PEARL PET-based Adaptive Radiotherapy Clinical Trial

Not Applicable

• Conditions: Oropharyngeal Cancer
• Interventions: Procedure: PET-CT scans; Procedure: Outlining the biological GTVs (bGTV_P and bGTV_iP); Procedure: Blood samples for cell-free DNA analysis; Procedure: Salivary samples for cell-free DNA analysis

• Registration Number: NCT03935672
• Lead Sponsor: Velindre NHS Trust

Brief Summary

The PEARL study will recruit approximately 50 patients with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) who are about to undergo primary treatment with concurrent chemo-radiation from South Wales (Velindre Cancer Centre and Singleton Hospital, Swansea) and Bristol. The main aim is to see whether it is feasible to preform a positron emission tomography-computed tomography (PET-CT) scan after 2 weeks of radiotherapy and re-plan the radiotherapy based on this PET-CT scan, to re-distribute the dose of radiotherapy being delivered, so that a smaller area of normal tissues in the mouth and throat are treated to a high dose of radiotherapy.

Detailed Description

PEARL is a prospective, interventional, non-randomised, phase II feasibility study for patients with good prognosis Human Papillomavirus (HPV)-associated oropharyngeal squamous cell cancer (OPSCC) who are suitable for treatment with concurrent chemo-radiotherapy (CCRT).

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) caused by Human Papillomavirus (HPV) infection (HPV-positive OPSCC) is increasing in the United Kingdom. It tends to affect younger patients and has a better outcome than most other head and neck cancers.

A large proportion of patients diagnosed with HPV-positive OPSCC will undergo non-surgical treatment. This usually involves 6 to 7 weeks of chemo-radiotherapy, with chemotherapy being given weekly or during the first and fourth week of the radiotherapy course (CCRT). Many patients with HPV-positive OPSCC are cured of their disease but often have to live for several decades with the side effects of their treatment. Side effects from radiotherapy are usually caused because normal tissues surrounding the cancer receive radiation whilst the cancer itself is being treated.

Positron emission tomography-computed tomography (PET-CT) scans are able to look at the metabolic (or biological) activity of cells and are currently recommended in the UK for response assessment after a patient has completed radiotherapy for a head and neck cancer but, as far as we know, have not yet been used routinely to adapt radiotherapy according to the individual patient's response during radiotherapy.

PEARL will explore the feasibility of individually adapting the radiotherapy plan for each patient after 2 weeks of radical CCRT, based on biological changes in tumour activity seen on an interim FDG-PET-CT scan, carried out early on during a course of treatment. The aim is to reduce the dose of radiotherapy received by surrounding normal tissues to ultimately reduce toxicity.

The study will establish the progression free survival rate (PFS) in patients who receive biologically adapted radiotherapy. Furthermore, it will also explore whether changes seen on PET-CT scan during treatment correlate with outcome and with changes in potential blood-based biomarkers of response. Toxicity rates will be assessed, particularly the effect of treatment on swallowing function.

Study Timeline

• Study First Submitted: 2018-10-03
• Status Verified: 2019-04
• Study First Submitted QC: 2019-04-30
• Last Update Submitted: 2019-04-30
• Study First Posted: 2019-05-02
• Last Update Posted: 2019-05-02
• Study Start: 2019-07-01
• Primary Completion: 2021-02-28
• Study Completion: 2023-02-28

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

1. Histologically confirmed squamous cell carcinoma of the oropharynx
2. Positive p16 Immunohistochemistry on local testing
3. UICC TNM (8th edition) stage T1 - T3 N0 - N1 M0
4. Multidisciplinary team (MDT) decision to treat with primary chemoradiotherapy
5. Patients considered fit for radical treatment with primary chemoradiotherapy (including sufficient renal function (GFR>50ml/min)
6. Aged 18 years or older
7. Not smoked in the last 2 years
8. Written informed consent provided
9. Patients with reproductive potential (male or female), who are sexually active during the duration of the trial consent to using a highly effective method of contraception for at least six months after the last dose of chemoradiotherapy. Effective forms of contraception are described in section 15.5.

Exclusion Criteria

1. Known HPV negative squamous cell carcinoma of the head and neck
2. T1 - T3 tumours where primary treatment with concomitant chemo-radiotherapy is not considered appropriate
3. T4 disease
4. N2 (TMN8) nodal disease
5. Distant metastatic disease
6. Current smokers or smokers who have stopped within the past 2 years
7. Diabetes mellitus
8. Any pre-existing medical condition likely to impair swallowing function and/ or a history of pre-existing swallowing dysfunction prior to index oropharyngeal cancer
9. Previous radiotherapy to the head and neck
10. History of malignancy in the last 5 years, except basal cell carcinoma of the skin, or carcinoma in situ of the cervix
11. Tumour non-avid on PET-CT or not visible on cross sectional imaging

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
All trial participants	Blood samples for cell-free DNA analysis	Baseline plasma and saliva tests for future translational analysis Baseline planning FDG PET CT scan Patients will start their 6 weeks of CCRT within two to three weeks following the planning scans. Cisplatin chemotherapy will be administered. 33 daily fractions of radiotherapy will be delivered over 6 weeks. A second FDG-PET-CT scan (iPET) and repeat plasma and saliva tests will be carried out after 2 weeks of CCRT (on RT days 9 - 12) and the iPET assessed for residual FDG-avid disease. The biological GTV will be re-outlined based on the residual avid region of the tumour on the second PET-CT (bGTV_iP) At the end of treatment, plasma and saliva tests will be carried out at 4 weeks post treatment and again at the 3 month post-treatment PET-CT Swallowing and QoL assessments will be repeated 4 weeks (+/- 2 weeks) after treatment and will be repeated at 6, 12 and 24 months post-treatment. The plasma and saliva samples will be repeated at 12 and 24 months
All trial participants	PET-CT scans	Baseline plasma and saliva tests for future translational analysis Baseline planning FDG PET CT scan Patients will start their 6 weeks of CCRT within two to three weeks following the planning scans. Cisplatin chemotherapy will be administered. 33 daily fractions of radiotherapy will be delivered over 6 weeks. A second FDG-PET-CT scan (iPET) and repeat plasma and saliva tests will be carried out after 2 weeks of CCRT (on RT days 9 - 12) and the iPET assessed for residual FDG-avid disease. The biological GTV will be re-outlined based on the residual avid region of the tumour on the second PET-CT (bGTV_iP) At the end of treatment, plasma and saliva tests will be carried out at 4 weeks post treatment and again at the 3 month post-treatment PET-CT Swallowing and QoL assessments will be repeated 4 weeks (+/- 2 weeks) after treatment and will be repeated at 6, 12 and 24 months post-treatment. The plasma and saliva samples will be repeated at 12 and 24 months
All trial participants	Outlining the biological GTVs (bGTV_P and bGTV_iP)	Baseline plasma and saliva tests for future translational analysis Baseline planning FDG PET CT scan Patients will start their 6 weeks of CCRT within two to three weeks following the planning scans. Cisplatin chemotherapy will be administered. 33 daily fractions of radiotherapy will be delivered over 6 weeks. A second FDG-PET-CT scan (iPET) and repeat plasma and saliva tests will be carried out after 2 weeks of CCRT (on RT days 9 - 12) and the iPET assessed for residual FDG-avid disease. The biological GTV will be re-outlined based on the residual avid region of the tumour on the second PET-CT (bGTV_iP) At the end of treatment, plasma and saliva tests will be carried out at 4 weeks post treatment and again at the 3 month post-treatment PET-CT Swallowing and QoL assessments will be repeated 4 weeks (+/- 2 weeks) after treatment and will be repeated at 6, 12 and 24 months post-treatment. The plasma and saliva samples will be repeated at 12 and 24 months
All trial participants	Salivary samples for cell-free DNA analysis	Baseline plasma and saliva tests for future translational analysis Baseline planning FDG PET CT scan Patients will start their 6 weeks of CCRT within two to three weeks following the planning scans. Cisplatin chemotherapy will be administered. 33 daily fractions of radiotherapy will be delivered over 6 weeks. A second FDG-PET-CT scan (iPET) and repeat plasma and saliva tests will be carried out after 2 weeks of CCRT (on RT days 9 - 12) and the iPET assessed for residual FDG-avid disease. The biological GTV will be re-outlined based on the residual avid region of the tumour on the second PET-CT (bGTV_iP) At the end of treatment, plasma and saliva tests will be carried out at 4 weeks post treatment and again at the 3 month post-treatment PET-CT Swallowing and QoL assessments will be repeated 4 weeks (+/- 2 weeks) after treatment and will be repeated at 6, 12 and 24 months post-treatment. The plasma and saliva samples will be repeated at 12 and 24 months

Primary Outcome Measures

Name	Time	Method
Progression free survival at 2 years	2 years following enrolment	To maintain a high progression free survival rate with biologically adapted radiotherapy in patients with good prognosis HPV positive OPSCC. To be certain that we are not having a negative impact on PFS by adapting the RT plan we will ensure that PFS is at least as high as expected after treatment with chemo-radiotherapy in patients with similarly staged HPV-positive OPSCC.

Secondary Outcome Measures

Name	Time	Method
Monthly recruitment rate	End of 2 years recruitment period	As this is a feasibility study, recruitment will be monitored and monthly recruitment rate over 2 years will be presented.
Acute toxicity rates	3 months post treatment	Cumulative acute CTCAE toxicity score percentages during and up to 3 months after treatment will be presented.
To test if individualized, adaptive, biologically-based radiotherapy planning is feasible and results in a significant change in the radiotherapy plan.	2 weeks (10 fractions) of chemo-radiotherapy	Percentage reduction in mean dose to OAR (superior pharyngeal constrictor muscles, contralateral parotids, contralateral submandibular gland, salivary glands) as a result of PET-CT during treatment. Percentage change to PTV will also be presented.
To assess the effect of treatment on swallowing function	3, 6, 12 and 24 months post treatment	QoL scores will be plotted over time.
Late toxicity rates	6, 12 and 24 months post treatment]	QoL scores will be plotted over time, scores will be presented at 6, 12, 18 and 24 months.
To test if individualized, adaptive, biologically-based radiotherapy planning results in a significant change in the radiotherapy plan.	2 weeks (10 fractions) of chemo-radiotherapy	Percentage reduction in mean dose to OAR (superior pharyngeal constrictor muscles, contralateral parotids, contralateral submandibular gland, salivary glands) as a result of PET-CT during treatment. Percentage change to PTV will also be presented.
To maintain high complete response rates 3 months after treatment	3 months post treatment	The proportion of patients who are complete metabolic responders at 3 months as per PERCIST criteria will be presented.

Trial Locations

Locations (3)

Singleton Hospital; 🇬🇧 Swansea, Wales, United Kingdom

University Hospitals Bristol NHS Foundation Trust; 🇬🇧 Bristol, United Kingdom

Velindre Cancer Center at Velindre Hospital; 🇬🇧 Cardiff, Wales, United Kingdom