Genomic characterization of metastatic castration-resistant prostate cancer patients undergoing PSMA radioligand therapy: A single-center experience.

BACKGROUND: Genomic defects in DNA-damage repair (DDR) mechanisms have been proposed to affect the radiosensitivity of prostate cancers. In this study, we intended to evaluate the prevalence of genetic alterations in a cohort of metastatic castration-resistant prostate cancer (mCRPC) patients undergoing radioligand therapy (RLT) with prostate-specific membrane antigen (PSMA)-inhibitors as well as the impact of such mutations on treatment outcomes. METHODS: Data of consecutive mCRPC patients from 2017 to 2021 who were treated with PSMA-RLT and underwent next-generation sequencing (NGS) were collected and analyzed for response and survival outcomes. RESULTS: In 95 patients of mCRPC treated with PSMA-RLT, 15 patients (median age: 66 years, range: 50-73 years; [177 Lu]Lu-PSMA-617, n = 12; [225 Ac]Ac-PSMA-617, n = 3) underwent NGS. The median progression-free survival (PFS) of this cohort was 3 months (95% confidence interval: 1.6-4.4 months). On NGS, 21 genetic alterations were reported in 10/15 (67%) patients, of which 13 were DDR-associated alterations involving the genes: ATM (n = 3), BRCA2 (n = 3), TP53 (n = 2), PTEN (n = 2), FANCD2 (n = 1), FANCM (n = 1), and NBN (n = 1). Overall, 5/15 (33%) patients harbored six pathogenic variants (BRCA2, n = 2; ATM, n = 1; TP53, n = 1; PTEN, n = 2). No significant difference was noted for the biochemical response, radiological response, PFS, and overall survival between the patients with and without genetic alterations. CONCLUSIONS: Patients of mCRPC undergoing PSMA-RLT were frequently seen to harbor DDR-associated aberrations, albeit with no significant impact on treatment outcomes. Large prospective trials comparing PSMA-RLT-related outcomes in DDR-deficient and -proficient patients are required to bring out the differences, if any, in a more observable manner.

Pancreatic hemorrhage contributes to late mortality in patients with acute necrotizing pancreatitis.

OBJECTIVES: The frequency, risk factors, and impact on survival of hemorrhage into (peri)pancreatic collections in patients with acute pancreatitis (AP) has not been well studied. The study was designed to evaluate the risk factors for hemorrhage, successful hemostasis and its effect on in-hospital mortality. METHODS: In a prospective cohort study for prediction of severity of AP, the incidence, risk factors, and outcomes of pancreatic hemorrhage were analyzed. Patients with significant hemorrhage were managed according to a predefined protocol including endovascular intervention. RESULTS: Out of 363 patients hospitalized during the study-period, 33(9%) patients developed hemorrhage. Median time from onset of AP to hemorrhage was 59(45-68) days. The cause of hemorrhage was arterial in 19(57.5%) patients and unlocalized in 14(42.5%) patients. Hemorrhage was managed by conservative approach in 7 (21.2%), radiographic angioembolisation in 16 (48.5%), radiographic angioembolisation followed by surgery in 3 (9.1%), and surgery in 7 (21.2%) patients. Persistent organ failure [aHR 2.3 (1.1-5.1), p = 0.03], use of large bore (>20 Fr) catheter for initial drainage [aHR 3.9 (1.7-9.1), p = 0.001] and extensive (>50%) necrosis [aHR 3.1 (1.4-6.9), p = 0.005] were significant risk factors for hemorrhage. Hemorrhage was an independent predictor of mortality [aHR 2.0 (1.2-3.4), p = 0.008] in addition to persistent organ failure (aHR 12.1 (5.7-25.8), p < 0.001). In-hospital mortality in patients with hemorrhage was 22/33 (66.7%) vs. 81/330 (25%) in no hemorrhage group [p <0.001]. CONCLUSION: Pancreatic hemorrhage occurs later in the course of acute pancreatitis in relatively sicker group of patients with organ failure and extensive necrosis, and is independently associated with a higher risk of in-hospital mortality.

Type of recurrence is associated with disease-free survival after salvage surgery for locally recurrent rectal cancer.

PURPOSE: To compare the characteristics and outcomes of rectal cancer patients with local recurrence at a perianastomotic site (PA), a surgical field (SF) site, or in lateral lymph nodes (LLN). METHODS: A total of 114 consecutive patients who underwent surgery for recurrent, non-metastatic rectal cancer at a single comprehensive cancer center between 1997 and 2012 were grouped on the basis of radiographic assessment of type of recurrence: PA, 76 (67%) patients; SF, 25 (22%) patients; LLN, 13 (11%) patients. Demographic, clinical, and pathological features were compared between the three groups, as were disease-free survival (DFS) and overall survival (OS). RESULTS: Recurrence type was associated with positive circumferential margin in the primary resection (PA, 4 [6%]; SF, 4 [19%]; LLN, 3 [25%]; P = 0.027), prior neoadjuvant therapy for the primary tumor (PA, 57 [75%]; SF, 18 [72%]; LLN, 4 [31%]; P = 0.007), and location of the primary tumor in the upper rectum (PA, 33 [45%]; SF, 5 [23%]; LLN, 1 [8%]; P < 0.001). Patients with PA had longer median DFS (PA, 5.1 years; SF, 1.5 years; LLN, 1.2 years; P = 0.036). There was a non-significant trend toward longer OS and higher rates of R0 resection for PA. CONCLUSION: Type of recurrence after salvage surgery for locally recurrent rectal cancer is associated with longer DFS in patients with PA recurrence.

Intracorporeal Anastomoses in Minimally Invasive Right Colectomies Are Associated With Fewer Incisional Hernias and Shorter Length of Stay.

BACKGROUND: Intracorporeal anastomosis is associated with several short-term benefits. However, it is a technically challenging procedure with potential risk OBJECTIVE:: The purpose of this study was to investigate differences in short-term complications and long-term incisional hernia rates after robotic right colectomy with intracorporeal versus extracorporeal anastomoses and standardized extraction sites. DESIGN: This was a historical cohort study. SETTINGS: The study was conducted at a single institution. PATIENTS: All of the patients undergoing robotic right colectomy with intracorporeal anastomosis and a Pfannenstiel extraction site or extracorporeal anastomosis with a vertical midline extraction site from 2013 to 2017 were eligible. Exclusion criteria were conversion to laparotomy for tumor-related reasons or lack of follow-up. INTERVENTION: Intracorporeal or extracorporeal anastomosis was performed, based on availability of the robotic stapler and appropriate bedside assistance. MAIN OUTCOME MEASURES: The primary outcome was incisional hernia, diagnosed either clinically or on postoperative imaging, and analyzed using time-to-event analysis. A Cox proportional hazards model was used for multivariable analysis. Secondary outcomes were analyzed using parametric and nonparametric tests. Statistical significance was set at p < 0.05. RESULTS: Of 164 patients who met all inclusion criteria, 67 had intracorporeal and 97 had extracorporeal anastomoses. Median follow-up time was similar in both groups (14 vs 15 mo; p = 0.73). The 1-year estimated incisional hernia rate was 12% for extracorporeal and 2% for intracorporeal anastomoses (p = 0.007); this difference was confirmed by multivariable modeling. The severity of postoperative complications was similar between the groups, but there was an increase in incisional infections and a shorter length of stay (1 day) for intracorporeal cases. LIMITATIONS: The study was limited by its retrospective, single-surgeon nature. CONCLUSIONS: Right colectomy with intracorporeal anastomosis and a Pfannenstiel extraction site may reduce the rate of incisional hernias compared with extracorporeal anastomosis with a vertical midline extraction site. The intracorporeal approach was also associated with a decreased length of stay but an increase in incisional surgical site infections. These findings have implications for healthcare use and patient-centered outcomes. See Video Abstract at http://links.lww.com/DCR/B147. ANASTOMOSIS INTRACORPÓREAS EN COLECTOMÍAS DERECHAS MÍNIMAMENTE INVASIVAS SE ASOCIAN CON MENOS HERNIAS INCISIONALES Y UNA ESTADÍA HOSPITALARIA MÁS BREVE: nastomosis intracorpórea se asocia con varios beneficios a corto plazo. Sin embargo, es un procedimiento técnicamente desafiante con riesgos potenciales.nvestigar las diferencias en las complicaciones a corto plazo y las tasas de hernia incisional a largo plazo después de la colectomía robótica derecha con anastomosis intracorpórea versus extracorpórea y sitios de extracción estandarizados.Estudio de cohorte histórico.cirujano individual, institución única.Todos los pacientes sometidos a colectomía robótica derecha con anastomosis intracorpórea y un sitio de extracción de Pfannenstiel o anastomosis extracorpórea con un sitio de extracción vertical de la línea media de 2013-2017 fueron elegibles. Los criterios de exclusión fueron la conversión a laparotomía por razones relacionadas con el tumor o la falta de seguimiento.nastomosis intracorpórea o extracorpórea, según la disponibilidad de grapadora robótica y la asistencia adecuada quirúrgica.El resultado primario fue la hernia incisional, diagnosticada clínicamente o en imágenes postoperatorias, y analizada mediante análisis de tiempo hasta el evento. Se usó un modelo de riesgos proporcionales de Cox para el análisis multivariable. Los resultados secundarios se analizaron mediante pruebas paramétricas y no paramétricas. La significación estadística se estableció en p < 0,05.De 164 pacientes que cumplieron con todos los criterios de inclusión, 67 tenían anastomosis intracorpóreas y 97 tenían anastomosis extracorpóreas. La mediana del tiempo de seguimiento fue similar en ambos grupos (14 versus 15 meses, p = 0,73). La tasa de hernia incisional estimada para un año fue del 12% para las anastomosis extracorpóreas y del 2% para las anastomosis intracorpóreas (p = 0,007); esta diferencia fue confirmada por el modelado multivariable. La gravedad de las complicaciones postoperatorias fue similar entre los grupos, pero hubo un aumento de las infecciones incisionales y una estancia más corta (un día) para los casos intracorpóreos.Retrospectiva, cirujano único.a colectomía derecha con anastomosis intracorpórea y un sitio de extracción de Pfannenstiel puede reducir la tasa de hernias incisionales en comparación con la anastomosis extracorpórea con un sitio de extracción vertical en la línea media. El enfoque intracorpóreo también se asoció con una disminución de la duración de la estadía, pero con un aumento de las infecciones del sitio quirúrgico incisional. Estos hallazgos tienen implicaciones para la utilización de recursos médicos y beneficios para pacientes. Consulte Video Resumen en http://links.lww.com/DCR/B147. (Traducción-Dr. Adrian Ortega).

Robotic Extended Right Hemicolectomy with Complete Mesocolic Excision and D3 Lymph Node Dissection.

BACKGROUND: Recent studies have shown the benefits of complete mesocolic excision and extended lymphadenectomy (D3 lymph node dissection) in patients with colon cancer.1-3 METHODS: We present the case of a 62-year-old male with hepatic flexure adenocarcinoma. No metastatic disease was identified by computed tomography. A robot-assisted extended right hemicolectomy with complete mesocolic excision, D3 lymph node dissection, and resection of the mesentery with intact visceral peritoneum was performed. RESULTS: The trocars are placed in the right lower (8 mm), lower midline (8 mm), and left upper (12 mm) quadrants. The camera port is placed superior to the umbilicus, and the assistant port is placed in the left lower quadrant. The robotic right lower port is used to place the cecum on tension in order to outline the ileocolic pedicle. The assistant retracts the transverse colon cephalad to outline the superior mesenteric artery and vein. Using two robotic arms, the surgeon begins dissection over the superior mesenteric vein inferior to the ileocolic pedicle. Cephalad dissection along the superior mesenteric vein proceeds with reflection of the mesentery and D3 lymph nodes laterally to allow en bloc resection. The ileocolic and middle colic vessels are identified, ligated and divided at their origins. The plane is then developed between the right colon mesentery and the retroperitoneum, including Gerota's fascia, duodenum, and head of the pancreas, in a medial-to-lateral fashion, with care taken to ensure an intact visceral peritoneum is maintained. The proximal transverse colon, hepatic flexure, and ascending colon are mobilized by taking down lateral attachments. The intervening mesentery is transected, and perfusion is assessed with indocyanine green fluorescence imaging. An intracorporeal, isoperistaltic, side-to-side anastomosis is performed using the 45-mm robotic stapler. The common enterotomy is sewn closed in two layers. Pathology showed T3N0 adenocarcinoma with all negative margins. CONCLUSION: Extended right hemicolectomy with complete mesocolic excision and D3 lymph node dissection is facilitated by a robotic approach, which improves visualization and instrument dexterity.

Tubercular Intestinal Strictures Show a Poor Response to Anti-Tuberculous Therapy.

BACKGROUND: The literature on resolution of intestinal strictures in patients with intestinal tuberculosis (ITB) after anti-tuberculous therapy (ATT) is sparse and ambivalent. We aimed to assess the frequency of stricture resolution after ATT and its predictors. METHODS: This ambispective cohort study included consecutive ITB patients with strictures who received ATT for ≥6 months and were on regular follow-up between January 2004 and December 2015. Resolution of stricture was assessed at the end of ATT by endoscopy/radiology. RESULTS: Of 286 patients, 128 had strictures, and 106 were finally included (63 males, median age 35 years). The stricture location was distal ileum/ileocecal in 52 (49.1%), colon in 37 (34.9%), ileocolonic in 4 (3.8%), proximal small bowel in 10 (9.4%), and gastroduodenal in 4 (3.8%) patients. Although all patients demonstrated mucosal healing (indicating resolution of active infection), stricture resolution occurred only in 25/106 (23.6%) patients. Symptoms pertaining to stricture (pain abdomen/recurrent SAIO) were present in 104/106 (98%) patients, and after a median of 6 (6-9) months of ATT, these symptoms resolved only in half, 88% (22/25) in patients with stricture resolution and 38% (30/79) in patients with persistent strictures. Colonic strictures had the least resolution (5.4%) followed by proximal small intestinal (20%) and distal ileal/ileocecal (36.5%). Although not statistically significant, stricture resolution was less frequent in patients with multiple strictures, longer strictures (>3 cm), and strictures in which scope was not negotiable prior to ATT. CONCLUSION: Only one-fourth of ITB patients with strictures show resolution of stricture following ATT. The resolution of strictures is dependent on disease location, and majority of them exhibit symptoms pertaining to stricture even after ATT.

Trangastric endo-organ resection of a proximal gastric lesion.

INTRODUCTION: Gastric tumors confined to mucosa and submucosa can be resected with endoscopic resection techniques. They include endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) [1, 2]. These techniques can be challenging when the tumor is large or is near the gastroesophageal (GE) junction. Transgastric resection is a novel technique of removing gastric tumors that are unresectable by endoscopy due to their size and location. MATERIALS AND METHODS: We present a case of a 41-year-old male where a suspicious appearing lesion near the GE junction was removed using combined trans-gastric laparoscopic and endoscopic technique. The stomach was inflated using endoscopy, and three 5-mm balloon-tipped trocars were inserted directly into the stomach. The lesion was lifted with submucosal injection of saline and was resected using ultrasonic dissection device. The specimen was retrieved using Rothnet through the endoscope. The mucosal defect was closed with absorbable sutures. Trocars were removed and gastrostomy sites were closed with Endostitch device. Swallow study done on post-op day 2 did not show any signs of leak. Patient was discharged home on post-op day 5. Final pathology was consistent with hyperplastic polyp. CONCLUSION: Proximal Gastric lesions can be safely removed with combined Laparoscopic trans-gastric and endoscopic approach.

Combined endovascular and percutaneous approach to the management of spontaneous splenic arteriovenous fistula.

A splenic arteriovenous fistula (AVF) is an uncommon splenic vascular disease which can be congenital or acquired. A 40yr old woman, without any history of chronic liver disease, presented with non-specific pain abdomen, underwent contrast-enhanced CT and was diagnosed to have a splenic AVF with multiple intervening venous aneurysms and early filling of the portal vein. The vascular abnormality was successfully treated with a combined percutaneous glue embolisation and endovascular balloon-assisted coil embolisation. Neither recurrence nor other complications were observed in the patient during the follow-up after 6 months.

Is fat-to-lean mass ratio a better predictor of heart variability than body mass index?

BACKGROUND: Body mass index (BMI) may not accurately predict cardiometabolic risk due to confounders like age, gender, relatively high lean mass, and the "thin-fat phenotype" prevalent in south Asian populations. Fat-to-lean mass ratio (FTLM), which assesses the balance between fat and lean body mass, may provide a more complete assessment of cardiometabolic health. MATERIALS AND METHODS: This cross-sectional analytical study investigated the relationship between FTLM ratio, BMI, and heart rate variability (HRV) in apparently healthy male adults. 88 participants recruited through convenience sampling underwent anthropometric assessments, bioimpedance body composition analysis, and HRV testing. Pearson's or Spearman's correlation and linear regression analyses were performed where appropriate to assess the relationship between FTLM ratio, BMI, and HRV. RESULTS: Both BMI and FTLM showed significant positive correlation with normalized LF power and LF-HF ratio and a negative correlation with normalized HF power, RMSSD, and pNN50. However, FTLM ratio showed a stronger association with HRV parameters than BMI and could explain a greater percentage of the variability in LF-HF ratio (32% compared to 18.4%, P < 0.001). CONCLUSION: Assessment of both fat and lean mass, expressed as a ratio, is a better index of quantifying adiposity and predicting the influence of altered body composition on cardiometabolic health.

Estimation of absorbed dose to salivary glands in mCRPC patients undergoing 177 Lu- PSMA-617 radioligand therapy using quantitative SPECT-CT at single time point: a single-center feasibility study.

OBJECTIVE: 177 Lu-PSMA-617-radioligand therapy (RLT) has shown promising therapeutic role in patients with metastatic castration-resistant prostate cancer. However, off-target action in salivary glands often presents with xerostomia. Personalized dosimetry can help in optimizing the treatment, however, has so far been tedious due to multiple time-point imaging. In this prospective study, we intended to estimate the absorbed dose delivered to the salivary glands in patients undergoing 177 Lu-PSMA-617-RLT using quantitative SPECT/CT at a single time point. METHODS: Patients undergoing 177 Lu-PSMA-617 RLT were included in this prospective study. Post-therapy whole-body images and regional quantitative single time-point SPECT/CT were acquired at 24 h with high-energy collimator. The data was processed and analyzed using Q.Metrix software. A scaling factor, that is, the time-integrated activity conversion factor was applied for the image acquired at 24 h. Absorbed doses were computed using MIRD scheme and OLINDA software. RESULTS: A total of 21 patients (mean age: 66 ±â€…9 years) were included. The value of mean absorbed dose for the parotid glands was 1.90 ±â€…1.31Gy (range: 0.26-6.23) and that for the submandibular glands was 1.37 ±â€…0.94Gy (range: 0.16-3.65). The mean absorbed doses per administered activity for the parotid and submandibular glands were 0.26 ±â€…0.18 Gy/GBq and 0.19 ±â€…0.12 Gy/GBq, respectively. The absorbed doses were estimated for one cycle of therapy and were well within acceptable limits. None of the patients experienced dryness of mouth. CONCLUSION: Single time-point dosimetry with quantitative SPECT/CT is feasible and can be standardized to estimate the absorbed dose to salivary glands instead of multiple time-point acquisitions.

Neoadjuvant Peptide Receptor Radionuclide Therapy in a Rare Case of Pediatric Primary Hepatic Gastrinoma.

ABSTRACT: Gastrinomas with predilection for the adult male population are located in the gastrinoma triangle (>90%). Primary hepatic gastrinoma especially in pediatric population is very rare. Peptide receptor radionuclide therapy has shown benefit in metastatic gastroenteropancreatic neuroendocrine tumors (NETs) with an increasing interest in expanding its role as neoadjuvant treatment modality to improve the surgical candidature in inoperable NETs. There is currently no literature supporting its role in the pediatric NET patients. We present a rare case of a young boy with primary hepatic gastrinoma where 177Lu-based peptide receptor radionuclide therapy in the neoadjuvant setting contributed to his final disease-free status.

Prostate-Specific Membrane Antigen-Avid Neurofibroma Mimicking Cutaneous Metastasis in Metastatic Castration-Resistant Prostate Cancer on 18 F-PSMA-1007 PET/CT.

ABSTRACT: The occurrence of cutaneous metastases in prostate cancer is exceedingly rare. Many benign lesions and nonprostatic cancers can express the prostate-specific membrane antigen (PSMA). They can potentially mimic metastasis of prostate cancer and lead to misinterpretation of PSMA PET/CT findings. Additionally, it has significant management and prognostic implications. We present a rare case of an 88-year-old man with metastatic castration-resistant prostate cancer who showed a PSMA-expressing subcutaneous nodule in the scalp on 18 F-PSMA-1007 PET/CT, raising the suspicion of cutaneous metastasis. However, its biopsy revealed a neurofibroma, altering the disease prognosis and management.

177 Lu-DOTATATE Salvage Therapy in Rapidly Progressing Neuroendocrine Tumor With Poor Performance Status.

ABSTRACT: Peptide receptor radionuclide therapy (PRRT) has shown to be effective and safe in metastatic gastroenteropancreatic and nongastroenteropancreatic neuroendocrine tumors. However, the selection criteria for PRRT are restricted to patients with good performance status (Eastern Cooperative Oncology Group score ≤2 or Karnofsky performance score ≥60). This denies many patients with adequate somatostatin receptor expression and biochemical profiles from the beneficial effects of PRRT on the quality of life, daily function, and overall survival. The 2 cases highlight the favorable response of PRRT in patients with metastatic neuroendocrine tumor having a very poor performance status initially.

Unusual Sites of Visceral Spread in Prostate Cancer: A Prostate-Specific Membrane Antigen-Based Theranostic Imaging Series.

ABSTRACT: Prostate cancer commonly metastasizes to lymphatic and skeletal systems with lesser frequency to visceral organs; however, uncommon visceral sites have also been found and reported as case reports. We present a series of uncommon metastatic visceral spread in prostate cancer on prostate-specific membrane antigen-based diagnostic and posttherapeutic imaging modalities.

Sunitinib in Tandem With 177 Lu-DOTATATE Therapy in Advanced Pancreatic Neuroendocrine Tumor : A New Treatment Approach.

ABSTRACT: Various systemic treatment options are available for advanced pancreatic neuroendocrine tumors (NETs); however, individual treatment may be suboptimally effective. Sunitinib inhibits multiple kinases and signaling pathways with delay in tumor growth, whereas peptide radioreceptor therapy (PRRT) delivers targeted radiation to the tumors in pancreatic NETs. There is a dearth of literature on the combined or tandem use of these systemic treatment modalities. We present a case of 40-year-old man with advanced pancreatic NET where PRRT or sunitinib as monotherapy had a suboptimal treatment response, but the use of sunitinib in tandem with 177 Lu-PRRT reinforced the response to the treatment.

Potential role of 68Ga-PSMA PET/CT in metastatic renal cell cancer: A prospective study.

PURPOSE: Prostate-specific membrane antigen (PSMA), in addition to its utility in prostate cancer, is also an angiogenic imaging marker for hypervascular tumors like renal cell carcinoma (RCC). Our study aims to assess the potential role of 68Ga-PSMA-11 positron emission tomography (PET)/CT in metastatic RCC and compare it with contrast-enhanced computed tomography (CECT). METHODS: Biopsy-proven RCC patients with known or suspected distant metastases who underwent 68Ga-PSMA-11 PET/CT for staging/restaging were prospectively recruited. Those patients who had undergone 18F-FDG PET/CT within six weeks of 68Ga-PSMA PET/CT were also included retrospectively for comparative analysis. A patient-based and lesion-based analysis was done to compare the lesion detection rates of CECT, 68Ga-PSMA-11 PET and 18F-FDG PET. PET-based quantitative parameters were also compared between both the PET modalities. Impact of baseline parameters on survival was assessed using Cox regression analysis. A p-value of < 0.05 was considered significant. RESULTS: Thirty-seven patients with median age 60 years ± 13 years (range = 26-76 years) were included in the study. Twenty-seven patients had clear cell (cc) RCC, six had papillary RCC (pRCC), and one each had an eosinophilic variant of ccRCC, collecting duct RCC, translocation RCC and poorly differentiated RCC. 68Ga-PSMA-11 PET performed better in detecting marrow and equivocal bone lesions and worse in detecting liver lesions compared to CECT. 68Ga-PSMA-11 PET-based angiogenic tumor burden estimation using Total Lesion-PSMA (TL-PSMA) and PSMA-Total volume (PSMA-TV) had a prognostic impact on the survival of patients. 68Ga-PSMA-11 PET also detected more lesions and showed significantly higher SUVmax than 18F-FDG PET. CONCLUSION: 68Ga-PSMA-11 PET/CT performs better than CECT and 18F-FDG PET/CT in metastatic evaluation and has prognostic value in the management of clear cell RCC.

68 Ga-Pentixafor PET/CT for in-vivo mapping of CXCR4 receptors as potential radiotheranostic targets in soft tissue and bone sarcoma: preliminary results.

OBJECTIVE: To evaluate the diagnostic utility of 68 Ga-Pentixafor PET/CT for in vivo imaging of CXCR4 receptors in soft tissue/bone sarcoma. METHODS: Ten (7M: 3F; mean age = 24.7 ± 14.2 years) consecutive patients with clinical and radiological evidence of bone/soft tissue sarcoma were recruited prospectively whole body 68 Ga-Pentixafor PET/CT imaging was performed at 60-min after tracer administration. After performing standard CT, PET acquisition from head to toe was done (3 min/bed position) in a caudocranial direction. PET/CT data was reconstructed and SUV max , SUV mean values, target-to-background ratio (TBR) and active tumor volume (cc) were computed for the tracer avid lesions. Histopathological and IHC analysis was performed on the surgically excised primary tumors. CXCR4 receptors' intensity was evaluated by visual scoring. RESULTS: The mean SUV max and SUV mean values in the primary tumors were 4.80 ±â€…1.0 (3.9-7.7) and 2.40 ±â€…0.60 (0.9-4.0). The mean TBR and tumor volume (cc) were 1.84 ±â€…1.3 and 312.2 ±â€…285. Diagnosis of osteosarcoma in 7, chondrosarcoma, leiomyosarcoma and synovial sarcoma in 1 patient each was confirmed on HP analysis. Distant metastatic lesions were seen in 3/10 patients. Nuclear CXCR4 receptors' positivity was seen in 5, cytoplasmic in 4 and both pattern seen in 1 patient. The mean CXCR4 receptors' intensity was found to be 7.6 ±â€…2. The highest SUV max value of 7.7 was observed in the patient having both cytoplasmic and nuclear CXCR4 expression. SUV max was found to be poorly correlated ( r  = 0.441) with CXCR4 expression. CONCLUSION: 68 Ga-Pentixafor PET/CT detects CXCR4 receptors over-expressed in sarcoma, its radio-theranostics potential needs detailed evaluation.

Incidentally Detected Gallbladder Carcinoma: Can F-18 FDG PET/CT Aid in Staging and Prognostication?

Purpose: Incidental gallbladder carcinoma (IGBC) is diagnosed in post-cholecystectomy specimens for benign indications, where the role of 2-fluro-2-deoxyglucose positron emission tomography/computed tomography(FDG-PET/CT) is not clearly defined. The present study aimed to assess the benefits of staging and prognosticating with FDG-PET/CT in IGBC. Materials and Methods: A retrospective observational study from a tertiary-care center from January 2010 to July 2020 was performed. The demographic, clinical, histopathological, and treatment-related histories were collected. FDG-PET/CT-image findings were compared with survival outcomes through telephonic follow-up. The chi-square test was used for comparing frequencies. The univariate and multivariate survival estimates were analyzed using the Kaplan-Meier analysis and the Cox-proportional hazard model, respectively. Log-rank test was used to compare the Kaplan-Meier curves. Results: The study included 280 postcholecystectomy participants (mean age: 52 ± 11 years; women: 227) of whom 52.1% had open surgery(146/280). Residual disease in the gallbladder fossa (54.8% vs. 36.6%, p = 0.002) and liver infiltration (32.9% vs. 22.4%, p = 0.05) were seen more frequently in open surgery compared to laparoscopic surgery, while anterior abdominal wall deposits were more common in laparoscopy(35.1% vs. 24%,p = 0.041). FDG-PET/CT changed the management in 10% (n = 28) of patients compared to contrast-enhanced CT. The median survival was 14 months (95%CI-10.3-17.7). A higher stage of the disease on the FDG-PET/CT (loco-regional disease-HR 4.86, p = 0.006; metastatic disease-HR 7.53, p < 0.001) and the presence of liver infiltration (HR-1.92, p = 0.003) were independent predictors of poor survival outcomes. Conclusion: FDG-PET/CT detects residual and metastatic disease in patients with IGBC, enabling the institution of appropriate management and acting as a tool for prognostication of survival.

Role of non-contrast CT component of prostate-specific membrane antigen PET/CT scan in the detection of peripheral zone prostate cancer.

OBJECTIVE: The aim of this study was to look for feasibility of non-contrast CT (NCCT) in detecting peripheral zone prostate cancer (PCa). METHODS: A retrospective analysis included 50 biopsy-proven PCa patients between April 2019 and March 2022 who underwent staging whole body prostate-specific membrane antigen (PSMA)/CT prior to treatment. The control subjects were 50 randomly selected adult male patients who underwent PET/CT for non-prostate malignancy during the same time period. Two readers independently calculated the Hounsfield unit (HU) of normal peripheral zone, central zone, and corresponding PSMA avid focus in cases. RESULTS: No significant difference was seen in the mean HU value of normal peripheral zone between cases and controls. Significant difference in the mean HU was seen between the PSMA avid focus in cases (40.1 ± 6.2) and normal peripheral zone of cases (28.2 ± 7.0) and controls (27.7 ± 5.8). No significant difference was found between the mean HU values of high-grade PCa and non-high-grade PCa. Receiver operating characteristic (ROC) curve analysis revealed a mean HU cut-off of ≥35 for detecting PCa with a sensitivity and specificity of 86% and 90%, respectively, between cases and controls (AUC 0.88). CONCLUSION: Detection of clinically significant PCa is possible on routinely performed NCCT scans. Radiologists should routinely look for and convey these findings to facilitate further work-up and early detection of PCa. ADVANCES IN KNOWLEDGE: Our study adds to the knowledge that NCCT scans performed for unrelated indications can serve as a screening tool for clinically significant PCa.