Search

An accurate and non-invasive histologic assessment of renal masses remains elusive, as approximately 15% of resected renal masses prove benign upon resection. Oncocytomas and hybrid oncocytoma/chromophobe tumors (HOCTs) are the most commonly-resected oncologically low-risk masses and are not reliably distinguished from malignant lesions with standard cross-sectional imaging. Histologically, these tumors are notable for densely-packed mitochondria. Technetium-99m-sestamibi single-photon emission CT/ x-ray CT is a nuclear imaging modality that utilizes a mitochondria-targeting tracer. Early series using 99mTc-sestamibi SPECT/CT showed promise in differentiating renal cell carcinoma (RCC) from oncocytomas and HOCTs, but recently published data from our institution found that oncocytomas still accounted for 20% of lesions with low 99mTc-sestamibi tracer uptake, as qualitatively interpreted by a senior nuclear radiologist. Here, we asses performance of 99mTc-sestamibi scans utilizing quantitative assessment thresholds, hypothesizing that this may improve test characteristics over qualitative assessments. Patients undergoing 99mTc-sestamibi SPECT/CT for evaluation of renal masses between February 2020 and December 2021 were included in our analysis. A mass was labeled as "hot" by the radiologist if its 99mTc-sestamibi uptake was qualitatively equivalent or higher than that of the ipsilateral renal parenchyma; otherwise it was labeled as "cold". Using nuclear medicine image processing software, TBRs were calculated by comparing signal counts of the masses to those of the normal ipsilateral renal parenchyma using manually generated regions of interest. Quantitative "hot"/"cold" determinations for each mass were then re-evaluated using previously published TBR cutoffs of 0.46 and 0.6. Masses for which TBRs could not be calculated were assumed to have unchanged classifications on quantitative analysis. Qualitative and quantitative 99mTc-sestamibi SPECT/CT findings were then correlated to histology for masses that underwent pathologic confirmation via biopsy or surgical excision. 78 patients underwent 99mTc-sestamibi SPECT/CT for 98 renal masses. 52 masses had diagnostic pathology available from biopsy or surgical excision. Of these, 7 were "hot" (1 RCC, 6 oncocytomas) and 45 were "cold" (34 RCC, 2 non-RCC malignancies, 9 oncocytomas). The negative predictive value of qualitatively-interpreted "cold" 99mTc-sestamibi scans for ruling out oncocytoma was 80%. 1/52 (1.9%) malignant masses were interpreted as "hot" and;likely benign. When a TBR cutoff of 0.46 was applied, 17/45 "cold" masses were reclassified as "hot" (13 RCC, 1 non-RCC malignancy, 6 oncocytomas). For a TBR cutoff of 0.6, 6/45 "cold" masses were reclassified as "hot" (1 RCC, 1 non-RCC malignancy, 4 oncocytomas) while 1 "hot" RCC was reclassified as "cold" (Figure 1).; TBR cutoffs of 0.46 and 0.6 improved the NPV;of 99mTc-sestamibi SPECT/CT to 89% and 88% but increased the rate of "hot" malignant tumors to 23.1% and 3.8%, respectively. When assessing histology of renal masses, applying previously-published quantitative TBR cutoffs to 99mTc-sestamibi SPECT/CT provides <10% improvement in the negative predictive value for ruling out oncocytomas compared to previously published qualitative interpretations of these scans. Conversely, the use of these thresholds in place of qualitative assessments tends to categorize more RCCs as "hot," thereby erroneously mimicking oncocytomas. Further work is needed to determine whether 99mTc-sestamibi SPECT/CT has a role in routine clinical practice. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To determine factors associated with symptomatic cardiac toxicity in patients with esophageal cancer treated with chemoradiotherapy. Material and methods: We retrospectively evaluated 102 patients treated with chemoradiotherapy for locally advanced esophageal cancer. Our primary endpoint was symptomatic cardiac toxicity. Radiation dosimetry, patient demographic factors, and myocardial changes seen on 18F-FDG PET were correlated with subsequent cardiac toxicity. Cardiac toxicity measured by RTOG and CTCAE v3.0 criteria was identified by chart review. Results: During the follow up period, 12 patients were identified with treatment related cardiac toxicity, 6 of which were symptomatic. The mean heart V20 (79.7% vs. 67.2%, p =0.05), V30 (75.8% vs. 61.9%, p =0.04), and V40 (69.2% vs. 53.8%, p =0.03) were significantly higher in patients with symptomatic cardiac toxicity than those without. We found the threshold for symptomatic cardiac toxicity to be a V20, V30 and V40 above 70%, 65% and 60%, respectively. There was no correlation between change myocardial SUV on PET and cardiac toxicity, however, a greater proportion of women suffered symptomatic cardiac toxicity compared to men (p =0.005). Conclusions: A correlation did not exist between percent change in myocardial SUV and cardiac toxicity. Patients with symptomatic cardiac toxicity received significantly greater mean V20, 30 and 40 values to the heart compared to asymptomatic patients. These data need validation in a larger independent data set. [Copyright &y& Elsevier]

Purpose: To correlate changes in 2-deoxy-2-[18F]fluoro-d-glucose (18-FDG) positron emission tomography (PET) (18-FDG-PET) uptake with response and disease-free survival with combined modality neoadjuvant therapy in patients with locally advanced rectal cancer. Methods and Materials: Charts were reviewed for consecutive patients with ultrasound-staged T3x to T4Nx or TxN1 rectal adenocarcinoma who underwent preoperative chemoradiation therapy at Fox Chase Cancer Center (FCCC) or Robert H. Lurie Comprehensive Cancer Center of Northwestern University with 18-FDG-PET scanning before and after combined-modality neoadjuvant chemoradiation therapy . The maximum standardized uptake value (SUV) was measured from the tumor before and 3 to 4 weeks after completion of chemoradiation therapy preoperatively. Logistic regression was used to analyze the association of pretreatment SUV, posttreatment SUV, and % SUV decrease on pathologic complete response (pCR), and a Cox model was fitted to analyze disease-free survival. Results: A total of 53 patients (FCCC, n = 41, RLCCC, n = 12) underwent pre- and postchemoradiation PET scanning between September 2000 and June 2006. The pCR rate was 31%. Univariate analysis revealed that % SUV decrease showed a marginally trend in predicting pCR (p = 0.08). In the multivariable analysis, posttreatment SUV was shown a predictor of pCR (p = 0.07), but the test results did not reach statistical significance. None of the investigated variables were predictive of disease-free survival. Conclusions: A trend was observed for % SUV decrease and posttreatment SUV predicting pCR in patients with rectal cancer treated with preoperative chemoradiation therapy. Further prospective study with a larger sample size is warranted to better characterize the role of 18-FDG-PET for response prediction in patients with rectal cancer. [Copyright &y& Elsevier]

Purpose: To determine whether 18-fluorodeoxyglucose positron emission tomography (PET) computed tomography scans predict the pathologic complete response and disease-free and overall survival in patients with esophageal carcinoma undergoing definitive or preoperative chemoradiotherapy.Methods and Materials: The records of patients with esophageal carcinoma presenting for definitive or preoperative treatment and undergoing pre- and post-treatment 18-fluorodeoxyglucose PET-computed tomography scans were retrospectively reviewed. The histologic type, T stage, and nodal status were the variables investigated to determine a relationship with the baseline standardized uptake value (SUV) of the primary tumor at diagnosis. We also attempted to determine whether a relationship exists between the percent decrease in SUV and a pathologic complete response, overall and disease-free survival.Results: A total of 81 patients, 14 women and 67 men, underwent 18-fluorodeoxyglucose PET-computed tomography scanning before treatment and 63 also had post-treatment scans. T stage and tumor location predicted in univariate, but not multivariate, analysis for the initial SUV. Of the patients with a postchemoradiotherapy SUV of <2.5, 66% had tumor in the surgical specimen and 64% of patients had positive lymph nodes at surgery that were not imaged on the postchemoradiotherapy PET scan. A trend existed for post-treatment SUV and the days from radiotherapy to surgery to predict for a pathologic complete response (p = 0.09 and p = 0.08, respectively). The post-treatment SUV predicted for disease-free survival in the definitive chemoradiotherapy group (p = 0.01).Conclusions: A correlation was found between the depth of tumor invasion and the baseline SUV. The post-treatment SUV predicted for disease-free survival in the definitive chemoradiotherapy group. Caution should be exercised in using post-treatment PET scans to determine the necessity for surgical resection. [ABSTRACT FROM AUTHOR]