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Cervical Lymphatics (cervical + lymphatic)
Selected AbstractsPET-CT vs contrast-enhanced CT: What is the role for each after chemoradiation for advanced oropharyngeal cancer?,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 6 2006Amy Y. Chen MD Abstract Purpose. The aim of our study was to assess the utility of positron emission tomography (PET) and 2 fluoro-2-deoxy- D -glucose coupled with neck CT compared with contrast-enhanced CT in predicting persistent cancer either at the primary site or cervical lymphatics in patients with oropharyngeal cancer treated with concurrent chemoradiation Methods. Thirty consecutive patients underwent clinical examination, PET-CT, and contrast-enhanced CT to assess response after the completion of the treatment. The outcome variable was positive tissue diagnosis or negative disease at 6 months. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the primary site as well as cervical disease. Results. Contrast-enhanced CT alone showed the best accuracy in detecting disease at the primary site after treatment (85.7%). Accuracy in evaluating residual tumor in the cervical lymphatics for contrast-enhanced CT and PET-CT was 59.3% and 74.1%, respectively. For evaluating the neck, PET-CT and contrast-enhanced CT demonstrated 100% NPV, but the PPV was 36.3% and 26.6%, respectively. Conclusions. In this preliminary study, PET-CT seems to be superior to contrast-enhanced CT in predicting persistent disease in the neck after chemoradiation for oropharyngeal or unknown primary cancer, but not at the primary site. However, the possibility of a false-positive result in the neck remains high, and thus overtreatment may result. Even more concerning are the false-negative results. Larger, prospective studies will be important in defining the role of PET-CT in obviating the need for salvage neck dissections after chemoradiation. © 2006 Wiley Periodicals, Inc. Head Neck 28:487,495, 2006 [source] Comparison of intensity modulated radiation therapy (IMRT) treatment techniques for nasopharyngeal carcinomaINTERNATIONAL JOURNAL OF CANCER, Issue 2 2001Jason Chia-Hsien Cheng M.D. Abstract We studied target volume coverage and normal tissue sparing of serial tomotherapy intensity modulated radiation therapy (IMRT) and fixed-field IMRT for nasopharyngeal carcinoma (NPC), as compared with those of conventional beam arrangements. Twelve patients with NPC (T2-4N1-3M0) at Mallinckrodt Institute of Radiology underwent computed tomography simulation. Images were then transferred to a virtual simulation workstation computer for target contouring. Target gross tumor volumes (GTV) were primary nasopharyngeal tumor (GTVNP) with a prescription of 70 Gy, grossly enlarged cervical nodes (GTVLN) with a prescription of 70 Gy, and the uninvolved cervical lymphatics [designated as the clinical tumor volume (CTV)] with a prescription of 60 Gy. Critical organs, including the parotid gland, spinal cord, brain stem, mandible, and pituitary gland, were also delineated. Conventional beam arrangements were designed following the guidelines of Intergroup (SWOG, RTOG, ECOG) NPC Study 0099 in which the dose was prescribed to the central axis and the target volumes were aimed to receive the prescribed dose ± 10%. Similar dosimetric criteria were used to assess the target volume coverage capability of IMRT. Serial tomotherapy IMRT was planned using a 0.86-cm wide multivane collimator, while a dynamic multileaf collimator system with five equally spaced fixed gantry angles was designated for fixed-beam IMRT. The fractional volume of each critical organ that received a certain predefined threshold dose was obtained from dose-volume histograms of each organ in either the three-dimensional or IMRT treatment planning computer systems. Statistical analysis (paired t -test) was used to examine statistical significance. We found that serial tomotherapy achieved similar target volume coverage as conventional techniques (97.8 ± 2.3% vs. 98.9 ± 1.3%). The static-field IMRT technique (five equally spaced fields) was inferior, with 92.1 ± 8.6% fractional GTVNP receiving 70 Gy ± 10% dose (P < 0.05). However, GTVLN coverage of 70 Gy was significantly better with both IMRT techniques (96.1 ± 3.2%, 87.7 ± 10.6%, and 42.2 ± 21% for tomotherapy, fixed-field IMRT, and conventional therapy, respectively). CTV coverage of 60 Gy was also significantly better with the IMRT techniques. Parotid gland sparing was quantified by evaluating the fractional volume of parotid gland receiving more than 30 Gy; 66.6 ± 15%, 48.3 ± 4%, and 93 ± 10% of the parotid volume received more than 30 Gy using tomotherapy, fixed-field IMRT, and conventional therapy, respectively (P < 0.05). Fixed-field IMRT technique had the best parotid-sparing effect despite less desirable target coverage. The pituitary gland, mandible, spinal cord, and brain stem were also better spared by both IMRT techniques. These encouraging dosimetric results substantiate the theoretical advantage of inverse-planning IMRT in the management of NPC. We showed that target coverage of the primary tumor was maintained and nodal coverage was improved, as compared with conventional beam arrangements. The ability of IMRT to spare the parotid glands is exciting, and a prospective clinical study is currently underway at our institution to address the optimal parotid dose-volume needs to be spared to prevent xerostomia and to improve the quality of life in patients with NPC. © 2001 Wiley-Liss, Inc. [source] Regional Variations of Contractile Activity in Isolated Rat LymphaticsMICROCIRCULATION, Issue 6 2004ANATOLIY A. GASHEV ABSTRACT Objective: To evaluate lymphatic contractile activity in different regions of the lymphatic system in a single animal model (the rat thoracic duct, mesenteric, cervical, and femoral lymphatics) in response to changes in lymph pressure and flow. Methods: The systolic and diastolic diameters of isolated, cannulated, and pressurized lymphatic vessels were measured. Contraction frequency, ejection fraction, and fractional pump flow were determined. The influences of incrementally increased transmural pressure (from 1 to 9 cm H2O) and imposed flow (from 1 to 5 cm H2O transaxial pressure gradient) were investigated. Results: The authors determined regional differences in lymphatic contractility in response to pressure and imposed flow. They found the highest pumping (at the optimal pressure levels) in mesenteric lymphatics and lowest pumping in thoracic duct. All lymphatics had their optimal pumping conditions at low levels of transmural pressure. Different degrees of the flow-induced inhibition of the pump were observed in the different types of lymphatics. During high flow, the active lymph pumps in thoracic duct and cervical lymphatics were almost completely abolished, whereas mesenteric and femoral lymphatics still exhibited significant active pumping. Conclusions: The active lymph pumps in different regions of the rat body express variable relative strengths and sensitivities that are predetermined by different hydrodynamic factors and regional outflow resistances in their respective locations. [source] Sentinel Lymph Node Biopsy in Head and Neck Squamous Cell CarcinomaTHE LARYNGOSCOPE, Issue 12 2002Karen T. Pitman MD Abstract Objectives/Hypothesis Sentinel lymph node biopsy is a minimally invasive method to stage the regional lymphatics that has revolutionized the management of patients with intermediate-thickness cutaneous melanoma. Head and neck surgeons have been encouraged by the accuracy of sentinel lymph node biopsy in cutaneous melanoma and have applied the technique to patients with head and neck squamous cell carcinoma (HNSCC). The objectives of the study were 1) to study the feasibility and accuracy of sentinel lymph node biopsy as a method to stage the regional lymphatics in HNSCC and 2) to determine whether there are qualitative differences between the cutaneous and mucosal lymphatics that would affect the technique used in HNSCC. Study Design Two methods of investigation were employed: a prospective laboratory study using a feline model for sentinel lymph node biopsy and a retrospective review of patients who received lymphoscintigraphy before neck dissection and intraoperative identification of the sentinel lymph node. Methods Lymphoscintigraphy and a gamma probe were used in four felines to study the kinetics of technetium-labeled sulfa colloid (Tc-SC) in the mucosal lymphatics. In the second part of the feline study, eight subjects were studied intraoperatively. Tc-SC and isosulfan blue dye were used to study the injection technique for the mucosal lymphatics and to determine the time course of the dye and Tc-SC to the sentinel lymph node. In Part II of the present study, a retrospective review of 33 patients with HNSCC was conducted. Twenty patients (stage N0) whose treatment included elective neck dissection were studied with preoperative lymphoscintigraphy and underwent intraoperative identification of the sentinel lymph node to determine the accuracy and feasibility of sentinel lymph node biopsy. Eight patients with palpable neck disease and five patients with recurrent or second primary disease whose previous treatment included neck dissection were also studied with lymphoscintigraphy before neck dissection. Results In the feline study, both Tc-SC and isosulfan blue dye traversed the lymphatics rapidly, appearing in the sentinel lymph node in less than 5 minutes. Modification of the injection technique used for cutaneous melanoma was required to depict the sentinel lymph node of the base of tongue. In the human study, the sentinel lymph node was accurately identified in 19 of 20 (95%) N0 patients. On average, 2.9 sentinel lymph nodes (range, 1,5) were identified in 2.2 (range, 1,4) levels of the neck. Sentinel lymph nodes were bilateral in 4 of 19 patients. When the sentinel lymph node was identified, it accurately predicted the pathological nodal status of the regional lymphatics. Three of 20 patients had cervical metastases, and the sentinel lymph node was identified in 2 of 3 patients with pathologic nodes (pN+). Focal areas of radiotracer uptake were identified in seven of eight patients with palpable disease. These areas corresponded to the level with palpable disease in four patients. The lymphatics delineated by lymphoscintigraphy in the five patients with previous neck dissection were outside the levels that had been dissected. Lymphoscintigraphy depicted collateral patterns of lymphatic drainage. Conclusions Sentinel lymph node biopsy is technically feasible and is a promising, minimally invasive method for staging the regional lymphatics in patients with stage N0 HNSCC. Lymphoscintigraphy alone may determine the levels that require treatment in patients with disrupted or previously operated cervical lymphatics. [source] | ||||||||||