Carotid blowout syndrome in pharyngeal cancer patients treated by hypofractionated stereotactic re-irradiation using CyberKnife: A multi-institutional matched-cohort analysis

Quantitative diagnosis of carotid blowout syndrome with CT perfusion: Carotid blowout syndrome CTP quantitative diagnosis

BACKGROUND AND PURPOSE

Carotid blowout syndrome (CBS) is a potentially fatal disease. The CBS diagnosis mainly relies on subjective observations and the quantitative diagnotic method was not well established. This study aimed to diagnose CBS severity by computed tomography perfusion (CTP) parameters with different region-of-interest (ROI) models.

MATERIALS AND METHOD

We prospectively recruited CBS patients between February 1, 2018 and July 31, 2023 in a tertiary medical center, and CTP was performed using the same 128-detector CT machine. Digital subtraction angiography (DSA) and elective endovascular intervention were performed within 3 days post-CTP for diagnosis confirmation and treatments. CBS severity was classified into ongoing (threatened + impending) or acute CBS based on DSA findings and clinical features. Pericarotid soft-tissue (PCST) CTP parameters, including blood flow (BF), blood volume (BV), mean transit time (MTT) and flow extraction product (FEP), were evaluated and correlated on DSA. We depicted models A, B and C for the small focal lesion in 1 cm of PCST, 1 cm around PCST and the whole PCST respectively.

RESULTS

CTP images of 110 patients (77 ongoing (45 threatened + 32 impending); 33 acute) were analyzed. Pericarotid BV (1.8 ± 1.2vs.3.5 ± 2.0; p < 0.001) in Model A and BF in Model B (42.6 ± 11.0vs.50.9 ± 20.4; p = 0.031) were lower in acute-CBS than in ongoing-CBS patients. Subgroup analysis demonstrated lower BV in acute (1.8 ± 1.2) compared with threatened (3.7 ± 2.3; p < 0.001; p < 0.001) and impending (3.2 ± 1.6; p = 0.009) CBS patients in Model A.

CONCLUSION

CBS severity can be quantitatively diagnosed by pericarotid soft-tissue CTP parameters. In Model A (small focus), BV was capable of differentiating acute CBS from other subtypes, demonstrating its potential role as a CBS imaging biomarker.

Stereotactic ablative radiotherapy for treating primary head and neck cancer and locoregional recurrence: A comprehensive review of the literature

Introduction

Although stereotactic ablative radiotherapy (SABR) has advance to standard-of-care for many different indications like lung and liver malignancies, it still remains in its infancy for treating head and neck cancer. Nevertheless there is a growing body of experience and evidence, which is summarized in this review Methods A thorough search of the literature was performed and critically reviewed both for SABR as a primary treatment as well as for treating locoregionally recurrent disease in a pre-irradiated field.

Results

There exist only few prospective data published so far for treating head and neck cancer with SABR. In the primary situation especially implementing SABR as a boost after definitive radiotherapy or a single-modality for locally limited, small glottic cancer appear promising. On the other hand, SABR can be a useful modality for treating local recurrence in a pre-irradiated field. However, caution is needed in the case of proximity to a pre-irradiated carotid artery or other serial organs at risk. Usually only limited gross volumes are treated with 3-6 fractions every other day and a cumulative dose of 24-44 Gy in dedicated radiosurgery platforms or modern linacs with the possibility of online image-guidance and adequate immobilsation.

Conclusions

SABR is an innovative, effective and promising treatment modality for small targets, especially in near proximity to organs at risk or in a pre-irradiated region. Prospective trials are further needed for this technique to become standard-of care.

Complication of head and neck cancer: Carotid blowout syndrome

Carotid blowout syndrome (CBS) is an uncommon but potentially life-threatening condition characterized by the spontaneous or traumatic rupture of the carotid artery in the neck. Oftentimes, CBS is due a loss of structural arterial integrity from local radiotherapy or surgical procedures. A vast majority of patients who develop CBS also have a previous diagnosis of head and neck cancer. Due to the specific patient population who develop CBS and its life-threatening nature, CBS should be a part of emergency physicians differential for those who present with a chronic neck wound or neurological symptoms in those with a previous head and neck cancer diagnosis. In this case report, a patient with a history of squamous cell carcinoma of the oropharynx who was treated with chemoradiation therapy, presented to the emergency department with spontaneous bleeding from an existing chronic wound on the left lateral neck. Conservative measures were taken including wound dressing, and the patient was discharged to see dermatology for biopsy of a suspected cancerous lesion. Once the chronic lesion was biopsied, the patient had to be immediately rushed to the operating room due to a brisk pulsatile bleeding from puncturing the carotid artery. Proper wound packing and an ultrasound of the neck for a proper diagnosis may have prevented the need for surgical intervention in this case. Although CBS is not common, complications can lead to death as seen in this case. Timely recognition and proper interventions are critical for preventing potentially fatal outcomes in those with CBS.

Re-irradiation for isolated neck recurrence in head and neck tumor: impact of rN category

Unresectable, isolated lymph node recurrence after radiotherapy is rare but a candidate for re-irradiation. However, severe toxicity is anticipated. Therefore, this study aimed to explore the efficacy and toxicity of re-irradiation in isolated lymph node recurrence of head and neck lesions. We analyzed 46 patients who received re-irradiation for lymph node recurrence without local progression. The primary tumor sites included the oral cavity in 17 patients, the hypopharynx in 12, the oropharynx in seven, the larynx in three, the nasopharynx in two, and other sites. During a median follow-up time of 10 months, the median survival time was 10.6 months, and the 1-year overall survival rate was 45.5%. The 1-year local control and progression-free survival rates were 49.8% and 39.3%, respectively. According to univariate analysis, age (≥ 65 years), the interval between treatment (≥ 12 months), rN category (rN1), and gross tumor volume (GTV < 25 cm3) were predisposing factors for better survival. In the multivariate analysis, the rN category and interval were identified as statistically significant predictors. Late toxicity grade ≥ 3 occurred in four patients (8.6%). These were all Grade 5 carotid blowout syndrome, which associated with tumor invasion of the carotid artery and/ or high doses administration for the carotid artery. Small-volume rN1 tumor that recur after a longer interval is a feasible candidate for re-irradiation. However, strict patient selection and meticulous care for the carotid are required.

[Therapy of tumor recurrences or secondary carcinomas in pretreated area is not compatible with the primary therapy in non-previously treated tissue - an overview]

There are different initial situations in the treatment of local or locoregional recurrences, secondary carcinomas or residual squamous cell carcinomas of the head and neck region after primary therapy. The majority of patients with locoregional recurrences have had prior treatment consisting of surgery and/or postoperative radiotherapy or radiochemotherapy or primary radiotherapy or radiochemotherapy. In any case, it is a matter of new tumor growth in a previously treated area, which must be taken into account for the therapy decision. The biological backgrounds are diverse and are described in more detail and clinically classified in the present work.

Delineation of Lingual Artery as an Additional Organ-At-Risk for Stereotactic Body Radiation Therapy of Head and Neck Cancers

Lingual artery (LA) stenosis or bleeding can be a potentially fatal consequence of stereotactic body radiation therapy of recurrent head and neck cancer. We aim to provide delineation guidelines for LA contouring during head and neck radiation. Three experienced radiation oncologists and 1 radiologist studied the course of LA and its anatomic relationships. A step-by-step guideline was formulated for its delineation on contrast-enhanced axial computed tomography scans. We recommend that LA should be considered an important organ at risk for stereotactic body radiation therapy of head and neck cancer. Its delineation and dose constraints should be considered on a case-to-case basis.

An Overview of Head and Neck Tumor Reirradiation: What Has Been Achieved So Far?

The recurrence rate of head and neck cancers (HNCs) after initial treatment may reach 70%, and poor prognosis is reported in most cases. Curative options for recurrent HNCs mainly depend on the treatment history and the recurrent tumor localization. Reirradiation for HNCs is effective and has been included in most guidelines. However, the option remains clinically challenging due to high incidence of severe toxicity, especially in cases of quick infield recurrence. Recent technical advances in radiation therapy (RT) provide the means for upgrade in reirradiation protocols. While the majority of hospitals stay focused on conventional and widely accessible modulated RTs, the particle therapy options emerge as tolerable and providing further treatment opportunities for recurrent HNCs. Still, the progress is impeded by high heterogeneity of the data and the lack of large-scale prospective studies. This review aimed to summarize the outcomes of reirradiation for HNCs in the clinical perspective.

Proton beam therapy in repeat irradiation of recurrent head and neck tumors: analysis of short-term results

Introduction. Recurrence of head and neck tumors occurs in 50 % of cases and usually has locoregional character. Due to the characteristics of dose distribution, proton beam therapy is a promising treatment option for patients with recurrences of tumors in this location who previously underwent radiation therapy.

Aim. To evaluate the effectiveness and tolerability of repeat irradiation using active scanning proton beam therapy in patients with recurrent head and neck tumors who previously underwent radiation therapy.

Materials and methods. Between November of 2015 and December of 2020, 40 patients with locoregional recurrence of head and neck tumors underwent treatment using active scanning proton beam therapy at the A. F . Tsyb Medical Radiological Research Center – branch of the National Medical Research Radiological Center. Median cumulative dose of primary irradiation was 64.5 Gy. Median time between primary and repeat irradiation was 35.7 months, mean irradiated volume of the repeat course was 94.5 cm3. Proton beam therapy was performed using standard mode (2 isoGy) and accelerated hypofractionation (2.4 isoGy / 3 isoGy) with mean equivalent cumulative dose of 56.4 Gy (α / β = 10). Radiation toxicity was evaluated using the Radiation Therapy Oncology Group European (RTOG) / Organization for Research and Treatment of Cancer (EORTC) scale.

Results. Treatment response was achieved in 34 (85 %) patients: in 17 (42.5 %) patients, stable disease was observed; in 10 (25 %) patients, partial response was observed; and in 7 (17.5 %) patients, complete response was observed. In 6 (15 %) cases, disease progression was diagnosed at first follow-up examination. One- and two-year locoregional control, progression-free survival and overall survival were 58.4 / 19.8; 44.5 / 19.8 and 82.3 / 38.8 % respectively with median follow-up duration of 14.2 months. Median survival was 19.5 months. Grade III and above early radiation toxicity was observed in 3 (7.5 %) patients. In total, 6 (15 %) cases of grade III complications and 2 (5 %) episodes of carotid artery rupture leading to death were observed. Overall frequency of complications of grade III and higher was 20 %.

Conclusion. Repeat irradiation using proton beam therapy can be considered an effective and safe treatment method for patients with recurrent head and neck tumors. Dosimetric and radiobiological benefits of proton beams allow to achieve balance between high doses and radiation exposure in previously irradiated tissues.

Reirradiation for local recurrence of oral, pharyngeal, and laryngeal cancers: a multi-institutional study

This study aimed to examine the efficacy and toxicity of reirradiation in patients with locally recurrent oral, pharyngeal, and laryngeal cancers. We conducted a retrospective, multi-institutional analysis of 129 patients with previously irradiated cancer. The most frequent primary sites were the nasopharynx (43.4%), oral cavity (24.8%), and oropharynx (18.6%). With a median follow-up duration of 10.6 months, the median overall survival was 14.4 months and the 2-year overall survival rate was 40.6%. For each primary site, the 2-year overall survival rates were 32.1%, 34.6%, 30%, 60.8%, and 5.7% for the hypopharynx, oral cavity, larynx, nasopharynx, and oropharynx, respectively. Prognostic factors for overall survival were primary site (nasopharynx versus other sites) and gross tumor volume (GTV) (≤ 25 cm³ versus > 25 cm³). The 2-year local control rate was 41.2%. Twenty-four patients (18.6%) presented with grade ≥ 3 toxicities, including nine with hemorrhages that led to grade 5 toxicities in seven patients. All nine tumors that caused hemorrhage showed tumor encasement of the carotid ≥ 180 degrees and eight of nine tumors had larger GTV > 25 cm³. Reirradiation is a feasible treatment option for small local recurrence of oral, pharyngeal, and laryngeal cancers, with the requirement of a strict eligibility assessment for large tumors with carotid encasement.

Efficacy and safety of a treatment in patients with locoregionally advanced nasopharyngeal carcinoma (LANC) involving carotid artery invasion

PURPOSE

Locally advanced nasopharyngeal carcinoma (LANC) often invades the parapharyngeal space and internal carotid artery. Are patients with LANC invading carotid artery are at risk of massive neck hemorrhage after radiotherapy?

METHODS

This retrospective study included 130 LANC patients with carotid artery invasion admitted to our hospital between January 2012 and September 2019. All patients were treated with induction chemotherapy followed by concurrent chemoradiotherapy (CCRT) ± epidermal growth factor receptor (EGFR) inhibitor. Univariate and multivariate analysis of risk factors were conducted for the prognosis and the occurrence of massive neck hemorrhage of LANC patients with carotid artery invasion.

OUTCOMES

The 5-year progression-free survival (PFS), distant metastasis-free survival (DMFS), local nodal recurrence-free survival (LNRFS), local recurrence-free survival (LRFS), nodal recurrence-free survival (NRFS) and overall survival (OS) of the 130 patients were 75.2%, 76.8%, 90.0%, 93.9%, 95.8% and 87.2%, respectively. The incidence of fatal bleeding after radiotherapy was 2.3% (3/130). The primary site of the three cases were all the pharyngeal recess, with more than 270° carotid artery invasion, suffering nasopharyngeal necrosis after radiotherapy (2 of which were diabetics and 1 received re-radiation after recurrence). Univariate analysis showed that clinical stage was negatively correlated with DMFS and PFS (P < 0.05). The induction chemotherapy TP regimen, platinum-based concurrent chemotherapy and EGFR inhibitors (Nituzumab/Cetuximab) significantly improved PFS and DMFS (P < 0.05). Patients with hemoglobin levels > 110 g/L had significantly inferior PFS, DMFS and OS than those with hemoglobin levels ≤ 110 g/L (P < 0.05). Multivariate analysis showed that the EGFR inhibitor was an independent risk factor for PFS and DMFS, while the lowest hemoglobin level was an independent risk factor for OS.

CONCLUSIONS

In LANC patients whose carotid artery invasion was < 270°, induction chemotherapy (IC) followed by helical tomotherapy (HT) and concurrent chemoradiotherapy (CCRT) with EGFR (epidermal growth factor receptor) inhibitor had mild and tolerable side effects, better PFS and DMFS, with no massive hemorrhage. In patients whose primary tumor was pharyngeal recess with carotid artery invasion ≥ 270°, poorly controlled diabetes or re-radiotherapy led to a higher risk of massive hemorrhage after radiotherapy.

Retreatment of Recurrent or Second Primary Head and Neck Cancer After Prior Radiation: Executive Summary of the American Radium Society® (ARS) Appropriate Use Criteria (AUC): Expert Panel on Radiation Oncology - Head and Neck Cancer

BACKGROUND

Re-treatment of recurrent or second primary head and neck cancers occurring in a previously irradiated field is complex. Few guidelines exist to support practice.

METHODS

We performed an updated literature search of peer-reviewed journals in a systematic fashion. Search terms, key questions, and associated clinical case variants were formed by panel consensus. The literature search informed the committee during a blinded vote on the appropriateness of treatment options via the modified Delphi method.

RESULTS

The final number of citations retained for review was 274. These informed five key questions, which focused on patient selection, adjuvant re-irradiation, definitive re-irradiation, stereotactic body radiation (SBRT), and re-irradiation to treat non-squamous cancer. Results of the consensus voting are presented along with discussion of the most current evidence.

CONCLUSIONS

This provides updated evidence-based recommendations and guidelines for the re-treatment of recurrent or second primary cancer of the head and neck.

Carotid Blowout Syndrome in the Emergency Department: A Case Report and Review of the Literature

BACKGROUND

Carotid blowout syndrome (CBS) is an infrequent but dangerous oncologic emergency that must be recognized due to a mortality rate that approaches 40% and neurologic morbidity that approaches 60%. Patients present with a variety of symptoms ranging from asymptomatic to frank hemorrhage, and appropriate recognition and management may improve their outcomes.

CASE REPORT

A man in his late 60s with squamous cell carcinoma of the oropharynx presented to the emergency department (ED) with hemoptysis and several episodes of post-tussive emesis with large clots. He had been cancer free for multiple years after treatment with chemotherapy and radiation to the neck. Evaluation revealed a necrotic tumor on the posterior pharynx on bedside laryngoscopy and an external carotid pseudoaneurysm that was stented by interventional radiology. The patient experienced recurrent hemorrhage several months later and opted for palliative measures and expired of massive hemorrhage in the ED on a subsequent visit. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: CBS can be fatal, and early suspicion and recognition are key to ensure that a threatened or impending carotid blowout are appropriately managed. Once carotid blowout is suspected, early resuscitation and consultation with interventional radiology and vascular surgery is warranted.

Case of papillary thyroid cancer presenting with an inoperable cervical mass successfully treated with high-dose radiation therapy

External-beam radiation therapy (EBRT) for differentiated thyroid cancer has been controversial. Palliative irradiation is usually recommended for patients with treatment-resistant relapse and/or distant metastases, but high-dose EBRT is not often indicated in this situation. A 50-year-old man had treatment-resistant recurrence of an inoperable cervical mass and multiple lung metastases after total thyroidectomy and neck dissection. Because the patient had good performance status and no other life-threatening metastases, he received high-dose intensity-modulated radiation therapy (IMRT). Remarkably, the tumour shrank during treatment. After 3 months, he had bleeding from the internal carotid artery. The bleeding was outside the high-dose irradiation site and was likely due to infection; emergency interventional radiology was performed. The post-EBRT clinical course was favourable and the cervical mass almost disappeared. The patient remained alive for 3 years post treatment. It is possible to extend the indication of high-dose intensity-IMRT in selected patients with differentiated thyroid cancer.

Predictive factors for bleeding carotid artery pseudoaneurysms in patients with previous radiations for head and neck cancers

BACKGROUND

Bleeding from carotid artery pseudoaneurysms is an emergency condition with high morbidity and mortality. We aimed to identify risk factors predicting pseudoaneurysmal bleeding as the cause of profuse epistaxis in irradiated head and neck cancer patients with suspect carotid blowout or pseudoaneurysms.

METHODS

We retrospectively reviewed consecutive patients with history of radiation therapy for head and neck cancers and with nasal, oral or ear bleeding requiring in-patient treatment from hospital database. Pseudoaneurysms were subgrouped into internal carotid artery (ICA) pseudoaneurysms, and external carotid artery (ECA) pseudoaneurysms. The treatment outcomes were evaluated using 30-day mortality rate, recurrent bleeding, and cerebral infarction.

RESULTS

There were 41 admissions for suspected carotid blowout or pseudoaneurysms from 1 July 2016 to 30 June 2020 with 17 bleeding pseudoaneurysms identified, including 11 internal carotid arteries (ICA) pseudoaneurysms and 6 external carotid arteries (ECA) pseudoaneurysms. Among ICA pseudoaneurysms, six patients passed Balloon occlusion test with embolization and parent artery occlusion (trapping) of ICA performed, and all ECA pseudoaneurysms were embolized with parent artery occlusion (trapping). Baseline hypertension and hypotension on arrival were predictive for pseudoaneurysmal bleeding. The degree of haemoglobin drop was not significantly different between pseudoaneurysmal bleeding and non-pseudoaneurysmal bleeding (2.1 ± 1.4 g/dL vs. 1.6 ± 1.4 g/dL, p = 0.234).

CONCLUSIONS

We identified baseline hypertension and hypotension on arrival as predictive factors for pseudoaneurysmal bleeding in patients with irradiated head and neck cancer. Presence of these risk factors should alert the clinicians to the possibility of carotid pseudoaneurysms.

Outcomes for the treatment of locoregional recurrent nasopharyngeal cancer: A systematic review and pooled analysis

Despite advances in the treatment of primary nasopharyngeal carcinoma, locoregional recurrence (lrNPC) occurs at 10%-50% at 5 years. This review aims to evaluate salvage treatment for locally recurrent nasopharyngeal cancer. A literature search for all original articles published on the treatment of lrNPC from January 1990 to January 2021 was conducted. Pooled analysis was performed using a random effects model and assessed statistical heterogeneity of the combined results with I² index. Overall, 66 studies were included for analysis. A total of 5286 patients treated with intensity-modulated radiation therapy (39%), conformal radiotherapy (31%), open nasopharyngectomy (12%), endoscopic nasopharyngectomy (10%), stereotactic radiosurgery (4%), and brachytherapy (4%) were included. Surgical therapy has similar overall survival outcomes to re-irradiation but with decreased treatment-related morbidity and mortality. Both surgical and re-irradiation for lrNPC have similar long-term survival. Surgical approaches to lrNPC may offer similar survival while avoiding treatment-associated morbidity and mortality.

Risk factors and nomogram for predicting carotid blowout syndrome based on computed tomography angiography

OBJECTIVES

To identify independent factors for head and neck cancer (HNC) patients with carotid blowout syndrome (CBS) and construct a nomogram to predict risk of CBS preoperatively based on computed tomography angiography (CTA) imaging.

SUBJECT AND METHODS

From January 2010 to July 2020, 73 HNC patients who had surgery in hospitalization and underwent CTA examination for head and neck region were included in this study. Vascular alterations and the relationship between carotid artery (CA) and tumor were evaluated in CTA. Clinical and CTA imaging features were distinguished by logistic regression analysis and used to perform receiver operating curve analysis. Nomogram was created to predict risk of CBS and assessed by concordance index (C-index) and calibration curve.

RESULTS

Three independent risk factors were identified, including radical neck dissection, CA surrounded by tumor, and CA invaded by tumor without clear boundary. Area under curve of the combination of 3 variables was 0.836 (95% CI, 0.72-0.952, p < 0.001). The C-index of nomogram was 0.84 (95% CI, 0.73-0.94), and the calibration plot showed a good fitting between prediction and observation.

CONCLUSIONS

We established a useful nomogram based on CTA imaging, which showed a satisfied efficacy for evaluating risk of CBS in HNC patients preoperatively.

A surveillance study of patterns of reirradiation practice using external beam radiotherapy in Japan

The aim of this study was to survey the present status and patterns of reirradiation (Re-RT) practice using external beam radiotherapy in Japan. We distributed an e-mail questionnaire to the Japanese Society for Radiation Oncology partner institutions, which consisted of part 1 (number of Re-RT cases in 2008-2012 and 2013-2018) and part 2 (indications and treatment planning for Re-RT and eight case scenarios). Of the 85 institutions that replied to part 1, 75 (88%) performed Re-RTs. However, 59 of these 75 institutions (79%) reported difficulty in obtaining Re-RT case information from their databases. The responses from 37 institutions included the number of Re-RT cases, which totaled 508 in the period from 2009 to 2013 (institution median 3; 0-235), and an increase to 762 cases in the period from 2014 to 2018 (12.5; 0-295). A total of 47 physicians responded to part 2 of the survey. Important indications for Re-RT that were considered were age, performance status, life expectancy, absence of distant metastases and time interval since previous radiotherapy. In addition to clinical decision-making factors, previous total radiation dose, volume of irradiated tissue and the biologically equivalent dose were considered during Re-RT planning. From the eight site-specific scenarios presented to the respondents, >60% of radiation oncologists agreed to perform Re-RT. Re-RT cases have increased in number, and interest in Re-RT among radiation oncologists has increased recently due to advances in technology. However, several problems exist that emphasize the need for consensus building and the establishment of guidelines for practice and prospective evaluation.

Initial Data Pooling for Radiation Dose-Volume Tolerance for Carotid Artery Blowout and Other Bleeding Events in Hypofractionated Head and Neck Retreatments

PURPOSE

Dose-volume data for injury to carotid artery and other major vessels in stereotactic body radiation therapy (SBRT)/SABR head and neck reirradiation were reviewed, modeled, and summarized.

METHODS AND MATERIALS

A PubMed search of the English-language literature (stereotactic and carotid and radiation) in April 2018 found 238 major vessel maximum point doses in 6 articles that were pooled for logistic modeling. Two subsequent studies with dose-volume major vessel data were modeled separately for comparison. Attempts were made to separate carotid blowout syndrome from other bleeding events (BE) in the analysis, but we acknowledge that all except 1 data set has some element of BE interspersed.

RESULTS

Prior radiation therapy (RT) dose was not uniformly reported per patient in the studies included, but a course on the order of conventionally fractionated 70 Gy was considered for the purposes of the analysis (with an approximately ≥6-month estimated interval between prior and subsequent treatment in most cases). Factors likely associated with reduced risk of BE include nonconsecutive daily treatment, lower extent of circumferential tumor involvement around the vessel, and no surgical manipulation before or after SBRT.

CONCLUSIONS

Initial data pooling for reirradiation involving the carotid artery resulted in 3 preliminary models compared in this Hypofractionated Treatment Effects in the Clinic (HyTEC) report. More recent experiences with alternating fractionation schedules and additional risk-reduction strategies are also presented. Complications data for the most critical structures such as spinal cord and carotid artery are so limited that they cannot be viewed as strong conclusions of probability of risk, but rather, as a general guideline for consideration. There is a great need for better reporting standards as noted in the High Dose per Fraction, Hypofractionated Treatment Effects in the Clinic introductory paper.

Prevention and early management of carotid blowout syndrome for patients receiving head and neck salvage boron neutron capture therapy (BNCT)

Background/purpose

The incidence rate of oral and pharyngeal cancers in Taiwan has increased gradually over the past few decades. The standard treatment strategy for oral and pharyngeal cancers includes surgery or radiotherapy, with concurrent chemotherapy in certain types of tumors. Unfortunately, in-field recurrence is sometimes inexorable. Furthermore, re-irradiation of the recurrence site may cause severe complications due to the tolerance of normal tissue to radiation therapy. One fatal complication is carotid blowout syndrome (CBS). Boron neutron capture therapy (BNCT) is a new modality of radiation therapy, which is also mentioned as targeted radiotherapy. It is a feasible treatment that has the potential to spare normal tissue from being damaged by irradiation while simultaneously treating the primary tumor. In this presentation, we will share our experience with BNCT in treating recurrent head and neck cancers, as well as the prevention and management of CBS.

Materials and methods

We evaluated 4 patients with head and neck cancers treated by BNCT in Taiwan. All patients had undergone surgery previously and had received postoperative concurrent chemoradiotherapy.

Results

The 4 patients in this study were diagnosed with head and neck malignancies. The median follow-up period after the first course of BNCT was 15.1 months. After BNCT, 2 patients developed impending CBS, and 1 of them died. The remaining 3 patients survived until the last date of follow-up.

Conclusion

Pre-BNCT carotid artery evaluation through computed tomography angiography and early intervention if necessary is crucial when treating patients with recurrent head and neck cancers by BNCT.

A systematic review and practical considerations of stereotactic body radiotherapy in the treatment of head and neck cancer

OBJECTIVES

Stereotactic radiotherapy (SBRT) is gaining popularity although its use in head and neck cancer (HNC) is not well defined. The primary objective was to review the published evidence regarding the use of stereotactic radiotherapy in HNC.

METHODS

A literature search was performed by using MEDLINE and EMBASE databases for eligible studies from 2000 to 2019 and 26 relevant studies were identified.

RESULTS

Literature demonstrates a heterogeneous use of this technique with regards to patient population, primary or salvage treatment, dose fractionation regimens, outcomes and follow-up protocols. Carotid blow out syndrome is a risk as with other forms of reirradiation but alternative treatment regimens may reduce this risk.

CONCLUSION

At present there is a lack of evidence regarding SBRT as a primary treatment option for HNC and definitive answers regarding efficacy and tolerability cannot be provided but there is growing evidence that SBRT reirradiation regimens are safe and effective. In lieu of evidence from large Phase III trials, we define appropriate organ at risk constraints and prescription doses, with accurate plan summation approaches. Prospective randomised trials are warranted to validate improved treatment outcomes and acceptable treatment morbidity.

ADVANCES IN KNOWLEDGE

This article provides a comprehensive review of evidence of use of stereotactic radiotherapy in HNC site (either as a primary treatment or as reirradiation). We also provide an evidence-based approach to the implementation and practical consideration of stereotactic radiotherapy in HNC.

Challenges in Combining Immunotherapy with Radiotherapy in Recurrent/Metastatic Head and Neck Cancer

Immunotherapy with immune checkpoint inhibitors (ICI) has recently become a standard part of the treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), although the response rates are low. Numerous preclinical and clinical studies have now illuminated several mechanisms by which radiotherapy (RT) enhances the effect of ICI. From RT-induced immunogenic cancer cell death to its effect on the tumor microenvironment and vasculature, the involved mechanisms are diverse and intertwined. Moreover, the research of these interactions is challenging because of the thin line between immunostimulatory and the immunosuppressive effect of RT. In the era of active research of immunoradiotherapy combinations, the significance of treatment and host-related factors that were previously seen as being less important is being revealed. The impact of dose and fractionation of RT is now well established, whereas selection of the number and location of the lesions to be irradiated in a multi-metastatic setting is something that is only now beginning to be understood. In addition to spatial factors, the timing of irradiation is as equally important and is heavily dependent on the type of ICI used. Interestingly, using smaller-than-conventional RT fields or even partial tumor volume RT could be beneficial in this setting. Among host-related factors, the role of the microbiome on immunotherapy efficacy must not be overlooked nor can we neglect the role of gut irradiation in a combined RT and ICI setting. In this review we elaborate on synergistic mechanisms of immunoradiotherapy combinations, in addition to important factors to consider in future immunoradiotherapy trial designs in R/M HNSCC.

Carotid blowout syndrome after reirradiation for head and neck malignancies: a comprehensive systematic review for a pragmatic multidisciplinary approach

AIM

To provide a literature review on risk factors and strategies to prevent acute carotid blowout (CBO) syndrome in patients who underwent reirradiation (reRT) for recurrent head and neck (HN) malignancies.

PATIENTS AND METHODS

Inclusion criteria were: 1) CBO following reRT in the HN region, 2) description on patient-, tumor- or treatment-related risk factors, 3) clinical or radiological signs of threatened or impending CBO, and 4) CBO prevention strategies.

RESULTS

Thirty-five studies were selected for the analysis from five hundred seventy-seven records. Results provided indications on clinical, radiological and dosimetric parameters possibly associated with higher risk of CBO. Endovascular procedures (artery occlusion and stenting) to prevent acute massive hemorrhage in high risk patients were discussed.

CONCLUSION

Literature data are still scarce with a low level of evidence. Nevertheless, the present work provides a comprehensive review useful for clinicians as a multidisciplinary pragmatic tool in their clinical practice.

Preliminary Simulation Study of Carotid Artery and Pharyngeal Constrictor Muscle Sparing-Radiotherapy in Glottic Carcinoma

Background:

This preliminary simulation study aimed to compare the dosimetric outcomes of carotid arteries (CAs) and pharyngeal constrictor muscle (PCM) in patients with T1N0M0 glottic carcinoma undergoing helical tomotherapy-intensity modulated radiotherapy (HT-IMRT) and 3-dimensional conformal radiotherapy (3D-CRT) plans.

Methods:

In addition to the clinical target volume (CTV) which was defined as the entire larynx, the CAs and PCM of 11 glottic carcinoma patients were delineated. The CTV was uniformly expanded 5 mm to create a planning target volume (PTV) relative to the PCM and at a distance of 2 mm from the CA. The dosimetric characteristics in HT-IMRT and lateral opposed fields-based 3D-CRT plans were analyzed.

Results:

Median D_95%and V_100% of PTV were significantly higher in HT-IMRT (p < 0.001) compared to 3D-CRT. The right/left CA dosimetric outcomes, including the mean doses (20.7/21.5 Gy versus 48.7/50.5 Gy), D_max (53.6/52.0 Gy versus 67.4/67.7 Gy), V₃₀ (25.0/27.1% versus 77.6/80.3%), V₄₀ (8.0/7.9% versus 74.6/71.9%), and V₅₀ (2.0/1.2% versus 70.0/71.6%) were also significantly lower in HT-IMRT (p < 0.05), similar to the mean PCM doses (49.6 Gy versus 62.6 Gy for 3D-CRT;p < 0.001), respectively.

Conclusions:

Our present results demonstrated the feasibility of simultaneous sparing of the CAs and PCM in HT-IMRT- compared to 3D-CRT plans in glottic carcinoma patients undergoing definitive radiotherapy.

Efficacy and Feasibility of Salvage Re-Irradiation with CyberKnife for In-Field Neck Lymph Node Recurrence: A Retrospective Study

Neck lymph node (LN) recurrence in the irradiated field represents an important aspect of treatment failure after primary radiotherapy owing to the lack of a standard treatment. The aim of this study is to investigate the efficacy and safety of CyberKnife treatment for neck LN recurrence after radiotherapy. Between 2008 and 2016, 55 neck LN recurrences after radiotherapy in 16 patients were treated with CyberKnife. The median follow-up period was 17 months (range, 2–53 months). The median previous radiotherapy dose was 68 Gy (range, 50–70 Gy). The median marginal dose as equivalent dose delivered in 2-Gy fractions (α/β = 10) was 50 Gy (range, 40–58 Gy). The one-year local control (LC) and overall survival rates were 81% and 71%, respectively. The one-year LC was higher with a target volume ≤1.0 cm³ than that with a target volume >1.0 cm³ (p = 0.006). Fatal bleeding was observed in one patient who had large (91 cm³) and widespread tumor with invasion to the carotid artery before CyberKnife treatment. CyberKnife treatment for neck LN recurrence is safe and feasible in most cases. Indication for the treatment should be carefully considered for large and widespread tumors.

Second infield re-irradiation with a resulting cumulative equivalent dose (EQD2max ) of >180 Gy for patients with recurrent head and neck cancer

BACKGROUND

For locally recurrent head and neck cancer, re-irradiation with modern techniques like stereotactic body radiotherapy is a promising, possibly curative alternative to palliative systemic therapy.

METHODS

We report on 1 patient with nasopharyngeal carcinoma (NPC) and 1 patient with cutaneous squamous cell carcinoma (SCC). Both patients received full dose primary treatment (>66 Gy, EQD2), full dose re-irradiation (>50 Gy, EQD2), and a second course of re-irradiation via robotic radiosurgery (CyberKnife) for a second local recurrence.

RESULTS

Both treatments resulted in adequate tumor response. No grade III-IV acute or late toxicities occurred. Follow-up at 6 months after third irradiation showed partial remission for the patient with NPC. In the second case (SCC), no toxicities occurred and the tumor was in remission 18 months after last treatment.

CONCLUSION

These cases show that a second course of re-irradiation utilizing modern techniques like robotic radiosurgery might be feasible for carefully selected patients with head and neck cancer.

Carotid blowout syndrome: modern trends in management

Carotid blowout syndrome (CBS) refers to rupture of the carotid artery and is an uncommon complication of head and neck cancer that can be rapidly fatal without prompt diagnosis and intervention. CBS develops when a damaged arterial wall cannot sustain its integrity against the patient’s blood pressure, mainly in patients who have undergone surgical procedures and radiotherapy due to cancer of the head and neck, or have been reirradiated for a recurrent or second primary tumor in the neck. Among patients irradiated prior to surgery, CBS is usually a result of wound breakdown, pharyngocutaneous fistula and infection. This complication has often been fatal in the past, but at the present time, early diagnosis and modern technology applied to its management have decreased morbidity and mortality rates. In addition to analysis of the causes and consequences of CBS, the purpose of this paper is to critically review methods for early diagnosis of this complication and establish individualized treatment based on endovascular procedures for each patient.

Topical steroid versus placebo for the prevention of radiation dermatitis in head and neck cancer patients receiving chemoradiotherapy: the study protocol of J-SUPPORT 1602 (TOPICS study), a randomized double-blinded phase 3 trial

Background

To date, the clinical benefit of topical steroid use has only been demonstrated for radiation dermatitis induced by 50–60 Gy irradiation in breast cancer. However, these agents are also often used clinically for the control of radiation dermatitis induced by high-dose (>60Gy) irradiation with chemotherapy in head and neck cancer. Despite this, the prophylactic efficacy of topical steroids for radiation dermatitis induced by high-dose irradiation is still unclear.

The aim of this study is to clarify the benefit of topical steroids in basic nursing care for radiation dermatitis induced by chemoradiotherapy in patients with head and neck cancer.

Methods

The study is being conducted as a multicenter 2-arm randomized double-blinded placebo-controlled Phase 3 trial in Japan. The study was started in May 2017, with participant enrollment between May 2017 and April 2019.

Patients scheduled to receive definitive or postoperative chemoradiotherapy for head and neck cancer are eligible for enrollment. All patients will receive chemoradiotherapy, consisting of single agent CDDP and 70-Gy irradiation. Bilateral neck irradiation is mandatory.

Supportive care for radiation dermatitis will consist of basic nursing care with topical steroid or placebo. When radiation dermatitis grade 1 is seen or total radiation dose reaches 30 Gy, minimally required intervention will be started as a first step.

If radiation dermatitis worsens to grade 2, the irradiated area will be covered with a moderately absorbent surgical pad and steroid or placebo topical cream.

The primary endpoint is a comparison of the proportion of patients with ≥ grade 2 radiation dermatitis by NCI Common Terminology Criteria for Adverse Events (CTCAE) Version 4.0.

Ethical approval has been obtained from all participating sites. The results of this study will be submitted for publication in international peer-reviewed journals and the key findings will be presented at international scientific conferences.

Discussion

Evidence supporting the benefit of adding topical steroids in general nursing care for radiation dermatitis induced by high-dose irradiation with chemotherapy is insufficient. This trial aims to clarify the clinical benefit of topical steroid for radiation dermatitis induced by high-dose irradiation with chemotherapy. The trial is ongoing and is currently recruiting.

Trial registration number

UMIN000027161. Protocol version 3.0, 18 April 2017.

Definitive re-irradiation using intensity-modulated radiation therapy in cancers of the head and neck, focusing on rare tumors

PURPOSE

To analyze the outcomes following re-irradiation for local recurrence of rare head and neck tumors.

MATERIAL AND METHODS

We retrospectively analyzed 11 patients who had received intensity-modulated radiation therapy (IMRT) for recurrent tumors in the head and neck except for laryngopharynx.

RESULTS

Primary tumor sites included the maxillary sinus, nasal cavity, and external ear canal in six, three, and two patients, respectively. The median follow-up times were 13 (range, 3-54) months. The median survival time was 17 months with 1- and 2-year survival rates of 63.64 and 39.77%, respectively. Among 11 patients, five experienced local failure in the follow-up period. The 1- and 2-year local control rates were 58 and 47%, respectively. Patients who had received a radiation dose of ≥3 Gy per fraction showed significantly better local control than those receiving less (p = .0419). One patient experienced Grade 3 facial pain as acute toxicity. Late toxicities included radiographic findings of partial central nervous system necrosis in three patients and Grade 3 osteonecrosis and Grade 3 facial nerve disorder in one patient.

CONCLUSIONS

Re-irradiation of rare head and neck tumors using IMRT for loco-regional recurrence may be an acceptable treatment option.

Carotid Dosimetry and the Risk of Carotid Blowout Syndrome After Reirradiation With Head and Neck Stereotactic Body Radiation Therapy

PURPOSE

To correlate carotid dose and risk of carotid blowout syndrome (CBOS) after stereotactic body radiation therapy (SBRT), hypothesizing that carotid dose does not correlate with CBOS.

METHODS AND MATERIALS

We retrospectively reviewed 186 patients with recurrent, previously irradiated head and neck cancer treated between January 2008 and March 2013. Patients treated early in our experience with incomplete dosimetry were excluded from analysis (n = 111). A total of 75 patients were identified, providing 150 carotid arteries for analysis. Median follow-up was 8 months (range, 1-91 months) for all patients, and 37 months for surviving patients (range, 31-91 months). Patients were treated with linear accelerator-based SBRT to a median dose up to 44 Gy (range, 40-50 Gy) in 5 fractions delivered on a twice-weekly basis. Concurrent cetuximab was used in 63 patients (84%). The bilateral common, internal, and external carotid arteries were delineated 2 cm above and below the planning target volume. The maximum dose to 0.1 cm³ (D_0.1cc), 1 cm³ (D_1cc), and 2 cm³ (D_2cc) of the carotid and the mean carotid dose from SBRT were recorded and analyzed for association with carotid bleeding events, using binary logistic regression.

RESULTS

Median reirradiation interval was 20 months (range, 3-423 months), and median prior radiation dose was 70 Gy (range, 52.5-140 Gy). Sixteen patients (21.3%) received more than 1 course of SBRT, and the cumulative carotid doses from fused summary plans were recorded. The overall median D_0.1cc, D_1cc, D_2cc, and mean carotid doses were 40.8 Gy (interquartile range [IQR], 21.6-47.6 Gy), 26.8 Gy (IQR, 14.1-42.1 Gy), 15.4 Gy (IQR, 8.4-32.7 Gy), and 15.0 Gy (IQR, 8.9-23.3 Gy), respectively. There were a total of 4 bleeding events (5.3%): 2 patients (2.7%) had mucosal bleeds that resolved after embolization of carotid branches, and 2 patients (2.7%) died from complications of CBOS. In the 2 patients with CBOS the D_0.1cc was 48.4 Gy and 47.6 Gy, respectively. There was no significant association between bleeding events and D_1cc (P = .280), D_2cc (P = .571), or mean dose (P = .568). There was a trend toward increased risk of bleeding and D_0.1cc (P = .080).

CONCLUSIONS

These results demonstrate a low risk of bleeding after reirradiation with SBRT when 5 fractions are delivered on nonconsecutive days, even when tumor is completely encasing the carotid artery. Although limited by the low number of events, no significant association was found between dose-volume parameters and the risk of carotid bleeding. No CBOS was noted when D_0.1cc was <47.6 Gy.

[Radiotherapy for head and neck squamous cell carcinoma: State of the art and future directions]

Therapeutic principles of radiation therapy in head and neck carcinomas will be discussed in this review. Intensity-modulated radiotherapy with concomitant cisplatin should be standard. In case of contraindication to chemotherapy, cetuximab is an option, while hyperfractionation should be considered in patients unfit for concomitant treatment. Concomitant chemotherapy should be administered in the presence of extracapsular extensions and positive margins in the postoperative setting. Current research areas such as desescalation in human papillomavirus-positive tumours, adaptive radiotherapy, radiomics and immunotherapy will also be addressed.

Effect of intratumoral abscess/necrosis on the outcome for head and neck cancer patients treated by hypofractionated stereotactic re-irradiation using CyberKnife®

The aim of the present study was to elucidate the effect of intratumoral abscess/necrosis (AN) on the outcome of patients with recurrent head and neck cancer (HNC) treated by stereotactic radiotherapy. The records of 67 patients treated with CyberKnife® in four institutes between August 2000 and July 2010 were reviewed. The frequency of AN appeared to be increased in younger postoperative patients with large ulcerative tumors. The AN⁺ group exhibited a better initial response rate compared with the AN⁻ group (64 vs. 33%, respectively; P=0.04). The 1-year local control rate was 51 and 75% in the AN⁺ and AN⁻ groups, respectively (P=0.01), while the respective 1-year overall survival rates were 53 and and 71% (P=0.0004). A total of 21 patients (31%) experienced grade ≥3 toxicities, and carotid blowout syndrome (CBOS) was found in 11 patients, resulting in 8 deaths. A significantly larger proportion of patients in the AN⁺ group developed CBOS (8/18; 44%) compared with the AN⁻ group (3/49; 6%) (P=0.001). Therefore, AN may be an important prognostic factor for patients with recurrent HNC, as well as a predictor of lethal toxicity due to CBOS.

Risk of carotid blowout after reirradiation with particle therapy

Purpose

Carotid blowout (CB) is a serious complication in retreatment of neoplasms in the head and neck (H&N) region. Rates seem to increase in hypofractionated or accelerated hyperfractionated regimens. In this study, we investigate the CB rate and the cumulative doses received by the carotid artery (CA) in a cohort of patients who were reirradiated at CNAO with particle therapy in the H&N region.

Methods and materials

The dosimetric information, medical records, and tumor characteristics of 96 patients were analyzed. For 49 of these patients, the quality of dosimetric information was sufficient to calculate the cumulative doses to the CA. The corresponding biological equivalent dose in 2 Gy fractions (EQD2) was calculated with an α/β-ratio of 3.

Results

In the final reirradiation at CNAO, 17 patients (18%) had been treated with protons and 79 (82%) with carbon ions. Two patients experienced profuse oronasal bleeding, of which one case was confirmed to be caused by CB. If attributing both cases to CB, we found an actuarial CB rate of 2.7%. Interestingly, there were no CB cases in the carbon ion group even though this was the large majority of patients and they generally were treated more aggressively in terms of larger fraction doses and higher cumulative EQD2.

Conclusions

The current practice of particle reirradiation at CNAO for recurrent neoplasms in the H&N region results in acceptable rates of CB.

Reirradiation for recurrent head and neck cancers using charged particle or photon radiotherapy

OBJECTIVE

To examine the outcomes of reirradiation for recurrent head and neck cancers using different modalities.

METHODS

This retrospective study included 26 patients who received charged particle radiotherapy (CP) and 150 who received photon radiotherapy (117 CyberKnife radiotherapy [CK] and 36 intensity-modulated radiotherapy [IMRT]). Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias.

RESULTS

Higher prescribed doses were used in CP than photon radiotherapy. The 1‑year overall survival (OS) rates were 67.9% for CP and 54.1% for photon radiotherapy (p = 0.15; 55% for CK and 51% for IMRT). In multivariate Cox regression, the significant prognostic factors for better survival were nasopharyngeal cancer, higher prescribed dose, and lower tumor volume. IPTW showed a statistically significant difference between CP and photon radiotherapy (p = 0.04). The local control rates for patients treated with CP and photon radiotherapy at 1 year were 66.9% (range 46.3-87.5%) and 67.1% (range 58.3-75.9%), respectively. A total of 48 patients (27%) experienced toxicity grade ≥3 (24% in the photon radiotherapy group and 46% in the CP group), including 17 patients with grade 5 toxicity. Multivariate analysis revealed that younger age and a larger planning target volume (PTV) were significant risk factors for grade 3 or worse toxicity.

CONCLUSION

CP provided superior survival outcome compared to photon radiotherapy. Tumor volume, primary site (nasopharyngeal), and prescribed dose were identified as survival factors. Younger patients with a larger PTV experienced toxicity grade ≥3.

Usefulness of Stereotactic Radiotherapy Using CyberKnife for Recurrent Lymph Node Metastasis of Differentiated Thyroid Cancer

A woman in her 60s presented with a recurrent lymph node metastasis from a papillary thyroid carcinoma in the right parapharyngeal space. She had already undergone total thyroidectomy, five resections for cervical lymph node metastases, and right carotid rebuilding. Surgical resection of the current metastasis was impossible. ¹³¹I-radioiodine therapy (RIT) with 3.7 GBq ¹³¹I was not effective; therefore, stereotactic radiation therapy (SRT) using a CyberKnife radiotherapy system was scheduled. The prescription dose was 21 Gy, and a dose covering 95% of the planning target volume (PTV) in three fractions was administered. The PTV was 4,790 mm³. Follow-up magnetic resonance imaging conducted 3 and 12 months after the SRT demonstrated a remarkable and gradual reduction of the recurrent lymph node metastasis in the right parapharyngeal space and no evidence of recurrence. For multidisciplinary therapy of unresectable and/or RIT unresponsive locoregional lymph node metastases and recurrences of DTC, SRT using the CyberKnife system should be considered.

Survey of current practices from the International Stereotactic Body Radiotherapy Consortium (ISBRTC) for head and neck cancers

Aim: To provide a multi-institutional description of current practices of stereotactic body radiotherapy (SBRT) for head and neck cancer. Materials & methods: 15 international institutions with significant experience in head and neck SBRT were asked to complete a questionnaire covering clinical and technical factors. Results: SBRT is used 10–100% of the time for recurrent primary head and neck cancer, and 0–10% of the time in newly diagnosed disease. Five centers use a constraint for primary disease of 3–5 cm and 25–30 cc. Nine institutions apply a clinical target volume expansion of 1–10 mm and 14 use a planning target volume margin of 1–5 mm. Fractionation regimens vary between 15 and 22 Gy in 1 fraction to 30–50 Gy in 5 or 6 fractions. The risk of carotid blowout quoted in the re-irradiation setting ranges from 3 to 20%. Conclusion: There is considerable heterogeneity in patient selection and techniques in head and neck SBRT practice among experienced centers.

A surveillance study of the current status of reirradiation and patterns of practice

The aim of this study was to survey the current status of reirradiation (Re-RT) and patterns of practice in Japan. An email questionnaire was sent to Kansai Cancer Therapist Group partner institutions, using questions similar to those in the Canadian radiation oncologist (RO) survey (2008). A total of 34 ROs from 28 institutions returned the survey. All 28 institutions experienced Re-RT cases in 2014. However, 26 of the 28 institutions (93%) reported difficulty in obtaining Re-RT case information from their respective databases. Responses from 19 institutions included the number of Re-RT cases; this rose from 183 in the period 2005-2009 (institution median = 4; 2-12.9) to 562 in the period 2010-2014 (institution median = 26; 2-225). Important considerations for indication of Re-RT were age (65%), performance status (83%), life expectancy (70%), absence of distant metastases (67%), and interval since previous treatment (73%). Previous total radiation dose (48%), volume of tissue irradiated (72%), and the biologically equivalent dose (BED; 68.5%) were taken into account during Re-RT planning. These factors were similar to those considered in the Canadian survey; however, the present study did not consider age. In eight site-specific scenarios, barring central nervous system recurrence, more than 90% of ROs agreed to perform Re-RT, which was higher than the percentage observed in the Canadian survey. Re-RT cases have increased in number and aroused interest among ROs in this decade of advanced technology. However, consensus building to establish guidelines for the practice and prospective evaluation of Re-RT is required.

Reirradiation using robotic image-guided stereotactic radiotherapy of recurrent head and neck cancer

The purpose of this study was to examine the prognosis for patients with head and neck cancer after reirradiation using Cyberknife stereotactic body irradiation with special focus on mucosal ulceration. We conducted a retrospective multi-institutional review of 107 patients with previously irradiated head and neck cancer. The median follow-up time for all patients was 15 months, and the 2-year overall survival rate was 35%. Significant prognostic factors for overall survival were primary site (nasopharynx versus other sites), presence of ulceration, and PTV volume. Detailed analysis of ulceration showed a lower response rate (28%) in the ulceration (+) group than the ulceration (-) group (63%; P = 0.0045). The 2-year overall survival rates were 8% in the ulceration (+) group and 42.7% (P = 0.0001) in the ulceration (-) group, respectively. We recorded 22 severe toxicities, including 11 patients with carotid blow-out syndrome (CBOS), which was fatal in 9 patients. CBOS occurred in 6 patients with ulceration (6/25; 24%), and 5 patients experienced CBOS without ulceration (5/82; 6%; P=0.027). In conclusion, ulceration is an important prognostic factor, not only for adverse events but also for survival after reirradiation using CyberKnife.

Stereotactic body radiotherapy for head and neck cancer: an addition to the armamentarium against head and neck cancer

In the recent years, stereotactic body radiation therapy (SBRT) has emerged as a potential therapy for head and neck malignancies. Although early results appear to be promising, serious acute and late effects have been observed, mainly in patients who have had prior external beam radiotherapy. This review will discuss the radiobiology of SBRT, clinical rationale and outcomes for SBRT in head and neck cancers and focus on the benefits and potential limitations in both de novo and re-irradiation settings.

Predictive value of skin invasion in recurrent head and neck cancer patients treated by hypofractionated stereotactic re-irradiation using a cyberknife

BACKGROUND

This study aimed to elucidate the influence of skin invasion in patients with recurrent head and neck cancer treated with re-irradiation using stereotactic radiotherapy.

MATERIALS

We reviewed 104 patients treated using CyberKnife in four institutions.

RESULTS

Nine cases of skin invasion were recognized (8.6 %). Larger tumors tended to exhibit skin invasion. The skin invasion (+) group showed a lower response rate (0/9, 0 %) than the skin invasion (-) group (56/95, 59 %) (p = 0.002). The skin invasion (+) group showed lower local control (LC) and progression free survival (PFS) rates, both 0 % at 6 months, than the skin invasion (-) group, which had a LC of 69 % (p = 0.0001) and a PFS of 48 % at 1 year (p = 0.0157). Median survival time and one-year survival rates for the skin invasion (+) and (-) groups were 6.6 vs. 15.3 months and 14 % vs. 59 % (p = 0.0005), respectively. No patient with skin invasion survived more than 14.4 months. The percentage of patients who developed grade 3 or higher toxicity was 44 % in the skin invasion (+) group and 18 % in the skin invasion (-) group (p = 0.14).

CONCLUSIONS

Skin invasion is an important predictor of poor prognosis in recurrent head and neck cancer after re-irradiation with stereotactic radiation therapy.