDG uptake in the RV and/or LV wall. With respect to the RV wall, 13 (22.0 %) showed abnormal ¹⁸F-FDG uptake. The number of LV-involved segments was 4.8 ± 2.4 in the patients with RV ¹⁸F-FDG uptake, which was significantly higher than in the patients without RV uptake, 1.8 ± 2.2 (P < 0.0001). Patients with RV uptake more frequently met the diagnostic criteria of the 1993 JMHW guidelines (n = 27), than did those without RV uptake (84.6 vs. 34.8 %, P = 0.0033).

Conclusion

¹⁸F-FDG PET identified RV involvement less frequently than LV involvement in this study population. However, patients who had RV uptake showed a greater number of LV-involved segments and met the JMHW diagnostic criteria more frequently. Although RV uptake is less frequent, ¹⁸F-FDG RV uptake may be useful in diagnosing cardiac involvement in sarcoidosis.

Clinical trial registration

UMIN000006533.     

Impact of 11C-choline PET/CT on clinical decision making in recurrent prostate cancer: results from a retrospective two-centre trial

Purpose

The aim of this retrospective two-centre study was to investigate the clinical impact of ¹¹C-choline PET/CT on treatment management decisions in patients with recurrent prostate cancer (rPCa) after radical therapy.

Methods

Enrolled in this retrospective study were 150 patients (95 from Bologna, 55 from Würzburg) with rPCa and biochemical relapse (PSA mean?±?SD 4.3?±?5.5 ng/mL, range 0.2–39.4 ng/mL) after radical therapy. The intended treatment before PET/CT was salvage radiotherapy of the prostatic bed in 95 patients and palliative androgen deprivation therapy (ADT) in 55 patients. The effective clinical impact of ¹¹C-choline PET/CT was rated as major (change in therapeutic approach), minor (same treatment, but modified therapeutic strategy) or none. Multivariate binary logistic regression analysis included PSA level, PSA kinetics, ongoing ADT, Gleason score, TNM, age and time to relapse.

Results

Changes in therapy after ¹¹C-choline PET/CT were implemented in 70 of the 150 patients (46.7 %). A major clinical impact was observed in 27 patients (18 %) and a minor clinical impact in 43 (28.7 %). ¹¹C-choline PET/CT was positive in 109 patients (72.7 %) detecting local relapse (prostate bed and/or iliac lymph nodes and/or pararectal lymph nodes) in 64 patients (42.7 %). Distant relapse (paraaortic and/or retroperitoneal lymph nodes and/or bone lesions) was seen in 31 patients (20.7 %), and both local and distant relapse in 14 (9.3 %). A significant difference was observed in PSA level and PSA kinetics between PET-positive and PET-negative patients (p?p?p?>?0.05). In both centres the same criteria to validate PET-positive findings were used: in 17.3 % of patients by histology and in 82.7 % of patients by correlative imaging and/or clinical follow-up (follow-up mean 20.5 months, median 18.3 months, range 6.2–60 months).

Conclusion

¹¹C-Choline PET/CT had a significant impact on therapeutic management in rPCa patients. It led to an overall change in 46.7 % of patients, with a major clinical change implemented in 18 % of patients. Further prospective studies are needed to evaluate the effect of such treatment changes on patient survival.