Predictive and prognostic potential of pretreatment 68Ga-PSMA PET tumor heterogeneity index in patients with metastatic castration-resistant prostate cancer (mCRPC)

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Background: 177Lu-PSMA therapy has been introduced as an effective therapeutic option for metastatic castration resistant prostate cancer (mCRPC). Since about one third of the treated patients show no biochemical response (BCR) after therapy, prediction of treatment outcome is important for patient selection. Therefore, this study was conducted to evaluate to the predictive values of volumetric parameters and radiomic features (RFs) extracted form pretreatment 68Ga-PSMA PET and baseline clinical parameters in response to 177Lu-PSMA therapy. Methods: In this multicenter study, mCRPC patients undergoing 177Lu-PSMA therapy were enrolled from September 2017 to January 2022. The available clinical data of all patients was collected and documented from three different centers. The patients underwent several cycles of therapy. According to the outcome of therapy, the patients were classified into two groups including positive BCR (≥ 50% reduction in the serum PSA value) and negative BCR (< 50%). Sixty-five RFs, eight volumetric parameters and also seventeen clinical parameters were evaluated for prediction of BCR. In addition, the impact of such parameters on overall survival (OS) was evaluated. Results: In this retrospective study, 33 prostate cancer patients with a median age of 69 years (range: 49-89) were enrolled. BCR was observed in 22 cases (66%), and 16 cases (48.5%) died during the follow-up time. The results of Spearman correlation test indicated a significant relationship between BCR and treatment cycle, administered dose, HISTO energy, GLCM entropy, and GLZLM LZLGE (p<0.05). In addition, according to the Mann-Whitney U test, age, cycle, dose, GLCM entropy, and GLZLM LZLGE were significantly different between BCR and non BCR patients (p<0.05). According to the ROC curve analysis for feature selection for prediction of BCR, GLCM entropy, age, treatment cycle, and administered dose showed acceptable results (p<0.05). According to SVM for the assessing of the best model for predication of response to therapy, GLCM entropy alone showed the highest predictive performance in treatment planning. For the entire cohort, the Kaplan-Meier test revealed a median OS of 21 months (95% CI: 12.12-29.88). The median OS was estimated at 26 months (95% CI: 17.43-34.56) for BCR patients and 13 months (95% CI: 9.18-16.81) for non BCR patients. Among all variables included in the Kaplan Meier, only response to therapy was statistically significant (p=0.01) and none of the RFs and other clinical factors achieved a p-value of less than 0.05. Conclusions: This exploratory study showed that heterogeneity parameter of pretreatment 68Ga-PSMA PET images might be a potential predictive value for response to 177Lu-PSMA therapy in mCRPC; however, further prospective studies need to be carried out to verify these findings.

Predictive and prognostic potential of pretreatment 68Ga-PSMA PET tumor heterogeneity index in patients with metastatic castration-resistant prostate cancer treated with 177Lu-PSMA

Introduction

This study was conducted to evaluate the predictive values of volumetric parameters and radiomic features (RFs) extracted from pretreatment 68Ga-PSMA PET and baseline clinical parameters in response to 177Lu-PSMA therapy.

Materials and methods

In this retrospective multicenter study, mCRPC patients undergoing 177Lu-PSMA therapy were enrolled. According to the outcome of therapy, the patients were classified into two groups including positive biochemical response (BCR) (≥ 50% reduction in the serum PSA value) and negative BCR (< 50%). Sixty-five RFs, eight volumetric parameters, and also seventeen clinical parameters were evaluated for the prediction of BCR. In addition, the impact of such parameters on overall survival (OS) was evaluated.

Results

33 prostate cancer patients with a median age of 69 years (range: 49-89) were enrolled. BCR was observed in 22 cases (66%), and 16 cases (48.5%) died during the follow-up time. The results of Spearman correlation test indicated a significant relationship between BCR and treatment cycle, administered dose, HISTO energy, GLCM entropy, and GLZLM LZLGE (p<0.05). In addition, according to the Mann-Whitney U test, age, cycle, dose, GLCM entropy, and GLZLM LZLGE were significantly different between BCR and non BCR patients (p<0.05). According to the ROC curve analysis for feature selection for prediction of BCR, GLCM entropy, age, treatment cycle, and administered dose showed acceptable results (p<0.05). According to SVM for assessing the best model for prediction of response to therapy, GLCM entropy alone showed the highest predictive performance in treatment planning. For the entire cohort, the Kaplan-Meier test revealed a median OS of 21 months (95% CI: 12.12-29.88). The median OS was estimated at 26 months (95% CI: 17.43-34.56) for BCR patients and 13 months (95% CI: 9.18-16.81) for non BCR patients. Among all variables included in the Kaplan Meier, the only response to therapy was statistically significant (p=0.01).

Conclusion

This exploratory study showed that the heterogeneity parameter of pretreatment 68Ga-PSMA PET images might be a potential predictive value for response to 177Lu-PSMA therapy in mCRPC; however, further prospective studies need to be carried out to verify these findings.

ImmunoPET: Antibody-Based PET Imaging in Solid Tumors

Immuno-positron emission tomography (immunoPET) is a molecular imaging modality combining the high sensitivity of PET with the specific targeting ability of monoclonal antibodies. Various radioimmunotracers have been successfully developed to target a broad spectrum of molecules expressed by malignant cells or tumor microenvironments. Only a few are translated into clinical studies and barely into clinical practices. Some drawbacks include slow radioimmunotracer kinetics, high physiologic uptake in lymphoid organs, and heterogeneous activity in tumoral lesions. Measures are taken to overcome the disadvantages, and new tracers are being developed. In this review, we aim to mention the fundamental components of immunoPET imaging, explore the groundbreaking success achieved using this new technique, and review different radioimmunotracers employed in various solid tumors to elaborate on this relatively new imaging modality.

Anticonvulsive Effects of Licofelone on Status Epilepticus Induced by Lithium-pilocarpine in Wistar Rats: a Role for Inducible Nitric Oxide Synthase

Background and Purpose

Status epilepticus (SE) is a neurological disorder with high prevalence and mortality rates, requiring immediate intervention. Licofelone is a cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) inhibitor, which its effectiveness to treat osteoarthritis has been approved. Increasing evidence suggests an involvement of COX and LOX enzymes in epileptic disorders. Thus, in the present study we investigate possible effects of licofelone on prevention and termination of SE. We also evaluated whether the nitrergic system could participate in this effect of licofelone.

Methods

We have utilized lithium-pilocarpine model of SE in adult Wistar rats to assess the potential effect of licofelone on seizure susceptibility. Licofelone was administered 1 h before pilocarpine. To evaluate probable role of nitric oxide (NO) system, L-arginine (60 mg/kg, i.p.), as a NO precursor; L-NAME (15 mg/kg, i.p.), as a non-selective nitric oxide synthase (NOS) inhibitor; aminoguanidine (100 mg/kg, i.p.), as an inducible NOS (iNOS) inhibitor and 7-nitroindazole (60 mg/kg, i.p.), as a neuronal NOS inhibitor were injected 15 min before licofelone. Also, licofelone and diazepam 10 mg/kg were administered 30 minutes after onset of SE.

Results

Pre-treatment with licofelone at the dosage of 10 mg/kg, significantly prevented the onset of SE in all subjects (p < 0.001). L-arginine significantly inverted this anticonvulsant effect (p < 0.05). However, L-NAME and aminoguanidine, potentiated the anticonvulsant effect of licofelone (p < 0.05, p < 0.01). Licofelone could not terminate seizures after onset which was terminated by diazepam.

Conclusions

Our findings showed that anticonvulsive effects of licofelone on SE could be mediated by iNOS. Also, we suggest that COX/5-LOX activation is possibly required in the initial stage of onset but SE recruits extra excitatory pathways with prolongation.

Serum and ascitic fluid levels of interleukin-1, interleukin-6, and tumor necrosis factor-alpha in patients with ovarian epithelial cancer

BACKGROUND

Recent studies have shown that multiple cytokines are secreted by ovarian epithelial cancer cells. Previous studies have shown that the cancer cell lines secrete macrophage colony-stimulating factor (M-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 (IL-1), interleukin-6 (IL-6), and transforming growth factor-alpha (TGF-alpha). Concomitantly, the serum levels of one of the growth factors (M-CSF) was found to be significantly elevated in patients with primary ovarian cancer and in second-look patients. The authors evaluated the serum levels of IL-1 alpha, IL-1 beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha) in patients with primary ovarian epithelial cancer. These levels were then compared with cytokine concentration found in normal peritoneal fluid.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of cytokines in normal peritoneal fluid, ascites, and serum.

RESULTS

In serum, TNF-alpha and IL-6 were significantly increased in primary ovarian cancer patients when compared with control subjects (P < 0.0001 for both cytokines). TNF-alpha and IL-6 were also significantly higher than the levels found in second-look patients (P < 0.007 for TNF-alpha, and P = 0.0002 for IL-6). The levels of IL-1 alpha and beta were not elevated in ovarian cancer. TNF-alpha in the ascites was higher when compared with normal peritoneal fluid and was statistically significantly different when a cut-off point between 71-110 pg was selected (P < 0.005). The levels of IL-6 in ascites from patients with primary ovarian cancer also showed a marked increase (P < 0.0001) when compared with peritoneal fluid from control subjects.

CONCLUSIONS

Levels of IL-1, IL-6, and TNF-alpha were determined in normal peritoneal fluid, ovarian malignant ascites, normal serum, and serum from patients with ovarian cancer. This study showed that the patients with ovarian cancer have elevated levels of IL-6 and TNF-alpha in serum and ascitic fluid. A larger study would help in evaluating the potential use of cytokines as tumor markers in ovarian cancer.

Ascites levels of haptoglobin in patients with ovarian cancer

BACKGROUND

Haptoglobin is an acute-phase reactant protein involved in immune regulation. It has been isolated from malignant ovarian ascites and has been shown to be capable of mediating nonspecific immune suppression in vitro in humans and in vivo in experimental animals. The range of concentrations under which such a nonspecific suppression is observed lies well within concentrations of haptoglobin observed in vivo. This immune suppression could adversely affect patient outcome.

METHODS

Based on this information, ascites haptoglobin levels of 21 consecutive patients with ovarian cancer who underwent initial surgical debulking were determined. After the patients received chemotherapy, they were divided into those having a positive and those have a negative second-look operation.

RESULTS

Seventeen patients with positive pathology at second look had an initial mean ascites haptoglobin level of 99 +/- 49 mg/dl. The mean haptoglobin level in the four patients with negative findings was 67 +/- 42 mg/dl. The difference in these mean haptoglobin levels is not statistically significant (P > 0.05).

CONCLUSION

Although the number of patients in this study is small, the wide range of values documented in both groups make it doubtful that an initial absolute ascites haptoglobin level will prove clinically prognostic of eventual disease status at the time of second look laparotomy.

Pseudomyxoma peritonei--experience from a tertiary referral centre

Pseudomyxoma peritonei is a clinical diagnosis of massive abdominal swelling by a gelatinous material, produced usually from an ovarian or appendiceal primary. It is a rare entity that is usually histologically benign but behaves clinically in a malignant fashion with recurrent growth, although not demonstrating histological stromal invasion. The disease remains localized to the peritoneal cavity and the clinical course is one of repeated episodes of intestinal obstruction caused by extrinsic compression that seem only to be relieved by surgical debulking. Variable responses have been obtained with adjuvant chemo-, radio- and immunotherapy, but these isolated responses are unable to be reproduced and so there is no accepted adjuvant treatment for this disease.