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

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.

Intraoperative radiation therapy in non-breast cancer patients: A report of 26 cases from Shiraz, south of Iran

Background: Intraoperative radiation therapy (IORT) is the delivery of radiation at the time of surgery. Whereas the dose delivered by external beam radiation therapy (EBRT) is limited by the tolerance of the surrounding normal tissues, IORT allows exclusion of a part or all of the dose-limiting sensitive structures by operative mobilization and/or direct shielding of these structures. The aim of the present study was to report the non-breast cancer patients' outcomes after receiving IORT in Shiraz, Iran. Methods: In this retrospective study, all cases who had received IORT and had non-breast malignancies were selected. Diagnosis was confirmed by biopsy. Additional imaging was done by sonography, magnetic resonance imaging (MRI) and computed tomography (CT). IORT was applied by self-shielded, LIAC 6-12 MeV Sordina mobile linear accelerator. Typically, a single dose of 10-21 Gy was given for maximally resected tumors. The statistical analyses were carried out using SPSS (version 21). Results: Twenty-six patients were treated with IORT alone or combined with EBRT. Different tumors were treated, including colorectal adenocarcinoma (10 cases, 38.4 %), Soft Tissue Sarcomas (STS, 11 cases, 42.3 %), head and neck cancers (3 cases, 11.5 %), one cervix malignancy case and one paravertebral fibromatosis case. Mean ± SD overall survival was 15±14.89 (0-38) and 34.3±15.72 (14-53) months for colorectal cancer and STS, respectively. Conclusion: IORT is mostly useful for pelvic and abdominal malignancies where normal bowel limits the dose that can be delivered with EBRT. However, the dose delivered in a single fraction with IORT is rarely sufficient for tumor control; therefore, IORT is usually preceded or followed by additional EBRT which should be further evaluated preferably in prospective randomized trials.

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 radiotherapy: review of techniques and results

Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct visualisation of the tumour bed and ability to space out the normal tissues from the tumour bed allows maximisation of the dose to the tumour while minimising the dose to normal tissues. This results in an improved therapeutic ratio with IORT. Although it was introduced in the 1960s, it has seen a resurgence of popularity with the introduction of self-shielding mobile linear accelerators and low-kV IORT devices, which by eliminating the logistical issues of transport of the patient during surgery for radiotherapy or building a shielded operating room, has enabled its wider use in the community.

Electrons, low-kV X-rays and HDR brachytherapy are all different methods of IORT in current clinical use. Each method has its own unique set of advantages and disadvantages, its own set of indications where one may be better suited than the other, and each requires a specific kind of expertise.

IORT has demonstrated its efficacy in a wide variety of intra-abdominal tumours, recurrent colorectal cancers, recurrent gynaecological cancers, and soft-tissue tumours. Recently, it has emerged as an attractive treatment option for selected, early-stage breast cancer, owing to the ability to complete the entire course of radiotherapy during surgery. IORT has been used in a multitude of roles across these sites, for dose escalation (retroperitoneal sarcoma), EBRT dose de-escalation (paediatric tumours), as sole radiation modality (early breast cancers) and as a re-irradiation modality (recurrent rectal and gynaecological cancers).

This article aims to provide a review of the rationale, techniques, and outcomes for IORT across different sites relevant to current clinical practice.

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.

Outcomes of patients with loco-regionally recurrent or new primary squamous cell carcinomas of the head and neck treated with curative intent reirradiation at Mayo Clinic

BACKGROUND

We reviewed outcomes of patients with loco-regionally recurrent (LRR) or new primary (NP) squamous cell carcinoma of the head and neck (SCCHN) treated at our institution with reirradiation (RRT).

METHODS

Patients received definitive RRT (DRRT) or post-operative RRT following salvage surgery (PRRT) from 2003 to 2011. Measured survival outcomes included loco-regional relapse free survival (LRFS) and overall survival (OS).

RESULTS

Among 81 patients (PRRT, 42; DRRT, 39), median PRRT and DRRT doses were 60 Gy (12-70 Gy) and 69.6 Gy (48-76.8 Gy). The majority of patients received IMRT-based RRT (n = 77, 95 %). With median follow-up of 78.1 months (95 % CI, 56-96.8 months), 2-year OS was 53 % with PRRT and 48 % with DRRT (p = 0.12); 23 % of patients were alive at last follow-up. LRFS at 2 years was 60 %, and did not differ significantly between PRRT and DRRT groups. A trend toward inferior LRFS was noted among patients receiving chemotherapy with RRT versus RRT alone (p = 0.06). Late serious toxicities were uncommon, including osteoradionecrosis (2 patients) and carotid artery bleeding (1 patient, non-fatal).

CONCLUSIONS

OS of PRRT- and DRRT-treated patients in this series appears superior to the published literature. We used IMRT for the majority of patients, in contrast to several series and trials previously reported, which may account in part for this difference. Future studies should seek to improve outcomes among patients with LRR/NP SCCHN via alternative therapeutic modalities such as proton radiotherapy and by incorporating novel systemic agents.

Recurrent and second primary squamous cell carcinoma of the head and neck: when and how to reirradiate

BACKGROUND

Local and/or regional recurrence and metachronous primary tumor arising in a previously irradiated area are rather frequent events in patients with head and neck squamous cell carcinoma (HNSCC). Re-treatment is associated with an increased risk of serious toxicity and impaired quality of life (QOL) with an uncertain survival advantage.

METHODS

We analyzed the literature on the efficacy and toxicity of photon/electron-based external beam reirradiation for previously irradiated patients with HNSCC of non-nasopharyngeal origin. Studies were grouped according to the radiotherapy technique used for reirradiation. Patient selection criteria, target volume identification method, tumor dose, fractionation schedule, systemic therapy administration, and toxicities were reviewed.

RESULTS

In addition to disease-related factors, current comorbidities and preexisting organ dysfunction must be considered when selecting patients for reirradiation. As morbidity from re-treatment may be considerable and differ depending on which mode of re-treatment is used, it is important to give patients information on potential morbidity outcomes so that an informed choice can be made within a shared decision-making context. With improved dose distribution and adequate imaging support, including positron emission tomography-CT, modern radiotherapy techniques may improve local control and reduce toxicity of reirradiation. A reirradiation dose of ≥60 Gy and a volume encompassing the gross tumor with up to a 5-mm margin are recommended. Concomitant administration of systemic therapeutics and reirradiation is likely to be of similar benefit as observed in large randomized studies of upfront therapy.

CONCLUSION

Reirradiation, administered either with or without concurrent systemic therapy, is feasible and tolerable in properly selected patients with recurrent or a new primary tumor in a previously irradiated area of the head and neck, offering a meaningful survival (in the range of 10% to 30% at 2 years). Whenever feasible, salvage surgery is the method of choice for curative intent; patients at high-risk for local recurrence should be advised that postoperative reirradiation is expected to increase locoregional control at the expense of higher toxicity and without survival advantage compared to salvage surgery without reirradiation. © 2014 Wiley Periodicals, Inc. Head Neck 37: 134-150, 2015.

Present status and future directions of intraoperative radiotherapy

In this Review, we summarise recent published work on the use of intraoperative radiotherapy to treat common tumour sites in the primary or recurrent setting. Techniques, radiobiology, and the physics of intraoperative radiotherapy are also explored. Disease sites discussed in this Review include head and neck cancer, breast cancer, sarcoma, gastrointestinal cancer, genitourinary cancer, gynaecological cancer, thoracic cancer, and palliative applications.

Intraoperative radiation therapy for advanced cervical metastasis: a single institution experience

BACKGROUND

The purpose of this study is to review our experience with the use of IORT for patients with advanced cervical metastasis.

METHODS

Between August 1982 and July 2007, 231 patients underwent neck dissections as part of initial therapy or as salvage treatment for advanced cervical node metastases resulting from head and neck malignancies. IORT was administered as a single fraction to a dose of 15 Gy or 20 Gy in most pts. The majority was treated with 5 MeV electrons (112 pts, 50.5%).

RESULTS

1, 3, and 5 years overall survival (OS) after surgery + IORT was 58%, 34%, and 26%, respectively. Recurrence-free survival (RFS) at 1, 3, and 5 years was 66%, 55%, and 49%, respectively. Disease recurrence was documented in 83 (42.8%) pts. The majority of recurrences were regional (38 pts), as compared to local recurrence in 20 pts and distant failures in 25 pts. There were no perioperative fatalities.

CONCLUSIONS

IORT results in effective local disease control at acceptable levels of toxicity. Our results support the initiation of a phase III trial comparing outcomes for patients with cervical metastasis treated with or without IORT.

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.

Second salvage surgery for re-recurrent oral cavity and oropharynx carcinoma

BACKGROUND

Salvage surgery is considered the best treatment approach for patients with recurrent oral carcinoma. Unfortunately, 50% to 60% of the patients who undergo salvage surgery will develop further locoregional recurrence, and they are not usually considered for further treatment. Our aim in this study was to report our experience with a second salvage surgery for selected patients with re-recurrent oral cavity and oropharyngeal squamous cell carcinoma (SCC).

METHODS

Forty-one patients underwent a second salvage surgical procedure, with curative intention for re-recurrent oral cancer. The surgical treatment used was wide local resection in 34 cases, neck dissection in 9 cases, and isolated neck dissection in 7 cases.

RESULTS

Cancer-specific survival (CSS) rate in 3 years was at 20%. Patients with re-recurrence in <6 months presented 3-year CSS null, whereas patients with re-recurrence after 6 months presented 3-year CSS of 32.3% (p = .007).

CONCLUSION

Second salvage surgery can be considered a potentially curative therapeutic approach for a selected group of patients with re-recurrent oral SCC. The disease-free interval was the main clinical factor associated with the prognosis.

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 therapy with liposomal drug delivery: retention and distribution in human head and neck squamous cell carcinoma xenograft model

The focus of this study is to investigate the retention and biodistribution of technetium-99m ((99m)Tc) labeled liposomes in a human head and neck squamous cell carcinoma (HNSCC) positive surgical margin animal xenograft model. Positive surgical margin (with margin<1mm) in HNSCC is associated with significant higher mortality and recurrence rate when compared to clear margin. An immediate intraoperative application of liposome-carried therapeutic agents may treat the residual disease intraoperatively and improve long term survival in these patients. To understand the feasibility of this intraoperative therapy in HNSCC, the in vivo behavior of liposomes after intraoperative administration of (99m)Tc-labeled liposomes using non-invasive nuclear imaging was investigated in an animal xenograft model. Neutral and cationic (99m)Tc-labeled liposomes of 100 nm, 1 microm and 2 microm in diameter (6 study groups with 4 rats per study group) were injected into a nude rat HNSCC positive surgical margin xenograft model. Intratumoral, locoregional, and systemic retention and distribution of the (99m)Tc-liposomes were determined using non-invasive nuclear imaging and post-mortem organ distribution. The (99m)Tc-liposomes demonstrated high locoregional retention rate of 55.9+/-3.7% to 72.9+/-2.4% at 44 h after intraoperative injection to allow significant radiation to the surgical cavity if therapeutic radionuclides were used. Overall, the cationic liposomes demonstrated higher intratumoral retention rate, and the neutral liposomes showed greater retention in the paratumoral cavity (p<0.05 respectively). In conclusion, intraoperative therapy with liposome carried radionuclide drug delivery system carries great potential in treating unresectable HNSCC, and further study using therapeutic radionuclide should be explored.

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.

Re-irradiation in the management of isolated neck recurrences: Current status and recommendations

Recent times have witnessed significant improvements in outcome for head and neck squamous cell carcinomas. Nevertheless, the major pattern of failure continues to remain loco-regional. Isolated neck recurrence, although uncommon, occurs in 5-7% of patients after radical treatment. The options for this subgroup are somewhat limited and are often guided by empiricism rather than evidence. This review attempts to systematically analyze the therapeutic options for patients with isolated neck recurrence following radical treatment for the primary and draining cervical lymph nodes, with a special emphasis on re-irradiation. Salvage neck dissection offers the best chance of cure to patients with resectable neck recurrences. The perceived increased risk of complications of re-irradiation following previous curative dose irradiation has precluded optimal evaluation of its potential in this setting. Post-operative adjuvant re-irradiation should be based on histo-pathological findings of the salvage surgery. Re-irradiation with or without chemotherapy may be considered for unresectable neck recurrences. The role of chemotherapy continues to evolve and is presently not optimally defined. There is lack of high-quality evidence pertinent to salvage therapy leading to vast variations in practice. More patients with recurrent disease should be enrolled onto prospective clinical trials with relevant and meaningful endpoints.

Perioperative high-dose-rate brachytherapy (PHDRB) in previously irradiated head and neck cancer: Initial results of a Phase I/II reirradiation study

BACKGROUND

This study was undertaken to determine the feasibility of salvage surgery and perioperative high-dose-rate brachytherapy (PHDRB) at the dose/fractionation schedule proposed in patients with previously irradiated, recurrent head and neck cancer or second primary tumors arising in a previously irradiated field.

METHODS AND MATERIALS

Twenty-five patients were treated with surgical resection and PHDRB. The PHDRB dose was 4 Gy b.i.d. x 8 (32 Gy) for R0 resections and 4 Gy b.i.d. x 10 (40 Gy) for R1 resections. Further external beam radiotherapy or chemotherapy was not given.

RESULTS

Resections were categorized as R0 (negative margins of at least 10 mm) in 3 patients (12.0%) and R1 (negative margins of less than 10 mm or microscopically positive margins) in 22 (88.0%). Twelve patients with R1 resections had microscopically positive margins (48%), and 10 patients had close margins (40%), with a median of 2.0 mm. Ten patients (40.0%) developed Radiation Therapy Oncology Group Grade 3 or greater toxicity. Seven patients (28%) presented complications requiring a major surgical procedure. Four of these complications appeared in the immediate postoperative period and were surgical in nature (flap failure, n = 2; fistula, n = 2), and the other three were mainly related to the brachytherapy procedure (n = 2) or the radiation dose delivered (n = 1). One patient died on postoperative day 11 due to bleeding. After a median followup of 14 months, the 4-year local control rate and overall survival were 85.6% and 46.4%, respectively.

CONCLUSIONS

Surgical salvage and PHDRB at the dose/fractionation proposed are feasible in this high-risk population. Toxicity is high, but not substantially different from other reirradiation series. Four-year local control results are encouraging taking into account that 22 of 25 patients (88%) had either close or microscopically positive margins.

A review on re-irradiation for recurrent and second primary head and neck cancer

The purpose of this paper is to review the results of studies regarding radiation as primary or adjuvant treatment modality for head and neck recurrences or second primary tumours (SPT) in previously irradiated areas, with emphasis on acute and late radiation induced morbidity, locoregional control and survival. The criteria for the studies to be included in this review were: (1) re-irradiation for locoregional recurrent disease or SPT in the head and neck region, (2) squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx and larynx, and (3) a minimum of 10 patients included in the study. Studies were divided in four categories, including (1) external beam re-irradiation, (2) re-irradiation with brachytherapy, (3) re-irradiation in combination with chemotherapy and (4) postoperative re-irradiation. Most studies were retrospective using heterogeneous treatment regimens and including heterogeneous groups of patients. A total number of 27 studies were included. Overall survival, locoregional control and acute and late radiation-induced morbidity are reported. High dose reirradiation as salvage treatment in case of recurrent or second primary head and neck cancer should be considered, particularly when salvage surgery is not feasible. Although long term survivors are reported is some studies, the relatively high incidence of treatment-related morbidity emphasize the need for further optimisation in order to improve locoregional control and reduce the risk on late morbidity.

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 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.

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.

Interstitial low-dose-rate brachytherapy as a salvage treatment for recurrent head-and-neck cancers: long-term results

PURPOSE

Recurrent cancers of the head and neck within previously irradiated volume pose a serious therapeutic challenge. This study evaluates the response and long-term tumor control of recurrent head-and-neck cancers treated with interstitial low-dose-rate brachytherapy.

METHODS AND MATERIALS

Between 1979 and 1997, 220 patients with prior radiation therapy with or without surgery for primary tumors of the head and neck were treated for recurrent disease or new primary tumors located within previously irradiated volumes. A majority of these patients had inoperable diseases with no distant metastasis. There were 136 male and 84 female patients, and median age was 56 years. All patients had previously received radiation therapy as the primary treatment or adjuvant treatment following surgery, with a median dose of 57.17 cGy (range, 39-74 cGy). The salvage brachytherapy consisted of a low-dose-rate, afterloading Iridium(192) implant, which delivered a median minimum tumor dose of 53 Gy to a mean tumor volume of 68.75 cm(2). Sixty percent of the patients also received interstitial hyperthermia, and 40% received concurrent chemotherapy as a radiosensitizing and potentiating agent.

RESULTS

At a minimum 6-month follow-up, local tumor control was achieved in 77% (217/282) of the implanted tumor sites. The 2, 5, and 10-year disease-free actuarial survival rates for the entire group were 60%, 33%, and 22%, respectively. The overall survival rate for the entire group at 5 years was 21.7%. Moderate to severe late complications occurred in 27% of the patients.

CONCLUSION

It has been estimated that approximately 20-30% of head-and-neck cancer patients undergoing definitive radiation therapy have recurrence within the initial treatment volume. Furthermore, similar percentages of patients who survive after successful irradiation develop new primary tumors of the head and neck or experience metastatic neck disease. A majority of such patients cannot be treated with a repeat course of external beam irradiation because of limited normal tissue tolerance, leading to unacceptable morbidity. However, in a select group of these patients, salvage interstitial brachytherapy may play an important role in providing patients with durable palliation and tumor control, as well as a chance for cure.

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.

Clinical experience with retreatment for palliation

Every radiation oncologist is faced occasionally with the need to consider reirradiation for palliation. Because reirradiation has the potential to exceed normal tissue tolerances, there is a need to have information on the efficacy and toxicity of retreatment. This article reviews the reirradiation literature and provides guidance to clinicians with regard to the risks, benefits, and side effects of retreatment.