Gerhard W. Sybrecht

18F-Deoxyglucose positron emission tomography (FDG-PET) for the planning of radiotherapy in lung cancer: high impact in patients with atelectasis

PURPOSE 18F-deoxyglucose positron emission tomography (FDG-PET) is increasingly applied in the staging of lung cancer (LC). This study analyzes the potential contribution of PET in radiotherapy planning for LC with special respect to tumor-associated atelectasis. METHODS AND MATERIALS Thirty-four patients with histologically confirmed LC, who had been examined by PET during pretreatment staging, were included. All were irradiated after CT-based therapy planning with anterior/posterior (AP) portals encompassing the primary tumor and the mediastinum (CT portals, CP). The result of the PET examination was unknown in treatment planning. In retrospect, a PET portal (PP) was delineated and compared with the CP. RESULTS In 12/34 cases, the shape and/or size of the portals were changed, primarily (n = 10) the size of the fields was reduced. The median area of CP was 182 cm2 versus 167 cm2 of PP. Seventeen of 34 patients had dys- or atelectasis caused by a central primary tumor. In these cases, differences between CP and PP were significantly more frequent than in the other patients (8/17 vs. 3/17, p = 0.03). CONCLUSION In this retrospective analysis, the information provided by FDG-PET would have contributed to a substantial reduction of the size of radiotherapy portals. This applies particularly for patients with tumor-associated dys- or atelectasis.

Effect of preoperative chemoradiation in addition to preoperative chemotherapy: a randomised trial in stage III non-small-cell lung cancer

BACKGROUND Preoperative chemotherapy improves survival in patients with stage III non-small-cell lung cancer (NSCLC) amenable to resection. We aimed to assess the additional effect of preoperative chemoradiation on tumour resection, pathological response, and survival in these patients. METHODS Between Oct 1, 1995, and July 1, 2003, patients with stage IIIA-IIIB NSCLC and invasive mediastinal assessment from 26 participating institutions of the German Lung Cancer Cooperative Group (GLCCG) were randomly assigned to one of two treatment groups. The intervention group were scheduled to receive three cycles of cisplatin and etoposide, followed by twice-daily radiation with concurrent carboplatin and vindesine, and then surgical resection (those with positive resection margins or unresectable disease were offered further twice-daily radiotherapy). The control group were scheduled to receive three cycles of cisplatin and etoposide, followed by surgery, and then further radiotherapy. The primary endpoint was median progression-free survival (PFS) in patients eligible for treatment after randomisation. Secondary endpoints in patients eligible for treatment after randomisation were overall survival (OS) and the proportion of patients undergoing surgery. Secondary endpoints in patients with tumour resection were the proportion with negative resection margins, the proportion with complete resection, the proportion with histopathological response, and the proportion with mediastinal downstaging. Additionally, exploratory (not prespecified) post-hoc analyses in terms of PFS and OS were done on patients not amenable to resection and on further subgroups of patients undergoing resection. Analyses were by intention to treat. This trial is registered on the ClinicalTrials.gov website, number NCT 00176137. FINDINGS 558 patients were randomly assigned. 34 patients did not meet inclusion criteria and were excluded. Of 524 eligible patients, 142 of 264 (54%) in the interventional group and 154 of 260 (59%) in the control group underwent surgery; 98 of 264 (37%) and 84 of 260 (32%) underwent complete resection. In patients with complete resection, the proportion of those with mediastinal downstaging (45 of 98 [46%] and 24 of 84 [29%], p=0.02) and pathological response (59 of 98 [60%] and 17 of 84 [20%], p<0.0001) favoured the interventional group. However, there was no difference in PFS (primary endpoint) between treatment groups-either in eligible patients (median PFS 9.5 months, range 1.0-117.0 [95% CI 8.3-11.2] vs 10.0 months, range 1.0-111.0 [8.9-11.5], 5-year PFS 16% [11-21] vs 14% [10-19], hazard ratio (HR) 0.99 [0.81-1.19], p=0.87), in those undergoing tumour resection, or in patients with complete resection. In both groups, 35% of patients undergoing surgery received a pneumonectomy (50/142 vs 54/154). In patients receiving a pneumonectomy, treatment-related mortality increased in the interventional group compared with the control group (7/50 [14%] vs 3/54 [6%]). INTERPRETATION In patients with stage III NSCLC amenable to surgery, preoperative chemoradiation in addition to chemotherapy increases pathological response and mediastinal downstaging, but does not improve survival. After induction with chemoradiation, pneumonectomy should be avoided. FUNDING German Cancer Aid (Bonn, Germany).

18F-FDG PET for Mediastinal Staging of Lung Cancer: Which SUV Threshold Makes Sense?

18F-FDG PET is the most accurate noninvasive modality for staging mediastinal lymph nodes in lung cancer. Besides using visual image interpretation, some institutions use standardized uptake value (SUV) measurements in lymph nodes. Mostly, an SUV of 2.5 is used as the cutoff, but this choice was never deduced from respective studies. Receiver operating characteristic (ROC) analyses demonstrated that SUV thresholds of more than 4 resulted in the highest accuracy. But these high cutoffs imply high false-negative rates (FNRs). The aim of our evaluation was to determine an optimal SUV threshold and to compare its diagnostic performance with the results of visual interpretation. Methods: This retrospective study included 95 patients with suspected lung cancer who underwent mediastinoscopy/mediastinal lymphadenectomy after 18F-FDG PET (90–150 min after 250 MBq of 18F-FDG). Maximum SUV was measured in 371 lymph node regions biopsied afterward and visually interpreted using a 6-level score (− − − through + + +). Diagnostic performance was assessed by ROC analysis. FNR and false-positive rate (FPR), the sum of both error rates (FNR + FPR), and diagnostic accuracy were plotted against a hypothetical SUV threshold to determine the optimum SUV threshold. Results: SUVs in metastatic lymph nodes were higher (mean ± SD, 7.1 ± 4.5; range, 1.4–26.9; n = 70) than in tumor-free lymph node stations (2.4 ± 1.7; range, 0.6–14.9; n = 301; P < 0.01). Inflammatory lymph nodes exhibited slightly increased SUVs (2.7 ± 2.0; range, 0.8–14.9; n = 146). The plot of error rates featured a minimum of the sum FNR + FPR for an SUV of 2.5. With increasing SUV threshold, the FPR decreased most prominently up to that value whereas a continuous rise of FNR was noticed. Highest diagnostic accuracy was achieved with an SUV of 4.5. The areas under the ROC curves demonstrated that visual interpretation tends to be more accurate than SUV quantification (visual, 0.930 ± 0.022; SUV, 0.899 ± 0.025; P = 0.241). Using an SUV of 2.5 as the threshold, the resulting sensitivity, specificity, and negative predictive value were 89%, 84%, and 96%, respectively. Conclusion: For mediastinal staging, the choice of an SUV of 2.5 as the threshold is justified because FNR + FPR is minimized. The resulting high negative predictive value of 96% allows the omission of mediastinoscopy in patients with negative mediastinal findings on 18F-FDG PET images. For the experienced observer, visual analysis should be relied on primarily, with calculation of the SUV used, at most, as a secondary aid. For the less experienced observer, the SUV may be of greater value.

Differences in CMV-Specific T-Cell Levels and Long-Term Susceptibility to CMV Infection after Kidney, Heart and Lung Transplantation

Patients after kidney, heart and lung transplantation differ in their immunosuppressive drug regimens and in susceptibility to infectious complications with cytomegalovirus (CMV). In this study, CMV‐specific T‐cell responses were characterized in long‐term transplant recipients and associated with the frequency of infectious complications. CMV‐reactive CD4 T cells from 50 healthy controls, 68 renal, 14 heart and 24 lung transplant recipients were flow cytometrically quantified by the induction of cytokines after specific stimulation. Moreover, the immunosuppressive effect of calcineurin inhibitors on specific T‐cell reactivity was quantified in vitro and compared with responses in vivo. Median CMV‐specific T‐cell frequencies in long‐term renal (1.48%; range 0.06–17.26%) and heart transplant recipients (0.90%; 0.13–12.49%) did not differ from controls (1.82%; 0.26–21.00%). In contrast, CMV‐specific T‐cell levels were significantly lower in lung transplant recipients (0.50%; <0.05–4.98%) and showed a significant correlation with the frequency of infectious episodes (r =−0.57, p = 0.005). The differences within the groups were associated with increasing dosages of immunosuppressive drugs, as exemplified for calcineurin inhibitors that dose dependently reduced specific T‐cell reactivity in vitro. In conclusion, monitoring CMV‐specific CD4 T cells may serve as a measure for long‐term disease susceptibility and may contribute to an improved management of CMV complications after lung transplantation.

Diagnostic performance and prognostic impact of FDG-PET in suspected recurrence of surgically treated non-small cell lung cancer

PurposeThe differentiation of recurrent lung cancer and post-therapeutic changes remains a problem for radiological imaging, but FDG-PET allows biological characterisation of tissues by visualising glucose metabolism. We evaluated the diagnostic performance and prognostic impact of FDG-PET in cases of suspected relapse of lung cancer.MethodsIn 62 consecutive patients, 73 FDG-PET scans were performed for suspected recurrence after surgical therapy of lung cancer. FDG uptake by lesions was measured as the standardised uptake value (SUV). PET results were compared with the final diagnosis established by biopsy or imaging follow-up. SUV and clinical parameters were analysed as prognostic factors with respect to survival.ResultsFDG-PET correctly identified 51 of 55 relapses and gave true negative results in 16 of 18 remissions (sensitivity, specificity, accuracy: 93%, 89%, 92%). SUV in recurrent tumour was higher than in benign post-therapeutic changes (10.6±5.1 vs 2.1±0.6, p<0.001). Median survival was longer for patients with lower FDG uptake in recurrent tumour (SUV<11: 18 months, SUV≥11: 9 months, p<0.01). Long-term survival was observed mainly after surgical re-treatment (3-year survival rate 38%), even if no difference in median survival for surgical or non-surgical re-treatment was detected (11 vs 12 months, p=0.0627). For patients subsequently treated by surgery, lower FDG uptake predicted longer median survival (SUV<11: 46 months, SUV≥11: 3 months, p<0.001). SUV in recurrent tumour was identified as an independent prognostic factor (p<0.05).ConclusionFDG-PET accurately detects recurrent lung cancer. SUV in recurrent tumour is an independent prognostic factor. FDG-PET helps in the selection of patients who will benefit from surgical re-treatment.

Matrix Metalloproteinase 1 (MMP1) Is Associated with Early-Onset Lung Cancer

Matrix metalloproteinases (MMP) play a key role in the breakdown of extracellular matrix and in inflammatory processes. MMP1 is the most highly expressed interstitial collagenase degrading fibrillar collagens. Overexpression of MMP1 has been shown in tumor tissues and has been suggested to be associated with tumor invasion and metastasis. Nine haplotype tagging and additional two intronic single nucleotide polymorphisms (SNP) of MMP1 were genotyped in a case control sample, consisting of 635 lung cancer cases with onset of disease below 51 years of age and 1,300 age- and sex-matched cancer-free controls. Two regions of linkage disequilibrium (LD) of MMP1 could be observed: a region of low LD comprising the 5′ region including the promoter and a region of high LD starting from exon 1 to the end of the gene and including the 3′ flanking region. Several SNPs were identified to be individually significantly associated with risk of early-onset lung cancer. The most significant effect was seen for rs1938901 (P = 0.0089), rs193008 (P = 0.0108), and rs996999 (P = 0.0459). For rs996999, significance vanished after correction for multiple testing. For each of these SNPs, the major allele was associated with an increase in risk with an odds ratio between 1.2 and 1.3 (95% confidence interval, 1.0-1.5). The haplotype analysis supported these findings, especially for subgroups with high smoking intensity. In summary, we identified MMP1 to be associated with an increased risk for lung cancer, which was modified by smoking. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1127–35)

Adenosine receptor-blocking xanthines as inhibitors of phosphodiesterase isozymes

The pharmacological actions of methylxanthines such as theophylline and caffeine may be due to blockade of adenosine receptors and/or inhibition of phosphodiesterase (PDE) activities. In the last years, potent xanthines have been developed that display some selectivity for A1 and A2 adenosine receptors. Little is known about the PDE inhibitory potency of these xanthines. The aim of the present study was to determine the potencies of A1 and A2 receptor selective xanthines as inhibitors of several PDE isozymes, the PDE I-V subtypes. The IC50 values of 8-phenyl- and 8-cycloalkyl-1,3-dialkylxanthines for inhibition of PDE isozymes from different sources are up to 10,000-fold higher than their antagonistic potencies at adenosine receptors. However, the A1 receptor selective antagonists 1,3-diethyl-8-phenylxanthine and 1,3-dipropyl-8-cyclopentylxanthine are comparatively potent inhibitors of PDE IV activity with IC50 values in the 10 microM range and are, therefore, nearly as potent as the PDE IV selective inhibitor, rolipram. The A2 receptor selective 1,3-dipropyl-7-methylxanthine is about 10-300-fold more potent as an adenosine receptor antagonist than as a PDE inhibitor. The results indicate that some of these novel xanthines can be used as selective adenosine receptor antagonists without interference due to inhibitory effects on PDEs.

A palliative accelerated irradiation regimen for advanced non-small-cell lung cancer vs. conventionally fractionated 60 Gy : Results of a randomized equivalence study

PURPOSE Radiation oncologists are often faced with patients with advanced non-small-cell lung cancer (NSCLC), who are not suitable candidates for state-of-the-art radical treatment, but who also are not judged to have a very short life expectancy. Some physicians treat these patients palliatively, whereas others advocate more intensive treatment. To find out if there is a substantial difference in outcome between these approaches, we performed a randomized prospective study. METHODS AND MATERIALS Between 1994 and 1998, 152 eligible patients with advanced NSCLC Stage III (n = 121) or minimal Stage IV (n = 31) were randomized to receive conventionally fractionated (cf; A: 60 Gy, 6 weeks, n = 79) or short-term treatment (PAIR; B: 32 Gy, 2 Gy b.i.d.; n = 73) of tumor and mediastinum. RESULTS One-year survival rate for all patients was 37% with no significant difference between the two treatment arms (A: 36%; B: 38%; p = 0.76). As far as can be judged from limited data available, palliation was adequate and similar for the two treatment arms. Apart from expected differences in the time course of esophagitis, acute side effects were moderate and equally distributed. No severe late effects were observed. CONCLUSIONS In the present randomized trial, survival and available data on palliation were not different after cf to 60 Gy compared to the palliative PAIR regimen. Therefore, for patients who are not suitable for radical treatment approaches, the prescription of a palliative short-term irradiation appears preferable compared to cf over several weeks.

Radioligand binding of antagonists of platelet-activating factor to intact human platelets

Two new antagonists of platelet‐activating factor (PAF), the pyrrolothiazole derivative 52770 RP and the triazolodiazepine WEB 2086, have been studied as radioligands in intact human platelets. [3H]52770 RP and [3H]WEB 2086 bound specifically to high‐affinity sites with dissociation constants (K d) of 14.8 and 6.1 nM, respectively. The maximal number of sites for [3H]52770 RP binding was approx. 15‐fold higher than for [3H]PAF and [3H]WEB 2086. In addition, C16‐PAF, lyso‐PAF, WEB 2086 and 52770 RP had K i values which were nearly identical for both [3H]PAF and [3H]WEB 2086, whereas only 52770 RP competed for [3H]52770 RP‐binding sites. These results demonstrate that in human platelets the sites of [3H]WEB 2086 binding are identical to [3H]PAF‐binding sites, whereas those of [3H]52770 RP are not. [3H]WEB 2086 appears, therefore, to be a suitable antagonist radioligand for labelling PAF receptors.

Do genetic factors protect for early onset lung cancer? A case control study before the age of 50 years.

BackgroundEarly onset lung cancer shows some familial aggregation, pointing to a genetic predisposition. This study was set up to investigate the role of candidate genes in the susceptibility to lung cancer patients younger than 51 years at diagnosis.Methods246 patients with a primary, histologically or cytologically confirmed neoplasm, recruited from 2000 to 2003 in major lung clinics across Germany, were matched to 223 unrelated healthy controls. 11 single nucleotide polymorphisms of genes with reported associations to lung cancer have been genotyped.ResultsGenetic associations or gene-smoking interactions was found for GPX1(Pro200Leu) and EPHX1(His113Tyr). Carriers of the Leu-allele of GPX1(Pro200Leu) showed a significant risk reduction of OR = 0.6 (95% CI: 0.4–0.8, p = 0.002) in general and of OR = 0.3 (95% CI:0.1–0.8, p = 0.012) within heavy smokers. We could also find a risk decreasing genetic effect for His-carriers of EPHX1(His113Tyr) for moderate smokers (OR = 0.2, 95% CI:0.1–0.7, p = 0.012). Considered both variants together, a monotone decrease of the OR was found for smokers (OR of 0.20; 95% CI: 0.07–0.60) for each protective allele.ConclusionSmoking is the most important risk factor for young lung cancer patients. However, this study provides some support for the T-Allel of GPX1(Pro200Leu) and the C-Allele of EPHX1(His113Tyr) to play a protective role in early onset lung cancer susceptibility.