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AIM: The manufacturers' recommended methods to calculate delivered activities in liver radioembolization are simplistic and only slightly personalized. Activity planning could also be based on a 99mTc-macroaggregated albumin SPECT/CT (MAA) using the partition model but its accuracy is controversial. This study evaluates the dose parameters in the normal liver and in the tumor compartments using MAA SPECT/CT (pre-therapeutic imaging) and 90Y TOF-PET/CT (post-therapy imaging). Finally, we propose a prescription of the activity as a function of the normal liver MAA distribution. METHOD: 66 procedures of RE (with resin microspheres) corresponding to 171 lesions were analyzed. Tumor to normal targeted liver uptake (T/NTL), tumor absorbed dose (TD) and whole normal liver absorbed (WNLD) were assessed with MAA and 90Y imaging. Secondly, activities were recalculated using the MAA distribution in the normal liver compartment to reach the maximal tolerable liver dose. These Activities were compared to activities defined with the BSA method. RESULTS: Compared to 90Y imaging, our study demonstrated an accurate estimation of the WNLD using MAA imaging (Pearson's R = 0.97, p < 0.001). On the contrary, significant variations were found for TD (R = 0.65, p < 0.001). The MAA T/NTL ratio has a 85% positive predictive value in identifying patients who will get a 90Y T/NTL ratio above 1.5. Moreover, activities calculated using the MAA distribution in the normal liver compartment were significantly higher to activities defined with the BSA method. CONCLUSION: Whole normal liver absorbed doses are accurately predicted with MAA imaging and could be used to optimize the activity planning.

PURPOSE: To compare the accuracy and safety of 0.56 GBq resin yttrium-90 ((90)Y) (scout(90)Y) microspheres with those of technetium-99m macroaggregated albumin (MAA) in predicting the therapeutic (90)Y (Rx(90)Y) dose for patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This prospective single-arm clinical trial (Clinicaltrials.gov: NCT04172714) recruited patients with HCC. Patients underwent same-day mapping with MAA and scout(90)Y. Rx(90)Y activity was administered 3 days after mapping. Using paired t test and Pearson correlation, the tumor-to-normal ratio (TNR), lung shunt fraction (LSF), predicted mean tumor dose (TD), and nontumoral liver dose (NTLD) by MAA and scout(90)Y were compared with those by Rx(90)Y. Bland-Altman plots compared the level of agreement between the TNR and LSF of scout(90)Y and MAA with that of Rx(90)Y. The safety of scout(90)Y was evaluated by examining the discrepancy in extrahepatic activity between MAA and scout(90)Y. RESULTS: Thirty patients were treated using 19 segmental and 14 nonsegmental (ie, 2 contiguous segments or nonsegmental) therapies. MAA had weak LSF, moderate TNR, and moderate TD linear correlation with Rx(90)Y. Scout(90)Y had a moderate LSF, strong TNR, strong TD, and very strong NTLD in correlation with those of Rx(90)Y. Furthermore, the TNR and LSF of scout(90)Y had a stronger agreement with those of Rx(90)Y than with those of MAA. In the nonsegmental subgroup, MAA had no significant correlation with the TD and NTLD of Rx(90)Y, whereas scout(90)Y had a very strong correlation with both of these factors. In the segmental subgroup, both MAA and scout(90)Y had a strong linear correlation with the TD and NTLD of Rx(90)Y. CONCLUSIONS: Compared with MAA, scout(90)Y is a more accurate surrogate for Rx(90)Y biodistribution for nonsegmental therapies.

Rationale: In muscle-invasive bladder cancer (MIBC), lymph node invasion has proven to be an independent predictor of disease recurrence and cancer-specific survival. We evaluated the feasibility of targeting the sentinel node (SN) for biopsy in MIBC patients using the hybrid tracer indocyanine green (ICG)-Tc-99m-nanocolloid for simultaneous radioguidance and fluorescence guidance. Methods: Twenty histologically confirmed cN0M0 MIBC patients (mean age, 63.3 years; range, 30-82 years), scheduled for radical cystectomy with SN biopsy and extended pelvic lymph node dissection (ePLND), were prospectively included. Twelve patients were operated on following neoadjuvant chemotherapy. The patients received lymphoscintigraphy as well as SPECT/CT after 4 transurethral injections of ICG-Tc-99m-nanocolloid (mean, 208 MBq; range, 172-229 MBq) around the tumor/scar in the detrusor muscle of the bladder on the day before radical cystectomy. Sentinel node resection was performed under radioguidance and fluorescence guidance. Results: Nineteen patients could be analyzed. On preoperative imaging, SNs could be identified in 10 patients (53%; mean, 1.6 SN/patient), which revealed drainage pathways outside the ePLND in 20% of the patients. Interesting to note is that 2 patients (10%) with preoperative nonvisualization displayed fluorescent and radioactive SNs during surgery. Location of the primary tumor near the left lateral side of the bladder seemed to be a factor for nonvisualization. Nodal harvesting with ePLND varied among patients (mean, 23.3). Histopathology confirmed tumor-positive nodes in 4 (21%) of all patients. In the 2 patients where an SN could be identified, the ePLND specimens were tumor-negative. All patients with tumor-positive nodes had advanced disease (stage III). Conclusion: Sentinel node biopsy in bladder cancer using the hybrid tracer ICG-Tc-99m-nanocolloid is feasible, and preoperative imaging is predictive for the ability to perform SN biopsy in 83% of the patients who displayed an SN. In patients with a successful preoperative SN mapping using lymphoscintigraphy and SPECT/CT, the intraoperative SN guidance and detection were effective, even outside the ePLND area. As such, this study underscores the critical role that preoperative imaging plays in challenging image-guided surgery applications.

To evaluate the role of dysmorphic intratumoral vessels as imaging marker for the prediction of high lung shunt fraction (LSF) in patients with hepatocellular carcinoma (HCC). This retrospective study included 403 patients with HCC who underwent a planning arteriography for transarterial radioembolization with administration of 99mTc-macroaggregated albumin to calculate LSF. The LSF was measured by using planar body scans. Two radiologists evaluated the pre-treatment contrast-enhanced CT findings, including tumor number, size, margin, distribution, tumor burden, portal and hepatic vein invasion, early hepatic vein enhancement, and dysmorphic intratumoral vessels. The logistic regression analysis was performed to determine significant predictors for high LSF > 20%. Using the identified predictors, diagnostic criteria for high LSF were proposed. Among 403 patients, 52 (13%) patients had high LSF > 20%, and dysmorphic tumor vessels were present in 115 (28.5%) patients. Predictors for LSF > 20% were tumor size > 11 cm, hepatic vein invasion, early hepatic vein enhancement, and dysmorphic intratumoral vessel. If the patient had three or more of the four predictors for LSF > 20% on imaging, the accuracy and specificity for diagnosing LSF > 20% were 88.8% and 96.3% respectively. Dysmorphic intratumoral vessel in HCC is an imaging marker suggesting a high LSF, which may be applicable to treatment modification or patient exclusion for radioembolization with combined interpretation of tumor size and hepatic vein abnormality.

Patients with severe acute liver injury (SLI) usually recover spontaneously. However, some SLI patients progress to acute liver failure with varying degrees of hepatic encephalopathy. Acute liver failure is associated with high mortality and can be substantially reduced by liver transplantation. Therefore, distinguishing SLI patients who might progress to acute liver failure and are at a risk of death is important when evaluating patients needing liver transplantation. The present study aimed to determine whether technetium-99m-diethylenetriaminepentaacetic acid galactosyl human serum albumin (Tc-99m GSA) scintigraphy can predict the prognosis of patients with SLI. This prospective observational study included 69 SLI patients. The accuracy of Tc-99m GSA for predicting death or liver transplantation for 6 months was assessed. Between the two groups of patients stratified based on the cut-off values from the receiver operating characteristic curves, 6-month transplant-free survival was compared. Sixteen (23.2%) patients died or underwent liver transplantation from admission (poor outcome). The hepatic accumulation index was calculated by dividing the radioactivity of the liver region of interest by that of the liver-plus-heart region of interest at 15 min (i.e., LHL15). The LHL15 in the 16 patients (0.686) was significantly lower than that in survivors (0.836; P

PURPOSE We aimed to evaluate whether the perfusion pattern from pretreatment hepatic artery perfusion scintigraphy (HAPS) in patients with liver malignancies can predict response to selective internal radiation therapy (SIRT). METHODS This retrospective study analyzed 152 consecutive patients treated with yttrium-90 (90Y) resin microspheres between April 2015 and July 2017. HAPS using single-photon emission computed tomography/computed tomography (SPECT/CT) with 99mtechnetium macroaggregated albumin (99mTc-MAA) was performed before SIRT. Investigators visually classified perfusion patterns of tumors as heterogeneous or diffuse in HAPS. Between diffuse and heterogeneous pattern group, positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) were performed in third and sixth month after SIRT, and tumor response assessed and compared by using RECIST 1.1 or mRECIST. Overall survival (OS) and progression-free survival (PFS) were also compared with Kaplan-Meier/log-rank analyses. RESULTS Of 216 SIRT procedures, 172 were classified as heterogeneous and 44 as diffuse. Diffuse 99mTc- MAA uptake was associated with longer median OS than heterogeneous (22.2 vs. 14.4 months, respectively; P = .047). Subsegmental infusion was associated with longer OS than either lobar or segmental infusion (P = .090). Mean estimated OS was longer in patients with hepatocellular carcinoma (HCC) (34.2 months) than with colorectal carcinoma (CRC) (16.4 months) (P = .044). Patients with both diffuse and heterogeneous patterns were able to show complete response after SIRT. No statistically significant differences were observed between perfusion patterns and PFS or response rates to SIRT. CONCLUSION Although tumor perfusion patterns from preplanning HAPS analyses are useful for estimating tumor uptake of 90Y, they may not reliably predict hepatic treatment response, as patients with different perfusion patterns can show clinical response to SIRT.

Technetium-99m macroaggregated albumin ([

Background To improve therapy outcome of Yttrium-90 selective internal radiation therapy (90Y SIRT), patient-specific post-therapeutic dosimetry is required. For this purpose, various dosimetric approaches based on different available imaging data have been reported. The aim of this work was to compare post-therapeutic 3D absorbed dose images using Technetium-99m (99mTc) MAA SPECT/CT, Yttrium-90 (90Y) bremsstrahlung (BRS) SPECT/CT, and 90Y PET/CT. Methods Ten SIRTs of nine patients with unresectable hepatocellular carcinoma (HCC) were investigated. The 99mTc SPECT/CT data, obtained from 99mTc-MAA-based treatment simulation prior to 90Y SIRT, were scaled with the administered 90Y therapy activity. 3D absorbed dose images were generated by dose kernel convolution with scaled 99mTc/90Y SPECT/CT, 90Y BRS SPECT/CT, and 90Y PET/CT data of each patient. Absorbed dose estimates in tumor and healthy liver tissue obtained using the two SPECT/CT methods were compared against 90Y PET/CT. Results The percentage deviation of tumor absorbed dose estimates from 90Y PET/CT values was on average −2 ± 18% for scaled 99mTc/90Y SPECT/CT, whereas estimates from 90Y BRS SPECT/CT differed on average by −50 ± 13%. For healthy liver absorbed dose estimates, all three imaging methods revealed comparable values. Conclusion The quantification capabilities of the imaging data influence 90Y SIRT tumor dosimetry, while healthy liver absorbed dose values were comparable for all investigated imaging data. When no 90Y PET/CT image data are available, the proposed scaled 99mTc/90Y SPECT/CT dosimetry method was found to be more appropriate for HCC tumor dosimetry than 90Y BRS SPECT/CT based dosimetry.

Selective internal radiation therapy (SIRT) is part of the treatment strategy for hepatocellular carcinoma (HCC). Strong clinical data demonstrated the effectiveness of this therapy in HCC with a significant improvement in patient outcomes. Recent studies demonstrated a strong correlation between the tumor response and the patient outcome when the tumor-absorbed dose was assessed by nuclear medicine imaging. Dosimetry plays a key role in predicting the clinical response and can be optimized using a personalized method of activity planning (multi-compartmental dosimetry). This paper reviews the main clinical results of SIRT in HCC and emphasizes the central role of dosimetry for improving it effectiveness. Moreover, some patient and tumor characteristics predict a worse outcome, and toxicity related to SIRT treatment of advanced HCC patient selection based on the performance status, liver function, tumor characteristics, and tumor targeting using technetium-99m macro-aggregated albumin scintigraphy can significantly improve the clinical performance of SIRT.

PURPOSE It may be challenging to select the optimal scan duration for single-photon emission computed tomography (SPECT) protocols because the activity distribution characteristics can differ in every scan. Using simulations and experiments, we investigated whether the scan duration can be optimized for every scan separately by evaluating the activity distribution during scanning. We refer to this as adaptive scanning. METHODS The feasibility of adaptive scanning was evaluated for the detection of extrahepatic depositions in the pretreatment procedure of radioembolization, in which 99m Tc-labeled macroaggregated albumin (99m Tc-MAA) is injected into the liver. We simulated fast 1-min detector rotations and updated the reconstruction with the newly collected counts after every rotation. The scan was terminated when one of the two criteria was met: (a) when the mask difference of the detected extrahepatic deposition between two consecutive rotations was lower than 5%; or (b) when the reconstructed extrahepatic activity was negligible with respect to the total reconstructed activity (

Background/Aim: Indocyanine green (ICG) clearance test is one of the most popular dynamic methods for evaluating preoperative liver function to avoid posthepatectomy liver failure (PHLF). Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl human serum albumin scintigraphy (GSA) also facilitates the direct estimation of functional hepatocytes and can estimate the ICG retention rate (R15); however, in some cases, there is a discrepancy between results of a preoperative examination of ICG-R15 and the estimated ICG-R15 obtained by 99mTc-GSA (GSA-R15). This study evaluated the gap between ICG-R15 and GSA-R15 (ΔICG) for predicting background liver fibrosis in patients who underwent hepatectomy. Patients and Methods: Sixty-four consecutive patients who underwent hepatectomy and preoperative ICG-R15 and GSA-R15 examinations from 2016 to 2019 were retrospectively evaluated. The gap between GSA-R15 and ICG-R15 was defined as ΔICG and the factors predicting liver fibrosis were investigated. Results: In the pathologically-proven cirrhotic group, platelet counts were significantly lower and ΔICG values were significantly larger than those in the non-/early-cirrhotic group. A multivariate analysis identified a higher total bilirubin level, a higher AST level, and a larger ΔICG level as significant predictive factors for liver cirrhosis. Conclusion: Larger ΔICG was found to be an independent preoperative predictor of liver fibrosis and may positively contribute to decision-making before hepatectomy to avoid PHLF.

PURPOSE: We aimed to determine whether antireflux (ARC) catheter may result in better tumor targeting in liver radioembolization using (90)Y-resin microspheres. METHODS: Patients treated with resin microspheres for hepatocellular carcinoma (HCC) and secondary liver malignancies were retrospectively analyzed. All patients underwent a (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) single photon emission computed tomography (SPECT) following the planning arteriography with a conventional end-hole catheter. For (90)Y-microspheres injection, two groups were defined depending on the type of catheter used: an ARC group (n=38) and a control group treated with a conventional end-hole catheter (n=23). (90)Y positron emission tomography computed tomography (PET/CT) was performed after the therapeutic arteriography. The choice of the catheter was not randomized, but left to the choice of the interventional radiologist. (99m)Tc-MAA SPECT and (90)Y PET/CT were co-registered with the baseline imaging to determine a tumor to normal liver ratio (T/NL([MAA or 90Y])) and tumor dose (TD([MAA or 90Y])) for the planning and therapy. RESULTS: Overall, 38 patients (115 lesions) and 23 patients (75 lesions) were analyzed in the ARC and control groups, respectively. In the ARC group, T/NL(90Y) and TD(90Y) were significantly higher than T/NL(MAA) and TD(MAA). Median (IQR) T/NL(90Y) was 2.16 (2.15) versus 1.74 (1.43) for T/NL(MAA) (p < 0.001). Median (IQR) TD(90Y) was 90.96 Gy (98.31 Gy) versus 73.72 Gy (63.82 Gy) for TD(MAA) (p < 0.001). In this group, the differences were highly significant for neuroendocrine metastases (NEM) and HCC and less significant for colorectal metastases (CRM). In the control group, no significant differences were demonstrated. CONCLUSION: The use of an ARC significantly improves tumor deposition in liver radioembolization with resin microspheres.

Albumin nanocolloids have been used as radiopharmaceuticals for more than 40 years. Their main use is in lymphoscintigraphy and the detection of the sentinel lymph node as part of the surgical treatment of a variety of solid tumours. The main licensed products are labelled with the gamma emitter technetium-99m. Recently, two analogues labelled with positron emitters have been reported, using gallium-68 and zirconium-89. For about 10 years, there has been interest in dual-modal agents with both radioactive and fluorescent labels to improve the localisation of the sentinel lymph node. Indocyanine green (ICG) has been the most widely used fluorescent label, largely due to its availability as a licensed agent and its ease of application. The further development of alternative radiolabels or improved fluorescent tags will require investment in the development and licensing. There is also a vast potential for the targeting of albumin nanocolloids using existing strategies, which could be promising for the development of both diagnostic and therapeutic agents.

Radiation pneumonitis is a rare but possibly fatal side effect of (90)Y radioembolization. It may occur 1–6 mo after therapy, if a significant part of the (90)Y microspheres shunts to the lungs. In current clinical practice, a predicted lung dose greater than 30 Gy is considered a criterion to exclude patients from treatment. However, contrasting findings regarding the occurrence of radiation pneumonitis and lung dose were previously reported in the literature. In this study, the relationship between the lung dose and the eventual occurrence of radiation pneumonitis after (90)Y radioembolization was investigated. Methods: We retrospectively analyzed 317 (90)Y liver radioembolization procedures performed during an 8-y period (February 2012 to September 2020). We calculated the predicted lung mean dose (LMD) using (99m)Tc-MAA planar scintigraphy (LMD(MAA)) acquired during the planning phase and left LMD (LMD(Y-90)) using the (90)Y PET/CT acquired after the treatment. For the lung dose computation, we used the left lung as the representative lung volume, to compensate for scatter from the liver moving in the craniocaudal direction because of breathing and mainly affecting the right lung. Results: In total, 272 patients underwent (90)Y procedures, of which 63% were performed with glass microspheres and 37% with resin microspheres. The median injected activity was 1,974 MBq (range, 242–9,538 MBq). The median LMD(MAA) was 3.5 Gy (range, 0.2–89.0 Gy). For 14 procedures, LMD(MAA) was more than 30 Gy. Median LMD(Y-90) was 1 Gy (range, 0.0–22.1 Gy). No patients had an LMD(Y-90) of more than 30 Gy. Of the 3 patients with an LMD(Y-90) of more than 12 Gy, 2 patients (one with an LMD(Y-90) of 22.1 Gy and an LMD(MAA) of 89 Gy; the other with an LMD(Y-90) of 17.7 Gy and an LMD(MAA) of 34.1 Gy) developed radiation pneumonitis and consequently died. The third patient, with an LMD(Y-90) of 18.4 Gy (LMD(MAA), 29.1 Gy), died 2 mo after treatment, before the imaging evaluation, because of progressive disease. Conclusion: The occurrence of radiation pneumonitis as a consequence of a lung shunt after (90)Y radioembolization is rare (

Aim: To evaluate the efficacy of chemoembolization versus radioembolization in reducing lung shunt fraction (LSF) in patients with hepatocellular carcinoma (HCC). Patients and Methods: In this retrospective study, from March 2012 to January 2021, 457 patients with HCC underwent planning angiography and (99m)Tc-macroaggregated albumin imaging for possible yttrium-90 radioembolization. Ten patients underwent radioembolization, and seven patients underwent conventional chemoembolization for LSF reduction, and a second (99m)Tc-macroaggregated albumin imaging was obtained approximately 1 month later. LSF under both procedures was compared with the Mann-Whitney U-test and the Wilcoxon signed-rank test. Results: In the radioembolization group, the mean first and second LSF were 13.0±6.9% and 20.9±9.6%, respectively (p=0.059); after radioembolization, LSF was lower in three patients but higher in seven patients. In the chemoembolization group, the mean first and second LSF were 26.1±17.3% and 8.7±5.5%, respectively (p=0.018); after chemoembolization, LSF was reduced in all seven patients. Conclusion: Chemoembolization appears to be more effective in reducing LSF within 1 month compared with radioembolization.

Purpose A multidisciplinary expert panel convened to formulate state-of-the-art recommendations for optimisation of selective internal radiation therapy (SIRT) with yttrium-90 ( 90 Y)-resin microspheres. Methods A steering committee of 23 international experts representing all participating specialties formulated recommendations for SIRT with 90 Y-resin microspheres activity prescription and post-treatment dosimetry, based on literature searches and the responses to a 61-question survey that was completed by 43 leading experts (including the steering committee members). The survey was validated by the steering committee and completed anonymously. In a face-to-face meeting, the results of the survey were presented and discussed. Recommendations were derived and level of agreement defined (strong agreement ≥ 80%, moderate agreement 50%–79%, no agreement ≤ 49%). Results Forty-seven recommendations were established, including guidance such as a multidisciplinary team should define treatment strategy and therapeutic intent (strong agreement); 3D imaging with CT and an angiography with cone-beam-CT, if available, and 99m Tc-MAA SPECT/CT are recommended for extrahepatic/intrahepatic deposition assessment, treatment field definition and calculation of the 90 Y-resin microspheres activity needed (moderate/strong agreement). A personalised approach, using dosimetry (partition model and/or voxel-based) is recommended for activity prescription, when either whole liver or selective, non-ablative or ablative SIRT is planned (strong agreement). A mean absorbed dose to non-tumoural liver of 40 Gy or less is considered safe (strong agreement). A minimum mean target-absorbed dose to tumour of 100–120 Gy is recommended for hepatocellular carcinoma, liver metastatic colorectal cancer and cholangiocarcinoma (moderate/strong agreement). Post-SIRT imaging for treatment verification with 90 Y-PET/CT is recommended (strong agreement). Post-SIRT dosimetry is also recommended (strong agreement). Conclusion Practitioners are encouraged to work towards adoption of these recommendations., info:eu-repo/semantics/published

Purpose Predictive 3-dimensional dosimetry requires spatial concordance between diagnostic and therapeutic activity distributions. We assess similarity between theranostic pairs ( 99m Tc–macroaggregated albumin [MAA] single photon emission computed tomography [SPECT] and 90 Y microsphere positron emission tomography [PET]) in patients using criteria that account for spatial resolution differences and misregistration. Methods and Materials Phantom-based acceptance criteria were determined using a liver phantom filled with 99m Tc and 90 YCl 3 and scanned with SPECT/computed tomography [CT] and PET/CT, respectively. Gaussian blurring was applied to PET to match 99m Tc phantom scan image quality. After rigid registration between SPECT/CT and PET/CT, perturbations up to ±3 voxels were applied to determine the similarity metric (SM) sensitivity. 99m Tc-MAA SPECT/CT and 90 Y microsphere PET/CT image pairs/patients (n = 23) were processed analogously. SMs calculated included the Pearson correlation coefficient ( ρ r ), Lin's concordance correlation coefficient ( ρ c ), Spearman's rank correlation coefficient ( ρ s ), the mean squared difference, and the Dice similarity coefficient (DSC). Patient-specific acceptance criteria were determined by evaluating the SMs of the blurred PET compared with itself misregistered. Results After transforming PET to SPECT resolution, high similarity was found in phantom, with ρ c , ρ r , ρ s > 0.98 ± 0.01, a mean squared difference of (4.1 ± 0.3) × 10 −4 and DSC > 0.85 ± 0.01 for investigated thresholds (5%, 30%, and 50%). SMs for patients varied from poor to good. A small percentage (13%-30%) of patient scans were acceptable using phantom-based acceptance criteria. The percentage increased slightly (17%-35%) using patient-specific acceptance criteria. DSC for most patients were substantially lower (average 0.95 vs 0.61 for 5% threshold) than phantom values. Conclusions At best, 35% of patients had an SM within the acceptance criteria established to account for imaging-related effects impacting spatial concordance between 99m Tc-MAA SPECT and 90 Y PET. Additional clinical factors should be evaluated in the future. The procedure of accounting for image-related effects when assessing spatial concordance can be applied to other theranostic pairs.

Purpose: Reported outcomes of patients with intra-hepatic cholangiocarcinoma (IH-CCA) treated with radioembolization are highly variable, which indicates differences in included patients’ characteristics and/or procedure-related variables. This study aimed to identify patient- and treatment-related variables predictive for radioembolization outcome. Methods: This retrospective multicenter study enrolled 58 patients with unresectable and chemorefractory IH-CCA treated with resin 90Y-microspheres. Clinicopathologic data were collected from patient records. Metabolic parameters of liver tumor(s) and presence of lymph node metastasis were measured on baseline 18F-FDG-PET/CT. 99mTc-MAA tumor to liver uptake ratio (TLRMAA) was computed for each lesion on the SPECT-CT. Activity prescription using body-surface-area (BSA) or more personalized partition-model was recorded. The study endpoint was overall survival (OS) starting from date of radioembolization. Statistical analysis was performed by the log-rank test and multivariate Cox’s proportional hazards model. Results: Median OS (mOS) post-radioembolization of the entire cohort was 10.3 months. Variables associated with significant differences in terms of OS were serum albumin (hazard ratio (HR) = 2.78, 95%CI:1.29–5.98, p = 0.002), total bilirubin (HR = 2.17, 95%CI:1.14–4.12, p = 0.009), aspartate aminotransferase (HR = 2.96, 95%CI:1.50–5.84, p < 0.001), alanine aminotransferase (HR = 2.02, 95%CI:1.05–3.90, p = 0.01) and γ-GT (HR = 2.61, 95%CI:1.31–5.22, p < 0.001). The presence of lymph node metastasis as well as a TLRMAA < 1.9 were associated with shorter mOS: HR = 2.35, 95%CI:1.08–5.11, p = 0.008 and HR = 2.92, 95%CI:1.01–8.44, p = 0.009, respectively. Finally, mOS was significantly shorter in patients treated according to the BSA method compared to the partition-model: mOS of 5.5 vs 14.9 months (HR = 2.52, 95%CI:1.23–5.16, p < 0.001). Multivariate analysis indicated that the only variable that increased outcome prediction above the clinical variables was the activity prescription method with HR of 2.26 (95%CI:1.09–4.70, p = 0.03). The average mean radiation dose to tumors was significantly higher with the partition-model (86Gy) versus BSA (38Gy). Conclusion: Radioembolization efficacy in patients with unresectable recurrent and/or chemorefractory IH-CCA strongly depends on the tumor radiation dose. Personalized activity prescription should be performed., SCOPUS: ar.j, info:eu-repo/semantics/published

The relationship between posthepatectomy complications and liver functional parameters was preliminary reported in a pilot study. The present study sequentially evaluated the clinical significance of maximal removal rate of technetium-99m-galactosyl human serum albumin (GSAR(max)) in the future remnant liver (rGSAR(max)) in patients to predict posthepatectomy complications. METHODS: Between 2010 and August 2017, GSAR(max), rGSAR(max), their difference (Dif), and the rGSAR(max) to GSAR(max) ratio were examined in 247 additional patients who underwent hepatectomy for liver and biliary diseases. Hepatectomy-related postoperative complications (i.e. long-term ascites, intra-abdominal infection, and hepatic failure) occurred in 73 (29.6%) patients. RESULTS: The median and mean preoperative GSAR(max) values were 0.477 and 0.498±0.166 mg/min, respectively; rGSAR(max) values were 0.341 and 0.366±0.145 mg/min, respectively; Dif values were 0.105 and 0.132±0.111 mg/min, respectively; and the rGSAR(max) to GSAR(max) ratio values were 0.774 and 0.746±0.177, respectively. Among these, the GSAR(max) and rGSAR(max) values were significantly correlated with the liver functional parameters ICGR15, LHL15, HH15, prothrombin activity, serum hyaluronic acid level, and platelet count (all P

Objective The aim of this study was to determine whether technetium-99m (99mTc) nanocolloid was a suitable alternative tracer for carrying out milk scan studies in pediatric patients. Participants and methods Twenty-seven milk scans performed with 99mTc nanocolloid were retrospectively assessed for identification of significant esophageal hold-up, gastroesophageal reflux, pulmonary aspiration, and gastric emptying (GE). Scans were also assessed for liver, spleen, and bone marrow uptake. GE results were compared with those of 27 randomly selected normal GE studies carried out using 99mTc tin colloid. Results None of the studies had liver, spleen, or bone marrow uptake, and all studies were interpretable. Significant esophageal hold-up and gastroesophageal reflux was observed in 11 and 48% of the patients, respectively. Only one patient had evidence of pulmonary aspiration, and all patients had normal GE at 2 h after radiolabeled milk ingestion. The average rate of GE at 2 h was faster in the 99mTc nanocolloid group compared with the 99mTc tin colloid group (8.85% retained±8.96% vs. 15.48% retained±10.52%, P=0.016). Conclusion Our findings show that 99mTc nanocolloid is technically a suitable alternative to 99mTc sulfur colloid for performing milk scans. However, we could not conclude with certainty on the comparison of the GE rates of 99mTc nanocolloid and 99mTc tin colloid. This was because of the variability in the two population groups as well as the fact that the milk that was used in each patient was individualized to the patient and was not standardized.

Highlights • The resolution conversion method allowed comparison of 99mTc and 90Y imaging. • 99mTc pre-therapy imaging was predictive of the 90Y absorbed dose to normal liver. • 99mTc pre-therapy imaging had poor predictability for tumours smaller than 100 cm3., Purpose The aims of this study were to develop and apply a method to correct for the differences in partial volume effects of pre-therapy Technetium-99 m (99mTc)-MAA SPECT and post-therapy Yttrium-90 (90Y) bremsstrahlung SPECT imaging in selective internal radiation therapy, and to use this method to improve quantitative comparison of predicted and delivered 90Y absorbed doses. Methods The spatial resolution of 99mTc SPECT data was converted to that of 90Y SPECT data using a function calculated from 99mTc and 90Y point spread functions. This resolution conversion method (RCM) was first applied to 99mTc and 90Y SPECT phantom data to validate the method, and then to clinical data to assess the power of 99mTc SPECT imaging to predict the therapeutic absorbed dose. Results The maximum difference between absorbed doses to phantom spheres was 178%. This was reduced to 27% after the RCM was applied. The clinical data demonstrated differences within 38% for mean absorbed doses delivered to the normal liver, which were reduced to 20% after application of the RCM. Analysis of clinical data showed that therapeutic absorbed doses delivered to tumours greater than 100 cm3 were predicted to within 52%, although there were differences of up to 210% for smaller tumours, even after the RCM was applied. Conclusions The RCM was successfully verified using phantom data. Analysis of the clinical data established that the 99mTc pre-therapy imaging was predictive of the 90Y absorbed dose to the normal liver to within 20%, but had poor predictability for tumours smaller than 100 cm3.

Facial edemas not secondary to surgery and/or radiotherapy for head and neck cancer are relatively uncommon. Our aim is to report a retrospective analysis of the lymphoscintigraphic and SPECT-CT investigations obtained in patients with such facial edema. Retrospective review of exams (planar imagings in all and with SPECT-CT in 5) obtained after the subcutaneous injection of 99mTc HSA Nanosized colloids between the eyebrows in five men and seven women. Four main lymphatic pathways were identified on sequential planar imagings: para-nasal left and right and supra- ocular left and right. For eleven patients, the absence of visualization of lymphatic drainage and/or their delayed appearance correlated well with the localisation of the edematous areas. In two patients with post-traumatic and post- surgical edemas, SPECT-CT showed one deep left sided cervical lymph node (LN) in front of the first cervical vertebra. This lymphoscintigraphic approach represents a simple and valuable way to assess the lymphatic drainage pathways of the face and to establish the diagnosis of facial lymphedema.

99mTc-macroaggregated albumin (MAA) imaging is performed before transarterial radioembolization (TARE), in which SPECT/CT is presumed more precise than planar image. However, additive role of SPECT/CT has not been well established. Thirty-four consecutive hepatocellular carcinoma patients of intermediate and advanced stages who underwent 90Y-microsphere TARE were recruited. On pre-treatment planning scan using 99mTc-MAA, image characteristics and absorbed dose for target tumors calculated by partition model methods were estimated on planar image and SPECT/CT, respectively. The measurements were repeated on post-treatment 90Y PET/CT, as the reference standard. Treatment response was assessed and predictive values of image parameters were analyzed. The image characteristics including heterogeneity, necrosis and thrombosis uptake were better delineated on SPECT/CT than planar scan. The agreement and correlation of TNr between SPECT/CT and PET/CT were stronger than those between planar scan and PET/CT. Tumor dose estimated on 99mTc-MAA SPECT/CT was more effective than planar image for prediction of treatment response, with cutoff value 125 Gy (sensitivity of 86% and specificity of 75%). In conclusion, 99mTc-MAA SPECT/CT is more closely correlated with post-treatment 90Y PET/CT, and is more effective for predicting treatment response than planar scan. SPECT/CT is superior to planar image in simulation before 90Y TARE.

SARS-CoV-2 (COVID-19) infection is a current public health problem that has been shown to cause multiple complications, including pulmonary thromboembolism. The first presented case is a 59-year-old woman with a history of COPD, paroxysmal atrial fibrillation and COVID-19 infection in September 2020, consultation in December 2020 for atypical chest pain with suspected PE, AngioCT of pulmonary vessels was performed negative for emboli, subsequently [99mTc]Tc MAA SPECT/CT was indicated with a report of multiple triangular defects concerning acute pulmonary thromboembolism. A second case is a 70-year-old man with a history of dyslipidaemia, presented COVID-19 infection in September 2020 with a complication of PE with involvement of the left pulmonary artery, followed by [99mTc]Tc MAA SPECT/CT report multiple triangular and not triangles defects concerning pulmonary thromboembolism with signs of reperfusion.

Introduction The classical lymphoscintigraphic investigations of lower-limb lymphatic edema [LLLE] sometimes reveal either no or few lymph nodes [LNs] at the root of the limb[s] and/or in the abdomen. The aim of the present paper is to report the results of performing one additional injection at the root of the edematous limb[s] to force the visualization of the LNs and/or to demonstrate the collateral lymphatic pathways in such patients. Methods and findings We retrospectively reviewed our database and found 99 patients [44 primary LLLE with 47 limbs injected and 55 with LLLE secondary to treatments for cancer with 64 limbs injected] where such an additional injection had been performed. In the 43 LLLE patients where no LNs were seen at the end of the classical exam [15 primary LLLE and 28 secondary LLLE], the extra injection showed lymphatic drainage toward LN[s] in all except 3 and when at least one LN was seen, the injection showed lymphatic drainage in every case toward the same ipsilateral [inguinal and/or iliac] LNs [as shown by the classical injection] and/or toward additional LNs. In 40.7% of patients, we observed one or more additional lymphatic pathways: prepubic superficial lymphatic vessels [LV] crossing the midline anteriorly toward contralateral inguinal LNs in 21 [18.9%], “posterior” LV [toward contralateral inguinal LNs and/or ipsi- or contralateral lumbo-aortic and/or para-renal LNs] in 14 [12.6%], but deep LV toward the ipsilateral common iliac LNs passing between the gluteal muscles in 32 [28.8%]. Conclusion Our work pinpoints one limitation of classical bipedal radionuclide lymphangiography. In patients with primary and secondary LLLE where inguinal and/or iliac LNs cannot be seen on bipedal radionuclide lymphangiography, this additional injection reveals the true lymphonodal status and shows unexpected collateral lymphatic pathways in 40% of cases. Such information is of the utmost importance in LLLE management and its acquisition is consequently recommended in these patients., SCOPUS: ar.j, info:eu-repo/semantics/published

BACKGROUND/AIM Intraarterial Technetium-99m-Macroaggregated Albumin (99mTc-MAA) administration is an established method to predict particle distribution prior to radioembolization. This study aimed to analyse the impact of intraarterial administration of 99mTc-MAA on changes in liver-specific laboratory parameters and to assess whether such changes are associated with post-radioembolization hepatotoxicity. PATIENTS AND METHODS A total of 202 patients treated with radioembolization received prior mapping angiography with 99mTc-MAA administration. All patients underwent clinical and laboratory examinations, including liver-specific parameters at certain times before and after mapping angiography/99mTc-MAA administration, as well as before radioembolization and during follow-up. RESULTS Bilirubin increased temporarily after 99mTc-MAA administration (p

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Background/Aim: A recent planning study suggested that (99m)Tc-labelled diethylene triamine pentaacetate-galactosyl human serum albumin ((99m)Tc-GSA) single-photon emission computed tomography (SPECT) image-guided inverse planning (IGIP) shows dosimetric superiority to conventional planning in sparing liver function. Here, we report the first clinical translation of (99m)Tc-GSA SPECT IGIP for stereotactic body radiotherapy (SBRT) in a patient with hepatocellular carcinoma (HCC). Case Report: A 60-year-old male developed obstructive jaundice caused by recurrent HCC in segment 1 after hepatic resection. He underwent repeated radiotherapy (RT) consisting of 45 Gy in 15 fractions 8 years ago and 30 Gy in 5 fractions 2 years ago. We performed SBRT consisting of 40 Gy in 8 fractions using (99m)Tc-GSA SPECT-IGIP. We confirmed the dosimetric superiority of functional IGIP to conventional planning. He achieved complete response as assessed using the target volume. The patient has remained alive without recurrence for 18 months. He did not experience radiation-induced liver disease. Conclusion: Recurrent HCC was successfully and safely salvaged via re-irradiation with SBRT using (99m)Tc-GSA SPECT-IGIP.