| BackgroundHypopharyngeal carcinoma is a predominantly squamous cell carcinoma of the head and neck cancer,risk hidden,early and often do not have any symptoms,easily missed diagnosis or misdiagnosis.Because hypopharyngeal cancer is prone to laryngeal and other early invasion and lymph node metastasis,leading to the diagnosis of more advanced.Hypopharyngeal cancer is a kind of head and neck tumor with high mortality.Although the incidence rate of it in head and neck tumors is low,its biological characteristics are bad,most of them are low-differentiated cancer.The prognosis of hypopharyngeal cancer is poor,with a 5-year survival rate of about 40% and a 10-year survival rate of only 13.8%.At present,surgery is still the main clinical treatment for most advanced hypopharyngeal cancer.In clinical practice,ultrasound,laryngoscope,CT,MRI and other imaging examinations are mainly used to determine the tumor size,morphology,lesion range and the presence or absence of invasion,so as to help determine the scientific surgical treatment plan.Ultrasound examination is based on the different reflection of ultrasound in different tissues to identify the tissue,can relatively clearly show the morphological structure of the lesion,has the advantages of economy and convenience,but depends on the experience and level of the doctor;Laryngoscope has a variety of different detection methods,such as indirect laryngoscope,direct laryngoscope,fiber laryngoscope,electronic laryngoscope,and so on.CT has a high resolution,which can clearly show the tissue range and degree of infiltration,but has strong ionizing radiation.MRI has high resolution,no radiation effect,and can clearly show soft tissue invasion,but the scanning time is long.Although these traditional imaging techniques can help to determine the tumor range of hypopharyngeal carcinoma,they cannot yet guide the complete resection of the tumor during the operation.Therefore,it is of greatsignificance for doctors and patients to find a method that can detect and locate tumor tissue safely,quickly,efficiently and with a high degree of objectivity.Numerous studies have shown that the complete removal of tumor tissue during surgery is critical to the patient’s recovery.The negative surgical margin is the main index to ensure the complete resection of the tumor.It is the independent and most important prognostic factor for head and neck malignant tumors.At present,frozen section is almost the only method to determine the surgical margin in head and neck surgery,and this diagnostic method still has a certain false negative and undiagnosed rate.It is urgent to find a method that can complement with frozen section during the operation and accurately determine the surgical margin of hypopharyngeal cancer.For biomedical detection,the non-ionizing terahertz detection technology with high sensitivity is undoubtedly an ideal detection method.Terahertz technology is a rise in the 1980 s has a broad application prospect of detection technology,relying on terahertz spectrum(electromagnetic wave which is between 0.1-10 THz)of high permeability,fingerprint spectrum,high resolution and high secrecy,terahertz technology shows in the medical,chemical,defense,security and communications,and other potential applications in the field of science.Although terahertz wave has many characteristics that other detection technologies do not have,the current understanding and application of terahertz technology is still in the exploratory stage.In the field of biomedicine,the application of terahertz technology has been extensively studied in the hope that terahertz technology can initiate a new reform in biological detection and clinical application.In particular,many studies have been conducted using terahertz to investigate tumors whose pathogenesis is not yet well understood.At present,a large number of studies have reported the detection of terahertz spectrum and imaging for basal cell carcinoma,breast cancer,liver cancer,glioma,etc.,and the detection of otolaryngological tumors is still rare.In this study,we used Terahertz time-domain spectroscopy system(THz-TDS)to detect paraffin specimens of hypopharyngeal cancer and xenograft tumor specimens of nude mice(including frozen sections and paraffin specimens).By analyzing its related optical indexes,the accuracy of the terahertz system in differentiating the tumor tissues and normal tissues of hypopharyngeal cancer was discussed,and its role in determining the pathological resection margin of hypopharyngeal cancer was evaluated.Methods1.Collect tumor tissue and normal tissue specimens of patients undergoing hypopharyngeal cancer total laryngectomy.Paraffin sections were prepared after fixation and dehydration,and tumor and normal tissues were determined by H&E staining.2.The 5-week-old male BALB/c nude mice of SPF grade were selected to construct the transplanted tumor model of human hypopharyngeal carcinoma Fa Du cell line in nude mice by subcutaneous injection.The obtained transplanted tumor specimens were pathologically diagnosed to determine the extent of the tumor tissue.3.The obtained transplanted tumor specimens were prepared into frozen sections and paraffin sections.Some sections contained both tumor tissue and normal tissue.4.Paraffin sections(including tumor tissue and normal tissue),frozen sections of transplanted tumor and paraffin sections(including tumor tissue,normal tissue and para-cancerous tissue)of human hypopharyngeal cancer were detected by transmission terahertz time-domain spectroscopy.5.Origin software was used to draw terahertz atlas of samples for statistical analysis.Results1.The terahertz detection results of hypopharyngeal cancer specimens showed that the terahertz absorption intensity of hypopharyngeal cancer tissues in different patients was higher than that of normal tissues,and the phase also showed different delays.The absorption coefficient of tumor tissues was significantly higher than that of normal tissues,and the difference showed an increasing trend within the effective spectrum and was significant(p<0.01).2.The terahertz absorption coefficient of transplanted tumor tissues was higher than that of normal tissues,and the difference was statistically significant when the detection frequency was greater than 0.48 THz in frozen sections(p<0.05);Within the effective spectrum range of 0.2-1.6 THz in paraffin sections,the difference was always statistically significant(p<0.01).The difference of refractive index between tumor tissues and normal tissues was significant(p<0.01).3.The terahertz absorption coefficient of paracancer tissues falls between the normal tissues and the tumor tissues.The absorption coefficient of paracancer tissues in the low-frequency stage is less different from that of normal tissues,and there is overlaparea.In the high frequency stage,the difference of absorption coefficients of the three groups becomes more and more significant with the increase of frequency.Conclusions1.The method of subcutaneous implantation on the back is an ideal method to construct human hypopharyngeal carcinoma transplanted tumor model in nude mice with fast tumor formation rate,high tumor formation rate and rapid tumor growth.2.The terahertz time-domain spectroscopy system can accurately determine tumor tissues and normal tissues through spectral differences such as tissue absorption coefficient and refractive index.3.The terahertz system can sensitively detect the spectral changes of the adjacent tissues.4.The terahertz spectrum system is simple to operate,the detection process is fast and efficient,and the instrument detection results are more objective.With the improvement of the system,the terahertz technique could be used as another tool for the diagnosis of pathological cutting edge in the future. |
PDF Full Text Request