RESUMEN

PURPOSE: To determine the efficacy and safety of target volume determination by 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) for intensity-modulated radiation therapy (IMRT) for locally advanced head and neck squamous cell carcinoma (HNSCC) extending into the oral cavity or oropharynx. METHODS: We prospectively treated 10 consecutive consenting patients with HNSCC using IMRT, with target volumes determined by PET-CT. Gross tumor volume (GTV) and clinical target volume (CTV) at the oral level were determined by two radiation oncologists for CT, magnetic resonance imaging (MRI), and PET-CT. Differences in target volume (GTVPET, GTVCT, GTVMRI, CTVPET, CTVCT, and CTVMRI) for each modality and the interobserver variability of the target volume were evaluated using the Dice similarity coefficient and Hausdorff distance. Clinical outcomes, including acute adverse events (AEs) and local control were evaluated. RESULTS: The mean GTV was smallest for GTVPET, followed by GTVCT and GTVMRI. There was a significant difference between GTVPET and GTVMRI, but not between the other two groups. The interobserver variability of target volume with PET-CT was significantly less than that with CT or MRI for GTV and tended to be less for CTV, but there was no significant difference in CTV between the modalities. Grade ≤ 3 acute dermatitis, mucositis, and dysphagia occurred in 55%, 88%, and 22% of patients, respectively, but no grade 4 AEs were observed. There was no local recurrence at the oral level after a median follow-up period of 37 months (range, 15-55 months). CONCLUSIONS: The results suggest that the target volume determined by PET-CT could safely reduce GTV size and interobserver variability in patients with locally advanced HNSCC extending into the oral cavity or oropharynx undergoing IMRT. Trial registration UMIN, UMIN000033007. Registered 16 jun 2018, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037631.

RESUMEN

This report describes an extremely rare case of a primary inflammatory myofibroblastic tumor of the trachea. The patient underwent surgical resection by a transtracheal approach and reconstruction with esophageal tracheoplasty. This case report highlights the rarity of such tumors and a minimally invasive and safe surgical technique for tumors around the central neck structures.

Asunto(s)

RESUMEN

Objectives: The goals of benign parotid gland tumor resection are complete resection of the lesion and preservation of the facial nerve function. As the facial nerve cannot be directly visualized via imaging modalities, several methods, including the facial nerve line, Utrecht line, retromandibular vein, Stenon duct, and minimum fascia-tumor distance techniques, have been developed to estimate its location. However, there are no reports on their accuracy in determining tumor location. In the present study, we aimed to assess the diagnostic accuracy of these methods based on tumor location. Methods: This retrospective study analyzed medical records and histological reports of 359 patients with various types of benign parotid gland tumors who underwent a parotidectomy between April 2014 and March 2020. The tumor location was subdivided into the following sections: anterior, superior, inferior, and middle. The tumor location was estimated using five methods: facial nerve line, Utrecht line, retromandibular vein, Stenon duct, and minimum fascia-tumor distance. The final diagnosis of superficial or deep lobe tumor was made based on surgical findings. Results: Each method showed a higher accuracy for superficial tumors (was more than 90%) than for deep lobe tumors. In contrast, for deep lobe tumors, the accuracy of diagnosis with the facial nerve line, Utrecht line, and retromandibular vein methods was low, in the 30% range. Among all methods, the Stenon duct method had the highest accuracy in the diagnosis of deep lobe tumors. The SD method was most useful in cases where both the duct and tumors were detected. The minimum fascia-tumor distance method had the second highest diagnostic accuracy (63%); however, for anterior tumors, it tended to provide false negatives. Conclusions: All tested methods were useful in diagnosing superficial lobe tumors; however, they were not helpful in diagnosing deep lobe tumors, especially anterior tumors.

RESUMEN

It is rare for intraductal papilloma, a benign papillary tumor, to occur in the salivary glands. To our knowledge, intraductal papilloma occurring in the minor salivary glands of the larynx has not been reported. In this report, we describe a case of intraductal papilloma that occurred in the minor salivary glands of the larynx. A woman in her 30s presented with hoarseness and dyspnea since a year. Fiber-optic laryngoscopy revealed a submucosal tumor involving the left aryepiglottic fold and the left false vocal fold. Computed tomography and magnetic resonance imaging revealed a 17 × 15 × 10 mm3 mass with homogenous isodensity, with regular, well-defined margins located on the left aryepiglottic fold and the left false vocal fold. Surgical resection was performed, and subsequently a diagnosis of intraductal papilloma was made by pathologic evaluation. During the follow-up period of over 3 years, the lesion has not recurred. In conclusion, intraductal papilloma of the minor salivary glands should be considered in the differential diagnosis of laryngeal submucosal tumors.

Asunto(s)

RESUMEN

OBJECTIVE: To determine the most appropriate radiologic criteria of metastatic retropharyngeal lymph nodes (RLNs) in patients with maxillary sinus cancer (MSC). MATERIALS AND METHODS: We retrospectively evaluated 16 consecutive patients who underwent magnetic resonance imaging (MRI) before and after the treatment of locally advanced squamous cell carcinoma of the maxillary sinus. The minimal and maximal diameters of all RLNS were recorded. RLNs were classified as metastatic on the basis of the MRI follow-up (f/u). RLNs were considered non-metastatic if stable disease continued until the final MRI f/u and metastatic in cases with different evaluations (complete response, partial response, progressive disease) determined using Response Evaluation Criteria in Solid Tumours (RECIST) ver. 1.1. The receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to assess the accuracy of various criteria in the diagnosis of metastatic RLNs. RESULTS: Of the 34 RLNs in 16 cases observed on pretreatment MRI, 7 were classified as metastatic RLNs and 27 as non-metastatic RLNs. Using the radiologic criteria, metastatic RLNs tended to be diagnosed more accurately with the minimal axial diameter than with the maximal axial diameter (AUC; 0.97 vs. 0.73, p = 0.06). The most accurate size criterion of metastatic RLNs was a minimal axial diameter of 5 mm or larger, with an accuracy of 94.1% (32 of 34). CONCLUSIONS: The most appropriate radiologic criterion of metastatic RLNs in MSC is a minimal axial diameter of 5 mm or longer.

Asunto(s)

RESUMEN

BACKGROUND: The aim of this study was to evaluate the long-term treatment results of combined superselective intraarterial chemotherapy and radiation therapy for advanced maxillary sinus cancer (MSC) and the incidence of regional lymph node failure, and to reveal the clinical and anatomical predictive factors for metastasis. METHODS: We retrospectively evaluated 55 consecutive patients with locally advanced squamous cell carcinoma of the maxillary sinus who were treated with external radiotherapy and superselective intraarterial chemotherapy. Elective nodal irradiation (ENI) was performed only in the clinical node-positive (cN+) cases and not in the clinical node-negative (cN0) cases. RESULTS: Thirty-eight patients were cN0, and 17 were cN+ at diagnosis. Regional lymph node metastases occurred in 7 of 38 patients with cN0, and 2 of 17 with cN+ during the median follow-up period of 36 months. There were more cases of high-grade (3 or 4) late adverse events in the ENI group than in the non-ENI group (13% vs. 41%, respectively; p = 0.03). In cN0 cases without ENI, invasion of the pterygoid plates (57% vs. 90%; p < 0.01) and oral cavity (35% vs. 92%, with invasion vs without invasion, respectively; p = 0.02) was significantly correlated with a low 5-year regional recurrence-free rate. CONCLUSIONS: Patients with MCS and invasion of the pterygoid plates and oral cavity can be considered appropriate candidates for ENI.

Asunto(s)

RESUMEN

OBJECTIVES: The goals of resection of benign parotid gland tumor are complete resection of lesion and preservation of the facial nerve function. Traditionally, the bayonet-shaped incision (Blair incision: BI) and the modified face lift incision (mFLI) are commonly used for parotidectomy. However, concerns exist about the adequacy of exposure and identification of the facial nerve in anterior or superior parotid lesions. The aim of this study was to compare the surgical outcomes between BI and mFLI and to evaluate the adequacy, possible indications, and limitations of mFLI for the resection of benign parotid gland tumors located anteriorly or superiorly. METHODS: This retrospective study analyzed the medical records of 175 patients with various types of benign parotid tumor who underwent partial parotidectomy via BI (97 patients) or mFLI (78 patients). Tumors were divided into five categories depending on their location: anterior, superior, inferior, middle, and deep lobe tumors. The outcomes of operation were analyzed according to tumor location between the incision types. RESULTS: Tumor locations were not significantly different between the two groups. Transient facial palsy occurred in 23 out of 152 patients (15.1%); permanent palsy was not observed in either group. The incidence rates of facial palsy were higher among patients with superior and deep lobe tumors; in the mFLI and BI groups, proportions of superior tumors were 22.2% and 27.2%, respectively, and those of deep lobe tumors were 35.7% and 23.5%, respectively. With regard to superior and anterior tumors, the incidence rate of postoperative facial palsy was insignificantly lower in the mFLI group (10.5%) than in the BI group (18.2%). CONCLUSIONS: There were no differences in the incidence rates of postoperative facial palsy between mFLI and BI for any tumor location. Use of the mFLI is feasible for the resection of most benign parotid tumors located anteriorly or superiorly.

Asunto(s)

RESUMEN

The epidermal growth factor receptor (EGFR) pathway is important in tumorigenesis of oropharyngeal carcinoma (OPC). However, the molecular mechanisms contributing to EGFR expression in OPC are not well-known. To detect relating factors and clinicopathological impact of EGFR protein expression in OPC, gene amplification/loss, point mutations including synonymous mutations, and promoter methylation of EGFR, and the viral genome load of human papillomavirus type 16 (HPV16)-E5, -E6, and -E7, after extracting HPV16-related OPCs with qPCR of HPV16-E6 and E7, were investigated in 74 OPC surgical cases, including 52 HPV-related (HPV-OPC) and 22 HPV-unrelated (nHPV-OPC). Immunohistochemical (IHC) data of EGFR expression (high, weak, and negative), validated by the qPCR of EGFR mRNA, were compared with molecular, viral, and clinicopathological data of patients. All nHPV-OPC cases were EGFR-IHC-high, whereas 21.2%, 65.4%, and 13.5% of HPV-OPC cases showed EGFR-IHC-high, -weak, -negative (p < 0.01), respectively. In HPV-OPC cases, EGFR-IHC-weak/negative status was related to promoter methylation of EGFR (p = 0.009), but not with gene amplification/loss or the point mutation of EGFR and was more often seen in HPV16-OPC cases (p = 0.049). Among HPV16-OPC cases, EGFR-IHC-weak/negative was related to high E6 expression. EGFR protein-loss was related to the tumor histology of non-keratinizing squamous cell carcinoma (SCC) (p = 0.035) but not with patient prognosis. In conclusion, decreased EGFR protein expression was more frequent in HPV-OPC than in nHPV-OPC and was related to EGFR methylation, infection of HPV16, and the viral genome load of HPV16-E6. Clinicopathologically, it was related to the tumor histology of non-keratinizing SCC.

Asunto(s)

RESUMEN

Deep neck abscess is a life-threatening infection that causes laryngeal edema and upper airway occlusion. The predominant bacterial species involved in this disorder is group A streptococcus. Group G streptococcus (GGS) constitutes the normal commensal flora of the human upper airway. Although rarely, it can cause pharyngitis, tonsillitis, and peritonsillar abscess. Here, we report a case of a woman with parapharyngeal abscess caused by GGS. A 56-year-old woman presented to the emergency department with complaints of sore throat and cervical swelling, and a diagnosis of parapharyngeal abscess was established. She had upper airway occlusion, requiring urgent tracheostomy. Endoscopic incision and drainage of the abscess using a specially designed, rigid curved laryngoscope was successfully performed. Since a rigid curved laryngoscope creates a wide viewing field and working space, it was useful for incision and drainage of the parapharyngeal abscess.

RESUMEN

We experienced a case of an elongated styloid process that was 8 cm in length. The patient was a 68-year-old Japanese man with frequent episodes of left-sided throat pain for 10 years. The elongated styloid process could be diagnosed by 3D-computed tomography (left and right length: 7.8 cm and 8.0 cm, respectively) and successfully treated with surgery, since the anatomic relationships could be fully visualized. Surgical methods for shortening an elongated styloid process involve an intraoral or external approach. The external approach to the styloid process involves a trans-cervical approach to the parapharyngeal space, which enables wider visualization in the operative field than an intraoral approach. In the present case, the styloid process reached the parapharyngal space. Therefore, we selected the external approach and shortened only the left-sided styloid process (the same side as the throat pain). The chief complaint disappeared immediately after the operation.

RESUMEN

OBJECTIVE: The optimal management of laryngeal carcinoma requires tumor treatment and preservation of laryngeal functions, such as swallowing and voice quality. Radiotherapy (RT) can fulfill both criteria, although it remains important to identify predictors of radioresistance and reduce unnecessary irradiation. Insulin-like growth factor-1 receptor (IGF-1R) is a transmembrane receptor that plays a key role in cancer development, although its prognostic value after RT remains unknown. We evaluated the predictive value of IGF-1R expression for RT response in patients with early glottic squamous cell carcinoma. METHODS: We retrospectively reviewed 43 patients with T1N0 and T2N0 glottic squamous cell carcinoma who were treated with RT alone. Biopsy specimens were stained using an anti-IGF-1R antibody, and we evaluated the relationships between IGF-1R expression and T classification or tumor recurrence. We also evaluated the loco-regional control (LRC) rate and the prognostic value of various clinical factors. RESULTS: All cases achieved complete response after the initial RT, and 10 (23.3%) patients experienced local tumor recurrence. Twenty-five patients (58.1%) exhibited high IGF-1R expression, although the level of IGF-1R expression was not correlated with T classification. Local recurrence was observed in 36% (9/25) of patients with high IGF-1R expression and in only 5% (1/18) of patients with low IGF-1R expression (p<0.05). The 2-year LRC rate was 94.1% for the low IGF-1R expression group, compared to 49.8% for the high IGF-1R expression group (p=0.04). Anterior commissure involvement and IGF-1R expression were independent adverse factors for LRC. CONCLUSION: High IGF-1R expression was more common among patients with recurrent early glottic carcinoma, which suggests that there is a biological relationship between IGF-1R expression and RT response. Thus, IGF-1R may be a useful screening parameter for RT response in laryngeal carcinoma.

Asunto(s)

RESUMEN

BACKGROUND: Dysphagia is a serious complication of chemoradiotherapy (CRT) in patients with head and neck cancer. Approximately 20% to 30% of patients who have dysphagia require feeding tubes. The purpose of this study was to evaluate the impact of prophylactic swallowing exercises on swallowing function. METHODS: Fifty-one patients with advanced oropharyngeal, hypopharyngeal, and laryngeal cancers were included in this study. Twenty-one patients performed the Shaker exercise and 30 practiced traditional Mendelsohn maneuvers (control group). Before and after treatment, videofluoroscopy and swallowing motion were analyzed to establish movement of the hyoid bone, larynx, and aspiration scores. RESULTS: Average movement of the hyoid bone, thyrohyoid shortening, and upper esophageal sphincter opening were significantly better maintained in the Shaker group. Aspiration score of the Shaker exercise was significantly lower than control group. Feeding tube rates for the Shaker and control groups were 14% and 40% (p < .05). CONCLUSION: Shaker exercises as a prophylactic exercise contributed to preservation of swallowing function in patients with head and neck cancer.

Asunto(s)

RESUMEN

BACKGROUND: Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (SCC) is associated with better prognosis than HPV-negative oropharyngeal SCC. The purpose of this study was to assess the expression of insulin-like growth factor-1 receptor (IGF-1R) in patients with oropharyngeal SCC, its relationship to HPV status and various clinical parameters, and its relationship with clinical outcome. METHODS: The study subjects were 59 patients with oropharyngeal SCC. IGF-1R expression was examined by immunohistochemistry in paraffin-embedded tumor tissues. HPV status was evaluated by in situ hybridization (ISH) in the same tissues. RESULTS: IGF-1R did not correlate with clinical parameters, but IGF-1R expression was more common in HPV-negative tumors than in HPV-positive tumors. The prognosis was poorer in patients of the IGF-1R-positive group than in the IGF-1R-negative group. CONCLUSION: The results suggested that IGF-1R expression in oropharyngeal SCC correlated with poor prognosis in HPV-negative patients. Treatment targeting IGF-1R could potentially improve the survival of patients with HPV-negative oropharyngeal SCC.

Asunto(s)

RESUMEN

BACKGROUND: Surgery remains the main treatment for locally advanced thyroid cancers invading the trachea, esophagus, and recurrent laryngeal nerve. However, extensive resection of such tumors can sometimes involve difficulties and may result in the deterioration of the patient's quality of life. The surgeon should consider not only the patient's prognosis but also the preservation of postoperative function. METHODS: This report describes a minimally invasive surgical procedure for recurrent poorly differentiated papillary thyroid carcinoma involving the trachea and esophagus. To decrease the potential for recurrent laryngeal nerve injuries and to preserve both the tracheal and esophageal blood supply, we adapted a transtracheal approach; the recurrent tumor was safely and completely removed without causing a dysfunction. After a tracheotomy to the right, the tumor was easily detected through the tracheostoma and delineated by palpation. The mucous membrane of the trachea was minimally incised along the right-hand border of the tumor and a mucosal flap was elevated. The left side of the trachea including the membranous wall and cartilage of the tracheal mucosa was maximally preserved, to maintain the vascular supply to the trachea. Finally, the membranous wall of the trachea was preserved to within one-third of the left-hand side. Furthermore, the risk of bleeding from major lateral vessels was reduced. A sternocleidomastoid muscle flap was elevated and inserted into the cavity resulting from the tumor resection and sutured between the esophagus and trachea. The membranous wall of the tracheal mucosa was also sutured submucosally. RESULTS: The tumor was removed completely with the muscular layer of the esophagus without injury to the intact recurrent laryngeal nerve and lateral major vessels. The patient started oral nutritional intake on the first postoperative day and was discharged without any significant postoperative complications. CONCLUSIONS: This new procedure for transtracheal resection for recurrent thyroid cancer involving the trachea and esophagus was useful and safe.

Asunto(s)

RESUMEN

OBJECTIVES: The objective of our study was to investigate the effectiveness of reconstructing the carotid artery using a superficial femoral vein (SFV). METHODS: Ten patients with malignant tumours involving the carotid artery underwent carotid artery resection and reconstruction with the SFV. We use the SFV between the deep femoral vein and perforator branches to the great saphenous vein or deep femoral vein at the popliteal region reconstructive vessel. RESULTS: The mean length and diameter of the grafted SFVs were 13.9 and 11.2 mm, respectively. The mean time for SFV acquirement was 18 min. The mean cerebral ischaemic period was 23.1 min. Nine patients did not experience any neurological complications. One patient experienced slight temporary hemiparesis. There was no postoperative vascular graft thrombosis. Donor site complications did not occur. CONCLUSIONS: Reconstructing the carotid artery using an SFV is very effective due to the ease in harvesting the vessel and its optimal size and length for carotid artery replacement.

Asunto(s)

RESUMEN

BACKGROUND: Advanced parotid cancers more than 4 cm are firmly fixed around the main trunk of the facial nerve that can be hardly detected in narrow working space between mastoid process and parotid cancer. Even though facial nerve was preserved, facial nerve stretching during surgery has significantly serious effect on postoperative facial palsy. OBJECTIVE: To evaluate usefulness of removing mastoid process in managing advanced parotid cancers to contribute identifying and preserving facial nerve. METHOD: The study was performed on 18 advanced parotid cancers which was more than 4 cm and invaded around the facial nerve. Thirteen cases were fresh cases and 5 were recurrent cases.According to a modified Blair incision, the sternocleidomastoid muscle is detached from the mastoid process with electrocautery. When the mastoid process is removed, the main trunk of the facial nerve can be observed from stylomastoid foramen.This procedure was evaluated based on the duration of surgery, working space, and postoperative facial nerve function. RESULTS: In eleven cases, facial nerves were sacrificed. Negative margins were achieved in 100% of the patients. The mean duration for removing of the mastoid process to identify facial nerves was 4.6 minutes. The mean size of the removed mastoid process was 2.1 cm in height and 2.3 cm in width, and 1.8 cm in depth. The extended mean working space was 16.0 cm3, and, as a result, the tumors could be resected without retraction. CONCLUSION: Removing the mastoid process for advanced parotid tumors facilitates identification of the facial nerve and better preservation of the facial nerve function.

Asunto(s)

RESUMEN

UNLABELLED: In parapharyngeal space dissection, significant complications such as dysphagia and carotid artery rupture have been reported. In order to resect tumours safely in narrow parapharyngeal space, we propose indocyanine green (ICG) florescence image for navigation surgery. OBJECTIVE: To evaluate the usefulness of ICG fluorescent image-guided surgery for parapharyngeal space tumours. METHODS: 0.5 mg/kg of ICG was injected via the cephalic vein. Observation of the fluorescent image was performed with HEMS (HyperEye Medical System) at 10-30 min after injection. At first, the position of the tumour was marked over pharyngeal mucosa according to ICG fluorescence imaging with HEMS. We also confirmed submucosal tumours hidden under fascia using HEMS imaging again and resected them. RESULTS: All tumours displayed bright fluorescence emissions which clearly contrasted with the normal structures. Even with the submucosal tumour covered with and obscured by fasciae, we could observe the tumour clearly under HEMS imaging. Tumours behind the carotid artery and lower cranial nerves also were displayed bright fluorescence emissions and were clearly detected. As a result, we could completely remove the tumour safely and noninvasively to preserve pharyngeal functions. CONCLUSION: ICG fluorescence imaging is effective for the detection and resection of the parapharyngeal space tumours with preserving functions.

Asunto(s)

RESUMEN

Recent advances in indocyanine green (ICG) fluorescence imaging have enabled the visualization of the blood supply to tissues. For advanced head and neck cancer, intra-arterial chemotherapy has been applied for improving the prognosis and organ preservation. To identify the tumor-feeding artery, CT angiography has been shown to be useful. However, the presence of dental metals sometimes disturbs the precise evaluation of paranasal sinus cancer patients by CT angiography. The objectives of the study were to assess the feasibility of the ICG fluorescence technique during intra-arterial chemotherapy for advanced maxillary cancer. Thirty-six patients with paranasal sinus cancer who were treated by intra-arterial chemotherapy were included. Conventional CT angiography followed by 5 mg of ICG injection was performed to confirm the areas in which the drug had dispersed. Intra-arterial chemotherapy was administered at 150 mg/m(2) of CDDP four times weekly. Additional information about the arteries feeding the tumors provided by ICG was evaluated. Out of 36 cases, in 17 (47%) the blood supply to the cancer was clearly detected by CT angiography. By adding the infrared ICG evaluation, the blood supply to the tumor was confirmed easily in all cases without radiation exposure. The information obtained from fluorescence imaging was helpful for making decisions concerning the administration of chemo-agents for paranasal sinus cancers in cases involving dental metal, or skin invasion. ICG fluorescence imaging combined with intra-arterial chemotherapy compensated for the deficiencies of CT angiography for paranasal sinus cancer. ICG fluorescence provided us clearer and more useful information about the feeders to cancers.

Asunto(s)

RESUMEN

BACKGROUND: Human papillomavirus-associated oropharyngeal carcinoma (HPV-OPC) is clinicopathologically distinct entity from the HPV-unassociated one (nHPV-OPC). This study aimed to determine the relationship between histological subtypes of OPC and HPV status for Japanese cases and to identify histological structures of HPV-OPC. METHODS: 66 OPC cases were categorized into conventional squamous cell carcinoma (SCC) and the variants. Conventional SCC was subcategorized into keratinizing (KSCC), non-keratinizing (NKSCC), and hybrid SCC (HSCC). HPV status of all cases was determined using p16-immunohistochemistry and HPV-DNA ISH. RESULTS: Two histological subtypes, NKSCC and HSCC, tended to be HPV-OPC and KSCC tended to be nHPV-OPC with statistical significance. Two histological structures, abrupt keratinization, defined in the text, and comedo-necrosis among non-maturing tumor island, were observed for 58.1% and 38.7% of HPV-OPC, and tended to exist for HPV-OPC with statistical significance. CONCLUSIONS: This study showed the association of NKSCC/HSCC with HPV-OPC in Japanese cases, and two histological structures, abrupt keratinization and comedo-necrosis among non-maturing island, were considered characteristic histological features of HPV-OPC. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1816432541113073.

Asunto(s)

RESUMEN

BACKGROUND: In order to minimize surgical stress and preserve organs, endoscopic or robotic surgery is often performed when conducting head and neck surgery. However, it is impossible to physically touch tumors or to observe diffusely invaded deep organs through the procedure of endoscopic or robotic surgery. In order to visualize and safely resect tumors even in these cases, we propose using an indocyanine green (ICG) fluorescence method for navigation surgery in head and neck cancer. OBJECTIVE: To determine the optimum surgical time for tumor resection after the administration of ICG based on the investigation of dynamic ICG fluorescence imaging. METHODS: Nine patients underwent dynamic ICG fluorescence imaging for 360 minutes, assessing tumor visibility at 10, 30, 60, 120, 180, and 360 minutes. All cases were scored according to near-infrared (NIR) fluorescence imaging visibility scored from 0 to 5. RESULTS: Dynamic NIR fluorescence imaging under the HyperEye Medical System indicated that the greatest contrast in fluorescent images between tumor and normal tissue could be observed from 30 minutes to 1 hour after the administration of ICG. The optimum surgical time was determined to be between 30 minutes to 2 hours after ICG injection. These findings are particularly useful for detection and safe resection of tumors invading the parapharyngeal space. CONCLUSION: ICG fluorescence imaging is effective for the detection of head and neck cancer. Preliminary findings suggest that the optimum timing for surgery is from 30 minutes to 2 hours after the ICG injection.