Stereotactic body radiotherapy for medically unfit patients with cancers to the head and neck

Stereotactic Body Radiotherapy as a Curative Treatment for De Novo Mucosal Carcinoma of the Head and Neck: A Feasible Alternative Option for Fragile Patients with Small Lesion: A Systematic Review

Stereotactic body radiotherapy (SBRT) is characterized by a high dose per fraction, well-defined small targets, superior dose conformity, and a steep off-target dose gradient. A literature search was conducted to examine the experience with SBRT as a curative treatment for newly diagnosed mucosal carcinoma of the head and neck (MCHN). Four retrospective case series and one prospective phase I clinical trial published between 2012 and 2020 described 124 patients. SBRT was mainly performed in older patients with different tumor sites. The median size of the planning target volumes ranged from 5.3 to 41 cm3. Different approaches were used to create margins. In two studies, limited elective nodal irradiation was performed. The equivalent doses used were 60-83.33 Gy delivered in five fractions. Considerable heterogeneity was observed in the radiation dose specification. The incidence of grade ≥3 late toxicity was 0-8.3%, with local and regional control ranging from 73% to 100%. Improved or stable quality of life after SBRT was reported in two studies. Curative-intent SBRT for de novo MCHN appears to be an effective and relatively safe treatment for small tumor targets, preferably without concomitant elective tissue irradiation. Standardization of SBRT practice and well-designed prospective clinical trials are needed to better define the role of SBRT in this setting.

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.

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.

Stereotactic body radiotherapy for distant metastases to the head and neck

PURPOSE

To report clinical outcomes for patients with metastatic disease to the head and neck (HN) treated with stereotactic body radiation therapy (SBRT).

METHODS

A retrospective review of patients treated with SBRT to HN sites from 2012 to 2020 was conducted. Treatment indications included the following: oligometastases, oligoprogression, and control a dominant area of progression (DAP). Kaplan-Meier method was used to estimate local control (LC), regional control (RC), overall survival (OS), and progression-free survival (PFS). Univariable (UVA) and multivariable analyses (MVA) were performed. Grade 3-4 acute and late toxicities were reported by the Common Terminology Criteria for Adverse Events v5.0.

RESULTS

Fifty-six patients (58 lesions) were analysed with a median follow-up of 16 months. Primary sites included lung (25.0%), kidney (19.6%), breast (19.6%) and other (35.8%). SBRT indications were as follows: oligometastases (42.9%), oligoprogression (19.6%) and local control of a dominant area of progression (37.5%). Most patients received SBRT to a single neck node (n = 47, 81.0%). Median SBRT dose was 40 Gy (range 25-50 Gy) in five fractions, with a median biologically effective dose (BED10) of 72 Gy (range 37.5-100 Gy). One- and 2-year LC and RC rates were 97.6% and 72.7% as well as 100% and 86.7%, respectively. Median OS was 19.2 months (95% [CI] 14.8-69.4), and median PFS was 7.4 months (95% [CI] 5.2-11.9). The 1-year OS and PFS rates for oligometastases, oligoprogression and DAP were 95.8%, 63.6% and 38.1% (p = 0.0039) as well as 56.5%, 27.3% and 19.1% (p = 0.0004), respectively. On MVA, treatment indication and histology were predictive for OS, while indication and prior systemic therapy were predictive for PFS. Cumulative late grade 3 + toxicity rate was 11.3%, without grade 5 events.

CONCLUSION

The use of SBRT for metastatic disease to the HN provided excellent LC rates with low rates of regional failure and an acceptable toxicity profile, highlighting its utility in these patients. Patients with oligometastatic disease had better OS and PFS than others.

Clinical predictors of premature radiotherapy terminations in senior adults with oral cavity and laryngeal carcinoma

INTRODUCTION

The underlying factors that contribute to early radiotherapy (RT) termination are understudied, especially in the era of hypofractionated treatment regimens. In this retrospective investigation, we examined the characteristics and causes of premature RT terminations in senior adults (>70 years old) with oral cavity (OC) and laryngeal carcinomas.

METHODS

Hundred and eighty-eight patients treated with RT ± systemic therapy for OC and laryngeal cancer from 2017 to 2022 were identified. Premature termination was defined as completion of less than 95% of the prescribed RT. Logistic regression analysis was performed to examine factors predictive of premature termination, and survival was determined using the Kaplan-Meier method.

RESULTS

Twenty patients (10.6%) experienced premature RT terminations. On regression analysis, ECOG score at initiation of RT was the only covariate studied to be independently associated with premature termination (OR 2.00, 95%CI: [1.21, 3.30], p = 0.007). Three-year overall survival (49.1% vs. 77.3%) was significantly reduced in the termination cohort (p < 0.0001).

CONCLUSIONS

This analysis demonstrated over 1 in 10 patients had premature RT termination, which prognosticated inferior survival outcomes. Poor performance status may highlight patients at risk for premature termination and thus identify good candidates for hypofractionated protocols.

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.

Expanding the role of combined immunochemotherapy and immunoradiotherapy in the management of head and neck cancer (Review)

Immunotherapy has become one of the most promising approaches in tumor therapy, and there are numerous associated clinical trials in China. As an immunosuppressive tumor, head and neck squamous cell carcinoma (HNSCC) carries a high mutation burden, making immune checkpoint inhibitors promising candidates in this field due to their unique mechanism of action. The present review outlines a comprehensive multidisciplinary cancer treatment approach and elaborates on how combining immunochemotherapy and immunoradiotherapy guidelines could enhance clinical efficacy in patients with HNSCC. Furthermore, the present review explores the immunology of HNSCC, current immunotherapeutic strategies to enhance antitumor activity, ongoing clinical trials and the future direction of the current immune landscape in HNSCC. Advanced-stage HNSCC presents with a poor prognosis, low survival rates and minimal improvement in patient survival trends over time. Understanding the potential of immunotherapy and ways to combine it with surgery, chemotherapy and radiotherapy confers good prospects for the management of human papillomavirus (HPV)-positive HNSCC, as well as other HPV-positive malignancies. Understanding the immune system and its effect on HNSCC progression and metastasis will help to uncover novel biomarkers for the selection of patients and to enhance the efficacy of treatments. Further research on why current immune checkpoint inhibitors and targeted drugs are only effective for some patients in the clinic is needed; therefore, further research is required to improve the overall survival of affected patients.

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.

Head and Neck Squamous Cell Carcinoma in Elderly Patients: Role of Radiotherapy and Chemotherapy

Simple Summary

The focus of this review deals with the management of elderly patients with head and neck squamous cell carcinoma, discussing the role of clinical management, geriatric evaluation and therapeutic approaches (radiation therapy and systemic therapies).

Abstract

Head and neck squamous cell carcinomas (HNSCC) constitute the sixth most common malignancy worldwide, with approximately 25–40% of the diagnosed patients older than 70 years. HNSCC patients are often frail and frequently have multiple comorbidities due to their unhealthy lifestyle, and evidence suggests that older patients may receive less aggressive and suboptimal treatment than younger patients with the same disease status. The aim of this review is to depict and summarize the evidence regarding the different strategies that can be used in the clinical management of elderly HNSCC patients. Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used. This paper contains a narrative report and a critical discussion of clinical approaches in the context of elderly HNSCC.

Stereotactic body radiotherapy for head and neck skin cancer

AIM

To report outcomes of Stereotactic Body Radiotherapy (SBRT) for head and neck skin cancer (HNSC) patients treated at a high-volume center.

MATERIALS

A retrospective review of HNSC SBRT patients from 2012 to 2019 was conducted. Kaplan-Meier method was used to estimate local control (LC), locoregional control (LRC) outside of SBRT field, overall survival (OS), progression-free survival (PFS) and late toxicity (LT). Univariate and multivariate analyses were performed. Grade 3-4 acute and late toxicities were reported by the Common Terminology Criteria for Adverse Events v5.0.

RESULTS

One hundred and six medically unfit HNSC patients (112 lesions) were included. Median follow-up was 8 months. Median patient age at diagnosis was 86 years (range: 56-102 years). The majority of patients had advanced disease (overall stage III-IV [n = 90, 85%]) with median gross tumor volumes (GTV) of 31 cm³ (range: 17-56 cm³). Treated sites were: primary (n = 51), nodal (n = 47) or primary plus nodal (n = 8). SBRT doses ranged from 32-50 Gy delivered twice weekly in 4-6 fractions to the gross tumor volume (GTV). One and 2-year LC rates were 78% (69-88) and 67% (53-82), respectively. One-year LRC outside of SBRT field, OS, PFS and LT rates were 72% (62-84), 53% (43-65), 52% (40-62), and 7% (2-17), respectively. Thirty-three patients (31%) developed acute grade ≥ 3 treatment-related toxicity, most commonly dermatitis (n = 31). Nine patients (8%) experienced late grade ≥ 3 toxicity, including 7 grade 3 fibrosis, 1 grade 3 bone radionecrosis and 1 grade 4 skin ulceration. No treatment-related deaths (grade 5) were observed.

CONCLUSION

SBRT provides durable disease control with acceptable toxicity for medically unfit high-risk HNSC patients unable to undergo standard of care curative treatment approaches.

Defining the Role of Immunotherapy in the Curative Treatment of Locoregionally Advanced Head and Neck Cancer: Promises, Challenges, and Opportunities

Recent advancements in the development of immunotherapies have raised the hope for patients with locally-advanced HNSCC (LA-HNSCC) to achieve improved oncologic outcomes without the heavy burden of treatment-related morbidity. While there are several ongoing late phase clinical trials that seek to determine whether immunotherapy can be effectively employed in the definitive setting, initial results from concurrent immuno-radiotherapy therapy trials have not shown strong evidence of benefit. Encouragingly, evidence from preclinical studies and early-phase neoadjuvant studies have begun to show potential pathways forward, with therapeutic combinations and sequences that intentionally spare tumor draining lymphatics in order to maximize the synergy between definitive local therapy and immunotherapy. The intent of this review is to summarize the scientific rationale and current clinical evidence for employing immunotherapy for LA-HNSCC as well as the ongoing efforts and challenges to determine how to optimally deliver and sequence immunotherapy alongside traditional therapeutics. In both the preclinical and clinical settings, we will discuss the application of immunotherapies to both surgical and radiotherapeutic management of HNSCC.

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.

Prognosis and management of recurrent and/or metastatic head and neck adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare tumor, usually arising in the salivary gland, accounting for 1% of all head and neck cancers. ACC may have a long-term poor prognosis, as about 40% of radically treated patients will recur locoregionally and up to 60% will develop distant metastasis. Factors influencing risk of recurrence have been well studied, but few data exist about prognostic factors in Recurrent/Metastatic (RM) setting. Moreover, treatment of RM ACC is often a challenge for clinicians, in the context of a rare disease, which may have an indolent clinical behavior or less frequently a quicker growth and with a paucity of available clinical trials. This review critically analyzes pathological and molecular prognostic factors in RM ACC and make an overview on actual therapeutic choices and future direction of therapy. Recognized prognostic factors in RM ACC are the presence and site of distant metastasis (lung vs other), the presence of nodal metastasis and of extranodal extension, skull base recurrence, disease free interval, lymphovascular invasion, solid histotypes and grading of disease, and the presence of mutation of NOTCH1 family, PI3K, and TP53. Due to disappointing results with chemotherapy, new approaches are under study, also on the basis of biomolecular research. Ongoing clinical trials are evaluating treatment targeting MYB and NOTCH1 alterations, immunotherapy or combination of targeted treatments and immune checkpoint inhibitors.

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.