How reliable is the high-volume definition in prostate cancer patients: the potential game-changing role of PSMA

PURPOSE

To evaluate whether metabolic and volumetric data from 68 Ga-PSMA PET/CT performed during staging of de-novo high-volume mCSPC patients who received docetaxel could be used to predict survival.

METHODS

Forty-two de-novo high-volume mCSPC patients, who received ADT + Docetaxel and underwent 68 Ga-PSMA PET/CT for staging, were included in the study. The association between patients' pathological data, all PSA measurements, treatments they received, the data obtained from 68 Ga-PSMA PET/CT and progression-free and overall survival were examined.

RESULTS

In the multivariate analysis, PSMA-TV (primary) and PSMA-TV (WB) variables were shown to be independent negative predictors of overall survival. For the threshold value of 19.91 cm 3 obtained for PSMA-TV (primary), HR was calculated as 6.31, the 95% confidence interval (CI): 1.01-39.18, P = 0.048. For the threshold value of 1226.5 cm 3 obtained for PSMA-TV (WB) variable, HR was calculated as 58.62, the 95% CI: 2.55-1344.43, P = 0.011. In our study, SUVmax (WB) variable was found to be an independent and negative predictor of progression-free survival. For the determined threshold value of 17.74, HR was calculated as 16.24, 95% CI: 1.18-22.76, P = 0.037.

CONCLUSION

Metabolic and volumetric data obtained from 68 Ga-PSMA PET/CT can be used to predict survival in de-novo high-volume mCSPC. Our results show that in ADT + Docetaxel receiving patients, a subgroup with higher PSMA-TV (WB) values have a significantly worse prognosis. This situation suggests that the high-volume disease definition in the literature may be insufficient for this group, and that 68 Ga-PSMA PET/CT can play an essential role in demonstrating the heterogeneity within the group.

Comparison of Radioactive Iodine Activities in Terms of Short- and Long-term Results in Ablation Therapy in Patients with Low-risk Differentiated Thyroid Cancer

Objectives

The aim of this study was to compare the treatment responses after ablation with 30-50 mCi radioactive iodine (RAI) and 100 mCi RAI in patients with differentiated thyroid cancer (DTC) who were in the low-risk group according to 2015 American Thyroid Associations Classification (ATA 2015) criteria.

Methods

Between February 2016 and August 2018, 100 patients who received RAI treatment in our clinic after total thyroidectomy and who were in the low-risk group DTC were included in this retrospective study. These patients were divided into 2 groups: low-activity (30-50 mCi) (group 1) and high-activity (100 mCi) (group 2). While 54 patients were treated with low activity, 46 patients received high activity RAI. The 2 groups were compared according to the 1^st- and 3^rd-year treatment response status.

Results

According to the first-year follow-up, 15 patients were accepted as indeterminate response and 85 patients as excellent response. Three (5.5%) of the patients who were accepted as indeterminate response were in group 1 and 12 (26%) were in group 2. According to the third year follow-up, 1 patient in group 1 and 3 patients in group 2 were accepted as indeterminate response. No biochemical incomplete response or recurrent disease was detected. In the chi-square analysis performed to investigate the relationship between the first-year treatment response and RAI activities, a significant relationship was found (p=0.004). In the Mann-Whitney U test performed to investigate the parameters that may be effective in the treatment response, only the preablative serum thyroglobulin value was shown to have a significant difference between the two groups (p=0.01). In the long-term follow-up of the patients, based on the third year treatment response data, chi-square analysis was performed to evaluate the two groups in terms of treatment responses, and no statistically significant relationship was found (p=0.73).

Conclusion

Ablation with 30-50 mCi can be safely applied in DTC patients who are in the ATA 2015 low-risk group and are planned for RAI ablation treatment.

Can 68Ga-PSMA PET/CT-derived prostate-specific membrane antigen expression parameters predict prostate-specific antigen response to enzalutamide treatment?

OBJECTIVE

In patients with metastatic castration-resistant prostate cancer (mCRPCa), enzalutamide is administered when docetaxel treatment fails. The purpose of the study was to evaluate the relationship between prostate-specific antigen (PSA) response and metabolic parameters obtained from 68Ga-PSMA PET/CT before treatment in this patient group.

METHODS

From February 2018 to May 2020, 34 patients with mCRPCa were enrolled in this study. The association between PSA response (at least 50% decrease compared to the pretreatment value) and quantitative prostate-specific membrane antigen (PSMA) expression parameters such as SUVmax, SUVmean, PSMA-TV (PSMA receptor-expressing tumor volume) and TL-PSMA (total lesion PSMA receptor expression) were evaluated.

RESULTS

Mean SUVmax, SUVmean, PSMA receptor-expressing tumor volume (PSMA-TV) and total lesion PSMA receptor expression (TL-PSMA) values were 33.66 ± 20.42; 8.82 ± 5.03; 319.85 ± 615.12 cm3; and 2894.76 ± 5195.13, respectively. In the posttreatment 12th week, 22 patients (64.7%) had PSA response, while 12 patients (35.3%) were nonresponders. In patients with PSA response, PSMA-TV values were significantly lower than nonresponders (78.37 ± 80.99 cm3 vs. 451.58 ± 734.61 cm3; P = 0.028). But there was no significant difference between responders and nonresponders in terms of age, ISUP grade, SUVmax, SUVmean, TL-PSMA, pretreatment PSA values, presence of local recurrence or metastases at any site.

CONCLUSION

PSMA-TV values on 68Ga-PSMA PET/CT imaging before starting enzalutamide treatment following docetaxel failure can predict PSA response in patients with mCRPCa.

The Predictive Value of Proportional Evaluation Based on the Metabolic Activity of Cervical Lymph Nodes on PET/CT Imaging in Patients with Larynx Cancer

Objectives

We aimed to evaluate the proportional values of maximum standardized uptake value (SUV_max) for cervical lymph nodes on ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for prediction of the presence of metastasis in patients with larynx squamous cell cancer (LSCC).

Methods

This retrospective study involved 43 patients with LSCC. All patients underwent resection of the primary tumor and neck dissection within 4 weeks after undergoing ¹⁸F-FDG PET/CT examinations. Receiver operating characteristic (ROC) analysis was performed to evaluate the lymph node SUV_max/primary tumor SUV_max (SUV_maxLN/SUV_maxPT), lymph node SUV_max/aortic SUV_max (SUV_maxLN/SUV_maxA), and lymph node SUV_max/ liver SUV_max (SUV_maxLN/SUV_maxL) ratios for diagnosis of lymph node metastasis.

Results

SUV_maxLN/SUV_maxA, SUV_maxLN/SUV_maxL, and SUV_maxLN/SUV_maxPT rates were significantly higher in metastatic lymph nodes compared to non-metastatic nodes. ROC analysis for metastasis showed that the cut-off thresholds were 3.87 for SUV_maxLN; 1.78 for SUV_maxLN /SUV_maxA; 1.08 for SUV_maxLN/SUV_maxL; and 0.36 for SUV_maxLN/SUV_maxPT. The diagnostic sensitivity, specificity and AUC were 83.7%, 77%, 0.856 for SUV_maxLN; 79.7%, 84%, 1.78 for SUV_maxLN/SUV_maxA; 84.1%, 76%, 0.833 for SUV_maxLN/SUV_maxL; and 53.6%, 76%, 0.666 for SUV_maxLN/SUV_maxPT, respectively.

Conclusion

SUV_maxLN/SUV_maxA, SUV_maxLN/SUV_maxL, and SUV_maxLN/SUV_maxPT ratios can be safely used for diagnosis of cervical lymph node metastasis in patients with LSCC.

Ileal Neuroendocrin Tumor Metastasis to Breast Diagnosed with Ga-68 DOTATATE PET/CT

Breast metastasis of the well differentiated neuroendocrin tumor (WDNET) of the ileum is very rare. A case of a 62-year-old woman with ileal WDNET, who underwent restaging with Ga-68 DOTATATE PET/CT due to progression of metastatic lesions under the treatment with somatostatin analog and mammalian target of rapamycin inhibitors. Ga-68 DOTATATE PET/CT demonstrated intense increased uptake in the subsantimetric nodular lesion in the upper outer quadrant of the left breast. The histopathologic findings obtained by tru-cut biopsy revealed WDNET metastasis (Ki-67 proliferation index 1%).

Missed retrosternal ectopic thyroid tissue in a patient operated for multinodular goiter

Ectopic thyroid tissue has been found from the tongue to the diaphragm. The most common ectopic thyroid tissue has been found in the tongue, submandibular region, cervical lymph nodes, larynx, trachea, oesophagus, mediastinum, diaphragm and heart respectively. "Forgotten goiter" is an extremely rare disease which is defined as a mediastinal thyroid mass found after total thyroidectomy. In this case report, we discussed a 49 year-old female patient whose retrosternal ectopic thyroid tissue was detected by thyroid scintigraphy taken in postoperative period after total thyroidectomy performed with diagnosis of multinodular goiter. Papillary carcinoma was determined by the histopathological examination. Ectopic thyroid tissue was removed by performing sternotomy. We did not observe any postoperative surgical complications. 100 mCi dose of radioactive iodine was administered to the patient. Retrosternal ectopic thyroid tissue detected after total thyroidectomy is a rarely encountered condition. Therefore, retrosternal ectopic thyroid tissue existence should be definitely kept in mind in patients with no increase in thyroid stimulating hormone level after total thyroidectomy.

Gamma Probe Guided Minimally Invasive Parathyroidectomy without Quick Parathyroid Hormone Measurement in the Cases of Solitary Parathyroid Adenomas

OBJECTIVE

In this study, our aim was to study the efficiency of gamma probe guided minimally invasive parathyroidectomy (GP-MIP), conducted without the intra-operative quick parathyroid hormone (QPTH) measurement in the cases of solitary parathyroid adenomas (SPA) detected with USG and dual phase 99mTc-MIBI parathyroid scintigraphy (PS) in the preoperative period.

MATERIAL AND METHODS

This clinical study was performed in 31 SPA patients (27 female, 4 male; mean age 51±11years) between February 2006 and January 2009. All patients were operated within 30 days after the detection of the SPA with dual phase 99mTc-MIBI PS and USG. The GP-MIP was done 90-120 min after the iv injection of 740 MBq 99mTc-MIBI. In all cases, except 1 patient, the GP-MIP was performed under local anesthesia; due to the enormity of size of SPA, then general anesthesia is chosen.

RESULTS

The operation time was 30-60 min, mean 38,2±7 min. In the first postoperative day, there was a more than 50% decrease in PTH levels in all patients and all but one had normal serum calcium levels. Transient hypocalcemia was detected in one patient.

CONCLUSION

GP-MIP without intra-operative QPTH measurement is a suitable method in the surgical treatment of SPA detected by dual phase 99mTc-MIBI PS and USG.

CONFLICT OF INTEREST

None declared.

Tc-99m radio-guided completion thyroidectomy for differentiated thyroid carcinoma

Background:

The purpose of this study is to investigate whether or not radio-guided surgery has any beneficial effects on completion thyroidectomy (CT) and the associated complication rates.

Patients and Methods:

Twenty-seven patients were scheduled for CT, for thyroid carcinoma, from December 2004 to June 2005, and were included in the study. All the patients had had initial thyroid surgery in other centers and been referred to our clinic for CT. Operation findings and the effectiveness of Tc-99m radio-guided CT were analyzed.

Results:

The intraoperative mean ratio of thyroid activity to background activity counted with a gamma probe was 1.3 ± 0.3. Average operation timing was 74 ± 9 minutes. Postoperatively, no residual tissue was detected in any of the patients with ultrasonography and thyroid scintigraphy. In the first postoperative month, serum TSH level was 61 ± 16.4 mIU / L, when preoperatively it was 7.3 ± 3.1 mIU / L (P < 0.001). In the postoperative period, one patient experienced temporary hypoparathyroidism (3.9%). Permanent hypoparathyroidism or recurrent laryngeal nerve damage was not detected in any patient.

Conclusion:

Tc-99 radio-guided CT is a reliable surgical method, which provides the detection and removal of residual thyroid tissues with minimal complications.