Role of stereotactic body radiotherapy for symptom control in head and neck cancer patients

Stereotactic Body Radiotherapy in Recurrent and Oligometastatic Head and Neck Tumours

The treatment of head and neck cancers (HNCs) encompasses a complex paradigm involving a combination of surgery, radiotherapy, and systemic treatment. Locoregional recurrence is a common cause of treatment failure, and few patients are suitable for salvage surgery. Reirradiation with conventional radiation techniques is challenging due to normal tissue tolerance limits and the risk of significant toxicities. Stereotactic body radiotherapy (SBRT) has emerged as a highly conformal modality that offers the potential for cure while limiting the dose to surrounding tissue. There is also growing research that shows that those with oligometastatic disease can benefit from curative intent local ablative therapies such as SBRT. This review will look at published evidence regarding the use of SBRT in locoregional recurrent and oligometastatic HNCs.

The Evolving Role of Stereotactic Body Radiation Therapy for Head and Neck Cancer: Where Do We Stand?

Stereotactic body radiation therapy (SBRT) is a precise and conformal radiation therapy (RT) that aims to deliver a high dose of radiation to the tumor whilst sparing surrounding normal tissue, making it an attractive option for head and neck cancer (HNC) patients who are not suitable for the traditional long course of RT with comprehensive RT target volume. Definitive SBRT for HNC has been investigated in different settings, including early stage glottis cancer, and as an alternative to brachytherapy boost after external beam RT. It is also used as a primary treatment option for elderly or medically unfit patients. More recently, an SBRT combination with immunotherapy in the neoadjuvant setting for HNC showed promising results. Salvage or adjuvant SBRT for HNC can be used in appropriately selected cases. Future studies are warranted to determine the optimum dose and fractionation schedules in any of these indications.

The immunogenic radiation and new players in immunotherapy and targeted therapy for head and neck cancer

Although treatment modalities for head and neck cancer have evolved considerably over the past decades, survival rates have plateaued. The treatment options remained limited to definitive surgery, surgery followed by fractionated radiotherapy with optional chemotherapy, and a definitive combination of fractionated radiotherapy and chemotherapy. Lately, immunotherapy has been introduced as the fourth modality of treatment, mainly administered as a single checkpoint inhibitor for recurrent or metastatic disease. While other regimens and combinations of immunotherapy and targeted therapy are being tested in clinical trials, adapting the appropriate regimens to patients and predicting their outcomes have yet to reach the clinical setting. Radiotherapy is mainly regarded as a means to target cancer cells while minimizing the unwanted peripheral effect. Radiotherapy regimens and fractionation are designed to serve this purpose, while the systemic effect of radiation on the immune response is rarely considered a factor while designing treatment. To bridge this gap, this review will highlight the effect of radiotherapy on the tumor microenvironment locally, and the immune response systemically. We will review the methodology to identify potential targets for therapy in the tumor microenvironment and the scientific basis for combining targeted therapy and radiotherapy. We will describe a current experience in preclinical models to test these combinations and propose how challenges in this realm may be faced. We will review new players in targeted therapy and their utilization to drive immunogenic response against head and neck cancer. We will outline the factors contributing to head and neck cancer heterogeneity and their effect on the response to radiotherapy. We will review in-silico methods to decipher intertumoral and intratumoral heterogeneity and how these algorithms can predict treatment outcomes. We propose that (a) the sequence of surgery, radiotherapy, chemotherapy, and targeted therapy should be designed not only to annul cancer directly, but to prime the immune response. (b) Fractionation of radiotherapy and the extent of the irradiated field should facilitate systemic immunity to develop. (c) New players in targeted therapy should be evaluated in translational studies toward clinical trials. (d) Head and neck cancer treatment should be personalized according to patients and tumor-specific factors.

Assessing the efficacy of palliative radiation treatment schemes for locally advanced squamous cell carcinoma of the head and neck: a meta-analysis

Background

The objective to assess the outcomes from different palliative radiotherapy (RT) schedules in incurable head and neck cancer (HNC), to evaluate if there is a relationship between RT dose, technique, and fractionation with tumor response in contrast to the occurrence of adverse effects.

Materials and methods

Eligible studies were identified on Medline, Embase, the Cochrane Library, and annual meetings proceedings through June 2020. Following PRISMA and MOOSE guidelines, a cumulative meta-analysis of studies for overall response rate (ORR), overall survival (OS), progression-free survival (PFS), pain/dysphagia relief, and toxicity was performed. A meta-regression analysis was done to assess if there is a connection between RT dose, schedule, and technique with ORR.

Results

Twenty-eight studies with 1,986 patients treated with palliative RT due to incurable HNC were included. The median OS was 6.5 months [95% confidence interval (CI): 5.6-7.4], and PFS was 3.6 months (95% CI: 2.7-4.3). The ORR, pain and dysphagia relief rates were 72% (95% CI: 0.6-0.8), 83% (95% CI: 52-100%), and 75% (95% CI: 52-100%), respectively. Conventional radiotherapy (2D-RT) or conformational radiotherapy (3D-RT) use were significantly associated with a higher acute toxicity rate (grade ≥ 3) than intensity-modulated radiation therapy (IMRT) or stereotactic body radiation therapy (SBRT). On meta-regression analyses, the total biological effective doses (BED) of RT (p = 0.001), BED > 60 Gy10 (p = 0.001), short course (p = 0.01) and SBRT (p = 0.02) were associated with a superior ORR.

Conclusions

Palliative RT achieves tumor response and symptom relief in incurable HNC patients. Short course RT of BED > 60 Gy using IMRT could improve its therapeutic ratio. SBRT should be considered when available.

A phase 2 study of stereotactic body radiation therapy for squamous cell carcinoma of the head and neck (SHINE): a single arm clinical trial protocol

BACKGROUND

Cancers of the head and neck region are often characterized by locally advanced, non-metastatic disease. Standard treatments for advanced cervico-facial cancers of the skin or primary head and neck squamous cell carcinoma (HNSCC) include combinations of surgery, radiation and chemotherapy, which are associated with high rates of acute toxicity and complications. Stereotactic body radiotherapy (SBRT) has been shown to be a promising modality of treatment for this patient population in retrospective studies; to our knowledge, there are no prospective clinical studies evaluating the safety and efficacy of SBRT in these patients.

METHODS

This phase 2, single institution, single arm study aims to evaluate response rates to SBRT in older age patients with locally advanced HNSCC for whom primary surgery is not recommended or performed. The intervention is SBRT 45 Gy in 5 fractions given every 3-4 days. Toxicity, quality of life and patient outcomes will be recorded regularly up to 24 months after completion of SBRT.

DISCUSSION

For this patient population, SBRT may offer a shorter and more effective treatment than the current standard of care palliative regimens. If the study demonstrates that SBRT is safe and effective, then this may lead to randomized studies comparing conventional radiotherapy to SBRT for selected head and neck cancer patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04435938 .  Date registered: June 17, 2020.

Patient-Reported Outcomes Assessing the Impact of Palliative Radiotherapy on Quality of Life and Symptom Burden in Head and Neck Cancer Patients: A Systematic Review

Incurable head and neck cancer has a poor prognosis and impairs a patient's health-related quality of life. Palliative radiotherapy may improve or stabilize health-related quality of life and symptoms, best measured by patient-reported outcomes. There is no systematic analysis if palliative radiotherapy for head and neck cancer improves or stabilizes health-related quality of life or symptoms as validly measured by patient-reported outcomes. Therefore, the primary objective of this systematic review (PROSPERO-ID: CRD42020166434) was to assess the effect of palliative radiotherapy for head and neck cancer on patient-reported outcomes. The secondary objective was to assess the rate and quality of use of patient-reported outcomes in relevant studies claiming a "palliative effect" of radiotherapy. The databases MEDLINE/PubMed, EMBASE, Cochrane CENTRAL, "ClinicalTrials.gov" were searched. Concerning the primary objective, four studies were eligible to assess the effectiveness of palliative radiotherapy as measured by patient-reported outcomes. A narrative synthesis suggests a favorable impact of palliative radiotherapy on health-related quality of life and symptom burden. The risk of bias, however, is considerable and the overall quality of evidence low. Concerning the secondary objective, over 90% of studies claiming a "palliative effect" of palliative radiotherapy did either not use patient-reported outcomes or did so by limited quality. In conclusion, implementation of patient-reported outcomes in studies assessing palliative radiotherapy for head and neck cancer should be fostered. Palliative radiotherapy remains an option for head and neck cancer patients, although more studies focusing on patient-reported outcomes are needed.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42020166434.

Palliative radiotherapy in older adults with head and neck squamous cell carcinoma: A systematic review

Locally advanced Head and neck squamous cell carcinoma (SCCHN) represents a common oncologic pathology in older adults (OA). While radiotherapy represents a cornerstone in this context, it is unclear what is the optimal radiation regimen for SCCHN in the palliative setting, especially for OA. This article addresses issues related to palliative radiotherapy (PRT) in this setting with a focus on treatment modalities and toxicity. We also explore the use of quality of life and geriatric assessment in this setting. Medline, Scopus and Embase databases were queried for articles in this setting. We included studies published from January 1, 2000 through June 1, 2020, that were independently evaluated by two authors. Analyzed endpoints were progression free survival (PFS), overall survival (OS) and PRT toxicities. The meta-analysis was performed using Stata v.14. A total of 33 studies were included in this meta-analysis. The pooled median OS is 7.7 months, 2-years OS was worse for higher radiation dose (p = 0.02). The pooled median PFS was 5.4 months, PFS was influenced by EQD2 (p = 0.01), with patients receiving an EQD2 < 40 Gy that presented a poorer outcome. Regarding acute toxicities, most common pooled G3 toxicities were mucositis (7%) and dysphagia (15%). Among late toxicity, most common G3 toxicity was dysphagia in 7% of patients. Radiotherapy should be the most effective palliative treatment in symptomatic SCCHN OA. A tailored approach, guided by geriatric tools, would be indicated to choose the right therapy.

Stereotactic body radiotherapy (SBRT) for primary non-metastatic head and neck cancer: When less is enough

The advantage of highly conformal dose distribution and steep dose gradient has resulted in rapidly increasing use of stereotactic body radiotherapy (SBRT) in multiple cancer sites. Also there has been a surge in the use of SBRT in head neck cancer over the last decade. It is predominantly exploited in retreatment setting for recurrent and second primary head neck cancer as well as in metastatic setting. The literature on SBRT in primary non-metastatic head neck cancer is sparse and evolving. In the current review, available literature was critically analyzed focusing on the potential applications of SBRT in primary untreated non-metastatic head neck cancer. SBRT boost following external beam radiotherapy is temping as a method of dose escalation. Special attention was paid to the application of SBRT as a sole modality of treatment. The shorter treatment schedule makes it an attractive option for treatment in primary head neck cancer especially in elderly, co-morbid and medically unfits patients. Future investigation is needed to establish SBRT as an additional armamentarium in the radiotherapeutic management of head and neck cancers.

Stereotactic Radiation Therapy for De Novo Head and Neck Cancers: A Systematic Review and Meta-Analysis

Purpose

Stereotactic body radiation therapy (SBRT) for de novo (previously untreated) head and neck cancers (HNCs) is increasingly being used in medically unfit patients. A systematic review of SBRT was conducted for previously untreated HNCs.

Methods and Materials

Medline (PubMed), excerpta medica database, and Cochrane Library databases were queried from inception until July 2020. Comparative outcome data were extracted where available up to 5 years. Results from random-effect models were presented in forest plots, with between-study heterogeneity evaluated by I² statistics and Q-tests.

Results

Nine studies met inclusion criteria, representing 157 patients. Local control rates at 1, 2, and 3 years were as follows: 90.7% (95% confidence interval, 80.6%-95.6%), 81.8% (67.2%-90.7%), and 73.5% (40.4%-90.5%), respectively. Overall survival at 1, 2, and 3 years was 75.9% (75.1%-76.6%), 61.1% (60.3%-61.9%), and 50.0% (48.8%-51.4%), respectively. Late grade 3 to 4 toxicity rate was 3.3% (0.2%-10.2%), and late grade 5 toxicity rate was 0.1% (0.0%-1.0%).

Conclusions

SBRT for de novo HNC is safe and effective in providing locoregional control, with acceptable toxicities in most subsites. This finding warrants broader validation to guide its scope.

Stereotactic body radiotherapy as primary treatment for elderly and medically inoperable patients with head and neck cancer

BACKGROUND

Patients with head and neck cancer (HNC) who are not candidates for definitive treatment represent an increasing challenge, with limited data to guide management. Conventional local therapies such as surgery and chemoradiation can significantly impact quality of life (QoL). There has been limited data published using stereotactic body radiotherapy (SBRT) as primary treatment in previously unirradiated patients. We hypothesize that SBRT provides high rates of control while limiting toxicity.

METHODS

A total of 66 medically unfit previously unirradiated patients with HNC were treated with SBRT, consisting of 35-40 Gy to gross tumor volume and 30 Gy to clinical target volume in five fractions.

RESULTS

Median age was 80 years. Local control (LC) and overall survival (OS) at 1 year were 73% and 64%. Two patients experienced grade 3 toxicity.

CONCLUSION

SBRT shows acceptable outcomes with relatively low toxicity in previously unirradiated patients with HNC who are medically unfit for conventional treatment. SBRT may provide an aggressive local therapy with high rates of LC and OS while maintaining QoL.

Palliative Radiation Therapy for Head and Neck Cancers

Patients with advanced head and neck cancers who are not eligible for curative treatment represent a challenging cohort of patients to manage given the complexity and severity of their presenting symptoms. Palliative radiation therapy, along with other systemic and surgical measures, has the potential to significantly improve the quality of life of such patients. There is little high-level evidence and a lack of consensus to direct the selection of an optimal palliative radiation regimen. An ideal palliative radiation regimen should alleviate symptoms secondary to the cancer with minimal treatment toxicity and side effects while improving a patient's quality of life. This review presents the treatment approaches, outcomes, and toxicities associated with different radiation regimens and proposes a multidisciplinary framework for the selection of an individualized treatment regimen for patients that centers around patient prognosis, goals of care, logistics of treatment, and the availability of other surgical and systemic therapies.

An Extended Hypofractionated Palliative Radiotherapy Regimen for Head and Neck Carcinomas

Background

Palliative radiotherapy to patients with head and neck cancer is often necessary, but there is a substantial variation in the treatment regimens reported in the literature, and consensus on the most appropriate schedules does not exist. In order to minimize acute toxicity while at the same time trying to achieve prolonged tumor control, a long hypofractionated regimen has been used routinely in Denmark. In the current retrospective study, we investigated the outcome in patients intended for palliative radiotherapy with this regimen.

Materials and methods

Patients with newly diagnosed head and neck cancer treated with palliative radiotherapy of 52-56 Gy in 13-14 fractions twice weekly from 2009 to 2014 were included. Patients were excluded if they had previously received radiotherapy. Data on disease location, stage, patient performance status (PS), treatment response, acute skin and mucosal toxicity, and late fibrosis were collected prospectively and supplemented with information from medical records.

Results

77 patients were included in the study. Fifty-eight patients (75%) completed the intended treatment. Loco-regional tumor response (complete or partial) was evaluated 2 months posttreatment and observed in 45% of the entire population corresponding to 71% of patients alive. PS had a significant influence on survival (p = 0.007) and on not completing the intended treatment. Grade III or IV acute mucositis were observed in 25%, and grade III or IV acute dermatitis observed in 15%.

Conclusion

Palliative hypofractionated radiotherapy with 52-56 Gy in 13-14 fractions shows good tumor response and tolerability in a vulnerable patient population. However, it may not be suited for patients in poor PS.

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.

Palliative Radiation Therapy for Advanced Head and Neck Carcinomas: A Phase 2 Study

PURPOSE

Incurable head and neck cancer is hard to manage with usual palliative care. Radiation therapy (RT) in this setting is sometimes omitted because there is an apprehension that the side effects in the head and neck region might counterbalance the benefits. The objective of this phase 2 study was to evaluate whether highly conformal RT could improve the therapeutic ratio with this comprehensive Quality of Life (QOL) and toxicity evaluation.

METHODS AND MATERIALS

Patients from 2 academic centers, deemed unfit for radical treatment because of their poor medical condition or advanced cancer stage by an experienced tumor board, were offered 25 Gy in 5 daily intensity modulated RT fractions over 1 week to the symptomatic tumor volume. QOL was evaluated with the European Organization for Research and Treatment of Cancer QLQ-C15-PAL and QLQ-H&N35 questionnaires, and toxicities with the Common Terminology Criteria for Adverse Events version 4.0. Survival and time to tumor progression were calculated with the Kaplan-Meier method.

RESULTS

Thirty-two patients were recruited, of whom 66% had at least T4, N3, or M1 disease. The QOL questionnaires completion rate was 86%. Eighty-eight percent of patients received the planned dose. The median overall survival and progression-free survival times were, respectively, 6.5 and 3.2 months. No grade 4 or 5 toxicity was seen. Only 13% of patients had any grade 3 toxicities, and 17% of patients reported no toxicity at all. The QOL was equal or improved, and head and neck symptoms remained equal to or lower than the baseline values for most patients at up to 6 months. Eighty-five percent of patients would have chosen to receive this RT regimen again when asked.

CONCLUSIONS

This palliative RT regimen was highly tolerable and effective in preserving or improving self-reported QOL in most patients for up to 6 months, which corresponds to this population's median overall survival. Given the minimal side effects, intensification could be considered to achieve longer locoregional control.

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.