Reproducibility of FDG PET based metabolic tumor volume measurements and of their FDG distribution within.

AIM: The aim of this study was to report on the reproducibility of F-18-fluorodeoxyglucose (FDG) PET MTV (metabolic tumor volume) 40% and MTV2.5, as well as on the intratumor reproducibility in patients, predominantly suffering from lung cancer and squamous cell carcinoma of the head and neck (SCCHN). METHODS: Nineteen patients (14 men) who underwent a baseline staging FDG PET-CT examination and a second radiotherapy treatment planning FDG PET-CT examination prior to treatment initiation within 17 days (range: 7-37 days) from each other were included. Bland-Altman analysis was performed on MTV40% and MTVSUV2.5 values obtained of the primary tumor. For voxelwise comparison of the FDG distribution within tumors the transformation matrices, defined on the CT images, were applied to the corresponding FDG images. Accordingly, the MTV40% of the primary tumor volume was defined and copied on the second FDG image. The coordinates and SUV values of each pixel in the corresponding volumes in both FDG images were used for paired comparison. RESULTS: The standard deviation of the percentage spread around the means of both measurements was respectively 32.5% for MTVSUV2.5 versus 18.8% for MTV40%. Using a cut-off value of 1.96 SD, differences exceeding 64% in MTVSUV2.5 and 37% in MTV40% may be considered to be clinically relevant. Correlation coefficients derived from the voxelwise paired comparison of SUV values within MTV40% volumes delineated on scan 1 and scan 2 ranged from 0.67 to 0.96 (mean: 0.83). Bland-Altman plots demonstrated a low reproducibility for low SUV values and a high(er) reproducibility for high SUV values (inverted triangular shape) in all tumor volumes under study. CONCLUSION: The reproducibility of MTV40% proved better than that of MTVSUV2.5 with a cut-off of 37% (increase or decrease) in MTV allowing to define clinically significant changes. Furthermore, intratumoral voxelwise FDG distribution did not change significantly in most of the patients during the time interval studied.

CA 15.3 measurements for separating FDG PET/CT positive from negative findings in breast carcinoma recurrence. Factors influencing the area under the ROC curve.

UNLABELLED: In breast cancer CA 15.3 is considered the tumour marker of choice. CA 15.3 is directly related to the disease extent and to hormone status (estrogen receptor ER+/ ER-, progesterone receptor PR+/PR-). This study was designed to assess the impact of disease extent, hormone receptor and HER2-status, and circulating blood volume on the area-under the ROC-curve of CA 15.3 to separate FDG PET positive from negative findings. PATIENTS, METHODS: We retrospectively evaluated 379 FDG PET/CT examinations performed in 80 patients with breast cancer. Blood volumes were derived using the formulas by Nadler and multiplied by their corresponding CA 15.3 measurement. RESULTS: ROC-curve analysis revealed an AUC of 0.695 (p = 0.0001) for CA 15.3 to separate FDG PET positive from negative findings. AUC measurements to separate normal scan findings from loco-regional disease and metastatic disease were 0.527 (p = 0.587) and 0.732 (p = 0.0001), respectively. AUC measurements for CA 15.3 to separate positive from negative FDG PET findings, in ER+ and ER- patients, were respectively 0.772 (p = 0.0001) and 0.596 (p = 0.143). AUC measurements for CA 15.3 to separate positive from negative FDG PET findings, in PR+ and PR- patients, were respectively 0.675 (p = 0.0001) and 0.694 (p = 0.0001). In HER2-positive and -negative patients, the AUC measurements were respectively 0.594 (p = 0.178) and 0.701 (p = 0.0001) to separate positive from negative FDG PET findings. CONCLUSION: The AUC for CA 15.3 measurements to separate FDG PET positive from negative findings in breast cancer patients with suspected recurrence proved to be directly related to the extent of the recurrent disease and hormone receptor status and inversely related to HER2-status. Correcting CA 15.3 measurements for blood volumes did not impact the AUC.

Comparison of L-758,298, a prodrug for the selective neurokinin-1 antagonist, L-754,030, with ondansetron for the prevention of cisplatin-induced emesis.

Substance P is localised in brainstem regions associated with emesis. Based on studies in the ferret, it was postulated that a neurokinin-1 (NK1) receptor antagonist would have antiemetic activity as monotherapy in humans receiving chemotherapy. L-758,298 is a water-soluble, intravenous (i.v.) prodrug for L-754,030, a potent and selective NK1 receptor antagonist. This double-blind, randomised, active-agent (ondansetron)-controlled study enrolled 53 cisplatin-naïve patients and evaluated the prevention of both acute (0-24 h) and delayed (days 2-7) emesis after cisplatin treatment (50-100 mg/m(2)). All patients received i.v. L-758,298 (60 or 100 mg) (n=30) or ondansetron (32 mg) (n=23) before cisplatin and efficacy was evaluated up to day 7 post-cisplatin. Nausea was assessed by means of a four-point ordinal scale at intervals over the 7 day period. In the acute period, the proportion of patients without emesis in the L-758,298 and ondansetron groups was 37 and 52%, respectively (no significant difference between the groups). Comparing the distribution of average nausea scores over the entire first 24 h revealed no significant difference between the groups. In the delayed period, the proportion of patients without emesis in the L-758,298 and ondansetron treatment groups was 72 and 30%, respectively (P=0.005). The distribution of average nausea scores in the delayed period was lower in the L-758,298 group compared with the ondansetron group (P=0.15 for the entire delayed period and P=0.043 for day 2 only). No serious adverse events were attributed to L-758,298. A single dose of L-758,298 substantially suppressed the delayed nausea and vomiting characteristic of high dose cisplatin and also appeared to reduce acute emesis post-cisplatin. The data also support the proposition that the underlying mechanism(s) of acute and delayed emesis are different.

Intra-arterial radionuclide infusion as an aid to assess chemotherapy perfusion patterns.

Regional treatment of advanced head and neck cancer by intra-arterial infusion has been tried for several years. The aim of such treatment is to increase the concentration of the drug in the tumor area while decreasing systemic toxicity. The exact localization of the intra-arterial catheter is thereby the key to effective treatment. This report describes the results of radionuclide imaging as an aid to defining the perfusion pattern in comparison with vital dye injection and contrast angiography. It is concluded that radionuclide infusion imaging is the best method to monitor the localization of the catheter.