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 1st- and 3rd-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.

The Predictive Value of Baseline Volumetric PET/CT Parameters on Treatment Response and Prognosis in Locally Advanced Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy.

PURPOSE: To investigate the prognostic effects of baseline volumetric PET/CT parameters including the maximum standard uptake value (SUVmax), metabolic tumor volume (MTV), and tumor lesion glycolysis (TLG) on treatment response and prognosis in locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (NACRT). METHODS: Between 2015 and 2018, 51 patients with LARC treated with NACRT followed by surgery were included in this retrospective study. Patients were divided into 2 groups by tumor regression grade (TRG) as follows: group I = TRG 1 (no detectable cancer cells) + TRG 2 (single cells and/or small groups of cancer cells) and group II = TRG3 (residual tumor outgrown by fibrosis) + TRG 4 (remarkable fibrosis outgrown by tumor cells) + TRG 5 (no fibrosis with extensive residual cancer). RESULTS: Of the 51 patients, 34 (66.7%) were male. The median age was 55 (range, 37-78) years. According to TRG status, 14 (27.4%) patients were in group I and 37 (72.6%) patients were in group II. The area under the curve (95% CI) was 0.749 (0.593-0.905) in the ROC curve plotted for MTV. The cut-off value for MTV was 12, with 70% sensitivity and 65% specificity. MTV was ≥ 12 in 32 (62.8%) patients. MTV and TLG values were significantly different between groups I and II, whereas there was no significant difference between the groups in terms of SUVmax values (p = 0.006, p = 0.033, and p = 0.673, respectively). The disease-free survival was not reached in patients with MTV < 12 vs. 20 months in those with MTV ≥ 12 (p = 0.323). In multivariate analysis, MTV (OR, 95% Cl, 5.00 [1.17-21.383]) was found to be the factor that affected pathological complete response. CONCLUSION: In LARC treated with NACRT, MTV prior to treatment can help predict the response to 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.

Correlations of the 68Ga-PSMA PET/CT derived primary prostate tumor PSMA expression parameters and metastatic patterns in patients with Gleason Score >7 prostate cancer.

OBJECTIVE: We aimed to investigate the correlations between the prostate specific membrane antigen (PSMA) expression parameters of the primary prostate tumor on gallium-68 (68Ga)-PSMA positron emission tomography/computed tomography (PET/CT) with metastatic patterns in patients with Gleason Score (GS) >7 prostate cancer (PCa). MATERIALS AND METHODS: This study included 55 PCa patients who had 68Ga-PSMA PET/CT performed for staging. According to metastatic pattern, patients were divided into 3 groups as non-metastatic (N0M0), those with isolated pelvic lymph node metastasis (N1M0) and with distant metastasis (M1). The correlations between the primary tumor PSMA expression parameters such as maximum standardize uptake value (SUVmax), SUVmean, PSMA-TV (PSMA receptor expressing tumour volume), and TL-PSMA (total lesion PSMA receptor expression) on 68Ga-PSMA PET/CT imaging and metastatic patterns were investigated. RESULTS: There were 21, 9 and 25 patients in the N0M0, N1M0 and M1 groups, respectively. The PSMA-TV and TL-PSMA values were significantly higher in the N1M0 and the M1 patient groups compared to the N0M0 group, but there was no significant difference between the N1M0 and M1 groups. The primary tumor SUVmax and SUVmean values were not significantly different between the three groups. The optimal PSMA-TV cut-off value for metastasis was >8.07cm3 (AUC 0.86) with sensitivity of 76.5% and specificity 85.7%. The optimal TL-PSMA cut-off value for metastasis was >93 (AUC 0.74) with sensitivity of 64%, and specificity 100%. CONCLUSION: The PSMA-TV and TL-PSMA values are strong markers for metastasis prediction in patients with GS >7 PCa but no other PSMA expression parameters can distinguish between N1M0 and M1 groups.

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 (SUVmax) 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 SUVmax/primary tumor SUVmax (SUVmaxLN/SUVmaxPT), lymph node SUVmax/aortic SUVmax (SUVmaxLN/SUVmaxA), and lymph node SUVmax/ liver SUVmax (SUVmaxLN/SUVmaxL) ratios for diagnosis of lymph node metastasis. RESULTS: SUVmaxLN/SUVmaxA, SUVmaxLN/SUVmaxL, and SUVmaxLN/SUVmaxPT 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 SUVmaxLN; 1.78 for SUVmaxLN /SUVmaxA; 1.08 for SUVmaxLN/SUVmaxL; and 0.36 for SUVmaxLN/SUVmaxPT. The diagnostic sensitivity, specificity and AUC were 83.7%, 77%, 0.856 for SUVmaxLN; 79.7%, 84%, 1.78 for SUVmaxLN/SUVmaxA; 84.1%, 76%, 0.833 for SUVmaxLN/SUVmaxL; and 53.6%, 76%, 0.666 for SUVmaxLN/SUVmaxPT, respectively. CONCLUSION: SUVmaxLN/SUVmaxA, SUVmaxLN/SUVmaxL, and SUVmaxLN/SUVmaxPT ratios can be safely used for diagnosis of cervical lymph node metastasis in patients with LSCC.

The predictive role of metabolic tumor volume on no response to neoadjuvant chemotherapy in patients with breast cancer.

INTRODUCTION: To evaluate the predictive significance of pretreatment metabolic tumor volume on pathologic response in patients who received neoadjuvant chemotherapy for breast cancer. METHODS: Seventy patients who received neoadjuvant chemotherapy between 2013 and 2017 years were enrolled in the study. Pathologic responses and 18-fluorodeoxyglucose positron emission tomography/computed tomography metabolic dates of patients were obtained from archive files. RESULTS: Forty-six (65.7%) patients were in stage II and 24 (34.3%) patients were in stage III; 25 (35.7%) patients were human epidermal growth factor receptor 2 positive, 46 (65.7%) patients were estrogen receptor-positive, 26 (37.1%) patients were progesterone receptor-positive. According to the Miller-Payne grading system, 24 (34.3%) patients constituted 100% pathological response; patients with 91-99% pathological response were 12 (17.1%), the number of patients with non-pathologic response was 6 (8.6%). Median metabolic tumor volume was 7.3 cm3 (7.1 ± 3.5), 8.8 (11.4 ± 9.4), 7.7 (8.3 ± 4.6) and 22 cm3 (19.8 ± 11.0) in patients with stages IIA, IIB, IIIA, and IIIB, respectively (p = 0.032). In Miller-Payne grading, the median metabolic tumor volume value was higher in patients with no pathologic response group than 100% response group (p = 0.003). The cut-off metabolic tumor volume value determining no pathologic response was calculated as higher than 13.62 cm3 (sensitivity 83.3% and specificity 82.8%). CONCLUSIONS: Our study results suggest that higher pretreatment metabolic tumor volume values are predictive on no pathologic response in patients treated with neoadjuvant chemotherapy for breast cancer.

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.

Relationship between pretreatment levels of serum Cyfra 21.1, CEA and PET metabolic parameters in NSCLC.

OBJECTIVE: No investigation has been conducted on the association between PET findings and serum Cyfra 21.1 and CEA levels in nonsmall cell lung cancers (NSCLC). The purpose of this study is to find out if the serum levels of Cyfra 21.1 and CEA are related to metabolic parameters by FDG PET in patients with NSCLC who had not received treatment. METHODS: Seventy-six NSCLC patients, who were admitted for initial staging by FDG PET/CT, were included in the study. Serum Cyfra 21.1 and CEA levels were assayed by enzyme-linked immunosorbent assay. FDG-PET images were analyzed with visual and quantitative methods. Standard uptake values (SUV), metabolic tumor volumes (MTV) and total lesion glycolysis were calculated for primary lesion (T) and whole-body lesions (primary and metastatic) (WB). RESULTS: Serum Cyfra 21.1 and CEA level was significantly higher in patients with locoregionally advanced disease (p < 0.05, p < 0.05, respectively) and metastatic disease (p < 0.01, p < 0.05, respectively) compared to those with localized disease. The serum ln-Cyfra-21.1 was significantly correlated with all volumetric tumor parameters (p < 0.001) and slightly with ln-SUVmean.WB (p < 0.05). There was no relationship between CEA levels and any PET metabolic parameters (p > 0.05). In multiple linear regression analysis incorporating ln-MTV.WB and ln-SUVmean.WB as independents, ln-MTV.WB correlated significantly and positively with ln-Cyfra-21.1 (ß = 0.744, p < 0.001), whereas ln-SUVmean.WB did not significantly predict ln-Cyfra-21.1 (ß = 0.019, p > 0.05). CONCLUSION: This study demonstrates the existence of a significant relationship between total tumor burden and the serum Cyfra 21.1 level in NSCLC patients who had not received treatment. However, it requires further confirmation in operated NSCLC patients.

Abdominal lymph node metastasis in patients with non-small-cell lung cancer as shown by PET/CT.

PURPOSE: The aim of this study is to investigate the frequency and the spread of abdominal lymph node metastasis in patients with non-small-cell lung cancer (NSCLC) by (18)F-FDG PET/CT. PATIENTS AND METHODS: Retrospective evaluation of the (18)F-FDG PET/CT examinations of 1191 patients diagnosed with NSCLC was performed. The metastatic abdominal lymph nodes of the patients were classified as inside the routine imaging field (covering the field of chest CT including adrenal glands) and outside the field. RESULTS: Seventy-four patients (6 F, 68 M; mean: 61 ± 11 years old) among 1191 patients (6%) were identified to have abdominal lymph node metastases. These abdominal lymph node metastasis changed management in 10 out of 74 patients (14%), and there were lymph node metastases outside the routine conventional imaging field in 43 (58%) patients. CONCLUSION: (18)F-FDG PET/CT provided identification of the distant metastatic lymph nodes out of conventional imaging field in more than half of NSCLC patients with abdominal metastasis which changed patient management in 14% of the patients due to abdominal lymph node metastasis outside the routine imaging field. This study shows the necessity of imaging NSCLC patients with an imaging protocol with larger imaging field like PET/CT.

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.

Small Bowel Intussusception due to Metastasized Sarcomatoid Carcinoma of the Lung: A Rare Cause of Intestinal Obstruction in Adults.

Although small bowel intussusception is one of the most common abdominal emergencies in childhood, it is rare in adults and usually occurs as a result of an underlying pathology. Sarcomatoid carcinoma, a very rare subtype of lung cancer, rarely metastasizes to small bowel and causes complications. In this paper, we aim to describe a patient with small bowel intussusception caused by an isolated small bowel metastasis of the sarcomatoid carcinoma of the lung by reviewing the literature.

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.

Subcutaneous metastases of colorectal cancer detected with PET/CT.

Cutaneous and subcutaneous metastases of colorectal cancer is rare. The authors present a case of a 63-year-old man with colorectal carcinoma, who underwent preoperative staging with positron emission tomography/computed tomography (PET/CT). PET/CT demonstrated intensely increased uptake in the subcutaneous nodular lesion in the anterior surface of the right thigh. Histopathological examination of the excised subcutaneous nodular lesion revealed adenocarcinoma metastases.

Gamma probe (99m)Tc-pertechnetate assisted completion thyroidectomy vs conventional thyroidectomy in differentiated thyroid carcinoma.

Patients undergoing partial thyroidectomy for benign diseases may need re-operation if differentiated thyroid carcinoma (DTC) is detected on histopathology. The aim of this study was to determine if using gamma probe during the above surgery in a procedure called: gamma probe completion thyroidectomy (GPCT) could support the diagnosis of DTC tissue and offer an advantage in the surgical treatment of DTC patients. We have studied 100 patients who after bilateral subtotal thyroidectomy for benign disease in several hospitals, were found to have DTC histopathologically and referred to our clinic for subsequent re-operation. Of these, 50 underwent conventional completion thyroidectomy (Group I) and 50 underwent GPCT (Group II). We compared retrospectively Group I and Group II in terms of volume of residual thyroid tissue, thyroid stimulating hormone (TSH) values, complication rates and incidence of tumor found in the residual thyroid. Our results showed that one month postoperatively, TSH was significantly higher in Group II (P<0.001). Volumes of residual thyroid were also significantly less in Group II (P<0.000). Complications and the incidence of tumor cells found in the residual thyroid tissue between the groups were not statistically different (P>0.05). In conclusion, GPCT in patients with DTC significantly increased the success of this operation in localizing and removing residual thyroid tissue.