Salvage surgery improves the treatment outcome of patients with residual/recurrent maxillary sinus cancer after superselective intra-arterial cisplatin infusion with concomitant radiation therapy.

PURPOSE: We have performed superselective intra-arterial cisplatin infusion with concomitant radiotherapy (RADPLAT) for patients with maxillary sinus cancer. The promising treatment outcomes of this non-surgical treatment were reported in past studies. However, few clinical studies have been conducted to evaluate the outcome of salvage surgery following RADPLAT. The purpose of this study was to analyze the treatment outcomes of salvage surgery for patients with recurrent maxillary sinus cancer after RADPLAT. METHODS: We assessed 45 patients who had recurrence following RADPLAT between 1999 and 2017, and conducted a retrospective analysis. We excluded patients who did not complete RADPLAT. Patients were not considered to have completed RADPLAT if they underwent intra-arterial cisplatin less than three times or received a total radiation dose of less than 60 Gy. The primary endpoint was overall survival. The median follow-up period for surviving patients after recurrence was 5.1 years. RESULTS: Twenty-five of the 45 (56%) patients underwent salvage surgery. The 5-year overall survival rate was 68% in patients who underwent salvage surgery, while all patients who did not undergo salvage surgery died during the observation period. Fifteen of 24 (63%) patients with local recurrence underwent salvage surgery. Eight patients did not undergo salvage surgery because of unresectable disease; five of the eight patients had unresectable posterior extension. All nine patients with nodal recurrence underwent neck dissection. CONCLUSION: Treatment outcomes of salvage surgery following RADPLAT were favorable enough for it to be generally recommended. To reduce unresectable recurrence, the posterior section should be eradicated by RADPLAT.

A case of maxillary cancer treated by intra-arterial therapy using a steerable microcatheter.

We report on a 69-year-old man with locally-advanced left maxillary sinus cancer who underwent treatment with intra-arterial chemoradiotherapy. Angiography showed that the main feeding arteries were the left maxillary artery and the ophthalmic artery, arising from the internal carotid artery. Due to acute branching of the ophthalmic artery, conventional microcatheters could not be inserted. Using a steerable microcatheter, we were able to repeatedly administer chemoradiotherapy via the ophthalmic artery. The tumor has mostly disappeared after intra-arterial chemoradiotherapy, and the patient is still alive two years after treatment. A steerable microcatheter is very useful for acute-angled vascular branches.

Intra-arterial chemoradiotherapy for head and neck cancer.

Intra-arterial chemotherapy has been used to treat localized malignant neoplasms in patients with head and neck cancer for over 50 years as the head and neck region is particularly well suited to regional chemotherapy. Early intra-arterial chemotherapy did not prove its efficacy. In addition, the additional complications associated with establishing and maintaining arterial access have further dampened enthusiasm for this approach. Subsequent significant advances in vascular radiology techniques and the development of new devices, such as fluoroscopy units and angiographic catheters, have made possible safe, accurate and repeated superselective intra-arterial chemotherapy. Intra-arterial infusion of high-dose cisplatin with systemic neutralization by intravenous sodium thiosulfate (RADPLAT) is a theoretically attractive approach to the treatment of advanced head and neck cancer. However, a Dutch trial comparing intra-arterial and intravenous chemoradiotherapy for advanced head and neck cancer showed that RADPLAT was not superior to intravenous chemoradiotherapy. Therefore, further investigation of RADPLAT, including the refinement of the indications for its application, is needed.

The importance of early diagnosis in patients with maxillary sinus carcinoma.

There are two major challenges in the early diagnosis of maxillary sinus carcinoma: the maxillary sinus is not susceptible to direct inspection and palpation, and symptoms are uncharacteristic. The aim of this study was to assess the impact of the time interval between first symptoms noticed by the patient and the detection of the tumor on survival. 88 patients with maxillary sinus tumors were included in the retrospective study. Prognostic factors were identified through univariate analysis. Univariate analysis (p = 0.019) revealed a significant impact of the time interval from first symptom to diagnosis on overall survival. With increasing duration of the symptoms 5-year overall survival was reduced from 65 % for duration between 0 and 2 months to 24 % for duration of symptoms longer than 12 months. Furthermore, we found a significant association (p = 0.033) between local extension of the tumor and time interval from first symptom to diagnosis. Early diagnosis is often difficult because of uncharacteristic symptoms, which are identical with benign diseases of the maxillary sinus. The delay between the occurrence of the first symptom and diagnosis often makes a curative treatment impossible.

Dose-finding and efficacy confirmation trial of superselective intra-arterial infusion of cisplatin and concomitant radiotherapy for patients with locally advanced maxillary sinus cancer (JCOG1212, RADPLAT-MSC).

A dose-finding and efficacy confirmation trial was started in Japan in April 2014 to evaluate the efficacy and safety of superselective intra-arterial infusion of cisplatin and concomitant radiotherapy for locally advanced maxillary sinus cancer. A total of 18 patients will be enrolled in the dose-finding phase for the determination of the recommended number of cisplatin cycles, and 65 patients with T4aN0M0 and 62 patients with T4bN0M0, including those who received the recommended number of or fewer cycles in the dose-finding phase, will be enrolled from 16 institutions within a 5-year period in the efficacy confirmation phase. The primary endpoints of the dose-finding and the efficacy confirmation phases are dose-limiting toxicities and 3-year overall survival, respectively. This trial was registered at the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/) under Trial No. UMIN000013706.

Combination treatment with paclitaxel, carboplatin and cetuximab in maxillary sinus cancer: A case report.

The standard treatment for maxillary sinus cancer is surgery; however, surgery for advanced cases often leads to significant aesthetic and functional disability. Combination treatment (induction chemotherapy) with paclitaxel, carboplatin and cetuximab (PCE) can be effective in head and neck cancer. The present study describes the case of a patient with advanced maxillary sinus cancer that was successfully treated using the PCE regimen. A 69-year-old man presented to the Department of Dentistry and Oral Surgery, Hokuto Hospital (Obihiro, Japan) with left buccal swelling and an irregular mass on the left maxillary gingiva. The lesion filled the ethmoid and maxillary sinus, and destroyed the pterygoid process. Numerous lymph node metastases were suspected in the bilateral cervical region. The patient was diagnosed with left maxillary sinus cancer T4aN2cM0 and treated with PCE. The size of the tumor was markedly reduced after the initial treatment. After six cycles of PCE, bioradiotherapy (BRT; 66 Gy/33 Fr) was performed for the remaining lesion, and a complete response was achieved. Ten months after BRT, the tumor recurred in the anterior wall of the left maxillary sinus, which was treated by partial maxillary resection and split-thickness skin grafting. No local or cervical recurrence was observed 2 years after the surgery. These findings suggested that PCE could be considered as the first step for the treatment of highly advanced malignant tumors in the head and neck.

Post-treatment magnetic resonance imaging predicts outcomes of maxillary sinus cancer treatment using super-selective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (RADPLAT).

OBJECTIVES: This study aimed to evaluate the prognostic value of magnetic resonance imaging (MRI) findings in predicting local recurrence in patients with maxillary sinus cancer treated with super-selective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (RADPLAT). METHODS: This single-center retrospective study included consecutive patients with maxillary sinus squamous cell carcinoma, who underwent RADPLAT between October 2016 and September 2021. MRI was performed before (within 2 weeks) and 1 month after (post-treatment MRI) the start of treatment. Tumor reduction rates and pre-treatment cross-sectional areas were calculated from the maximum cross-sectional areas on pre- and post-treatment MRI T2-weighted axial images. Statistical analyses, including receiver operating characteristic analysis, were performed to assess the predictive value of the tumor reduction rates. RESULTS: Twenty-four patients were included in this study. Recurrence occurred in seven patients with a median time of 213 days. The tumor reduction rates were significantly higher in the benign post-treatment changes group compared to the recurrence group (median, 0.814 vs. 0.174; p < 0.001). The cut-off value for the reduction rate between the groups was 0.3578. No significant difference was observed in the maximum pre-treatment cross-sectional area between the groups (p = 0.664). The inter-observer agreement for the tumor areas was excellent. CONCLUSIONS: The tumor reduction rate calculated from MRI T2-weighted images may be a predictor of local recurrence in patients with maxillary sinus cancer treated with RADPLAT. Patients with lower reduction rates may benefit from early salvage surgeries.

Abscopal effect in maxillary sinus cancer: Insights from two case reports and a literature review.

BACKGROUND: The abscopal effect is a rare phenomenon in which localized radiation therapy triggers tumor reduction in nontargeted areas. Although this phenomenon has been observed in various cancer types, it remains infrequent and not fully understood. CASE: Two patients with maxillary sinus cancer with distant metastases were treated with radiotherapy after immune checkpoint inhibitor (ICI) therapy. The patients demonstrated abscopal effects following ICI therapy and radiotherapy, showing shrinkage in metastatic areas not directly targeted by radiation. CONCLUSION: This report was reviewed to examine the synergistic effects of ICI and radiotherapy and to identify optimal strategies to enhance the abscopal effect in clinical practice. It has also touched on various ongoing debates and clinical trials aimed at understanding and exploiting this effect to improve cancer treatment. The exact mechanisms and optimal treatment protocols remain areas for future research.

Impact of Radiation Dose on Treatment of Maxillary Cancer With Superselective Intra-arterial Cisplatin With Radiotherapy.

BACKGROUND/AIM: Maxillary sinus cancer is a relatively rare disease, and treatment is still evolving. We compared the efficacy of superselective intra-arterial infusion of high-dose cisplatin (CDDP) with concomitant radiotherapy (RADPLAT) using three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) and analyzed the relationship between the total radiation dose and the treatment outcome in localized maxillary sinus cancer. PATIENTS AND METHODS: We reviewed the cases of 58 patients with localized maxillary sinus cancer treated with RADPLAT at our institution from March 2004 to November 2020. These 58 patients included 34 who received 3DCRT and 24 who received IMRT. RESULTS: The median follow-up period was 38.4 months. The median prescribed dose to the local lesion was 66 Gy in the 3DCRT group and 70 Gy in the IMRT group. CDDP (100-120 mg/m2) was administered once a week for a median of 6 cycles. The 5-year local control rate and overall survival rate were 69.9% and 72.2%, respectively. The patients treated with 70 Gy had a significantly higher local control rate (87.7%) than those treated with 60 Gy or less (41.0%) (p=0.011). No late grade 3 or higher eye disorders except for cataracts developed in the IMRT group, while grade 4 eye disorders occurred in four patients receiving 3DCRT. CONCLUSION: IMRT can escalate radiation dose safely with acceptable toxicities. The total dose may have an impact on the local control rate in RADPLAT.

Pterygoid Muscle Necrosis Caused by Radiation and Intra-Arterial Cisplatin Infusion Chemotherapy (RADPLAT): A Case Report.

Introduction: Radiation and intra-arterial cisplatin infusion chemotherapy (RADPLAT) for advanced maxillary sinus cancer has accumulated evidence as a treatment with fewer complications and better 5-year survival rates. In this study, we report a case in which pterygoid muscle necrosis occurred 6 months following RADPLAT treatment for maxillary sinus cancer. Case Presentation: The 45-year-old woman had a long history of taking immunosuppressants against rheumatoid arthritis (RA) prior to treatment. Although achieving complete response (CR) to RADPLAT, the patient developed trismus (1 fingerbreadth or less) 6 months following treatment. Abscess formation and recurrence were suspected from the imaging findings; however, the biopsy with endoscopy indicated necrotic tissue. Currently, 18 months have passed without cancer recurrence. Although trismus temporarily improved with rehabilitation, the width of the mouth opening is currently a few millimeters, so the patient can only take liquid food. Conclusion: Pterygoid muscle necrosis should be recognized as a new major complication.

Palatal mucoperiosteal flap for oro-nasal fistula following maxillectomy for maxillary sinus cancer.

OBJECTIVES: This study aimed to describe the technique and clinical outcomes of using a palatal mucoperiosteal flap for oro-nasal fistula closure following resection of maxillary sinus cancer. METHODS: The study was conducted with the permission of the internal review board of the Japanese Red Cross Wakayama Medical Center. Five consecutive cases from 2016 to 2020 of surgically treated maxillary sinus cancer in which the oro-nasal fistulas were closed using a palatal mucoperiosteal flap were retrospectively reviewed. RESULTS: Following tumor resection, the oro-nasal fistula was closed using a palatal mucoperiosteal flap. Complete separation of the oral and nasal cavities was achieved in four patients. Oral intake was resumed within two weeks in four patients. All the patients were able to eat foods similar to those in the preoperative period. Their postoperative speech function was excellent, with no difficulty in communicating with others. CONCLUSION: In the selected cases of maxillary sinus cancer, preservation of the palatal mucosa and closure of an oro-nasal fistula using a palatal mucoperiosteal flap was possible with reasonable outcomes for swallowing and speech functions. The use of this local flap is recommended as a minimally invasive procedure that can be performed especially in patients with limited physiological reserves which preclude free flap reconstruction.

Regression of advanced maxillary sinus cancer with orbital invasion by combined chemotherapy and immunotherapy: A one-year follow-up case report.

A case of advanced maxillary cancer undergoing a combination of chemotherapy and immunotherapy is reported. The subject a 59-year-old man had a history of nasopharyngeal carcinoma treated with concurrent chemoradiotherapy in 2004. The patient was diagnosed with a right maxillary sinus carcinoma invading the right orbital fossa (cT4aN0M0, stage IVA) in 2019. Computed tomography revealed soft tissue swelling involving the right maxillary sinus, right nasal cavity, inferior extraconal space of the right eye, right cheek and right hard palate with extension into the right pterygopalatine fossa. The patient refused surgery and radiotherapy but accepted chemotherapy in combination with immunotherapy. A marked regression of advanced maxillary sinus cancer with orbital invasion using this regimen was noted in the one-year follow-up period. A literature review on treatment for advanced maxillary sinus cancer was also conducted and the results revealed that this combination regimen may play a role in the treatment of advanced maxillary sinus cancer but further investigation is required to determine the effect of combination of chemotherapy and immunotherapy on advanced maxillary sinus cancer.

Organized Hematoma after Intra-Arterial Chemoradiotherapy for Maxillary Sinus Cancer: A Case Report.

An organized hematoma (OH) is a relatively rare benign lesion of the paranasal sinuses. Traditionally, it has been reported to occur following trauma, surgery, and sinus hemorrhagic lesions and in various bleeding predispositions. OHs are sometimes difficult to differentiate from malignancy because of the similar clinical symptoms and bone destruction. It is especially difficult when OHs occur in the same location as the primary tumor after treatment of a malignant tumor. In this paper, we report two cases of OH that occurred after intra-arterial chemoradiotherapy (IACRT) for maxillary sinus cancer. In one case, FDG accumulation was found in PET/CT and suspected to be a cancer recurrence. However, the postoperative pathology showed no malignant findings. This suggests that OH may show accumulation on 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET). In both cases, bleeding from the maxillary sinus continued after surgery. In one case, recurrence was observed, and in the other, nasal irrigation prevented the pooling of blood in the maxillary sinus, and no recurrence was observed. These cases suggest that OH after IACRT may easily recur because the bleeding continues even after surgery. In such cases, nasal irrigation or preoperative embolization may be helpful to avoid recurrence.

Invasion of the pterygoid plates: an indicator for regional lymph node failure in maxillary sinus cancer.

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.

Imaging predictor of ophthalmic involvement in maxillary sinus cancer during super selective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT).

OBJECTIVE: To investigate the predictability of ophthalmic artery involvement in maxillary sinus cancer using preprocedural contrast enhanced CT and MRI. METHODS: We analyzed advanced (T3, T4a, and T4b) primary maxillary sinus squamous cell carcinoma treated with super-selective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT) from Oct 2016 to Mar 2020. Two diagnostic radiologists evaluated the tumor invasion site around the maxillary sinus using preprocedural imaging. These results were compared with the angiographic involvement of the ophthalmic artery using statistical analyses. We also evaluated our RADPLAT quality using complication rate, response to treatment, local progressive free survival (LPFS), and overall survival (OS). RESULTS: Twenty patients were included in this study. There were ten cases of ophthalmic artery tumor stain and there was a correlation between ophthalmic artery involvement and invasion for ethmoid sinus with statistically significant differences. Other imaging findings were not associated with ophthalmic artery involvement. CONCLUSIONS: Ethmoid sinus invasion on preprocedural imaging could suggest ophthalmic artery involvement in maxillary sinus cancer. It may be useful in predicting prognosis and treatment selection.

Radiologic criteria of retropharyngeal lymph node metastasis in maxillary sinus cancer.

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.

Survival Outcomes for Induction vs Adjuvant Chemotherapy in Squamous Cell Carcinoma of the Maxillary Sinus.

OBJECTIVE: In advanced maxillary sinus cancers treated with surgery and radiotherapy, poor local control rates and the potential for organ preservation have prompted interest in the use of systemic therapy. Our objective was to present outcomes for induction compared to adjuvant chemotherapy in the maxillary sinus. STUDY DESIGN: Secondary database analysis. SETTING: National Cancer Database (NCDB). SUBJECTS AND METHODS: In total, 218 cases of squamous cell maxillary sinus cancer treated with surgery, radiation, and chemotherapy between 2004 and 2012 were identified from the NCDB and stratified into induction chemotherapy and adjuvant chemotherapy cohorts. Univariate Kaplan-Meier analyses were compared by log-rank test, and multivariate Cox regression was performed to evaluate overall survival when adjusting for other prognostic factors. Propensity score matching was also used for further comparison. RESULTS: Twenty-three patients received induction chemotherapy (10.6%) and 195 adjuvant chemotherapy (89.4%). The log-rank test comparing induction to adjuvant chemotherapy was not significant ( P = .076). In multivariate Cox regression when adjusting for age, sex, race, comorbidity, grade, insurance, and T/N stage, there was a significant mortality hazard ratio of 2.305 for adjuvant relative to induction chemotherapy (confidence interval, 1.076-4.937; P = .032). CONCLUSION: Induction chemotherapy was associated with improved overall survival in comparison to adjuvant chemotherapy in a relatively small cohort of patients (in whom treatment choice cannot be characterized), suggesting that this question warrants further investigation in a controlled clinical trial before any recommendations are made.

Dose distribution of intensity-modulated proton therapy with and without a multi-leaf collimator for the treatment of maxillary sinus cancer: a comparative effectiveness study.

BACKGROUND: Severe complications, such as eye damage and dysfunciton of salivary glands, have been reported after radiotherapy among patients with head and neck cancer. Complications such as visual impairment have also been reported after proton therapy with pencil beam scanning (PBS). In the case of PBS, collimation can sharpen the penumbra towards surrounding normal tissue in the low energy region of the proton beam. In the current study, we examined how much the dose to the normal tissue was reduced by when intensity-modulated proton therapy (IMPT) was performed using a multi-leaf collimator (MLC) for patients with maxillary sinus cancer. METHODS: Computed tomography findings of 26 consecutive patients who received photon therapy at Okayama University Hospital were used in this study. We compared D2% of the region of interest (ROI; ROI-D2%) and the mean dose of ROI (ROI-mean) with and without the use of an MLC. The organs at risk (OARs) were the posterior retina, lacrimal gland, eyeball, and parotid gland. IMPT was performed for all patients. The spot size was approximately 5-6 mm at the isocenter. The collimator margin was calculated by enlarging the maximum outline of the target from the beam's eye view and setting the margin to 6 mm. All plans were optimized with the same parameters. RESULTS: The mean of ROI-D2% for the ipsilateral optic nerve was significantly reduced by 0.48 Gy, and the mean of ROI-mean for the ipsilateral optic nerve was significantly reduced by 1.04 Gy. The mean of ROI-mean to the optic chiasm was significantly reduced by 0.70 Gy. The dose to most OARs and the planning at risk volumes were also reduced. CONCLUSIONS: Compared with the plan involving IMPT without an MLC, in the dose plan involving IMPT using an MLC for maxillary sinus cancer, the dose to the optic nerve and optic chiasm were significantly reduced, as measured by the ROI-D2% and the ROI-mean. These findings demonstrate that the use of an MLC during IMPT for maxillary sinus cancer may be useful for preserving vision and preventing complications.

The Synergistic Effect of Immune Checkpoint Blockade and Radiotherapy in Recurrent/Metastatic Sinonasal Cancer.

Treatment options for recurrent/metastatic sinonasal cancer (RMSNC) patients are limited. We present two cases with RMSNC treated with a combination of immune checkpoint blockade and hypo-fractionated stereotactic radiotherapy (HSRT).  Case 1 presented with RMSNC three months after the primary treatment. The patient progressed under first-line chemotherapy and pembrolizumab was offered. The disease progressed after the sixth cycle. We performed reirradiation with HSRT to the primary site. Case 2 presented with local recurrence eight years after the primary treatment for maxillary sinus cancer. He refused surgery and chemotherapy and was offered nivolumab treatment. After two doses, we performed reirradiation with HSRT. Case 1 showed regression at both the local and the metastatic sites after radiotherapy. The second patient's symptoms resolved completely three months after radiotherapy. The HSRT and immune checkpoint blockade combination is a promising treatment option for patients with RMSNC.

Dose-finding and efficacy confirmation trial of the superselective intra-arterial infusion of cisplatin and concomitant radiotherapy for locally advanced maxillary sinus cancer (Japan Clinical Oncology Group 1212): Dose-finding phase.

BACKGROUND: We are currently undertaking a multi-institutional prospective trial of the superselective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy for patients with T4aN0M0 or T4bN0M0 locally advanced maxillary sinus squamous cell carcinomas (SCC). We herein report the results of the dose-finding phase. METHODS: The dose-finding phase sought to evaluate the incidence of dose-limiting toxicities and determine the recommended number of cycles of the intra-arterial infusion of cisplatin. In this phase, 100 mg/m2 of cisplatin was administered intra-arterially weekly for 7 weeks with concomitant radiotherapy (70 Gy). RESULTS: All 18 patients received a full dose of radiotherapy. The number of cycles of cisplatin was 7 in 13 patients and 6 in 5 patients. The dose-limiting toxicities were observed in 5 patients. CONCLUSION: These results indicated that this therapy is safe and well-tolerated at 7 cycles of cisplatin, which was determined to be the recommended number of cycles for locally advanced maxillary sinus SCC.