The stairstep graft: an alternative technique in nasal valve surgery.

IMPORTANCE: The stairstep graft is a novel method to modify the lateral anchoring point of lateral grafts for nasal valve correction. OBSERVATIONS: Eight consecutive patients with a diagnosis of nasal valve collapse were included in the study. The novel method of stairstep grafts was performed to reinforce the lateral crus and to widen the nasal valve. Postoperative evaluations were performed by using questionnaires and photographs. After a minimum follow-up of 3 months, all patients reported an improvement of nasal airway postoperatively. Persistent normalization of the preoperatively narrow alar base was noted. CONCLUSIONS AND RELEVANCE: The stairstep graft introduces a new concept in nasal valve surgery by lateralization of the lateral anchoring point for the alar strut graft (or other lateral functional grafts). The concept seems logical, enhances an existing technique, and may be performed through a minimally invasive approach, and the potential for untoward effects seems to be low.

pO polarography, contrast enhanced color duplex sonography (CDS), [18F] fluoromisonidazole and [18F] fluorodeoxyglucose positron emission tomography: validated methods for the evaluation of therapy-relevant tumor oxygenation or only bricks in the puzzle of tumor hypoxia?

BACKGROUND: The present study was conducted to analyze the value of ([18F] fluoromisonidazole (FMISO) and [18F]-2-fluoro-2'-deoxyglucose (FDG) PET as well as color pixel density (CPD) and tumor perfusion (TP) assessed by color duplex sonography (CDS) for determination of therapeutic relevant hypoxia. As a standard for measuring tissue oxygenation in human tumors, the invasive, computerized polarographic needle electrode system (pO2 histography) was used for comparing the different non invasive measurements. METHODS: Until now a total of 38 Patients with malignancies of the head and neck were examined. Tumor tissue pO2 was measured using a pO2-histograph. The needle electrode was placed CT-controlled in the tumor without general or local anesthesia. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO2 readings, with values < or = 2.5, < or = 5.0 and < or = 10.0 mmHg, as well as mean and median pO2 were stated. FMISO PET consisted of one static scan of the relevant region, performed 120 min after intravenous administration. FMISO tumor to muscle ratios (FMISOT/M) and tumor to blood ratios (FMISOT/B) were calculated. FDG PET of the lymph node metastases was performed 71 +/- 17 min after intravenous administration. To visualize as many vessels as possible by CDS, a contrast enhancer (Levovist, Schering Corp., Germany) was administered. Color pixel density (CPD) was defined as the ratio of colored to grey pixels in a region of interest. From CDS signals two parameters were extracted: color hue--defining velocity (v) and color area--defining perfused area (A). Signal intensity as a measure of tissue perfusion (TP) was quantified as follows: TP = vmean x Amean. RESULTS: In order to investigate the degree of linear association, we calculated the Pearson correlation coefficient. Slight (|r| > 0.4) to moderate (|r| > 0.6) correlation was found between the parameters of pO2 polarography (pO2 readings with values < or = 2.5, < or = 5.0 and < or = 10.0 mmHg, as well as median pO2), CPD and FMISOT/M. Only a slight correlation between TP and the fraction of pO2 values < or = 10.0 mmHg, median and mean pO2 could be detected. After exclusion of four outliers the absolute values of the Pearson correlation coefficients increased clearly. There was no relevant association between mean or maximum FDG uptake and the different polarographic- as well as the CDS parameters. CONCLUSION: CDS and FMISO PET represent different approaches for estimation of therapy relevant tumor hypoxia. Each of these approaches is methodologically limited, making evaluation of clinical potential in prospective studies necessary.

Contrast-enhanced color duplex sonography (CDS): an alternative for the evaluation of therapy-relevant tumor oxygenation?

PURPOSE: To evaluate the predictive value of radiotherapeutically relevant tumor hypoxia by contrast-enhanced color duplex sonography (CDS). The objectification was based on pO(2) histography. MATERIAL AND METHODS: 25 patients with metastatic neck lymph node from a primary squamous carcinoma of the head and neck were examined. To visualize as many vessels as possible, a contrast enhancer (Levovist), Schering Corp., Germany) was administered. Horizontal and longitudinal sonographic scans with a thickness of 5 mm were performed on the metastatic neck lymph node. Color pixel density (CPD) was defined as the ratio of colored to gray pixels in a region of interest. It represents the extent of vascularization in the investigated slice. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO(2) readings < or = 2.5, 5.0, and 10.0 mmHg, as well as mean and median pO(2), were documented. RESULTS: In order to investigate the degree of linear association, the Pearson correlation coefficient was calculated. Moderate (/r/ > 0.5) to high (/r/ > 0.7) correlation was found between the CPD and the parameters of hypoxic fraction (pO(2) readings with values < or = 5.0 and 10.0 mmHg, as well as mean and median). There was only a slight correlation between CPD and the fraction of pO(2) values < or = 2.5 mmHg (r = -0.479). CONCLUSION: CPD represents the mean degree of vascularization. As a noninvasive measurement, this method seems feasible for evaluating the state of global oxygenation in superficial tumors. Nevertheless, this method is limited through its deficiency in describing the vascular heterogeneity of tumors.

Evaluation of tumor oxygenation by color duplex sonography: a new approach.

OBJECTIVE: Description of a new noninvasive method for the evaluation of tissue oxygenation in head and neck cancer. STUDY DESIGN AND SETTING: Prospective nonrandomized controlled study in an academic medical center on 20 patients with neck metastases of head and neck cancer. Metastases were investigated using color duplex sonography and pO2 histography. The vascularization in sonography was quantitatively evaluated by color pixel density and compared to the pO2 values of the same nodes. RESULTS: The correlation between vascularization and flow velocity was 0.71. For the mean/median pO2 -values and for the pO2 readings <10.0 mmHg correlations were r = 0.65 / 0.76 and 0.71. CONCLUSION: This sonographic method allows a safe and reliable evaluation of oxygenation in metastases of head and neck cancer. SIGNIFICANCE: The new approach is an alternative to pO2 histography and may play a future role in the planning of radiotherapy in the neck.

New method of dynamic color doppler signal quantification in metastatic lymph nodes compared to direct polarographic measurements of tissue oxygenation.

Tumor growth depends on sufficient blood and oxygen supply. Hypoxia stimulates neovascularization and is a known cause for radio- and chemoresistance. The objective of this study was to investigate the use of a novel ultrasound technique for the dynamic assessment of vascularization and oxygenation in metastatic lymph nodes. Twenty-four patients (age 44-78 years) with cervical lymph node metastases of squamous cell head and neck cancer were investigated by color duplex sonography and 17 (age 46-78 years) were investigated additionally with polarography. Sonography was performed after contrast enhancer infusion under defined conditions. Intranodal perfusion data (color hue, colored area) were measured automatically by a novel software technique. This allows an evaluation of blood flow dynamics by calculating perfusion intensity--velocity, perfused area, as well as the novel parameters tissue resistance index (TRI) and tissue pulsatility index (TPI)--for each point of a complete heart cycle. Tumor tissue pO(2) was measured by means of polarographic needle electrodes placed intranodally. The sonographic and polarographic data were correlated using Pearson's test. Sonography demonstrated a statistically significant inverse correlation between hypoxia and perfusion and significant TPI and TRI changes with different N-stages. The percentage of nodal fraction with less than 10 mmHg oxygen saturation was significantly inversely correlated with lymph node perfusion (r = -0.551; p = 0.021). Nodes with a perfusion of less than 0.05 cm/sec flow velocity showed significantly larger hypoxic areas (p = 0.006). Significant differences of TPI and TRI existed between nodes in stage N(1) and N(2)/N(3) (p = 0.028 and 0.048, respectively). This new method of dynamic signal quantification allows a noninvasive and quantitative assessment of tumor and metastatic lymph node perfusion by means of commonly available ultrasound equipment.

pO(2) Polarography versus positron emission tomography ([(18)F] fluoromisonidazole, [(18)F]-2-fluoro-2'-deoxyglucose). An appraisal of radiotherapeutically relevant hypoxia.

BACKGROUND AND PURPOSE: The aim of the present study was to validate ([(18)F] fluoromisonidazole (FMISO) and [(18)F]-2-fluoro-2'-deoxyglucose (FDG) positron emission tomography (PET) for determination of radiotherapeutically relevant hypoxia by the gold standard for measuring tissue oxygenation in human tumors, the computerized polarographic needle electrode system (pO(2) histography). PATIENTS AND METHODS: Up to now, a total of 16 patients with a metastatic neck lymph node from a primary squamous carcinoma of the head and neck underwent pO(2) and PET measurements. Tumor tissue pO(2) was measured with polarographic needle electrodes using a pO(2) histograph (Eppendorf). Under CT control, the needle electrode was placed in the tumor without general or local anesthesia. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO(2) readings, with values < or = 2.5, < or = 5.0, and < or = 10.0 mmHg, as well as mean and median pO(2) were recorded. All PET studies were carried out using an ECAT EXACT 922/47 scanner with an axial field of view of 16.2 cm. FMISO PET consisted of one static scan of the relevant region, performed 120 min after intravenous administration. The acquisition and reconstruction parameters were as follows: 15-min emission scanning and 4-min transmission scanning with (68)Ge rod sources. FDG PET of the lymph node metastasis was performed 68 +/- 11 min after intravenous administration, applying the whole-body tool with 8-min emission scanning and 4-min transmission scanning per bed position. RESULTS: In order to detect possible relations between the different relevant polarographically measured parameters of tumor hypoxia and FMISO PET data-based oxygenation values, the Pearson correlation coefficient was calculated. Average (r > 0.5) to high correlation (r > 0.7) was found between tumor-to-muscle ratio of FMISO after 2 h and parameters of hypoxic fraction (pO(2) readings with values