Feasibility of Dose-escalated Hypofractionated Chemoradiation in Human Papilloma Virus-negative or Smoking-associated Oropharyngeal Cancer

Multicentric Cross-Sectional Survey to Assess the Variation of Fractionation Strategies Used in the Management of Head and Neck Cancers in the Asian Region (INNOCENCE-ASIA)

PURPOSE

Head and neck cancers (HNCs) are in general treated with conventional fractionation regimen of 1.8-2 Gy per fraction. Altered fractionation (ALFT) strategies such as hypofractionation radiotherapy (HYPO-RT), accelerated fractionation radiotherapy (AFRT), and hyperfractionation radiotherapy (HFRT) have not been practiced uniformly across centers in different parts of the world. Countries in Asia share common cancer demographics, and we designed this survey for Federation of Asian Radiation Oncology (FARO) member countries to understand the usage and challenges in the delivery of ALFT in HNCs.

MATERIALS AND METHODS

A 21-point electronic survey (Federation of Asian Radiation Oncology Research Network [FERN]-S-005) was designed by the FERN and was circulated through the FARO research secretariat to the FARO council member countries and the responses were collected between August and November 2023.

RESULTS

Twelve of 14 member countries (85.7%) responded to the survey. Twenty-seven responses were received and 78% of the respondents belonged to government/teaching academic institute. 4/27 (14.8%) reported never using HYPO-RT for any of the clinical subsite of HNCs, while the majority (85.2%) used it for glottic cancers and 22% also used it for postoperative setting. Majority (77.7%) used a fractionation schedule with dose per fraction ranging between 2.2 and 2.5 Gy. 6/27 (22.2%) used AFRT for definitive setting and five of these also used concurrent chemoradiotherapy. 4/27 (14.8%) centers reported using HFRT. The most common reason (62.9%) for the limited usage of AFRT/HFRT was reported to be logistical, such as unavailability of machine slots, patient load, and so on.

CONCLUSION

The result of the survey suggests that among the ALFT strategies for HNCs, HYPO-RT schedules have common interest and feasibility among the FARO member countries and also highlights the challenges in the delivery of AFRT/HFRT in the Asian region.

HYpofractionated, dose-redistributed RAdiotherapy with protons and photons to combat radiation-induced immunosuppression in head and neck squamous cell carcinoma: study protocol of the phase I HYDRA trial

BACKGROUND

Radiotherapy (RT) is the standard of care for most advanced head and neck squamous cell carcinoma (HNSCC) and results in an unfavorable 5-year overall survival of 40%. Despite strong biological rationale, combining RT with immune checkpoint inhibitors does not result in a survival benefit. Our hypothesis is that the combination of these individually effective treatments fails because of radiation-induced immunosuppression and lymphodepletion. By integrating modern radiobiology and innovative radiotherapy concepts, the patient's immune system could be maximally retained by (1) increasing the dose per fraction so that the total dose and number of fractions can be reduced (HYpofractionation), (2) redistributing the radiation dose towards a higher peak dose within the tumor center and a lowered elective lymphatic field dose (Dose-redistribution), and (3) using RAdiotherapy with protons instead of photons (HYDRA).

METHODS

The primary aim of this multicenter study is to determine the safety of HYDRA proton- and photon radiotherapy by conducting two parallel phase I trials. Both HYDRA arms are randomized with the standard of care for longitudinal immune profiling. There will be a specific focus on actionable immune targets and their temporal patterns that can be tested in future hypofractionated immunoradiotherapy trials. The HYDRA dose prescriptions (in 20 fractions) are 40 Gy elective dose and 55 Gy simultaneous integrated boost on the clinical target volume with a 59 Gy focal boost on the tumor center. A total of 100 patients (25 per treatment group) will be recruited, and the final analysis will be performed one year after the last patient has been included.

DISCUSSION

In the context of HNSCC, hypofractionation has historically only been reserved for small tumors out of fear for late normal tissue toxicity. To date, hypofractionated radiotherapy may also be safe for larger tumors, as both the radiation dose and volume can be reduced by the combination of advanced imaging for better target definition, novel accelerated repopulation models and high-precision radiation treatment planning and dose delivery. HYDRA's expected immune-sparing effect may lead to improved outcomes by allowing for future effective combination treatment with immunotherapy.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov; NCT05364411 (registered on May 6th, 2022).

Moderately Hypofractionated Intensity-modulated Radiotherapy With a Simultaneous Integrated Boost for Locally Advanced Head and Neck Cancer - Do Modern Techniques Fulfil Their Promise?

BACKGROUND

Intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) and moderate hypofractionation offers an opportunity for defining individual doses and a reduction in overall treatment time in locally advanced head and neck cancer (HNSCC). We present retrospective data on toxicity and locoregional control of a patient cohort treated with an IMRT-SIB concept in comparison to normo-fractionated 3D-conformal radiotherapy (3D-RT).

PATIENTS AND METHODS

Between 2012 and 2014, 67 patients with HNSCC (stages III-IVB) were treated with IMRT-SIB either definitively or in the postoperative setting. These patients were matched with those of patients treated with normo-fractionated 3D-RT before mid-2012 and their clinical courses were compared. Chemotherapy or cetuximab was given concomitantly in both groups in the definitive situation (postoperatively, dependent on risk factors).

RESULTS

Significantly less toxicity was found in favor of IMRT-SIB concerning dysphagia, dermatitis, xerostomia, fibrosis, and lymphedema. After a median follow-up of 31 months (range=2-104 months), 3-year locoregional control was 73% for those treated with IMRT-SIB versus 78% for those treated with 3D-RT.

CONCLUSION

This moderately hypofractionated IMRT-SIB concept was shown to be feasible, incurring less toxicity than conventional 3D-RT.

Hypofractionated chemoradiation for head and cancer: Data from the PET NECK trial

There has been increased interest in hypofractionated accelerated chemoradiation for head and neck cancer during the recent first peak of the COVID-19 pandemic. Prospective data regarding this approach from randomised trials is lacking. In the PET NECK study, 564 patients with squamous cell carcinoma of the head and neck receiving definitive chemoradiation were randomised to either planned neck dissection or PET CT scan guided surveillance. In this surgical trial, three radiotherapy fractionation schedules delivered over 7, 6 or 4 weeks were permitted with synchronous chemotherapy. The purpose of this study was to determine efficacy and quality of life outcomes associated with the use of these schedules. Primary local control and overall survival in addition to quality of life measures at immediately post treatment and 6, 12 and 24 months post-treatment were compared between the three fractionation cohorts. In the 525 patients where fractionation data was available, 181 (34%), 288 (55%) and 56 (11%) patients received 68-70 Gy in 34-35 fractions (#), 60-66 Gy in 30# and 55 Gy in 20# respectively. At a minimum follow up of two years following treatment there was no significant difference between the three fractionation schemes in local control, overall survival or any quality of life measure. Despite the obvious limitations of this study, some data is provided to support the use of hypofractionated accelerated chemoradiation to avoid delays in cancer treatment and reduce hospital visits during the peak of a pandemic. Data from on-going randomised trials examining hypofractionated chemoradiation may be useful for selecting fractionation schedules during future pandemics.

Practice recommendations for risk-adapted head and neck cancer radiotherapy during the COVID-19 pandemic: An ASTRO-ESTRO consensus statement

PURPOSE

Because of the unprecedented disruption of health care services caused by the COVID-19 pandemic, the American Society of Radiation Oncology (ASTRO) and the European Society for Radiotherapy and Oncology (ESTRO) identified an urgent need to issue practice recommendations for radiation oncologists treating head and neck cancer (HNC) in a time of limited resources and heightened risk for patients and staff.

METHODS AND MATERIALS

A panel of international experts from ASTRO, ESTRO, and select Asia-Pacific countries completed a modified rapid Delphi process. Topics and questions were presented to the group, and subsequent questions were developed from iterative feedback. Each survey was open online for 24 hours, and successive rounds started within 24 hours of the previous round. The chosen cutoffs for strong agreement (≥80%) and agreement (≥66%) were extrapolated from the RAND methodology. Two pandemic scenarios, early (risk mitigation) and late (severely reduced radiation therapy resources), were evaluated. The panel developed treatment recommendations for 5 HNC cases.

RESULTS

In total, 29 of 31 of those invited (94%) accepted, and after a replacement 30 of 30 completed all 3 surveys (100% response rate). There was agreement or strong agreement across a number of practice areas, including treatment prioritization, whether to delay initiation or interrupt radiation therapy for intercurrent SARS-CoV-2 infection, approaches to treatment (radiation dose-fractionation schedules and use of chemotherapy in each pandemic scenario), management of surgical cases in event of operating room closures, and recommended adjustments to outpatient clinic appointments and supportive care.

CONCLUSIONS

This urgent practice recommendation was issued in the knowledge of the very difficult circumstances in which our patients find themselves at present, navigating strained health care systems functioning with limited resources and at heightened risk to their health during the COVID-19 pandemic. The aim of this consensus statement is to ensure high-quality HNC treatments continue, to save lives and for symptomatic benefit.

Practice Recommendations for Risk-Adapted Head and Neck Cancer Radiation Therapy During the COVID-19 Pandemic: An ASTRO-ESTRO Consensus Statement

PURPOSE

Because of the unprecedented disruption of health care services caused by the COVID-19 pandemic, the American Society of Radiation Oncology (ASTRO) and the European Society for Radiotherapy and Oncology (ESTRO) identified an urgent need to issue practice recommendations for radiation oncologists treating head and neck cancer (HNC) in a time of limited resources and heightened risk for patients and staff.

METHODS AND MATERIALS

A panel of international experts from ASTRO, ESTRO, and select Asia-Pacific countries completed a modified rapid Delphi process. Topics and questions were presented to the group, and subsequent questions were developed from iterative feedback. Each survey was open online for 24 hours, and successive rounds started within 24 hours of the previous round. The chosen cutoffs for strong agreement (≥80%) and agreement (≥66%) were extrapolated from the RAND methodology. Two pandemic scenarios, early (risk mitigation) and late (severely reduced radiation therapy resources), were evaluated. The panel developed treatment recommendations for 5 HNC cases.

RESULTS

In total, 29 of 31 of those invited (94%) accepted, and after a replacement 30 of 30 completed all 3 surveys (100% response rate). There was agreement or strong agreement across a number of practice areas, including treatment prioritization, whether to delay initiation or interrupt radiation therapy for intercurrent SARS-CoV-2 infection, approaches to treatment (radiation dose-fractionation schedules and use of chemotherapy in each pandemic scenario), management of surgical cases in event of operating room closures, and recommended adjustments to outpatient clinic appointments and supportive care.

CONCLUSIONS

This urgent practice recommendation was issued in the knowledge of the very difficult circumstances in which our patients find themselves at present, navigating strained health care systems functioning with limited resources and at heightened risk to their health during the COVID-19 pandemic. The aim of this consensus statement is to ensure high-quality HNC treatments continue, to save lives and for symptomatic benefit.

Prognostic impact of PD-L1 in oropharyngeal cancer after primary curative radiotherapy and relation to HPV and tobacco smoking

Background: Incidence of oropharyngeal squamous cell carcinoma (OPSCC) is rising rapidly in many western countries due to Human papillomavirus (HPV) and tobacco smoking, with a considerable overlap. Immunotherapy directed at the PD1/PD-L1 axis have shown promise in head and neck cancer and other cancer types. PD-L1 expression may indicate a poorer prognosis, and at the same time indicate a possible benefit of anti-PD-L1 immunotherapeutic agents. The primary aim of this study was to establish the prognostic effect of PD-L1 expression after primary curative radiotherapy alone.Material and methods: A cohort of 303 OPSCC patients treated with primary, curative intended radiotherapy was established. PD-L1 expression was evaluated by immunohistochemistry on formalin fixed, paraffin embedded tissue sections. PD-L1 positivity was defined as a Combined Positive Score (CPS) ≥1, indicating staining of either tumor cells, lymphocytes or macrophages.Results: Median follow-up was 5.3 years. With 199 deaths, there was no difference in overall survival between patients with PD-L1+ and PD-L1- tumors (adjusted hazard ratio [aHR] and 95% confidence interval [CI]: 1.0 [0.71-1.4]). Also, locoregional failure was similar between the two groups (aHR 1.1 [CI: 0.68 - 1.7]). Tumors were PD-L1+ in 76% of cases, significantly more among HPV p16+ tumors (82% vs. 70%, p = .01). Interestingly, higher prevalence of PD-L1+ expression was seen in HPV p16+ patients with <10 pack-years of tobacco-smoking (93%) compared to HPV p16+ smokers (76%) or HPV p16-negative patients (70%) (p = .003).Conclusion: PD-L1 expression had no prognostic significance in OPSCC patients treated with primary radiotherapy alone. A substantial proportion of OPSCC tumors show PD-L1 overexpression, especially in HPV p16+ tumors in patients with little or no smoking history.

Hypofractionated radiotherapy alone with 2.4 Gy per fraction for head and neck cancer during the COVID-19 pandemic: The Princess Margaret experience and proposal

Background

The objective of this study was to identify a subgroup of patients with head and neck squamous cell carcinoma (HNSCC) who might be suitable for hypofractionated radiotherapy (RT‐hypo) during the COVID‐19 pandemic.

Methods

HNSCC cases (oropharynx/larynx/hypopharynx) treated with definitive RT‐hypo (60 Gy in 25 fractions over 5 weeks), moderately accelerated radiotherapy (RT‐acc) alone (70 Gy in 35 fractions over 6 weeks), or concurrent chemoradiotherapy (CCRT) during 2005‐2017 were included. Locoregional control (LRC) and distant control (DC) after RT‐hypo, RT‐acc, and CCRT were compared for various subgroups.

Results

The study identified 994 human papillomavirus–positive (HPV+) oropharyngeal squamous cell carcinoma cases (with 61, 254, and 679 receiving RT‐hypo, RT‐acc, and CCRT, respectively) and 1045 HPV– HNSCC cases (with 263, 451, and 331 receiving RT‐hypo, RT‐acc, and CCRT, respectively). The CCRT cohort had higher T/N categories, whereas the radiotherapy‐alone patients were older. The median follow‐up was 4.6 years. RT‐hypo, RT‐acc, and CCRT produced comparable 3‐year LRC and DC for HPV+ T1‐2N0‐N2a disease (seventh edition of the TNM system [TNM‐7]; LRC, 94%, 100%, and 94%; P = .769; DC, 94%, 100%, and 94%; P = .272), T1‐T2N2b disease (LRC, 90%, 94%, and 97%; P = .445; DC, 100%, 96%, and 95%; P = .697), and T1‐2N2c/T3N0‐N2c disease (LRC, 89%, 93%, and 95%; P = .494; DC, 89%, 90%, and 87%; P = .838). Although LRC was also similar for T4/N3 disease (78%, 84%, and 88%; P = .677), DC was significantly lower with RT‐hypo or RT‐acc versus CCRT (67%, 65%, and 87%; P = .005). For HPV– HNSCC, 3‐year LRC and DC were similar with RT‐hypo, RT‐acc, and CCRT in stages I and II (LRC, 85%, 89%, and 100%; P = .320; DC, 99%, 98%, and 100%; P = .446); however, RT‐hypo and RT‐acc had significantly lower LRC in stage III (76%, 69%, and 91%; P = .006), whereas DC rates were similar (92%, 85%, and 90%; P = .410). Lower LRC in stage III predominated in patients with laryngeal squamous cell carcinoma receiving RT‐acc (62%) but not RT‐hypo (80%) or CCRT (92%; RT‐hypo vs CCRT: P = .270; RT‐acc vs CCRT: P = .004). CCRT had numerically higher LRC in comparison with RT‐hypo or RT‐acc in stage IV (73%, 65%, and 66%; P = .336).

Conclusions

It is proposed that RT‐hypo be considered in place of CCRT for HPV+ T1‐T3N0‐N2c (TNM‐7) HNSCCs, HPV– T1‐T2N0 HNSCCs, and select stage III HNSCCs during the COVID‐19 outbreak.

Hypo‐fractionated radiotherapy has disease control comparable to that of chemoradiotherapy in select head and neck cancers, and it is a potential alternative for this subgroup during the COVID‐19 pandemic.

Assessing Novel Drugs and Radiation Technology in the Chemoradiation of Oropharyngeal Cancer

Integrating immunotherapy, proton therapy and biological dose escalation into the definitive chemoradiation of oropharyngeal cancer poses several challenges. Reliable and reproducible data must be obtained in a timely fashion. However, despite recent international radiotherapy contouring guidelines, controversy persists as to the applicability of such guidelines to all cases. Similarly, a lack of consensus exists concerning both the definition of the organ at risk for oral mucositis and the most appropriate endpoint to measure for this critical toxicity. Finally, the correlation between early markers of efficacy such as complete response on PET CT following treatment and subsequent survival needs elucidation for biological subsets of oropharyngeal cancer.

Revised Modelling of the Addition of Synchronous Chemotherapy to Radiotherapy in Squamous Cell Carcinoma of the Head and Neck-A Low α/β?

Background: The effect of synchronous chemotherapy in squamous cell carcinoma of the head and neck (SCCHN) has been modelled as additional Biologically Effective Dose (BED) or as a prolonged tumour cell turnover time during accelerated repopulation. Such models may not accurately predict the local control seen when hypofractionated accelerated radiotherapy is used with synchronous chemotherapy. Methods: For the purposes of this study three isoeffect relationships were assumed: Firstly, from the RTOG 0129 trial, synchronous cisplatin chemotherapy with 70 Gy in 35 fractions over 46 days results in equivalent local control to synchronous cisplatin chemotherapy with 36 Gy in 18# followed by 36 Gy in 24# (2# per day) over a total of 39 days. Secondly, in line with primary local control outcomes from the PET-Neck study, synchronous cisplatin chemotherapy with 70 Gy in 35# over 46 days results in equivalent local control to synchronous cisplatin chemotherapy delivered with 65 Gy in 30# over 39 days. Thirdly, from meta-analysis data, 70 Gy in 35# over 46 days with synchronous cisplatin results in equivalent local control to 84 Gy in 70# over 46 days delivered without synchronous chemotherapy. Using the linear quadratic equation the above isoeffect relationships were expressed algebraically to determine values of α, α/β, and k for SCCHN when treated with synchronous cisplatin using standard parameters for the radiotherapy alone schedule (α = 0.3 Gy⁻¹, α/β = 10 Gy, and k = 0.42 Gy₁₀day⁻¹). Results: The values derived for α/β, α and k were 2 Gy, 0.20 and 0.21 Gy⁻¹, and 0.65 and 0.71 Gy₂day⁻¹. Conclusions: Within the limitations of the assumptions made, this model suggests that accelerated repopulation may remain a significant factor when synchronous chemotherapy is delivered with radiotherapy in SCCHN. The finding of a low α/β for SCCHN treated with cisplatin suggests a greater tumour susceptibility to increasing dose per fraction and underlines the importance of the completion of randomized trials examining the role of hypofractionated acceleration in SCCHN.