Preoperative Positron Emission Tomography Research Articles

Maximum standardised uptake value of positron emission tomography as a predictor of oesophageal cancer outcomes

ObjectivesThis study aimed to analyse the value of pre-operative 18F-fluorodeoxyglucose positron emission tomography (PET)-computed tomography that can predict tumour pathological complete response, tumour histology grade, overall survival, and recurrence-free survival in patients with locally advanced oesophageal squamous cell carcinoma who underwent neoadjuvant chemoradiotherapy (NCRT) followed by surgery.MethodsWe retrospectively reviewed the cases of patients with locally advanced oesophageal squamous cell carcinoma undergoing NCRT followed by surgery. Patients who did not undergo PET within 3 months of surgery were excluded. We set a pre-operative PET maximum standardised uptake value (SUVmax) of > 5 as the threshold and classified the patients into two groups. We analysed the tumour response and histology grade, and compared the overall survival and recurrence-free survival between the two groups.ResultsThis cohort included 92 patients with oesophageal squamous cell carcinoma who underwent NCRT followed by surgery; 49 patients had a pre-operative PET SUVmax < 5, and 43 patients had a pre-operative PET SUVmax > 5. The patients’ pre-operative PET SUVmax correlated with tumour histology, ypT stage, and tumour response. Patients with a pre-operative SUVmax < 5 had better 2-year-overall survival (78% vs. 62%, P < 0.05) and 2-year recurrence-free survival (62% vs. 34%, P < 0.05) than those with a pre-operative SUV > 5.ConclusionsPre-operative SUVmax may be useful to predict tumour response, survival, and recurrence in patients with locally advanced oesophageal squamous cell carcinoma who undergo NCRT followed by surgery.

Is 18F-fluoride PET/CT an Accurate Tool to Diagnose Loosening After Total Joint Arthroplasty?

Several studies using positron emission tomography (PET) show highly elevated periprosthetic bone uptake of fluorine-18 sodium fluoride (18F-fluoride), suggestive of implant loosening after arthroplasty. Focus so far has been on qualitative but not on quantitative assessment. There is also a lack of intraoperative confirmation of preoperative 18F-fluoride PET findings. Although the method seems to have acceptable accuracy and high sensitivity, an attempt to improve the specificity and an overall validation of the method appear warranted. (1) Is there a difference in 18F-fluoride uptake around loose versus well-fixed THA and TKA components? (2) Can 18F-fluoride uptake measures provide a threshold that differentiates loose from well-fixed implants undergoing revision for a variety of septic and aseptic indications? (3) In a population restricted to THA and TKA undergoing revision for aseptic indications, can measurement of 18F-fluoride uptake still distinguish loose from well-fixed components? (4) What is the interrater reliability of measuring 18F-fluoride uptake? This was a retrospective assessment of a diagnostic test, 18F-fluoride PET/CT, which was performed prior to revision surgery. We included 63 patients with 31 THAs and 32 TKAs. Sixty-five percent of patients were female, and the mean age at 18F-fluoride PET/CT was 66 years. The THA had different modes of fixation (cemented, cementless, and hybrid; 45%, 32%, and 23%, respectively), whereas all TKAs were cemented. Imaging was conducted using routine protocols 1 hour after tracer injection. The interobserver reproducibility was analyzed using Spearman rank correlations and Bland-Altman analyses. Two independent observers were trained separately by a nuclear physician to measure maximal periprosthetic standardized uptake values (SUVmax) for each arthroplasty component (n = 126). Findings at surgery (whether the components were well fixed or loose, as well as the presence or absence of infection) were used as a reference. Presence of periprosthetic joint infection was retrospectively determined based on the criteria suggested by the European Bone and Joint Infection Society (EBJIS): clinical features in combination with blood analysis, synovial fluid cytologic analysis, and microbiology test results. Receiver operating characteristic (ROC) curves were plotted to assess the area under the curve (AUC) for each investigated component separately, indicating suitable SUVmax thresholds that differentiate loose from well-fixed components. After excluding patients with confirmed or suspected PJI per the EBJIS criteria (n = 12), the above analysis was repeated for the remaining patients with aseptic loosening (n = 51). We found higher 18F-fluoride uptake around loose versus well-fixed components in all but femoral TKA components (median [range] SUVmax for well-fixed versus loose THA cups 10 [7 to 30] versus 22 [6 to 64], difference of medians 12; p = 0.003; well-fixed versus loose TKA femoral components 14 [4 to 41] versus 19 [9 to 42], difference of medians 5; p = 0.38). We identified favorable ROC curves for all investigated components except femoral TKA components (THA cups AUC 0.81 [best threshold 13.9]; THA femoral stems AUC 0.9 [best threshold 17.3]; femoral TKA components AUC 0.6 [best threshold 14.3]; tibial TKA components AUC 0.83 [best threshold 15.8]). 18F-fluoride was even more accurate at diagnosing loosening when we limited the population to those patients believed not to have prosthetic joint infection (THA cups AUC 0.87 [best threshold 14.2]; THA femoral stems AUC 0.93 [best threshold 15.0]; femoral TKA components AUC 0.65 [best threshold 15.8]; tibial TKA components AUC 0.86 [best threshold 14.7]). We found strong interrater correlation when assessing SUVmax values, with Spearman ρ values ranging from 0.96 to 0.99 and Bland-Altman plots indicating excellent agreement between the two independent observers. Measuring SUVmax after 18F-fluoride PET/CT is a useful adjunct in the diagnostic evaluation for suspected implant loosening after THA and TKA. The method appears to be both accurate and reliable in diagnosing implant loosening for all components except femoral TKA components. In a real-world mixed population with both low-grade infection and aseptic loosening, the method seems to be fairly easy to learn and helpful to subspecialized arthroplasty clinicians. When infection can be ruled out, the method probably performs even better. Further prospective studies are warranted to explore the reason why femoral TKA component loosening was more difficult to ascertain using this novel technique. Level III, diagnostic study.

18F-FDG brain PET: a metabolic predictive factor for gait improvement after cerebrospinal fluid shunting in normal pressure hydrocephalus?

The pathophysiology of normal pressure hydrocephalus (NPH) has not been fully elucidated. Treating NPH with cerebrospinal fluid shunts to improve gait disturbances may have some risks and inconsistent benefits. No clear predictive factor has been identified thus far. This preliminary study aimed to evaluate the predictive value of preoperative brain 18F-FDG positron emission tomography (PET) on overall gait response in patients with NPH. Sixteen patients with NPH who underwent 18F-FDG PET before shunt surgery between 2012 and 2022 were included retrospectively and separated into two groups based on their gait response one year after surgery: responders (R) or nonresponders (NR). Brain glucose metabolism was assessed using visual and semiquantitative analyses using SPM8 software (Welcome Department of Cognitive Neurology, University College, London, UK). Five regions of interest were selected: global cortex, cerebellum, thalamus, striatum, and midbrain. Visual interpretation showed more frequent hypometabolism of the striatum, thalamus and global cortex in NR. None of the patients showing hypometabolism of these regions were R. Based on these results, the visual interpretation allowed us to identify 3/8 NR and 8/8 R. Semiquantitative analysis confirmed significantly lower thalamic metabolism in the NR group (P=0.037) and a trend towards lower metabolism of the striatum (P=0.075) with an area under the curve of 0.77 for thalamic metabolism to discriminate between R and NR. This preliminary study using brain 18F-FDG PET suggests that reduced brain metabolism in the thalamus and striatum along with cortical hypometabolism may be associated with poorer gait response to CSF shunting in normal pressure hydrocephalus (NPH). Although these findings suggest that preoperative brain 18F-FDG PET could potentially aid in selecting appropriate candidates for shunt surgery, further research with larger sample sizes is needed to confirm these results.

Clinical significance of the maximum standardized uptake value on positron emission tomography to predict treatment response and outcomes in patients with rectal cancer undergoing neoadjuvant chemoradiotherapy.

The association between the reduction rate of the maximum standardized uptake value (SUVmax) on positron emission tomography (PET) during neoadjuvant chemoradiotherapy (NACRT) and the prognosis in patients with locally advanced rectal cancer is unknown. We retrospectively analyzed 62 patients with locally advanced rectal cancer who underwent curative surgery after NACRT at Kobe University between 2008 and 2021. The SUVmax reduction rate was calculated from preoperative and postoperative PET scans, and its association with the prognosis was investigated. The cutoff value for SUVmax reduction rate was 61.5%. Twenty patients had an SUVmax reduction rate > 61.5% (SUV responder group) and 38 patients had an SUVmax reduction rate ≤ 61.5% (SUV nonresponder group). Regarding pathological outcomes, the rate of a good histological response was significantly higher in the SUV responder group than in the SUV nonresponder group (80.0% vs. 21.1%, p < 0.001). Both the overall (OS) and relapse-free survival (RFS) rates were significantly better in the SUV responder group than in the SUV nonresponder group (OS, p = 0.035; RFS, p = 0.019). In the SUV responder group, only 1 case of recurrence was observed, with a median follow-up period of 56months. The rate of SUVmax reduction during NACRT might predict the long-term prognosis of patients with locally advanced rectal cancer.

Radiologic Parameters Predicting the Histologic Invasiveness of Pure Ground-Glass Nodules

BackgroundThis study aimed to investigate the diagnostic performance of combined computed tomography (CT) and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for predicting histologic invasiveness of pure ground-glass nodules (pGGNs). MethodsThe study analyzed 91 patients who underwent resection of pGGNs and examined the correlation of pathologic invasiveness with preoperative CT and FDG PET findings. ResultsOverall, 24, 36, and 31 patients had adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAD), respectively. Compared with AIS and MIA, IAD was significantly correlated with larger CT size (P = .001), maximum CT value (P = .026), and high maximum standardized uptake value (SUVmax; P < .001). Multivariable logistic analyses revealed that CT size (odds ratio [OR], 3.848; P = .019) and SUVmax (OR, 4.968; P = .009) were independent predictors of histologic invasiveness. Receiver operating characteristic curve analysis revealed that a cutoff CT size value of 18 mm predicted histologic invasiveness with a sensitivity and specificity of 65% and 80%, respectively; similarly, a cutoff SUVmax value of 1.5 predicted histologic invasiveness with a sensitivity and specificity of 61% and 90%, respectively. Of 20 lesions with CT size ≥18 mm and SUVmax ≥1.5, 16 (80%) were IAD. Of 54 lesions with CT size <18 mm and SUVmax <1.5, 46 (85%) were non-IAD lesions. Furthermore, all pGGNs with SUVmax ≥2.5 were IAD. ConclusionsCT size and SUVmax were significantly correlated with the histologic invasiveness of pGGNs. These factors may aid in determining optimal surgical procedures.

Identifying G6PC3 as a Potential Key Molecule in Hypoxic Glucose Metabolism of Glioblastoma Derived from the Depiction of 18F-Fluoromisonidazole and 18F-Fluorodeoxyglucose Positron Emission Tomography.

Glioblastoma is the most aggressive primary brain tumor, characterized by its distinctive intratumoral hypoxia. Sequential preoperative examinations using fluorine-18-fluoromisonidazole (18F-FMISO) and fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) could depict the degree of glucose metabolism with hypoxic condition. However, molecular mechanism of glucose metabolism under hypoxia in glioblastoma has been unclear. The aim of this study was to identify the key molecules of hypoxic glucose metabolism. Using surgically obtained specimens, gene expressions associated with glucose metabolism were analyzed in patients with glioblastoma (n = 33) who underwent preoperative 18F-FMISO and 18F-FDG PET to identify affected molecules according to hypoxic condition. Tumor in vivo metabolic activities were semiquantitatively evaluated by lesion-normal tissue ratio (LNR). Protein expression was confirmed by immunofluorescence staining. To evaluate prognostic value, relationship between gene expression and overall survival was explored in another independent nonoverlapping clinical cohort (n = 17) and validated by The Cancer Genome Atlas (TCGA) database (n = 167). Among the genes involving glucose metabolic pathway, mRNA expression of glucose-6-phosphatase 3 (G6PC3) correlated with 18F-FDG LNR (P = 0.03). In addition, G6PC3 mRNA expression in 18F-FMISO high-accumulated glioblastomas was significantly higher than that in 18F-FMISO low-accumulated glioblastomas (P < 0.01). Protein expression of G6PC3 was consistent with mRNA expression, which was confirmed by immunofluorescence analysis. These findings indicated that the G6PC3 expression might be facilitated by hypoxic condition in glioblastomas. Next, we investigated the clinical relevance of G6PC3 in terms of prognosis. Among the glioblastoma patients who received gross total resection, mRNA expressions of G6PC3 in the patients with poor prognosis (less than 1-year survival) were significantly higher than that in the patients who survive more than 3 years. Moreover, high mRNA expression of G6PC3 was associated with poor overall survival in glioblastoma, as validated by TCGA database. G6PC3 was affluently expressed in glioblastoma tissues with coincidentally high 18F-FDG and 18F-FMISO accumulation. Further, it might work as a prognostic biomarker of glioblastoma. Therefore, G6PC3 is a potential key molecule of glucose metabolism under hypoxia in glioblastoma.

Utility of Preoperative Positron Emission Tomography (PET) in Localizing Perforator Vessels of Anterolateral Thigh Free Flap

Utility of Preoperative Positron Emission Tomography (PET) in Localizing Perforator Vessels of Anterolateral Thigh Free Flap

Navigated ultrasound bronchoscopy with integrated positron emission tomography-A human feasibility study.

Patients suspected to have lung cancer, undergo endobronchial ultrasound bronchoscopy (EBUS) for the purpose of diagnosis and staging. For presumptive curable patients, the EBUS bronchoscopy is planned based on images and data from computed tomography (CT) images and positron emission tomography (PET). Our study aimed to evaluate the feasibility of a multimodal electromagnetic navigation platform for EBUS bronchoscopy, integrating ultrasound and segmented CT, and PET scan imaging data. The proof-of-concept study included patients with suspected lung cancer and pathological mediastinal/hilar lymph nodes identified on both CT and PET scans. Images obtained from these two modalities were segmented to delineate target lymph nodes and then incorporated into the CustusX navigation platform. The EBUS bronchoscope was equipped with a sensor, calibrated, and affixed to a 3D printed click-on device positioned at the bronchoscope's tip. Navigation accuracy was measured postoperatively using ultrasound recordings. The study enrolled three patients, all presenting with suspected mediastinal lymph node metastasis (N1-3). All PET-positive lymph nodes were displayed in the navigation platform during the EBUS procedures. In total, five distinct lymph nodes were sampled, yielding malignant cells from three nodes and lymphocytes from the remaining two. The median accuracy of the navigation system was 7.7 mm. Our study introduces a feasible multimodal electromagnetic navigation platform that combines intraoperative ultrasound with preoperative segmented CT and PET imaging data for EBUS lymph node staging examinations. This innovative approach holds promise for enhancing the accuracy and effectiveness of EBUS procedures.

Preoperative PET imaging and fluorescence-guided surgery of human glioblastoma using dual-labeled antibody targeting ETA receptors in a preclinical mouse model: A theranostic approach.

Rationale: Glioblastoma (GBM) poses significant challenges regarding complete tumor removal due to its heterogeneity and invasiveness, emphasizing the need for effective therapeutic options. In the last two decades, fluorescence-guided surgery (FGS), employing fluorophores such as 5-aminolevulinic acid (5-ALA) to enhance tumor delineation, has gained attraction among neurosurgeons. However, some low-grade tumors do not show any accumulation of the tracers, and the lack of patient stratification represents an important limitation. Since 2000, endothelin axis has been extensively investigated for its role in cancer progression. More specifically, our team has identified endothelin A receptors (ETA), overexpressed in glioblastoma cancer stem cells, as a target of interest for GBM imaging. This study aims to evaluate the efficacy of a novel preclinical bimodal imaging agent, [89Zr]Zr-axiRA63-MOMIP, as a theranostic approach to: i) detect ETA + cells in an orthotopic model of human GBM, ii) achieve complete tumoral resection. Methods: Monomolecular multimodal imaging platform (MOMIP) - containing both a fluorophore (IRDye800CW) and a chelator for a positron-emitting radiometal (desferroxamine B, DFO) - was conjugated to the axiRA63 antibody targeting ETA receptors, overexpressed on the surface of GBM stem cells. Mice bearing orthotopic human GBM were imaged 48 h post injection of [89Zr]Zr-axiRA63-MOMIP via positron emission tomography (PET) and optical imaging. Subsequently, post-mortem proof-of-concept FGS was implemented as well as ex vivo analyses (H&E staining, autoradiography, serial block face imaging) on brains with resected or unresected tumor to assess the correlation between PET and fluorescence signals. Results: PET imaging of [89Zr]Zr-axiRA63-MOMIP enabled a clear detection of ETA + cells in an orthotopic model of human GBM. Intraoperative optical imaging allowed a near-complete tumor resection together with the visualization of a weak fluorescence signal, after a prolonged exposure time, that was attributed to residual tumor cells via H&E staining. Besides, a qualitative correlation between the signals of both modalities was observed. Conclusions: The use of [89Zr]Zr-axiRA63-MOMIP provides an effective theranostic approach to detect and treat GBM by surgery in a preclinical mouse model. Thanks to the high correlation between PET and fluorescence signal allowing patients stratification, this bimodal agent should have a great potential for clinical translation and should present a significant advantage over non-targeted fluorophores already used in the clinic.

NIMG-53. IMAGING FEATURES AND CONSIDERATION OF PROGRESSION PATTERN OF DIFFUSE HEMISPHERIC GLIOMAS, H3 G34-MUTANT

Abstract BACKGROUND Diffuse hemispheric gliomas, H3 G34-mutant (DHGs-G34m) are newly recognized pediatric-type diffuse high-grade gliomas. We describe detail imaging features of seven cases of DHGs-G34m and consider about progression pattern of DHGs-G34m. RESULTS H3 G34R or H3 G34V was detected by sanger sequencing in all tumors. Mean age of onset was 16.5 years (range: 10-26). Tumors were located on frontal (2), parietal (2), temporal lobe (1) and insular cortex (1), respectively. In one case, gliomatosis cerebri-like multiple lesions involving the cortex and basal ganglia occurred. Magnetic resonance imaging showed T2/FLAIR high lesions with poor contrast enhancement in all cases. All tumors harbored restriction of diffusion. Cystic component and hemorrhage were observed in five and three cases, respectively. Six patients underwent preoperative positron emission tomography. Strong accumulation of methionine and partial accumulation of FDG in all cases. All tumors harbored T2/FLAIR high lesions in the deep white matter, most of which showed methionine accumulation. All patients underwent surgery (total resection in one case, partial resection in five cases, and biopsy in one case) followed by radiation chemotherapy. The mean progression free survival was 9.9 months (range: 1.6-33.1 months). All tumors harbored diffuse infiltration along the white matter, which was temporarily reduced by bevacizumab, but eventually invaded into cerebral peduncle via pyramidal tract and into contralateral brain via corpus callosum or anterior commissure in six cases. Extensive infiltration of tumor cells into the contralateral brain and brain stem was confirmed histopathologically in the autopsy brain of one case. The mean overall survival was 21.6 months (range: 8.9-48.3 months). CONCLUSION DHGs-G34m showed deep white matter infiltration from the time of initial onset, which made gross total resection difficult. Residual lesions extensively infiltrated along the white matter and eventually invaded the brainstem and contralateral brain, leading to death.

Preoperative predictors for recurrence sites associated with poor post-recurrence survival after surgery of non-small cell lung cancer: a multicenter study

BackgroundThe recurrence site that influences post-recurrence survival (PRS) in patients with non-small cell lung cancer (NSCLC) undergoing surgery and the preoperative predictors of recurrence remain unclear.MethodsCohorts 1 and 2 had 4520 (who underwent complete resection for p-stage 0-IIIA NSCLC) and 727 (who experienced recurrence after surgery) patients, respectively. The initial sites of recurrence were the lungs (309 cases), thoracic lymph nodes (225 cases), pleura (112 cases), bone (110 cases), central nervous system (86 cases), adrenal gland (25 cases), abdomen (60 cases), cervical and axillary lymph nodes (38 cases), chest wall (13 cases), skin (5 cases), and eye and tongue (3 cases). For cohort 2 analysis, the initial recurrence site that resulted in poor PRS was analyzed by multivariable analysis using a Cox proportional hazard model. For cohort 1 analysis, the preoperative predictors of recurrence patterns with poor PRS were analyzed by multivariable analysis using a logistic regression model.ResultsIn cohort 2 analysis, recurrence in the central nervous system (hazard ratio [HR], 1.70; p < 0.001), bone (HR, 1.75; p < 0.001), abdomen (HR, 2.39; p < 0.001), and pleura (HR, 1.69; p < 0.001) were independent poor prognostic recurrent sites for PRS and they were high-risk sites (HRS). Intrathoracic lymph nodes, cervical and axillary lymph nodes, lungs, chest wall, adrenal gland, eye and tongue, and skin were low-risk sites (LRS) that did not affect PRS. Patients with multiple LRS without HRS recurrence had a worse prognosis than those with a single LRS without HRS recurrence (5-year PRS 20.2% vs. 37.7%, p < 0.001) and were comparable to those with HRS recurrence (p = 1.000). In cohort 1 analysis, preoperative predictors for HRS and multiple LRS recurrences were positron emission tomography (PET) maximum standardized uptake value (maxSUV) ≥ 3.2 (HR, 5.09; p < 0.001), clinical nodal metastasis (HR, 2.00; p < 0.001), tumor size ≥ 2.4 cm (HR, 1.96; p < 0.001) and carcinoembryonic antigen (CEA) ≥ 5 ng/ml (HR, 1.41; p = 0.004). The cumulative incidence rates of HRS and multiple LRS recurrences within 5 years were 55.9%, 40.9%, 26.3%, 11.1%, and 3.5% (p < 0.001) in patients with 4, 3, 2, 1 and 0 of the above risks, respectively.ConclusionsHRS and multiple LRS were vital recurrences associated with poor PRS. Preoperative PET maxSUV, clinical nodal metastasis, tumor size, and CEA level predicted the incidence of vital recurrence.

Accuracy of DOTATATE PET imaging in the preoperative planning of small bowel neuroendocrine tumor resection.

We assessed the accuracy of preoperative gallium-68 DOTA-Tyr3-octreotate (DOTATATE) positron emission tomography (PET) imaging in estimating multifocality and nodal metastases of small bowel neuroendocrine tumors (sbNETs). A multicenter analysis was performed on patients with sbNETs who underwent preoperative DOTATATE PET imaging and surgical resection, with manual palpation of the entire length of the small bowel, between January 2016 and August 2022. Preoperative imaging reports and blinded secondary imaging reviews were compared to the final postoperative pathology reports. Descriptive statistics were applied. One-hundred and four patients met inclusion criteria. Pathology showed 53 (51%) patients had multifocal sbNETs and 96 (92%) had nodal metastases. The original preoperative DOTATATE PET imaging identified multifocal sbNET in 28 (27%) patients and lymph node(LN) metastases in 80 (77%) patients. Based on original radiology reports, sensitivity for multifocal sbNET identification was 45%, specificity was 92%, positive predictive value (PPV) was 86%, and negative predictive value (NPV) was 62%. For the identification of LN metastases, sensitivity was 82%, specificity was 88%, PPV was 99%, and NPV was 29%. Although DOTATATE PET imaging is specific and relatively accurate, sensitivity and NPV are insufficient to guide surgical planning. Preoperative use should not replace open palpation to identify additional synchronous lesions or to omit regional lymphadenectomy.

Prognostic prediction using maximum standardized uptake value ratio of lymph node-to-primary tumor in preoperative PET-CT for oral squamous cell carcinoma

This study aimed to calculate the ratio of maximum standardized uptake values of cervical lymph nodes to maximum standardized uptake values of primary tumors measured by preoperative fluorodeoxyglucose positron-emission tomography in oral cancer patients, and to retrospectively examine the prognostic association and evaluate whether it could be a prognostic factor. We retrospectively examined consecutive Japanese patients diagnosed with oral squamous cell carcinoma who underwent oral cancer resection and cervical dissection between January 2014 and December 2018. The study included 52 patients aged 39–89 years (median age 66.5 years), excluding non-cervical dissection surgery and/or non-underwent preoperative positron-emission tomography. The maximum standardized uptake value of the cervical lymph nodes and primary tumor was measured, and the ratio of maximum standardized uptake values of the lymph nodes to that of the primary tumor was calculated. The median follow-up of 52 patients was 1,465 days (198–2,553 days), and overall survival was significantly worse in patients with a high lymph node-to-tumor standardized uptake values ratio (>0.4739) (5 years, 58.8% vs. 88.2%; P<0.05). Pretreatment lymph node-to-tumor standardized uptake values ratio can be easily calculated, and as a predictor of prognosis, it may be of assistance when considering the treatment strategy for oral cancer.

Role of minimally invasive secondary cytoreduction in patients with recurrent ovarian cancer

ObjectiveRetrospective series have shown minimally invasive secondary cytoreductive surgery is a feasible approach in selected cases of recurrent ovarian cancer. However, no predictors of minimally invasive secondary cytoreductive surgery feasibility...

The oncological characteristics of non-prostate-specific membrane antigen (PSMA)-expressing primary prostate cancer on preoperative PSMA positron emission tomography/computed tomography.

The oncological characteristics of non-prostate-specific membrane antigen (PSMA)-expressing primary prostate cancer on preoperative PSMA positron emission tomography/computed tomography.

Retrospective audit: Utility of PET scan in routine preoperative rectal cancer staging.

Accurate staging for rectal cancer is pertinent with recent introduction of rectum-sparing approaches for patients showing complete clinical response on restaging. Positron emission tomography(PET) is used in detection of recurrence or metastasis, but its value in routine preoperative rectal cancer staging remains unclear. Studies report that preoperative PET altered the stage in 39% and changed the management in 17-27% of patients. Our study aims to look at the utility of PET in routine preoperative staging of rectal cancer within 2 two colorectal units, and to determine if PET did result in a change in management. Patients in Nepean Hospital (NSW) and Peter MacCallum Cancer Centre (VIC) who were diagnosed with rectal cancer between 1 January 2017 and 31 December 2021 were included in this retrospective study. All patients who did not have a PET scan were excluded. PET scan results were then compared with MRI and CT results. Three hundred and fifty-seven patients were included in the study. 30.3% of the patients had Stage 3 rectal cancer. 71.7% received neoadjuvant therapy. PET scan provided additional information in 55.5% of patients when compared with CT and MRI alone; 18.2% of the PET findings resulted in an altered management for the patient. PET scan can be a valuable tool in accurate staging, especially for ambiguous or equivocal lesions on CT. Our study demonstrated that additional information from PET scan resulted in an altered management plan in 18.2% of the patients. PET/MRI as a newer modality may be more accurate with reduced radiation exposure.

PET/NIR-II fluorescence imaging and image-guided surgery of glioblastoma using a folate receptor α-targeted dual-modal nanoprobe.

The surgery of glioblastoma (GBM) requires a maximal resection of the tumor when it is safe and feasible. The infiltrating growth property of the GBM makes it a challenge for neurosurgeons to identify the tumor tissue even with the assistance of the surgical microscope. This highlights the urgent requirement for imaging techniques that can differentiate tumor tissues during surgery in real time. Fluorescence image-guided surgery of GBM has been investigated using several non-specific fluorescent probes that emit light in the visible and the first near-infrared window (NIR-I, 700-900nm), which limit the detection accuracy because of the non-specific targeting mechanism and spectral characteristics. Targeted NIR-II (1000-1700nm) fluorescent probes for GBM are thus highly desired. The folate receptor (FR) has been reported to be upregulated in GBM, which renders it to be a promising target for specific tumor imaging. In this study, the folic acid (FA) that can target the FR was conjugated with the clinically approved indocyanine green (ICG) dye and DOTA chelator for radiolabeling with 64Cu to achieve targeted positron emission tomography (PET) and fluorescence imaging of GBM. Surprisingly it was found that the resulted bioconjugate, DOTA-FA-ICG and non-radioactive natCu-DOTA-FA-ICG, were both self-assembled into nanoparticles with NIR-II emission signal. The radiolabeled DOTA-FA-ICG, 64Cu-DOTA-FA-ICG, was found to specifically accumulate in the orthotopic GBM models using in vivo PET, NIR-II, and NIR-I fluorescence imaging. The best time window of fluorescence imaging was demonstrated to be 24h after DOTA-FA-ICG injection. NIR-II fluorescence image-guided surgery was successfully conducted in the orthotopic GBM models using DOTA-FA-ICG. All the fluorescent tissue was removed and proved to be GBM by the H&E examination. Overall, our study demonstrates that the probes, 64Cu-DOTA-FA-ICG and DOTA-FA-ICG, hold promise for preoperative PET examination and intraoperative NIR-II fluorescence image-guided surgery of GBM, respectively.

Survival after liver resection and liver transplantation for colorectal liver metastases: a comparative analysis stratified by metabolic tumor volume assessed by 18F-FDG PET/CT.

Many patients undergoing resection for colorectal liver metastases (CRLM) recur with poor survival. Overall survival (OS) following liver transplantation (LT) for CRLM is reported to be about 80% at 5 years. In this study, survival following resection versus transplantation for CRLM in patients with moderate (6-70cm3) metabolic tumor volume (MTV) from the preoperative positron emission tomography (PET) was compared. Disease-free survival (DFS), OS and post recurrence survival (PRS) following resection (n=18) and LT (n=12) was compared by using the Kaplan Meier method and log rank test for patients with moderate MTV. Patients undergoing LT had unresectable metastases, significantly lower age, higher tumor burden score and number of liver metastases, longer time from diagnosis to surgery, and more patients received neoadjuvant chemotherapy. OS at 5 years was 39% in the resection group and 83% in the LT group (P=0.012). PRS was significantly improved in patients treated with LT compared to resection with 71% alive at 5 years from recurrence compared to 17% in the resection group (P=0.017). LT for selected patients seems to be superior to resection as treatment for CRLM for patients with moderate MTV.

\u201cMYH9 mutation and squamous cell cancer of the tongue in a young adult: a novel case report\u201d

BackgroundThe incidence of tongue cancer in young adults is on the rise. This trend is more pronounced in females. Although the aetiology is still unclear, there is mounting evidence that genetic syndromes can play a key role in development of oral cancers in this patient group. We report the first case of oral squamous cell carcinoma (oSCC) in a young adult with an MYH9-related disorder (MYH9-RD).Case presentationA 19-year-old female with a germline MYH9 variant (missense variant in exon 2: c.287C > T, (p.Ser96Leu)) was referred to the head and neck surgery department for investigation of a painful, thick right tongue ulcer. She was diagnosed with Epstein syndrome, an MYH9-RD, at 12 years of age. Her main phenotypic features were profound thrombocytopenia and marked renal impairment. The tongue biopsy confirmed SCC. Preoperative positron emission tomography (PET) revealed avidity in the right tongue and ipsilateral level 2A neck lymph node. With substantial preoperative multidisciplinary input, she underwent cancer ablation and microvascular free flap reconstruction. Her pathology showed a 35 mm diameter, 14 mm thick moderately differentiated SCC with perineural and lymphovascular invasion. Two out of 38 right neck nodes were positive for metastasis with extranodal extension. None of the 34 left neck nodes was involved.She had an uneventful recovery and was discharged home on day 6 postoperative day. On day 15 postoperative day, she had catastrophic bleeding in the neck with a respiratory arrest after a forceful cough. She required an emergency tracheostomy and returned to the theatre for haemostasis. Following a short inpatient stay, she was again discharged home and underwent adjuvant therapy consisting of external beam radiotherapy of 60Gy in 30 fractions. On clinical examination and PET at 6 months after surgery, she had no evidence of disease recurrence.ConclusionsMYH9-RD can present with advanced locoregional oral cavity malignancy at an early age. The combination of profound thrombocytopenia and marked renal impairment can impact heavily on routine major head and neck cancer surgery and adjuvant treatment. This rare and challenging condition underlines the importance of early detection of cancer and multidisciplinary team input.

Diagnostic performance of positron emission tomography in the staging of pseudomyxoma peritonei

BackgroundPseudomyxoma peritonei (PMP) is a rare clinical entity, commonly derived from a mucin-producing tumour of the appendix. International consensus is unclear on the role of positron emission tomography (PET) in preoperative staging. This study aimed to assess the ability of preoperative PET in predicting the histological grade of PMP. MethodsAll patients scheduled for cytoreductive surgery (CRS) +/− hyperthermic intraperitoneal chemotherapy (HIPEC) for PMP who underwent preoperative PET at a single centre between June 2007 and June 2020 were included. A nuclear medicine physician, blinded to patient outcomes, retrospectively reviewed imaging studies to assess for maximum tumour standardised uptake value (SUV) to mean liver SUV ratio (SUVTLR) and maximum porta hepatis SUV to mean liver SUV ratio (SUVPLR). ResultsBetween April 2007 and December 2020, a total of 204 patients underwent surgical intervention for PMP. Of these, 124 (60.8%) met the inclusion criteria. Median peritoneal carcinomatosis index for the entire cohort was 9 and complete cytoreduction (CC0/1) was achieved in 109 (88%) patients. Patients with high-grade PMP were more likely to have diffuse peritoneal disease (p < 0.001) and higher SUVTLR (p<0.001). The area under the ROC curve (AUC) of SUVTLR in predicting high-grade pathology was 71% (p = 0.003). Patients with a SUVTLR ≤ 0.78 had improved disease-free survival (p = 0.042). ConclusionPreoperative PET showed positive correlation with high-grade PMP and acceptable sensitivity and specificity as a diagnostic tool. PET should be considered a useful adjunct to standard imaging for predicting histological grade in the staging of patients with PMP.