A Phase 2 interventional study of De-escalation of irradiated volume in Oropharynx Cancer, sponsored by University of Zurich. Recruiting at 7 sites in Switzerland. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-08.
Sponsored by University of Zurich · Phase 2, Interventional, and Treatment
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Multicentric prospective model-based de-escalation of the elective clinical target volumes (CTV) in radiotherapy of oropharyngeal carcinoma of all stages with the goal to reduce toxicity.
The study investigates the feasibility of this approach as measured by the number of expected out-of-field recurrencies based on the individual patient's state of disease progression and risk factors
Local treatment of squamous cell carcinoma (SCC) of the oropharynx can consist of surgery, radiotherapy, or a combination of both. When treated with radiation, the target volume contains not only the primary tumor and clinically detected lymph node metastases. In addition, a large part of the lymph drainage system of the neck which is at risk of harboring occult metastases is irradiated, the so called "elective clinical target volume (CTV)". This elective CTV is currently based on clinical recommendations, but there is limited data and evidence on (occult) lymphatic spread and the required size of the elective CTV. This standard radiotherapy approach is associated with early and late toxicity. Toxicities such as pain, dermatitis, mucositis, but also long-term sequela like swallowing dysfunction, lymphedema and dysgeusia are commonly described, which can even lead to hospitalization or long-term symptoms with subsequent life-quality impairment.
A de-escalation of the treatment could result in less toxicity. Multiple studies have evaluated potential ways to de-escalate treatment and reduce toxicity, such as dose reduction or change of chemotherapeutic agent. Another possible de-escalation strategy, which is pursued here, is to reduce the elective clinical target volume.
A multi-institutional dataset of 598 oropharyngeal SCC patients in whom the detailed patterns of lymph node involvement are reported was collected. The publicly available online platform www.LyProX.org was developed to share and visualize the data. Based on this data, a statistical model of lymphatic tumor progression to perform a statistical analysis to estimate the probability of occult metastases in the clinically negative lymph node levels was developed. The patient's state of metastatic lymphatic progression is described via a hidden Markov model. The state of tumor progression is described by a collection of hidden binary random variables that indicate the involvement of lymph node levels. The model parameters are the probabilities for the tumor to spread to and between lymph node levels and are learned from the dataset. Supporting clinical experience, these statistical calculations can subsequently be used as a basis, to personalize the risk estimation of occult lymph node metastases in newly diagnosed patients based on their distribution of macroscopic metastases, T-stage, and lateralization of the primary tumor. A table with the possible different combinations of clinically observed lymph node involvement and the associated risk of occult lymph node involvement in the remaining, clinically negative lymph node levels (LNL) was created. By interpreting the results from both the statistical analysis and clinical experience, the elective clinical target volume (CTV) was personalized based on a patient's individualized risk profile. As a final measure of quality assurance, the elective CTVs (CTV-3s) constructed in this way have been discussed individually by the investigators, to ensure consistency with data and clinical judgement and experience. This leads to a reduction of irradiated volume and, potentially, to a reduction in early and late toxicity.
The aim of this clinical trial is to determine the safety of the use of a personalized de-escalated elective nodal CTV in oropharynx SCC patients treated with primary (chemo)radiotherapy.
369 studies on the registry are indexed under Oropharyngeal Neoplasms; 103 are open to participants now.
This study's planned enrollment of 120 is above the median of 52 across 265 interventional studies indexed under Oropharyngeal Neoplasms.
Browse Oropharyngeal Neoplasms studies →University of Zurich is the lead sponsor of 1,051 studies on the registry; 134 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria:
Exclusion Criteria:
Inclusion Criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Target volume de-escalation
Radiation: De-escalation of irradiated volume
De-escalation of elective clinical target volumes as recommended by a model-based approach
out-of field nodal recurrence rate at 2 years
efficacy of personalized CTV-N reduction in oropharyngeal SCC patients 2 years after the end of the primary (chemo)radiotherapy treatment measured by the Kaplan-Meier estimator for the cumulative probability of out-of-field N-site recurrences (incidence of lymph node metastases in non-irradiated LNLs).
Time frame: from completion of treatment up to 2 years after radiotherapy
out-of field nodal recurrence rate at 3 years
efficacy of personalized CTV-N reduction in oropharyngeal SCC patients measured by the Kaplan-Meier estimator for the cumulative probability of out-of-field N-site recurrences (incidence of lymph node metastases in non-irradiated LNLs)
Time frame: from completion of treatment up to 3 years after radiotherapy
Loco-regional control (LCR) rate at 2 years
assessed by the Kaplan-Meier estimator for the cumulative probability of local recurrence of the primary tumor or recurrence in any cervical LNL (both irradiated and non-irradiated LNLs)
Time frame: from completion of treatment up to 2 years after radiotherapy
Loco-regional control (LCR) rate at 3 years
assessed by the Kaplan-Meier estimator for the cumulative probability of local recurrence of the primary tumor or recurrence in any cervical LNL (both irradiated and non-irradiated LNLs)
Time frame: from completion of treatment up to 3 years after radiotherapy
Progression-free survival (PFS) at 2 years
assessed by the Kaplan-Meier estimator for the cumulative probability of any local, regional, distant progression or death
Time frame: from completion of treatment up to 2 years after radiotherapy
Progression-free survival (PFS) at 3 years
assessed by the Kaplan-Meier estimator for the cumulative probability of any local, regional, distant progression or death
Time frame: from completion of treatment up to 3 years after radiotherapy
Overall Survival (OS) at 2 years
assessed by the Kaplan-Meier estimator for the cumulative probability of death from any cause
Time frame: from completion of treatment up to 2 years after radiotherapy
Overall Survival (OS) at 3 years
assessed by the Kaplan-Meier estimator for the cumulative probability of death from any cause
Time frame: from completion of treatment up to 3 years after radiotherapy
Early toxicity of treatment
assessed by grading of toxicities according to CTCAE v5.0 - overall toxicity will be evaluated according to the TAME methodology.
Time frame: treatment start up to 3 months after treatment
Late toxicity of treatment
assessed by grading of toxicities according to CTCAE v5.0 - overall toxicity will be evaluated according to the TAME methodology.
Time frame: >3 months up to 3 years after treatment
Overall Quality of life at end of treatment
assessed according to paper-based questionnaires EORTC QLQ C30 All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at the last day of radiotherapy (+/- 1week)
Quality of life regarding head and neck specific symptoms at end of treatment
assessed according to paper-based questionnaires, i.e. head and neck module HN43: All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at the last day of radiotherapy (+/- 1week)
Overall Quality of life at 6 months after treatment
assessed according to paper-based questionnaires EORTC QLQ C30: All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at 6 months after the last day of radiotherapy (+/- 2 weeks)
Quality of life regarding head and neck specific symptoms at 6 months after treatment
assessed according to paper-based questionnaires, i.e. head and neck module HN43: All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at 6 months after the last day of radiotherapy (+/- 2 weeks)
Overall Quality of life at 12 months after treatment
assessed according to paper-based questionnaires EORTC QLQ C30: All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at 12 months after the last day of radiotherapy (+/- 2 weeks)
Quality of life regarding head and neck specific symptoms at 12 months after treatment
assessed according to paper-based questionnaires, i.e. head and neck module HN43: All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at 12 months after the last day of radiotherapy (+/- 2 weeks)
Overall Quality of life at 24 months after treatment
assessed according to paper-based questionnaires EORTC QLQ C30: All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at 24 months after the last day of radiotherapy (+/- 2 weeks)
Quality of life regarding head and neck specific symptoms at 24 months after treatment
assessed according to paper-based questionnaires, i.e. head and neck module HN43: All of the scales and single-item measures range in score from 0 to 100. A high scale score A high score for the global health status / QoL represents a high QoL, A high score for a symptom scale / item represents a high level of symptomatology / problems
Time frame: at 24 months after the last day of radiotherapy (+/- 2 weeks)
Assessement of values and longitudinal changes in total blood count, including lymphocytes (explorative assessement)
Full blood count will be longitudinally assessed at begin of treatment and at every follow up (descriptive analyses and correlation with all oncological outcomes)
Time frame: Treatment start and every 3 months up to 3 years after radiotherapy
Plan to share: No
Started Feb 2025 (actual). Primary completion is estimated for Sep 2029, 55 months after the start.
Of 63 non-industry phase 2 interventional studies under Oropharyngeal Neoplasms, half reached primary completion within 60 months of starting (the median), counting those still running; a quarter within 49 and three quarters within 99. This study's planned 55 months is close to that.
Counting every sponsor, half of 64 studies reached it within 63 months; a quarter within 49 and three quarters within 99.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 8, 2026: primary completion Feb 2029 → Sep 2029 and completion Feb 2030 → Sep 2030.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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