Conformal radiotherapy for paranasal sinus and nasal cavity tumors: three-dimensional treatment planning and preliminary results in 40 patients

Stage III-IV Sinonasal and Nasal Cavity Carcinoma Treated with Three-Dimensional Conformal Radiotherapy

Aims and Background

To report the dosimetric data and clinical outcomes of patients with advanced neoplasm of the paranasal sinuses and nasal cavity, treated by three-dimensional conformal radiotherapy.

Methods

Between 2000 and 2005, 31 consecutive patients were treated for locally advanced tumors of paranasal sinuses and nasal cavity. The primary tumor was located as follows: maxillary sinus 15 (48.4%); ethmoid sinus 10 (32.3%); nasal cavity 6 (19.3%). The patients were separated in two groups according to the modality of treatment: group Aincluded 21 patients treated with postoperative three-dimensional conformal radiotherapy with or without chemotherapy; group B included 10 patients treated with radical three-dimensional conformal radiotherapy with or without chemotherapy. The median radiation dose to the planning target volume was 60 Gy (range, 56–63) for patients who underwent complete surgical resection and 68 Gy (range, 64–70) for those who did not have tumor resection or patients with residual disease.

Results

The median follow-up was 42 months. Five-year local tumor control and overall survival actuarial rates were 74% and 72%, respectively, in the postoperative setting, 20% and 25%, respectively, with the primary radiotherapy. Local recurrence was the most common site of failure. No patient developed radio-induced blindness; 4 patients underwent enucleation as part of radical surgery. Dosimetric data are reported.

Conclusions

The local control rate for these tumors remains low. The prognosis depends on localization, tumor stage and treatment modality. Three-dimensional conformal radiotherapy reduces the risk on optical pathways but does not modify outcome.

Treatment outcomes of intensity-modulated radiotherapy versus 3D conformal radiotherapy for patients with maxillary sinus cancer in the postoperative setting

BACKGROUND

In this study, we compared the treatment outcomes of postoperative 3D conformal radiotherapy (RT) and intensity-modulated radiotherapy (IMRT) for patients with maxillary sinus carcinoma.

METHODS

Fifty-four patients underwent surgery and postoperative RT, of whom 27 (50%) had squamous cell carcinoma and 14 (26%) had adenoid cystic carcinoma. Nineteen patients (35%) were treated with IMRT and 35 patients (65%) received 3D conformal RT. The median radiation dose for 3D conformal RT and IMRT were 62.1 and 63 Gy, respectively.

RESULTS

IMRT produced significantly superior radiation dose distribution to planning target volumes (PTVs) than 3D conformal RT. Over a median follow-up of 60 months, IMRT provided better 3-year locoregional recurrence-free survival (89.2% vs 59.5%; p = .035) and distant metastasis-free survival (94.7% vs 55.3%; p = .042) rates than 3D conformal RT.

CONCLUSION

Postoperative IMRT for patients with maxillary sinus carcinoma resulted in excellent disease control, and should be considered as the first treatment option in these cases. © 2015 Wiley Periodicals, Inc. Head Neck 38: E207-E213, 2016.

Perioperative image-adapted brachytherapy for the treatment of paranasal sinus and nasal cavity malignancies

PURPOSE

Sinonasal malignancies are a rare group of cancers often associated with late presentation and poor prognosis. In the past, there was little progress regarding survival rate, and often, multimodal treatment regimens are required. The aim of this study was to evaluate the clinical outcome of perioperative image-adapted brachytherapy (IABT) as part of a multidisciplinary treatment regimen for the therapy of sinonasal cancer.

METHODS AND MATERIALS

Since 2006, patients with sinonasal cancer at the University Hospital of Schleswig-Holstein Campus Luebeck, Germany, were offered a multimodal treatment concept including head and neck surgery, perioperative IABT with or without external beam radiation therapy, and chemotherapy. In a retrospective study, such patients were analyzed for survival rate, tumor control, and toxicity of the interdisciplinary treatment.

RESULTS

Thirty-five consecutive patients were analyzed. The majority of patients (63%) were treated for a primary tumor and 62% presented with tumor Stages III-IV. The mean follow-up time with IABT was 28 months. Overall survival estimate was 72% after 3 years. Disease-specific survival, disease-free survival, and local control rates were 83%, 63%, and 67%, respectively. On univariate analysis, a significant better disease-free survival rate was found in patients treated for primary, but not recurrent, sinonasal cancer (p = 0.006). The overall treatment toxicities were mainly classified Grade I.

CONCLUSIONS

Interdisciplinary perioperative IABT is associated with excellent locoregional control and survival rates. IABT is well tolerated and shows low toxicity. Furthermore, visual acuity can be preserved in advanced cases. The implementation of perioperative IABT into multimodal treatment regimens improves the oncologic outcome.

Intensity modulated radiotherapy for sinonasal malignancies with a focus on optic pathway preservation

PURPOSE

To assess if intensity-modulated radiotherapy (IMRT) can possibly lead to improved local control and lower incidence of vision impairment/blindness in comparison to non-IMRT techniques when treating sinonasal malignancies; what is the most optimal dose constraints for the optic pathway; and the impact of different IMRT strategies on optic pathway sparing in this setting.

METHODS AND MATERIALS

A literature search in the PubMed databases was conducted in July, 2012.

RESULTS

Clinical studies on IMRT and 2D/3D (2 dimensional/3 dimensional) RT for sinonasal malignancies suggest improved local control and lower incidence of severe vision impairment with IMRT in comparison to non-IMRT techniques. As observed in the non-IMRT studies, blindness due to disease progression may occur despite a lack of severe toxicity possibly due to the difficulty of controlling locally very advanced disease with a dose ≤ 70 Gy. Concurrent chemotherapy's influence on the the risk of severe optic toxicity after radiotherapy is unclear. A maximum dose of ≤ 54 Gy with conventional fractionation to the optic pathway may decrease the risk of blindness. Increased magnitude of intensity modulation through increasing the number of segments, beams, and using a combination of coplanar and non-coplanar arrangements may help increase dose conformality and optic pathway sparing when IMRT is used.

CONCLUSION

IMRT optimized with appropriate strategies may be the treatment of choice for the most optimal local control and optic pathway sparing when treating sinonasal malignancy.

Inverted papilloma with associated carcinoma of the nasal cavity and paranasal sinuses: treatment outcomes

CONCLUSIONS

Degenerated inverted papilloma is a rare, aggressive, and lethal disease. To avoid missing the target, it is absolutely necessary to consider the microscopic extension even in cases of complete exeresis and to irradiate the whole of the adjacent sinuses. A dose increase may lead to better locoregional control.

OBJECTIVE

To evaluate overall survival and progression-free survival of external radiotherapy in the management of nasal cavity and paranasal sinus inverted papilloma with associated carcinoma.

METHODS

Clinical data from 11 patients treated by surgery followed by external radiotherapy (three-dimensional conformational radiotherapy until 2007 then intensity-modulated radiation therapy) for degenerated inverted papilloma in the Léon Bérard Cancer Centre between 1985 and 2009 were retrospectively analyzed.

RESULTS

Five patients (45%) had a local recurrence and died from their recurrence. Three had a premature recurrence, just before or during radiotherapy. We could not determine the prognostic factors for overall survival and progression-free survival.

[Principles of radiation therapy for malignant tumors of the orbit and the periorbital area]

Primary malignant tumors of the orbit and the orbital adnexal area are rare, variform and in the majority of cases need an interdisciplinary treatment. According to tumor entity, tumor localization, and tumor extent the complete spectrum of radiotherapeutic therapy options is necessary. In the majority of malignant tumors, such as those of the eyelids, lachrymal glands, orbit, metastases, sarcoma or lymphoma, radiotherapy is used as a high energy therapy by means of medical linear accelerators as so-called teletherapy. In addition, new therapy methods, such as stereotactic highly conformal radiation or intensity-modulated radiation therapy (IMRT) were developed to achieve a higher local tumor control by a better configuration of the radiotherapy fields to the tumor borders and to contribute to a reduction of acute and chronic side effects in normal tissue by blurring of the dose. The application of ionizing radiation sources, such as so-called interstitial brachytherapy can also be just as carefully as effectively used. Particle beam radiotherapy is limited only to specially licensed centers and light hydrogen ions as proton therapy or carbon ions as heavy ion radiotherapy are in use. This overview will show the options as well as important progress in the field of radiotherapy in the treatment of tumors of the orbit and periorbital area.

A comparison of treatment plans using linac-based intensity-modulated radiation therapy and helical tomotherapy for maxillary sinus carcinoma

This study evaluated whether helical tomotherapy (TOMO) planning could achieve better isodose distribution for the maxillary sinus while concomitantly sparing the adjacent _critical normal organs than linac-based step-and-shoot IMRT (s-IMRT) planning. TOMO and s-IMRT were established for 10 patients with maxillary sinus cancer. The prescription (66 Gy, 30 fractions) was used to cover the planning target volume (PTV) with a 95% isodose line. Each plan was independently optimized using the CORVUS planning system and Tomotherapy Hi-Art system. The treatment plans were compared using dose volume histogram (DVH), a dose homogeneity index (DHI) of the PTV, and equivalent uniform dose (EUD) and DVH of organs at risk (OARs). The TOMO plans demonstrated better dose homogeneity compared to the s-IMRT plans. The average V95% of the TOMO plans was similar to that of the s-IMRT (92.92% vs. 95.07%, respectively), but the average V107% was 0% for TOMO compared with 18.74% for s-IMRT. The average maximum dose reduction was 7 Gy, and DHI increased by 8% for PTV1 in TOMO compared with s-IMRT (79 Gy vs. 71 Gy and, 89% vs. 97%, respectively). The average EUD reduction for the optic nerve was 17%. In summary, planning with TOMO was superior to s-IMRT planning with respect to dose homogeneity within the PTV and sparing of the optic nerve.

Comparative study of dose distribution between carbon ion radiotherapy and photon radiotherapy for head and neck tumor

PURPOSE

A comparative treatment planning study has been performed between carbon ion radiotherapy (CIRT) and photon radiotherapy [three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)] to assess the potential improvements and limitations that could result for locally advanced, nonresectable head and neck tumors.

MATERIALS AND METHODS

Seven patients, originally treated with CIRT, were randomly selected for the comparative study. The evaluations analyzed using dose-volume histogram parameters, conformity index, inhomogeneity coefficient, and dose to the organs at risk (OARs).

RESULTS

The mean conformity index was 1.46, 1.43, and 1.22 for 3D-CRT, IMRT, and CIRT, respectively. The mean inhomogeneity coefficient was 0.05, 0.07, and 0.02 for 3D-CRT, IMRT, and CIRT respectively. Photon plans resulted in greater volumes of normal tissues at 10% to 95% isodose levels compared with the corresponding carbon ion plans where the volumes increased by a factor of 1.2 to 2.7 for 3D-CRT and 1.2 to 2.0 for IMRT.

CONCLUSION

CIRT has the potential to improve the target dose conformity, inhomogeneity coefficient, and OAR sparing when compared with 3D-CRT and IMRT. Compared with 3D-CRT, normal tissue exposure was reduced mainly in the mid-to low-isodose levels using IMRT. Additional improvement was obtained using CIRT.

Dosimetric comparison between coplanar and non coplanar field radiotherapy for ethmoid sinus cancer

Background

To compare non coplanar field (NCF) with coplanar field (CF) -intensity-modulated radiotherapy (IMRT) planning for ethmoid cancer.

Methods

Seven patients treated with NCF IMRT for ethmoid cancer were studied. A CF IMRT optimization was prepared with the same constraints as for the NCF treatment. The maximum point doses (D max) obtained for the different optic pathway structures (OPS) should differ no more than 3% from those achieved with the NCF IMRT plan. The distribution of the dose in the target volume and in the critical structures was compared between the two techniques, as well as the Conformity (CI) and the Homogeneity Indexes (HI) in the target volume.

Results

We noted no difference between the two techniques in the OPS for the D1, D2, and D5%, in the inner ear and controlateral lens for the average Dmax, in the temporo-mandibular joints for the average mean dose, in the cord and brainstem for the average D1%. The dose-volume histograms were slightly better with the NCF treatment plan for the planning target volume (PTV) with a marginally better HI but no impact on CI. We found a great improvement in the PTV coverage with the CF treatment plan for two patients with T4 tumors.

Conclusion

IMRT is one of the treatment options for ethmoid cancer. The PTV coverage is optimal without compromising the protection of the OPS. The impact of non coplanar versus coplanar set up is very slight.

Conformal therapy improves the therapeutic index of patients with anal canal cancer treated with combined chemotherapy and external beam radiotherapy

PURPOSE

To evaluate the clinical outcomes of three-dimensional conformal radiotherapy (3D-CRT) in patients with anal canal cancer, in terms of local control (LC), freedom from relapse (FFR), and overall survival (OS) rates, and to estimate long-term toxicity data.

METHODS AND MATERIALS

Sixty historical patients, treated with conventional radiation techniques (C-RT), were used as controls, and 62 consecutive patients were treated with 3D-CRT. Patients treated with 3D-CRT received 54 Gy in 30 fractions delivered continuously, compared with 45-58.9 Gy (median dose, 54 Gy) in a split course in patients treated with C-RT. Chemotherapy consisted of 5-fluorouracil with either mitomycin-C or cis-platinum given concurrently with radiation. Survival curves were performed using the Kaplan-Meier model, and the Cox proportional hazards model was used for multivariate analysis of risk factors.

RESULTS

No differences in stage and age distribution were observed between the two groups. Patients treated with 3D-CRT and C-RT had an actuarial 5-year LC rate of 85.1% and 61.1%, respectively (p = 0.0056); the FFR rate was 70.2% and 46.1% (p = 0.0166), and the OS rate was 80.7% and 53.9% (p = 0.0171). In multivariate analysis, factors of significance for LC were nodal (N) status (p < 0.001); for OS, 3D-CRT (p = 0.038), N status (p = 0.011), and T status (p = 0.012); and for FFR, 3D-CRT (p = 0.024) and N status (p < 0.001).

CONCLUSION

The use of 3D-CRT allows patients with anal canal cancer to complete radiation and chemotherapy without interruption for toxicity, with significant improvements in LC, FFR, and OS.

Intensity-modulated radiation therapy for malignancies of the nasal cavity and paranasal sinuses

PURPOSE

To report the clinical outcome of patients treated with intensity-modulated radiation therapy (IMRT) for malignancies of the nasal cavity and paranasal sinuses.

METHODS AND MATERIALS

Between 1998 and 2004, 36 patients with malignancies of the sinonasal region were treated with IMRT. Thirty-two patients (89%) were treated in the postoperative setting after gross total resection. Treatment plans were designed to provide a dose of 70 Gy to 95% or more of the gross tumor volume (GTV) and 60 Gy to 95% or more of the clinical tumor volume (CTV) while sparing neighboring critical structures including the optic chiasm, optic nerves, eyes, and brainstem. The primary sites were: 13 ethmoid sinus, 10 maxillary sinus, 7 nasal cavity, and 6 other. Histology was: 12 squamous cell, 7 esthesioneuroblastoma, 5 adenoid cystic, 5 undifferentiated, 5 adenocarcinoma, and 2 other. Median follow-up was 51 months among surviving patients (range, 9-82 months).

RESULTS

The 2-year and 5-year estimates of local control were 62% and 58%, respectively. One patient developed isolated distant metastasis, and none developed isolated regional failure. The 5-year rates of disease-free and overall survival were 55% and 45%, respectively. The incidence of ocular toxicity was minimal with no patients reporting decreased vision. Late complications included xerophthalmia (1 patient), lacrimal stenosis (1 patient), and cataract (1 patient).

CONCLUSION

Although IMRT for malignancies of the sinonasal region does not appear to lead to significant improvements in disease control, the low incidence of complications is encouraging.

Treatment of nasal cavity and paranasal sinus cancer with modern radiotherapy techniques in the postoperative setting--the MSKCC experience

PURPOSE

To perform a retrospective analysis of patients with paranasal sinus (PNS) cancer treated with postoperative radiotherapy (RT) at Memorial Sloan-Kettering Cancer Center.

METHODS AND MATERIALS

Between January 1987 and July 2005, 85 patients with PNS and nasal cavity cancer underwent postoperative RT. Most patients had squamous cell carcinoma (49%; n = 42), T4 tumors (52%; n = 36), and the maxillary sinus (53%; n = 45) as the primary disease site. The median radiation dose was 63 Gy. Of the 85 patients, 76 underwent CT simulation and 53 were treated with either three-dimensional conformal RT (27%; n = 23) or intensity-modulated RT (35%; n = 30). Acute and late toxicities were scored according to the Radiation Therapy Oncology Group radiation morbidity scoring criteria.

RESULTS

With a median follow-up for surviving patients of 60 months, the 5-year estimates of local progression-free, regional progression-free, distant metastasis-free, disease-free, and overall survival rates were 62%, 87%, 82%, 55%, and 67%, respectively. On multivariate analysis, squamous cell histology and cribriform plate involvement predicted for an increased likelihood of local recurrence, and squamous cell histologic features predicted for worse overall survival. None of the patients who underwent CT simulation and were treated with modern techniques developed a Grade 3-4 late complication of the eye.

CONCLUSION

Complete surgical resection followed by adjuvant RT is an effective and safe approach in the treatment of PNS cancer. Emerging tools, such as three-dimensional conformal treatment and, in particular, intensity-modulated RT for PNS tumors, may minimize the occurrence of late complications associated with conventional RT techniques. Local recurrence remains a significant problem.

Visual outcome of accelerated fractionated radiation for advanced sinonasal malignancies employing photons/protons

PURPOSE

To investigate the visual outcomes of patients with advanced sinonasal malignancies treated with proton/photon accelerated fractionated radiation (AFR).

PATIENTS AND METHODS

Between 1991 and 2001, AFR was used to treat 36 patients with advanced stage primary (n=33) or recurrent (n=3) nasal or paranasal malignant tumors. Full ophthalmologic follow-up was documented. The median dose to the gross tumor volume (GTV) was 69.6 CGE (range 60.8-77). Visual complications were graded according to the National Cancer Institute Common Toxicity Criteria (CTC) and the late effects of normal tissue (LENT) scoring systems. The median follow-up was 52.4 months (range 17-122.8).

RESULTS

Thirteen patients developed late visual/ocular toxicity. Cataracts were LENT grade 1 and 3 in 2 patients and 1 patient, respectively. One LENT grade 1 vascular retinopathy and 1 optic neuropathy were also observed. Three and five patients presented with nasolacrimal duct stenosis (CTC grade 2, 2 patients; CTC grade 3, 1 patient) and dry-eye syndrome (CTC grade 1, 1 patient; CTC grade 2, 4 patients), respectively. The 3- and 5-year probability of LENT/CTC grade > or =2 visual toxicity were 15.8+/-6.7% and 20.7+/-7.8%, respectively.

CONCLUSIONS

AFR for locally advanced nasal cavity and paranasal sinus tumors enables delivery of 70 CGE to the tumor with acceptable ophthalmologic complications.

Intensity modulated radiotherapy (IMRT) in patients with carcinomas of the paranasal sinuses: clinical benefit for complex shaped target volumes

INTRODUCTION

The aim of the study was to evaluate the clinical outcome of intensity modulated radiotherapy (IMRT) in 46 patients with paranasal sinus tumors with special respect to treatment-related toxicity.

PATIENTS AND METHODS

We treated 46 patients with histologically proven tumors of the paranasal sinuses with IMRT. Histological classification included squamous cell carcinoma in 6, adenocarcinoma in 8, adenoidcystic carcinoma in 20 and melanoma in 8 patients, respectively. Six patients had been treated with RT during initial therapy after primary diagnosis, and IMRT was performed for the treatment of tumor progression as re-irradiation.

RESULTS

Overall survival rates were 96% at 1 year, 90% at 3 years. Calculated from the initiation of IMRT as primary radiotherapy, survival rates at 1 and 3 years were 95% and 80%. In six patients IMRT was performed as re-irradiation, and survival rate calculated from re-irradiation was 63% at 1 year. Local control rates were 85% at 1, 81% at 2 and 49% at 3 years after primary RT and 50% at 1 year after re-irradiation. Distant metastases-free survival in patients treated with IMRT as primary RT was 83% after 1 and 64% after 3 years. For patients treated as primary irradiation with IMRT, the distant control rate was 83% at 1 year and 0% at 2 years. No severe radiation-induced side-effects could be observed.

CONCLUSION

IMRT for tumors of the paranasal sinuses is associated with very good tumor control rates. Treatment-related acute and long-term toxicity can be minimized as compared to historical results with conventional RT.

Treatment planning comparison of conventional, 3D conformal, and intensity-modulated photon (IMRT) and proton therapy for paranasal sinus carcinoma

PURPOSE

To determine the potential improvements in patients with paranasal sinus carcinoma by comparing proton and intensity-modulated radiotherapy (IMRT) with conventional and conformal photon treatment planning techniques.

METHODS AND MATERIALS

In 5 patients, comparative treatment planning was performed by comparing proton plans and related conventional, conformal, and IMRT photon plans. The evaluations analyzed dose-volume histogram findings of the target volumes and organs at risk (OARs, i.e., pituitary gland, optical pathway structures, brain, nontarget tissue).

RESULTS

The mean and maximal doses, dose inhomogeneities, and conformity indexes for the planning target volumes were comparable for all techniques. Photon plans resulted in greater volumes of irradiated nontarget tissues at the 10-70% dose level compared with the corresponding proton plans. The volumes thereby increased by a factor of 1.3-3.1 for conventional, 1.1-3.8 for conformal, and 1.1-3.7 for IMRT. Compared with conventional techniques, conformal and IMRT photon treatment planning options similarly reduced the mean dose to the OARs. The use of protons further reduced the mean dose to the OARs by up to 65% and 62% compared with the conformal and IMRT technique, respectively.

CONCLUSION

Compared with conventional treatment techniques, conformal RT and IMRT similarly enabled dose reductions to the OARs. Additional improvements were obtained using proton-based treatment planning modalities.

Comparison of treatment plans using intensity-modulated radiotherapy and three-dimensional conformal radiotherapy for paranasal sinus carcinoma

PURPOSE

To compare intensity-modulated radiotherapy (IMRT) treatment planning with three-dimensional conformal radiotherapy (3D-CRT) planning for paranasal sinus carcinoma.

MATERIALS AND METHODS

Treatment plans using traditional 3-field technique, 3D-CRT planning, and inverse planning IMRT were developed for a case of paranasal sinus cancer requiring adjuvant radiotherapy. Plans were compared with respect to dose conformality, dose-volume histograms, doses to critical normal tissues, and ease of treatment delivery.

RESULTS

The inverse-planned IMRT technique was more conformal around the tumor target volume than conventional techniques. The dose-volume histograms demonstrated significantly better critical normal-tissue sparing with the IMRT plans, while able to deliver a minimum dose of 60 Gy to the clinical tumor volume and 70 Gy to the gross tumor volume. Acute toxicities in our analysis were minimal.

CONCLUSIONS

IMRT planning provided improved tumor target coverage when compared to 3D-CRT treatment planning. There was significant sparing of optic structures and other normal tissues, including the brainstem. Inverse planning IMRT provided the best treatment for all paranasal sinus carcinomas, but required stringent immobilization criteria. Further studies are needed to establish the true clinical advantage of this modality.

Three-dimensional conformal radiotherapy for paranasal sinus carcinoma: clinical results for 25 patients

PURPOSE

To assess local control, survival, and clinical and dosimetric prognostic factors in 25 patients with locally advanced maxillary or ethmoid sinus carcinoma treated by three-dimensional conformal radiotherapy (RT).

MATERIALS AND METHODS

Surgery was performed in 22 patients and was macroscopically complete in 16. Seven patients received chemotherapy (concomitant with RT in four). The following quality indexes were defined for the 95% and 90% isodoses: tumor conformity index, normal tissue conformity index, and global conformity index.

RESULTS

The median radiation dose to the planned treatment volume was 63 Gy, with a minimal dose of 60 Gy, except in 2 patients whose cancer progressed during RT. The maximal doses tolerated by the structures involved in vision were respected, except for tumors that involved the optic nerve. After a median follow-up of 25 months, 14 local tumor recurrences developed. The major prognostic factors were central nervous system involvement by disease and the presence of nonresectable tumors. The radiation dose and tumor conformity index value were not significant prognostic indicators. Two patients died of acute infectious toxicity, and two developed late ipsilateral ocular toxicity.

CONCLUSIONS

Improving local control remains the main challenge in RT for paranasal tumors.

[Upper aerodigestive tract cancers: clinical benefits of conformal radiotherapy and intensity modulation]

The conformal radiotherapy approach, three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT), is based on modern imaging modalities, efficient 3D treatment planning systems, sophisticated immobilization systems and rigorous quality assurance and treatment verification. The central objective of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of normal tissues. These techniques would then allow further tumor dose escalation. Head-and-neck tumors are some of the most attractive localizations to test conformal radiotherapy. They combine ballistic difficulties due to particularly complex shapes (nasopharynx, ethmoid) and problems due to the number and low tolerance of neighbouring organs like parotids, eyes, brainstem and spinal cord. The therapeutic irradiation of head-and-neck tumors thus remains a challenge for the radiation oncologist. Conformal radiotherapy does have a significant potential for improving local control and reducing toxicity when compared to standard radiotherapy. However, in the absence of prospective randomized trials, it is somewhat difficult at present to evaluate the real benefits drawn from 3DCRT and IMRT. The published clinical reports on the use of conformal radiotherapy are essentially dealing with dosimetric comparisons on relatively small numbers of patients. Recently, a few publications have emphasized the clinical experience of several precursor teams with a suitable follow-up. This paper describes the current state-of-the-art of 3DCRT and IMRT in order to evaluate the impact of these techniques on head-and-neck cancers irradiation.

Malignant tumors of the nasal cavity and paranasal sinuses

PURPOSE

To evaluate the role of radiation therapy in patients with nasal cavity and paranasal sinus tumors.

MATERIALS AND METHODS

Between October 1964 and July 1998, 78 patients with malignant tumors of the nasal cavity (48 patients), ethmoid sinus (24 patients), sphenoid sinus (5 patients), or frontal sinus (1 patient) were treated with curative intent by radiation therapy alone or in the adjuvant setting. There were 25 squamous cell carcinomas, 14 undifferentiated carcinomas, 31 minor salivary gland tumors (adenocarcinoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma), 8 esthesioneuroblastomas, and 1 transitional cell carcinoma. Forty-seven patients were treated with irradiation alone, 25 with surgery and postoperative irradiation, 2 with preoperative irradiation and surgery, and 4 with chemotherapy in combination with irradiation with or without surgery.

RESULTS

The 5-year actuarial local control rate for stage I (limited to the site of origin; 22 patients) was 86%; for stage II (extension to adjacent sites (eg, adjacent sinuses, orbit, pterygomaxillary fossa, nasopharynx; 21 patients) was 65%; and for stage III (destruction of skull base or pterygoid plates, or intracranial extension; 35 patients) was 34%. The 5-year actuarial local control rate for patients receiving postoperative irradiation was 79% and for patients receiving irradiation alone was 49% (p =.05). The 5-, 10-, 15-, and 20-year ultimate local control rates for all 78 patients were 60%, 56%, 48%, and 48%, respectively. The 5-, 10-, 15-, and 20-year cause-specific survival rates for all 78 patients were 56%, 45%, 39%, and 39%, respectively. The 5-, 10-, 15-, and 20-year absolute survival rates for all 78 patients were 50%, 31%, 21%, and 16%, respectively. Of the 67 (86%) patients who were initially seen with node-negative disease, 39 (58%) received no elective neck treatment, and 28 (42%) received elective neck irradiation. Of the 39 patients who received no elective neck treatment, 33 (85%) did not experience recurrence in the neck compared with 25 (89%) of 28 patients who received elective neck irradiation. Most patients who received elective neck irradiation (57%) had stage III disease. Twenty-one (27%) of 78 patients had unilateral blindness develop secondary to radiation retinopathy or optic neuropathy; the complication was anticipated in most of these patients, because the ipsilateral eye was irradiated to a high dose. Four patients (5%) unexpectedly had bilateral blindness develop because of optic neuropathy. All four of these patients received irradiation alone.

CONCLUSION

Surgery and postoperative radiation therapy may result in improved local control, absolute survival, and complications when compared with radiation therapy alone. Elective neck irradiation is probably unnecessary for patients with early-stage disease.