Intraoperative radiation therapy (IORT) for head and neck cancer

Reirradiation of head and neck squamous cell carcinomas: a pragmatic approach, part II: radiation technique and fractionations

INTRODUCTION

Reirradiation (reRT) of local recurrent/second primary tumors of the head and neck represents a potential curative treatment for patients not candidate to a salvage surgery. Aim of the present study is to summarize literature data on modern radiation techniques and fractionations used in this setting of patients.

MATERIALS AND METHODS

A narrative review of the literature was conducted on three topics: (1) target volume delineation (2) reRT dose and techniques and (3) ongoing studies. Patients treated with postoperative reRT and palliative intent were not considered for the current analysis.

RESULTS

Recommendations on the target volume contouring have been reported. 3D-Conformal Radiotherapy, Intensity Modulated Radiotherapy, Stereotactic body Radiotherapy Intraoperative Radiotherapy, Brachytherapy and Charged Particles have been analyzed in terms of indication and fractionation in the field of reRT. Ongoing studies on the topic have been reported for IMRT and Charged Particles. Moreover, according to literature data a stepwise approach has been proposed aiming to provide a useful tool to select patients candidate to a curative reRT in daily clinical practice. Two clinical cases were also provided for its application.

CONCLUSION

Different radiation techniques and fractionations can be used for a second course of radiotherapy in patients with recurrent/second primary tumor of head and neck region. Tumor characteristics as well as radiobiological considerations should be take into account to define the best reRT approach.

Systematic review of intraoperative radiation therapy for head and neck cancer

Multidisciplinary treatments with surgery, radiation therapy, and chemotherapy are the cornerstones in the management of locally advanced head and neck malignancies. In most cases, radiation is delivered via external beam radiation therapy (EBRT). Intraoperative radiation therapy (IORT), on the other hand, is the delivery of precise doses of radiation to selected target volumes within the exposed surgical field while at the operating room. Most studies on its use on head and neck cancers are limited to single-institutional retrospective case series. We performed a systematic review to consolidate the existing literature on IORT for head and neck malignancies. Fifty-two studies representing a mixed population of 2,389 patients were included in this review. IORT via electrons (intraoperative electron radiation therapy), brachytherapy (intraoperative high dose-rate brachytherapy) or photons was administered in numerous settings, but most commonly as part of a reirradiation regimen following salvage surgery for recurrent tumours. Often, additional EBRT was also planned postoperatively. This review illustrates that IORT is a promising treatment modality in head and neck cancer. Multiple single-institutional studies spanning several decades have demonstrated benefit in terms of local control with reasonable toxicity. However, randomised trials comparing it with current standards of care are still needed.

Risk of internal carotid artery stenosis or occlusion after single-fraction radiosurgery for benign parasellar tumors

OBJECTIVE

Stereotactic radiosurgery (SRS) is an accepted treatment option for patients with benign parasellar tumors. Here, the authors' objective was to determine the risk of developing new or progressive internal carotid artery (ICA) stenosis or occlusion after single-fraction SRS for cavernous sinus meningioma (CSM) or growth hormone-secreting pituitary adenoma (GHPA).

METHODS

The authors queried their prospectively maintained registry for patients treated with single-fraction SRS for CSM or GHPA in the period from 1990 to 2015. Study criteria included no prior irradiation and ≥ 12 months of post-SRS radiological follow-up. Pre-SRS grading of ICA involvement was applied according to the 1993 classification schemes of Hirsch for CSM or Knosp for GHPA.

RESULTS

The authors conducted a retrospective review of 283 patients, 155 with CSMs and 128 with GHPAs. Ninety-three (60%) CSMs were Hirsch category 2 and 3 tumors; 97 (76%) GHPAs were Knosp grade 2-4 tumors. Median follow-up after SRS was 6.6 years (IQR 1-24.9 years). No GHPA or category 1 CSM developed ICA stenosis or occlusion. Three (5.2%) patients with category 2 CSMs had asymptomatic ICA stenosis (n = 2) or occlusion (n = 1); 1 (1.1%) category 2 CSM patient had transient ischemic symptoms. Five (14.3%) category 3 CSMs progressed to ICA occlusion (4 asymptomatic, 1 symptomatic). The median time to stenosis/occlusion was 4.8 years (IQR 1.8-7.6). Five- and 10-year risks of ICA stenosis/occlusion in category 2 and 3 CSM patients were 7.5% and 12.4%, respectively. Five- and 10-year risks of ischemic stroke from ICA stenosis/occlusion in category 2 and 3 CSM patients were both 1.2%. Multivariate analysis showed patient age (HR 0.92, 95% CI 0.86-0.98, p = 0.01), meningioma pathology (HR and 95% CI not defined, p = 0.03), and pre-SRS carotid category (HR 4.51, 95% CI 1.77-14.61, p = 0.004) to be associated with ICA stenosis/occlusion. Internal carotid artery stenosis/occlusion was not related to post-SRS tumor growth (HR and 95% CI not defined, p = 0.41).

CONCLUSIONS

New or progressive ICA stenosis/occlusion was common after SRS for CSM but was not observed after SRS for GHPA, suggesting a tumor-specific mechanism unrelated to radiation dose. Pre-SRS ICA encasement or constriction increases the risk of ICA stenosis/occlusion; however, the risk of ischemic complications is very low.

A prospective, single-arm, phase II clinical trial of intraoperative radiotherapy using a low-energy X-ray source for local advanced Laryngocarcinoma (ILAL): a study protocol

BACKGROUND

Laryngocarcinoma (LC), in most cases a squamous cell carcinoma, accounts for 1 ~ 5% of the incidence of all tumors. At present, laryngocarcinoma is mainly managed with the integration of surgery and radio- and chemo-therapies. The current development trend of treatment is to improve the local control rate of tumor and the quality of life of patients. Intraoperative radiation therapy (IORT) is a radiotherapy that delivers single high dose irradiation at a close range to the tumor bed during the surgical operation process. It has particular radiobiological advantages in protecting normal surrounding tissues by directly applying the irradiation dose to the high-risk tumor bed area. Two forms of IORT, i.e., high dose rate (HDR) brachytherapy and external beam radiotherapy (EBRT, including electron and photono IORT), had been studied before the treatment of head and neck tumors (including laryngocarcinoma). However, no relevant assessment had been carried out on 50KV low-energy X-ray. We are convinced by certain arguments that the application of low-energy X-ray for intraoperative local radiotherapy of laryngocarcinoma can not only achieve the therapeutic effect of IORT but also reduce the incidence of high-energy irradiation related toxic and side effects. The purpose of this study is to observe the safety and short-term efficacy of IORT when used in conjunction with standard of care for the treatment of local advanced laryngocarcinoma (LAL).

METHODS/DESIGN

In consideration of the applications of precise targeted IORT in oncosurgery and in line with the application range and reference clinical medical guidances approved by SFDA (ZEISS radiosurgical operation system has been used for the treatment of solid tumors since 31 December, 2013 with an approval from SFDA), we have preliminarily planned the tumors suitable for IORT, determined the members of MDT in our hospital, improved the MDT diagnosis and treatment processes for the tumors, established the standards, indications and contraindications for the application of IORT, determined the indicators to be observed after the treatment of tumors with surgical operations plus IORT, and carried out follow-up visits and statistical analysis. This is a single-arm, prospective Phase II clinical trial of the treatment of LAL patients with IORT + EBRT. The study subjects are followed up for statistics and information of their acute/chronic toxic reactions and local control rate, DFS, and OS etc. The safety and short-term efficacy of the application of IORT as SIB for the treatment of LAL. The sample size of the study is 125 subjects.

DISCUSSION

The safety and efficacy of IORT for the treatment of head and neck cancers have been proven in studies by multiple institutions (1-3). The purpose of this study is to investigate the maximum safe dose and short-term efficacy of IORT for providing a theoretical basis for clinical trials.

TRIAL REGISTRATION

Trial registration: Clinicaltrials.gov , NCT04278638. Registered 18 February 2020 - prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04278638.

Intraoperative Radiation Therapy: A Promising Treatment Modality in Head and Neck Cancer

Every year, almost 62,000 are diagnosed with a head and neck cancer (HNC) and 13,000 will succumb to their disease. In the primary setting, intraoperative radiation therapy (IORT) can be used as a boost in select patients in order to optimize local control. Addition of external beam radiation to limited volumes results in improved disease control over surgery and IORT alone. In the recurrent setting, IORT can improve outcomes from salvage surgery especially in patients previously treated with external beam radiation. The use of IORT remains limited to select institutions with various modalities being currently employed including orthovoltage, electrons, and high-dose rate brachytherapy. Practically, execution of IORT requires a coordinated effort and careful planning by a multidisciplinary team involving the head and neck surgeon, radiation oncologist, and physicist. The current review summarizes common uses, outcomes, toxicities, and technical aspects of IORT in HNC patients.

Intraoperative radiation therapy (IORT) in head and neck cancer: A systematic review

BACKGROUND

Multimodality therapy constitutes the standard treatment of advanced and recurrent head and neck cancer. Since locoregional recurrence comprises a major obstacle in attaining cure, the role of intraoperative radiation therapy (IORT) as an add-on in improving survival and local control of the disease has been investigated. IORT allows delivery of a single tumoricidal dose of radiation to areas of potential residual microscopic disease while minimizing doses to normal tissues. Advantages of IORT include the conformal delivery of a large dose of radiation in an exposed and precisely defined tumor bed, minimizing the risk of a geographic miss creating the potential for subsequent dose reduction of external beam radiation therapy (EBRT). This strategy allows for shortening overall treatment time and dose escalation. The aim of this review is to summarize recent published work on the use of IORT as an adjuvant modality to treat common head and neck cancer in the primary or recurrent setting.

METHODS

We searched the Medline, Scopus, Ovid, Cochrane, Embase, and ISI Web of Science databases for articles published from 1980 up to March 2016.

RESULTS

Based on relevant publications it appears that including IORT in the multimodal treatment may contribute to improved local control. However, the benefit in overall survival is not so clear.

CONCLUSION

IORT seems to be a safe, promising adjunct in the management of head and neck cancer and yet further well organized clinical trials are required to determine its role more precisely.

Intraoperative high-dose-rate radiotherapy in the management of locoregionally recurrent head and neck cancer

BACKGROUND

The purpose of this article was to present the Beth Israel Medical Center experience using high-dose-rate intraoperative radiotherapy (HDR-IORT) in the management of recurrent head and neck cancer.

METHODS

We conducted a retrospective review of all patients with locally or regionally recurrent head and neck cancer who underwent HDR-IORT at our institution between 2001 and 2010.

RESULTS

Seventy-six patients were identified who underwent treatment to a total of 87 sites after gross-total resection. The 2-year estimate of in-field tumor control was found to be 62%. Median overall survival was 19 months with 42% of the patients surviving at least 2 years. Significantly longer survival was found for patients achieving in-field control versus infield progression (33 months vs 17 months, respectively; p = .01).

CONCLUSION

HDR-IORT is well tolerated and associated with encouraging in-field disease control. In-field control is associated with improved survival. Further study is warranted to more fully investigate HDR-IORT in the salvage setting.

Intraoperative radiotherapy for parotid cancer: a single-institution experience

PURPOSE

Our practice policy has been to provide intraoperative radiotherapy (IORT) at resection to patients with head-and-neck malignancies considered to be at high risk of recurrence. The purpose of the present study was to review our experience with the use of IORT for primary or recurrent cancer of the parotid gland.

METHODS AND MATERIALS

Between 1982 and 2007, 96 patients were treated with gross total resection and IORT for primary or recurrent cancer of the parotid gland. The median age was 62.9 years (range, 14.3-88.1). Of the 96 patients, 33 had previously undergone external beam radiotherapy as a component of definitive therapy. Also, 34 patients had positive margins after surgery, and 40 had perineural invasion. IORT was administered as a single fraction of 15 or 20 Gy with 4-6-MeV electrons. The median follow-up period was 5.6 years.

RESULTS

Only 1 patient experienced local recurrence, 19 developed regional recurrence, and 12 distant recurrence. The recurrence-free survival rate at 1, 3, and 5 years was 82.0%, 68.5%, and 65.2%, respectively. The 1-, 3-, and 5-year overall survival rate after surgery and IORT was 88.4%, 66.1%, and 56.2%, respectively. No perioperative fatalities occurred. Complications developed in 26 patients and included vascular complications in 7, trismus in 6, fistulas in 4, radiation osteonecrosis in 4, flap necrosis in 2, wound dehiscence in 2, and neuropathy in 1. Of these 26 patients, 12 had recurrent disease, and 8 had undergone external beam radiotherapy before IORT.

CONCLUSIONS

IORT results in effective local disease control at acceptable levels of toxicity and should be considered for patients with primary or recurrent cancer of the parotid gland.

High-dose-rate intraoperative radiation therapy for recurrent head-and-neck cancer

PURPOSE

To report the use of high-dose-rate intraoperative radiation therapy (HDR-IORT) for recurrent head-and-neck cancer (HNC) at a single institution.

METHODS AND MATERIALS

Between July 1998 and February 2007, 34 patients with recurrent HNC received 38 HDR-IORT treatments using a Harrison-Anderson-Mick applicator with Iridium-192. A single fraction (median, 15 Gy; range, 10-20 Gy) was delivered intraoperatively after surgical resection to the region considered at risk for close or positive margins. In all patients, the target region was previously treated with external beam radiation therapy (median dose, 63 Gy; range, 24-74 Gy). The 1- and 2-year estimates for in-field local progression-free survival (LPFS), locoregional progression-free survival (LRPFS), distant metastases-free survival (DMFS), and overall survival (OS) were calculated.

RESULTS

With a median follow-up for surviving patients of 23 months (range, 6-54 months), 8 patients (24%) are alive and without evidence of disease. The 1- and 2-year LPFS rates are 66% and 56%, respectively, with 13 (34%) in-field recurrences. The 1- and 2-year DMFS rates are 81% and 62%, respectively, with 10 patients (29%) developing distant failure. The 1- and 2-year OS rates are 73% and 55%, respectively, with a median time to OS of 24 months. Severe complications included cellulitis (5 patients), fistula or wound complications (3 patients), osteoradionecrosis (1 patient), and radiation-induced trigeminal neuralgia (1 patient).

CONCLUSIONS

HDR-IORT has shown encouraging local control outcomes in patients with recurrent HNC with acceptable rates of treatment-related morbidity. Longer follow-up with a larger cohort of patients is needed to fully assess the benefit of this procedure.

Intraoperative radiation therapy as an "early boost" in locally advanced head and neck cancer: preliminary results of a feasibility study

BACKGROUND

The acute toxicity of intraoperative radiation therapy (IORT) delivered as an "early boost" after tumor resection in patients with locally advanced head and neck cancer was evaluated.

METHODS

Twenty-five patients were enrolled in the study. All patients underwent surgery with radical intent, and 17 had microvascular flap reconstruction. The IORT was delivered in the operating room. Twenty patients received adjuvant external beam radiation therapy (EBRT).

RESULTS

Five patients experienced various degrees of complications in the postoperative period, all of which were treated conservatively. One patient had a partial flap necrosis after EBRT that was treated with flap removal. Six deaths were recorded during the mean follow-up period of 8 months; none of the deaths were related to radiation treatment.

CONCLUSION

This feasibility study shows that the use of IORT as an early boost is feasible with no increase in acute toxicity directly attributable to radiation.

Feasibility of flap reconstruction in conjunction with intraoperative radiation therapy for advanced and recurrent head and neck cancer

BACKGROUND

Radiation is a known risk factor for poor wound healing. Patients undergoing intraoperative radiation therapy (IORT) typically receive higher cumulative doses to their wound beds than patients treated with conventional radiation therapy. We review our experience with IORT in patients undergoing resection of head and neck cancer and flap reconstruction. Logistics of delivery and outcomes are discussed.

METHODS

A retrospective chart review was performed on all patients at Beth Israel Medical Center who underwent IORT for head and neck cancer between 2000 and 2007. Twenty-one patients receiving 22 treatments involving flap reconstruction were identified. The results of these reconstructions were evaluated for complications and functional outcome.

RESULTS

All patients had complex surgical wounds of the face, upper aerodigestive tract, or neck who received IORT in conjunction with pedicled or free flap closure. Twenty-five flaps in 21 patients were performed in the setting of IORT. All patients received between 10 and 15 Gy of IORT administered directly to the wound bed. There were no perioperative mortalities. Wound breakdown occurred in three cases, all of which were treated successfully by operative revision. Functionally, most patients did well and performed similarly to historic controls for their type of reconstruction.

CONCLUSIONS

Reconstruction using flaps in the context of IORT can be achieved with expectation of good wound healing in the majority of cases despite heavy cumulative doses of radiation to recipient wound beds.

Intraoperative radiation therapy for recurrent head-and-neck cancer: the UCSF experience

PURPOSE

To review a single-institutional experience with the use of intraoperative radiation therapy (IORT) for recurrent head-and-neck cancer.

METHODS AND MATERIALS

Between 1991 and 2004, 137 patients were treated with gross total resection and IORT for recurrence or persistence of locoregional cancer of the head and neck. One hundred and thirteen patients (83%) had previously received external beam radiation as a component of definitive therapy. Ninety-four patients (69%) had squamous cell histology. Final surgical margins were microscopically positive in 56 patients (41%). IORT was delivered using either a modified linear accelerator or a mobile electron unit and was administered as a single fraction to a median dose of 15 Gy (range, 10-18 Gy). Median follow-up among surviving patients was 41 months (range, 3-122 months).

RESULTS

The 1-year, 2-year, and 3-year estimates of in-field control after salvage surgery and IORT were 70%, 64%, and 61%, respectively. Positive margins at the time of IORT predicted for in-field failure (p = 0.001). The 3-year rates of locoregional control, distant metastasis-free survival, and overall survival were 51%, 46%, and 36%, respectively. There were no perioperative fatalities. Complications included wound infection (4 patients), orocutaneous fistula (2 patients), flap necrosis (1 patient), trismus (1 patient), and neuropathy (1 patient).

CONCLUSIONS

Intraoperative RT results in effective disease control with acceptable toxicity and should be considered for selected patients with recurrent or persistent cancers of the head and neck.

Intraoperative single fraction high-dose-rate brachytherapy for head and neck cancers

PURPOSE

To report on the use of single fraction high-dose-rate brachytherapy in delivering localized intraoperative radiation therapy to sites in the head and neck region inaccessible to intraoperative electron beam radiotherapy (IOERT).

METHODS AND MATERIALS

After maximal surgical resection, 7.5-20 Gy intraoperative high-dose-rate brachytherapy (IOHDR) was delivered to 65 patients using custom-made surface applicators.

RESULTS

The 1-, 3-, and 5-year local control rates for the entire group were 77%, 69%, and 59%, respectively. The 1-, 3-, and 5-year overall survival rates were 83%, 63%, and 42%, respectively, with a median overall survival of 50 months. There were no major intraoperative or postoperative complications.

CONCLUSIONS

IOHDR can be used to treat selected locally advanced head and neck tumors arising at sites inaccessible to IOERT or at institutions not using IOERT. A prospective multi-institutional study with a larger number of patients treated with IOHDR is needed to firmly establish the efficacy of IOHDR in this population group.

Intraoperative radiation therapy in the multimodality approach to upper aerodigestive tract cancer

The cure rate of operable lung cancer and locally advanced head and neck cancer remains suboptimal, with a limited rate of local control despite improvements in the surgical removal of primary tumors and in methods for mediastinal lymph node dissection, in particular. The efficacy of adjuvant therapy, such as EBRT, has improved, and the immediate efficacy of new chemotherapeutic drugs is increasingly significant, although local recurrences remain frequent. Locoregional failure is not uncommon in upper aerodigestive tract cancers. Factors limiting radiocurability for locally advanced (stage III) lung cancer include mediastinal intolerance of irradiation (high risk of mediastinal fibrosis, which increases exponentially when levels of much more than 50 Gy are administered to the whole mediastinum) and the very high radiosensitivity of the healthy lung, which can develop fibrosis with relatively small or moderate doses starting at 18 to 20 Gy, and even more frequently when larger volumes are irradiated. Head and neck neoplasms are less difficult sites in which to administer doses of up to 70 Gy of external beam radiotherapy initially, but, like locoregionally recurrent lung cancers, they are not easily reirradiated with tumoricidal doses of EBRT. For these reasons, IORT seems to be a good option for increasing local control, because areas of [figure: see text] residual microscopic disease may be irradiated using IOERT approaches without affecting critical organs to the same extent. In addition, careful patient selection is paramount. Combined modality treatment regimens incorporating IORT may benefit patients with locally advanced disease. The ability of IORT to sterilize microscopic residual disease can enhance the "completeness" of resection and thus, theoretically, improve local control. Although distant disease dissemination remains by far the overriding issue, as newer effective agents emerge, local failure will continue to be a problem. Preliminary studies have demonstrated that IORT can be administered to patients who have locally advanced NSCLC and head and neck cancer, in the context of aggressive combined modality therapy, and is generally well tolerated. Long-term efficacy and benefit can only be determined in the setting of carefully designed clinical trials. (See the article by Thomas and Merrick elsewhere in this issue for further discussion of this topic.) Several relatively small, single-institution pilot studies exploring the utility and benefit of IORT for locally advanced upper aerodigestive tract cancers have been conducted. Clear conclusions have been difficult to determine because of the mixing of disease stages, varying degrees and completeness of surgical resection, varying radiation doses, different schemas, and other factors. Yet, given the major morbidity and mortality associated with locally recurrent lung cancer, methods of improving local control need to be pursued and refined. Encouraging preliminary data suggest that IOERT can be safely administered and may benefit local control. Based on several centers' expertise in the combined modality treatment of locally advanced lung cancer and familiarity with IORT, the UCSF Thoracic Oncology Program has proposed a multicenter phase 2 study incorporating IORT in a combined multimodality treatment schema for patients who have completely resected locally advanced stage IIIA and IIIB NSCLC (nonpleural effusion, non-N3) (Fig. 1). It is hoped that this study will commence in the upcoming year.

Rationale for integrating high-dose rate intraoperative radiation (HDR-IORT) and postoperative external beam radiation with subcutaneous amifostine for the management of stage III/IV head and neck cancer

Locoregional recurrence remains a major obstacle to achieving cure of locally advanced head and neck cancers despite maximal resection and postoperative external beam radiation therapy (EBRT). Locoregional failure occurs in 30% to 40% of high-risk resected head and neck cancer patients after standard postoperative EBRT. In an effort to overcome this problem, a number of strategies have been designed to enhance the effectiveness of radiation including concurrent postoperative chemoradiation, accelerated radiation schedules, incorporation of targeted biologic therapies, and improved radiation delivery techniques such as intensity modulated radiation and high-dose rate (HDR) intraoperative radiation therapy. Intraoperative radiation therapy (IORT) represents an important approach to improve outcome in head and neck cancer patients treated with definitive surgery. High-dose rate IORT is defined as the delivery of a single, large dose of radiation at the time of surgery when the tumor bed is exposed. In conjunction with EBRT, HDR-IORT offers several advantages including: (1) conformal delivery of a large dose of radiation while the tumor bed is precisely defined, minimizing the risk of a geographic miss; (2) potential for subsequent dose reduction of EBRT; (3) shortening overall treatment time; and (4) dose-escalation. Because mucositis represents the dose-limiting acute toxicity and xerostomia ranks as the most common long-term quality-of-life complaint, a reduction of the EBRT dose may provide an important benefit in reducing toxicity, especially when combined with the radioprotectant amifostine (Ethyol, WR-2721; MedImmune, Inc, Gaithersburg, MD). The purpose of this article is to review the rationale for integrating HDR-IORT with a reduced dose of postoperative EBRT combined with amifostine to improve locoregional control and quality of life outcomes in advanced-stage resected head and neck cancer patients.

Intraoperative high-dose-rate brachytherapy for paranasal sinus tumors

PURPOSE

Advanced and recurrent tumors of the paranasal sinuses can be difficult to irradiate to high doses with standard external beam radiotherapy (EBRT), conventional brachytherapy, or intraoperative electron beams. We, therefore, explored the role of intraoperative high-dose-rate brachytherapy (IOHDR) as a boost to EBRT in primary tumors or as sole adjuvant treatment in recurrent disease.

METHODS AND MATERIALS

Between 1992 and 1998, 34 patients with locally advanced tumors arising in the paranasal sinuses were treated with IOHDR after maximal surgical excision. Twenty-seven patients with new primaries underwent gross resection and 10-12.5 Gy IOHDR followed by 45-50 Gy EBRT. Seven previously irradiated (45-63 Gy) patients with recurrent disease were treated with 15-20 Gy of IOHDR alone after gross excision. Local control and overall survival were analyzed using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

After a mean follow-up of 6 years (range 34-120 months), the 1-, 3-, and 5-year actuarial survival rate was 80%, 62%, and 44%, respectively. The overall local control rate at 1 and 5 years was 75% and 65%, respectively, and distant failure was documented in 44% of patients. Subgroup analysis revealed that the presence of gross disease after surgical resection was the strongest prognosticator, with a 5-year survival and local control rate of 17% and 50%, respectively, compared with 60% and 68%, respectively, for microscopic disease. The local control rates of patients with new primaries were similar to those of patients treated for recurrent disease (63% vs. 71%), probably because gross residual disease occurred only in the group of patients with new primaries. The addition of EBRT to IOHDR increased the 5-year disease-free survival rate from 27% to 44% but had no effect on local control (64% vs. 65%).

CONCLUSION

IOHDR can be safely used to deliver a high radiation dose to locally advanced and recurrent tumors in the paranasal sinuses. In an attempt to improve outcome, we are now adding limited-dose EBRT (20-30 Gy) after 17.5 Gy of IOHDR in previously irradiated patients and increasing the EBRT dose for both microscopic (50-54 Gy) and gross residual disease (60-65 Gy) after 15 Gy of IOHDR in previously unirradiated patients. Chemosensitization should also be considered in previously irradiated patients and in those with gross residual disease. Interstitial boosting techniques, which can deliver higher doses at depth, should also be considered in patients with gross residual disease.

Intraoperative radiotherapy for head and neck and skull base cancer

BACKGROUND

The purpose of this study was to evaluate the use of intraoperative electron beam radiotherapy (IORT) as an adjuvant modality in the treatment of advanced head and neck and skull base cancer.

METHODS

Between 1991 and 1996, 34 patients with squamous cell carcinoma (SCCA) and 10 patients with non-SCCA were enrolled in this prospective nonrandomized clinical trial. Most patients had been previously treated with combinations of surgery, external beam radiotherapy, and chemotherapy. The most frequent sites treated were the skull base (56%) and the neck (44%). IORT was delivered in a dedicated operating room suite with energies of 6 to 15 MeV (6 MeV most commonly used) at doses of 12.5 to 22.5 Gy.

RESULTS

At 2 years overall and disease-free survival was 32% and 21%, respectively, for the SCCA patients and 50% and 40%, respectively, for the non-SCCA patients. Tumor control rates at 2 years in the IORT field were 46% for the SCCA patients and 52% for the non-SCCA patients. For squamous cell histology, survival in patients with microscopic residual tumor did not differ from those with no residual tumor, but they both had significantly longer disease-free survival than those patients with gross residual at the time of IORT (p =.03), with a trend toward longer overall survival (p =.09). The only complication directly attributable to IORT was a neuropathy in a patient who received an IORT dose of 22.5 Gy (cumulative dose 130.1 Gy).

CONCLUSIONS

IORT at a dose of 12.5 Gy is safe and produces tumor control and survival for patients likely to have microscopic residual disease in sites difficult to resect such as the skull base.

Carotid resection and reconstruction for locally advanced head and neck tumors

Head and neck surgeons hesitate to resect the carotid artery because of the postoperative risk of neurologic sequelae. However, there is no curative therapeutic option for head and neck neoplasms involving the carotid artery, with the exception of complete tumor removal. To evaluate the benefits and risks of carotid revascularization techniques in locally advanced head and neck tumors we performed a retrospective analysis in an institutional, tertiary care medical center. Seven patients (5 males, 2 females) with a median age of 58 years underwent en bloc removal of locally advanced head and neck tumors, including carotid resection and revascularization, in the University of Vienna General Hospital, over a 15-year period. In six patients carotid reconstruction was accomplished by bypass grafting (five autologous grafts, one synthetic graft) and in one patient angiopatchplasty was used. There were no perioperative neurologic complications or deaths. Survival was > 12 months in 5/7 patients; the other 2 patients died within 6 months due to untractable progression of cancer. We conclude that carotid revascularization techniques offer the possibility of better local control for advanced head and neck tumors without additional risks of neuromorbidity or mortality.

Radiotherapy-induced mandibular bone complications

The mandible is among the bones most frequently affected by irradiation. The most severe post-radiation injury of the mandible is osteoradionecrosis (ORN). Conflicting data have been reported on the incidence of this complication, its aetiology and management. The incidence of mandibular ORN in head and neck cancer patients managed with radical or postoperative irradiation, has varied widely in the literature from 0.4% to 56%. The interpretation of data derived from particular series are difficult due to the different scoring methods and classification systems used for the evaluation of post-radiation bone damage. Although ORN occurs typically in the first three years after radiotherapy, patients probably remain at indefinite risk. The diagnosis of ORN is principally based on the clinical picture of chronically exposed bone. Radiological symptoms include decreased bone density with fractures, cortical destruction and loss of spongiosa trabeculation. Numerous factors that may be associated with the risk of ORN include treatment-related variables (for example, total radiotherapy dose, biologically effective dose, photon energy, brachytherapy dose rate, combination of external beam irradiation and interstitial brachytherapy, field size, fraction size, volume of the mandible irradiated with a high dose), patient-related variables (like deep parodontitis, pre-irradiation bone surgery, bad oral hygiene, alcohol and tobacco abuse, bone inflammation, dental extraction after radiotherapy) and tumour-related factors (tumour size or stage, proximity of the tumour to bone, anatomic tumour site). Primary management of post-radiation bone lesions include conservative modalities such as saline irrigations, antibiotics during infectious episodes, topically applied antiseptics, gentle sequestrectomy and removal of visibly loosened bone elements as well as treatment with hyperbaric oxygen (HBO). Surgery is reserved for persistent ORN and includes radical resection of the lesion(sequestrectomy, hemimandibulectomy etc.) with reconstruction. In recent years the introduction of preventive oral hygiene measures and meticulous dental evaluations before and after irradiation, improvement in radiotherapy techniques and the development of reliable diagnostic and therapeutic procedures have resulted in a decreased incidence of ORN. Nevertheless, given the severe impact of ORN on patient quality of life, research should be continued to further ameliorate this problem.

High-dose-rate intraoperative irradiation: current status and future directions

Intraoperative irradiation (IORT) refers to the delivery of a single high dose of radiation therapy at the time of surgery when the tumor bed can be precisely defined and adjacent normal tissue maximally protected. It can be effectively delivered using either electrons (IOERT) or photons produced from a high-dose-rate gamma emitting radioisotope (HDR-IORT) and has been explored primarily for locally advanced or recurrent tumors at high risk for local failure despite extensive resection and full dose external beam radiation. With coordinated multidisciplinary interaction, IORT can be integrated in a combined-modality setting without undue additional toxicity. The purpose of this review will be to summarize the growing HDR-IORT experience in the treatment of various cancers, to compare its efficacy and toxicity vis a vis the IOERT data, and to discuss future trials as well as new areas of potential application.

Recent Advances in Radiotherapy for Head and Neck Cancers

Advancements in surgery have made it possible to resect cancers that had previously been regarded as incurable. Similarly, new developments in radiation oncology have helped improve the outlook for patients with locally advanced or recurrent head and neck cancers. Among these advancements are refinements in altered fractionation, three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, stereotactic radiosurgery and fractionated stereotactic radiotherapy, neutron-beam radiotherapy, charged-particle radiotherapy, and intraoperative radiotherapy. These recent developments have allowed radiation oncologists to escalate the dose of radiation delivered to tumors while minimizing the dose delivered to surrounding normal tissue. Additionally, more continues to be learned about the optimum delivery of chemotherapy. This article provides an update on the status of these new developments in the treatment of head and neck cancers.

Palliative radiotherapy in recurrent head-and-neck tumors by a percutaneous superfractionated treatment schedule

PURPOSE

A frequent problem in treatment of patients with head-and-neck tumors is recurrence in pre-irradiated areas, thus limiting dose for another full-course radiotherapy. We present our experience with a percutaneous superfractionated short-term radiotherapy regimen that may be useful for palliative irradiation.

METHODS AND MATERIALS

Twenty-three patients with head-and-neck tumor recurrence after radiotherapy or extensive tumor growth have been treated by a superfractionated regimen. At each of two subsequent days, eight fractions of 1 Gy were applied with an interfraction interval of 1 h, resulting in a total dose of 16 Gy. Time between the last fraction of the first day and the first fraction of the second day was 17 h.

RESULTS

In 16 of 23 patients (70%), our irradiation schedule could achieve a palliative effect such as tumor necrosis or reduction of swelling or pain. Seven patients showed erythema (WHO I) at the end of the second day. Neither mucositis nor late effects of treatment were observed.

CONCLUSIONS

Our superfractionated schedule is feasible without severe acute side reactions and can achieve a palliative effect in advanced or recurrent head-and-neck cancer.

Intraoperative radiotherapy for pre-irradiated head and neck cancer

BACKGROUND AND PURPOSE

Radiotherapy of recurrent head and neck tumours is limited in dose due to pre-treatment up to normal tissue tolerance doses. Surgery alone is limited by the problems related to pre-surgery, post-radiation fibrosis, and infiltration of tumours into nerves and vessels too closely to be completely removed. Our aim was to evaluate the possible role of intraoperative radiotherapy (IORT) in such tumours treated with palliative intent.

METHODS

In the last 10 years, we performed 113 intraoperative irradiations in a total of 84 pre-irradiated patients with head and neck cancer. The patient data were evaluated with regard to palliative effect, complications of treatment, recurrence and survival after IORT.

RESULTS

Palliation of symptoms, as assessed by clinical evaluation, was achieved in 88% of symptomatic patients, often just by removal of large exophytic or exulcerating tumours, with IORT preventing their immediate recurrence after surgery. The complication rate did not exceed that expected after surgery alone. The median survival after IORT was 6.8 months, with a median time to local tumour recurrence or progression of 3.7 months.

CONCLUSION

Intraoperative irradiation can be used as a palliative treatment option in pre-treated head and neck tumours with satisfactory results. With large and infiltrating tumours, however, recurrences or tumour progression occur close to the IORT portals, thus rendering this method unsuitable for achieving long-term control in such extended tumours.

Intraoperative electron beam radiotherapy for previously irradiated advanced head and neck malignancies

PURPOSE

This is a retrospective review to evaluate the role of surgery and intraoperative electron beam radiotherapy (IOERT) in the treatment of patients with previously irradiated advanced head and neck cancers.

METHODS AND MATERIALS

Between January 1992 and March 1997, 38 patients (31 males, 7 females; median age of 62 years) with recurrent head and neck cancer were treated with maximal resection and IOERT at the Ohio State University (OSU). All had been previously treated with full-course radiotherapy (median 65.1 Gy, range 50-74.4 Gy). Twenty-nine patients (76%) had previously undergone one or more surgical procedures. After maximal surgery the tumor bed was treated with IOERT (single field in 36 patients and 2 fields in 2 patients), most commonly with 6 MeV electrons (87%). The dose administered (at 90% isodose line) was 15 Gy for close or microscopically positive margins in 34 patients and 20 Gy for gross disease in 1 patient. Further external beam radiation therapy (EBRT) was not given.

RESULTS

After a median follow-up of 30 months (range 8-39 months), 24 of the 38 patients (66%) recurred within the IOERT field. Median time to IOERT failure was 6 months (95% CI: 4.3-7.7). The 6-month, 1-, and 2-year control rates within the IOERT volume were 41%, 19%, and 13%, respectively. Thirty of the 38 patients (79%) recurred in locoregional areas. Median time to locoregional failure was 4 months (95% CI: 3.3-4.7). The 6-month, 1-, and 2-year locoregional control rates were 33%, 11%, and 4%, respectively. Distant metastases occurred in 7 patients, 5 in association with IOERT failure and 2 with locoregional failure. Median overall survival was 7 months (95% CI: 4.7-9.3). The 6-month, 1-, 2-, and 3-year actuarial survival rates were 51%, 21%, 21%, and 8%, respectively. Major treatment-related complications occurred in 6 patients (16%).

CONCLUSION

IOERT alone, at the dose used, is not sufficient for control of recurrent, previously irradiated head and neck cancers. Since higher IOERT doses are associated with high morbidity, we are currently evaluating the addition of limited EBRT dose and/or brachytherapy to improve the local control of these poor prognostic recurrent tumors, with acceptable morbidity.

Preliminary results of a phase I/II study of post-operative high-dose rate brachytherapy for advanced or recurrent pelvic tumours

Electron beam intraoperative radiation therapy (EB-IORT) and intraoperative low-dose rate brachytherapy (IOLB) seem able to improve the local control of advanced or recurrent pelvic tumours (ARPT). We report the usefulness, technical considerations and potential advantages of employing post-operative high-dose rate brachytherapy (POHB) as a treatment for ARPT. From February 1995 to February 1997, 14 patients underwent POHB for ARPT. The mean age was 58 years (range: 37-74). Six patients presented with recurrent rectal carcinoma, three with cervix carcinoma (one primary T3; two recurrences), two with bladder carcinoma (one primary T4; one recurrence), one with prostate carcinoma, one with recurrent pre-sacral lymphoma and one with undifferentiated carcinoma. At the time of resection, blind-end HDR catheters were implanted in a single plan in the tumour bed and stabilized by absorbable sutures. Eight days later, POHB delivered 20Gy in 5 fractions or 40Gy in 10 fractions for advanced and recurrent tumours, respectively. To decrease the incidence of late side-effects, a change was made after the tenth patient to deliver 2 Gy per fraction twice a day, with an interval of 6 h between each fraction. With a median follow-up of 8 months (range: 1-22), local control was achieved in all cases. Six patients developed metastatic disease. One patient presented a perineal wound dehiscence requiring surgery 2 months after POHB. POHB is feasible for patients with recurrent or advanced pelvic diseases, and appears more cost-effective than EB-IORT for dosimetric and radiobiological considerations. Compared with IOLB, POHB allows the total radioprotection of the medical staff, and, in the context of cost reduction, a reduction of the overall time of hospitalization.

Pilot study of intraoperative high dose rate brachytherapy for head and neck cancer

PURPOSE

To develop a new technique, intraoperative high dose rate brachytherapy (IOHDR), to deliver localized radiation therapy intraoperatively to head and neck tumors at sites inaccessible to intraoperative electron beam radiotherapy (IOEBRT) in the skull base region.

METHODS

After maximal surgical resection, afterloading catheters spaced 1 cm apart embedded in custom surface applicators made of foam or silicone were placed on resected tumor beds. IOHDR was delivered in a shielded operating room using preplanned dosimetry with a nominal 10 Ci iridium-192 source in an HDR micro-Selectron afterloader. Twenty-nine patients (20 males, 9 females) ranging in age from 9 to 80 years (median = 61) were irradiated intraoperatively for advanced head and neck tumors at sites inaccessible to IOEBRT. Six patients who had previously received external beam radiation (EBRT) ranging from 50 to 75 Gy, were given 15 Gy of IOHDR only. Twenty-three patients who had no prior radiation received 7.5 to 12.5 Gy IOHDR, and 45 to 50 Gy EBRT was planned post-operatively; however, six of these patients did not complete the planned EBRT. Doses to normal tissues were reduced whenever possible by shielding with lead or by displacement with gauze or retractors. Treatment time ranged from 3.8 to 23 min (median = 6.5 min). Five patients received concurrent cis-platinum based chemotherapy.

RESULTS

Twenty-nine patients treated to 30 sites had local tumor control of 67% and crade survival of 72%, with the follow-up ranging from 3 to 33 months (median = 21 months). In the group of 17 previously unirradiated patients who had completed full treatment (IOHDR and EBRT) to 18 sites, the local tumor control was 89%, and all of these patients survived. Tumor control in the six previously unirradiated patients who did not complete EBRT was 50% with a crude survival of 50%. In the group of six previously irradiated patients treated by IOHDR only, the local tumor control was 17% with a crude survival of 17%. No intraoperative complications were noted. The delayed morbidity included cerebrospinal fluid (CSF) leak with bone exposure (1), chronic subdural hematoma (1), septicemia (1), otitis media (1), and severe xerostomia (1). We cannot comment on long-term morbidity due to the relatively short follow-up period of 21 months.

CONCLUSIONS

It is feasible to deliver IOHDR, with acceptable toxicity, to skull base tumors at sites inaccessible to IOEBRT. The use of IOHDR as a pre-radiotherapy boost produced excellent local control and survival in the selected group of patients who had no previous radiation therapy. The use of exclusive IOHDR in the previously irradiated group resulted in poor outcome, possibly due to the limitations on re-irradiation doses and/or volumes determined by normal tissue tolerance or because these patients have inherently radioresistant tumors. Higher IOHDR doses, additional EBRT, and/or chemotherapy should be considered for this group. The use of IOHDR as a pre-EBRT boost to maximize local control has a promising future in the treatment of carefully selected patients with advanced skull base tumor.

Resection of the internal carotid artery and replacement with greater saphenous vein: a safe procedure for en bloc cancer resections with carotid involvement

PURPOSE

Many patients who have advanced cancer of the neck will have involvement of the internal carotid artery. The management of this condition remains controversial, and a wide range of therapeutic options have been suggested including ligation, "shaving" the tumor off the carotid, or en bloc resection and replacement of the internal carotid artery by polytetrafluoroethylene, vein, or superficial femoral artery. We reviewed our experience with en bloc resections of the internal carotid artery in a consecutive series of patients who had malignancies involving the internal carotid artery at a single institution from 1989 to 1995.

METHODS

We used a retrospective chart review based on a list of 20 patients generated by the Hospital Cancer Registry and our Vascular Surgery clinical database.

RESULTS

All patients had their internal carotid artery removed and replaced with a greater saphenous vein while they were under general anesthesia. A resection of their cervical malignancy was also performed. Concomitant myocutaneous flaps were rotated over the carotid bypass in six (30%) patients. Eight (40%) of the bypass grafts were nonreversed, and 12(60%) were reversed, with a clear trend towards using nonreversed veins more recently. Shunts were used in 18(90%). Eighteen of the 20 patients had some form of intraoperative contamination including tracheostomies, pharyngostomies, or fistulas. Half of the patients had intraoperative radiation therapy, and 16(80%) patients underwent operation for recurrent cancer. During the follow-up period two (10%) patients had strokes (one minor and one major), and one patient had a graft blowout, which was treated by ligation without stroke. One patient had an asymptomatic occlusion of his graft.

CONCLUSIONS

From these results we conclude that the use of the greater saphenous vein to replace the internal carotid artery after en bloc resection is not attended by a high rate of infectious complications or graft blowout even in the presence of intraoperative tracheopharyngeal contamination and that the greater saphenous vein is the conduit of choice for replacing an internal carotid artery after cancer resections.

Radiation therapy in the treatment of oral neoplasia

Oral neoplasia occasionally may be treated adequately with a single modality. Multimodality therapy, however, more often is indicated. This article reviews the recommendations of treatment of oral neoplasia focusing on the role of radiation therapy both singly and as a part of multimodality therapy.

Intraoperative electron beam radiation therapy: technique, dosimetry, and dose specification: report of task force 48 of the Radiation Therapy Committee, American Association of Physicists in Medicine

Intraoperative radiation therapy (IORT) is a treatment modality whereby a large single dose of radiation is delivered to a surgically open, exposed cancer site. Typically, a beam of megavoltage electrons is directed at an exposed tumor or tumor bed through a specially designed applicator system. In the last few years, IORT facilities have proliferated around the world. The IORT technique and the applicator systems used at these facilities vary greatly in sophistication and design philosophy. The IORT beam characteristics vary for different designs of applicator systems. It is necessary to document the existing techniques of IORT, to detail the dosimetry data required for accurate delivery of the prescribed dose, and to have a uniform method of dose specification for cooperative clinical trials. The specific charge to the task group includes the following: (a) identify the multidisciplinary IORT team, (b) outline special considerations that must be addressed by an IORT program, (c) review currently available IORT techniques, (d) describe dosimetric measurements necessary for accurate delivery of prescribed dose, (e) describe dosimetric measurements necessary in documenting doses to the surrounding normal tissues, (f) recommend quality assurance procedures for IORT, (g) review methods of treatment documentation and verification, and (h) recommend methods of dose specification and recording for cooperative clinical trials.