TORPEdO: A phase III trial of intensity-modulated proton beam therapy versus intensity-modulated radiotherapy for multi-toxicity reduction in oropharyngeal cancer

Proton therapy for primary and recurrent HPV-related oropharyngeal cancer

The incidence of Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) has risen over the past two decades, now accounting for 44-75 % of cases in Europe and the USA. This review synthesized data from PubMed, additional academic sources, and ongoing studies to summarize the potential role of proton therapy (PT) role in treating HPV-related OPSCC. In vitro studies support PT radiosensitization of HPV-positive cells and clinical experiences report high locoregional control (LRC) rates of 88.6-97 % with significantly reduced side effects such as xerostomia by 12.5 % and brain necrosis by 2.3 %, compared to intensity-modulated radiation therapy (IMRT). A randomized trial (NCT01893307) has also recently provided level 1 evidence showing that PT is non-inferior to IMRT for tumor control while reducing treatment-related toxicities, such as feeding tube dependence (28 % vs. 42 %, p = 0.019) and facilitating better work resumption outcomes (71 % vs. 52 % at 2 years). Despite the success of radiation de-escalation achieving LRC up to 95 %, recent trials indicate potential survival risks when standard treatments are modified. Failure pattern analysis showed that up to 70 % of locoregional recurrences occurred in-field, highlighting the potential role of PT in achieving LRC while minimizing toxicity. PT could also play a role in the reirradiation of recurrent OPSCC, with reported 1-year LRC rates of 71.8-80.8 %, 2-year LRC rates of 72.8-80.3 %, 1-year overall survival (OS) rates of 65.2-81.3 %, 2-year OS rates of 32.7-69 %, and late grade ≥2 toxicities of 11.9-36.3 %. Methodologies improving reRT approaches include dose/volume histogram comparisons, which recommended PT when it resulted in lower predicted toxicities.

Toxicity and Oncologic Outcomes of Proton Radiotherapy for Oropharyngeal Cancer: A Systematic Review and Meta-Analysis

Intensity-modulated radiotherapy (IMRT) for oropharyngeal cancer (OPC) is associated with acute and late toxicities that impact patient quality of life. Proton radiotherapy (PRT) can reduce exposure to surrounding tissues, but the clinical magnitude of this advantage is unclear. A systematic review and meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included studies reported toxicity or oncologic outcomes from patients treated with PRT for OPC. Pooled outcomes were estimated using random-effects models. Comparisons between PRT and IMRT were performed using log odds ratios. Primary outcomes were the pooled rates of adverse events, overall survival (OS), and progression-free survival (PFS). A total of 18 studies (16 retrospective, two prospective) consisting of 956 patients were identified. Pooled rates of acute grade 3+ toxicities were as follows: dermatitis 19%, mucositis 32%, xerostomia 1.3%, dysphagia 13%, and weight loss 1.4%. The pooled rate of acute hospitalizations was 10%. Among studies reporting late toxicities, the rates of grade 3+ xerostomia and dysphagia were 1.1% and 1.6%, respectively. Compared to IMRT, PRT was associated with lower rates of acute feeding tube use (21% versus 31%; P = 0.0012), but not long-term feeding tube use (1.4% versus 2.7%; P = 0.24). After PRT, OS at two and three years were 98% and 96%, while PFS at two and three years were 93% and 86%. PRT for patients with OPC is associated with favorable toxicity and oncologic outcomes. While randomized clinical trials are ongoing, these data provide additional evidence regarding the efficacy of PRT in the upfront treatment of OPC.

The timed 100 mL water swallow test for patients with head and neck cancer: What constitutes a clinically significant difference?

OBJECTIVES

Swallowing function in patients with head and neck cancer (HNC) is often assessed pre-treatment, during and at intervals post-treatment to identify those with dysphagia as early as possible. This study aims to investigate the minimal clinical important difference (MCID) for the 100 mL water swallow test (100 mL WST) to increase its utility in clinical practice and in clinical trials.

METHODS

Data from 211 HNC patients, treated by either single or combined modality were included. Patients completed both the 100 mL WST and M.D. Anderson Dysphagia Inventory (MDADI) at baseline (i.e., prior to treatment) and 12 months post-treatment. The MCID for the 100 mL WST was calculated using two approaches of the anchor-based method (using the MDADI), including mean change, and ROC curve. Additionally, the distribution-based method was used utilizing the half standard deviation approach.

RESULTS

In the anchor-based method, a 4 mL/s in the 100 mL WST was defined as an MCID for deterioration, with a sensitivity of 75% and a 1-specificity of 46%. In contrast, a change of 5 mL/s was deemed as an MCID for improvement, based on the distribution-based method.

CONCLUSION

The findings showed that deterioration of 4 mL, or an increase of 5 mL from baseline to 12 months post-HNC treatment equates to an MCID from the patients' perspective. Based on these findings, it may be beneficial to increase the utilization of the 100 mL WST in clinical practice to observe the changes, and in clinical trials to interpret and compare different study arms.

Acute toxicities in proton therapy for head and neck cancer - A matched analysis of the DAHANCA 35 feasibility study

Background and purpose

As preparation for a national randomized study comparing proton radiotherapy to photon radiotherapy, DAHANCA 35, we performed a non-randomized pilot study to investigate patient selection, logistics, planning, and treatment delivery. With the present study, as a comprehensive safety analysis, we want to compare toxicity during and up to two months after therapy to a historically matched group of patients treated with photon radiotherapy.

Materials and methods

62 patients treated with protons were matched to 124 patients who received photon treatment outside a protocol. Available data were retrieved from the DAHANCA database. Patients were matched on treatment centre, concurrent chemotherapy, tumour site, stage, p16 status for oropharynx cancers. Selection of patients for proton therapy was based on comparative treatment plans with a NTCP reduction for dysphagia and xerostomia at six months.

Results

Baseline characteristics between groups were well balanced, except for the type of drug used concurrently; more photon patients received Carboplatin (21.2 % vs 5.8 %, p = 0.01). Proton therapy was associated with significantly less weight loss at the end of treatment, mean weight loss of 3 % for protons and 5 % for photons (p < 0.001). There were more grade 3 skin reactions and grade 3 mucositis after proton treatment compared with photons at the end of treatment, Risk Ratio (RR) 1.9 (95 % CI: 1.01-3.5, p = 0.04) and RR 1.5 (95 % CI: 1.3-1.7, p < 0.001), respectively. All differences resolved at follow up two months after treatment. There were no significant differences between groups on opioid use, use of feeding tubes, or hospitalization during the observation period.

Conclusion

Proton treatment resulted in excess objective mucositis and dermatitis, which was transient and did not seem to negatively influence weight or treatment compliance and intensity. Selection bias was likely especially since NTCP models were used for selection of proton treatment and photon treated patients were matched manually. We are currently including patients in a randomized controlled trial.

Assessment of patients with head and neck cancer using the MD Anderson Dysphagia Inventory: Results of a study into its comprehensiveness, comprehensibility and relevance to clinical practice

BACKGROUND

The MD Anderson Dysphagia Inventory (MDADI) is a widely used patient-reported outcome measure (PROM) which assesses dysphagia-related quality of life (QoL) in head and neck cancer (HNC). Despite its common use in HNC research and clinical practice, few of its psychometric properties have been reappraised since its inception. The aim of this study was to perform a survey-based qualitative analysis of UK HNC clinicians' perceptions of the content validity of the MDADI, evaluating it across the parameters of relevance, comprehensiveness and comprehensibility as per the COSMIN guideline for PROM assessment.

RESULTS

Four themes relating to the content validity of the MDADI were identified: (1) MDADI items lack clarity of definition of the terms 'swallowing', 'eating' and 'dysphagia'; (2) the MDADI is perceived to be overly negative in tone including items that service users may find distressing or disempowering; (3) items in the tool are exclusory to specific subgroups of patients, such as those who are nil by mouth or socially isolated; and (4) modifications to the MDADI were suggested and encouraged to make it more clinically useful and patient-centred.

CONCLUSIONS

This study indicates that MDADI's content validity is 'insufficient' when rated by COSMIN parameters. This has significant implications for its continued use in HNC research and clinical practice. Further re-evaluation of the content validity of the MDADI is warranted, with potential future amendment of items being indicated if the results of this study are corroborated in subsequent research.

WHAT THIS PAPER ADDS

What is already known on the subject The MD Anderson Dysphagia Inventory (MDADI) patient-reported outcome measure of dysphagia-related quality of life is widely used in clinical practice and international clinical trials. Content validity is considered to be the most important property of a tool when assessing its psychometric strengths and weaknesses; however, the MDADI's content validity has not been reappraised since its initial development. What this paper adds to existing knowledge This study presents UK speech and language therapists' opinions and experience of the content validity of the MDADI and this first reappraisal of its content validity since its initial development highlights several issues with this psychometric parameter of the tool. This study highlights that further re-evaluation of the content validity of the MDADI is warranted, with potential future amendment of items being indicated if the results of this study are corroborated in subsequent research. What are the potential or actual clinical implications of this work? Clinicians cannot assume that commonly used outcomes tools have strong psychometric profiles. Consideration of the content validity of outcomes tools during selection for use in clinical and research practice should be key, as this will encourage use of tools that produce relevant, valid data that can contribute meaningfully to patient-centred care.

Failure patterns of locoregional recurrence after reducing target volumes in patients with nasopharyngeal carcinoma receiving adaptive replanning during intensity-modulated radiotherapy: a single-center experience in China

BACKGROUND

Previous researches have demonstrated that adaptive replanning during intensity-modulated radiation therapy (IMRT) could enhance the prognosis of patients with nasopharyngeal carcinoma (NPC). However, the delineation of replanning target volumes remains unclear. This study aimed to evaluate the feasibility of reducing target volumes through adaptive replanning during IMRT by analyzing long-term survival outcomes and failure patterns of locoregional recurrence in NPC.

METHODS

This study enrolled consecutive NPC patients who received IMRT at our hospital between August 2011 and April 2018. Patients with initially diagnosed, histologically verified, non-metastatic nasopharyngeal cancer were eligible for participation in this study. The location and extent of locoregional recurrences were transferred to pretreatment planning computed tomography for dosimetry analysis.

RESULTS

Among 274 patients, 100 (36.5%) received IMRT without replanning and 174 (63.5%) received IMRT with replanning. Five-year rates of locoregional recurrence-free survival (LRFS) were 90.1% (95%CI, 84.8% to 95.4%) and 80.8% (95%CI, 72.0% to 89.6%) for patients with and without replanning, P = 0.045. There were 17 locoregional recurrences in 15 patients among patients with replanning, of which 1 (5.9%) was out-field and 16 (94.1%) were in-field. Among patients without replanning, 19 patients developed locoregional recurrences, of which 1 (5.3%) was out-field, 2 (10.5%) were marginal, and 16 (84.2%) were in-field.

CONCLUSIONS

In-field failure inside the high dose area was the most common locoregional recurrent pattern for non-metastatic NPC. Adapting the target volumes and modifying the radiation dose prescribed to the area of tumor reduction during IMRT was feasible and would not cause additional recurrence in the shrunken area.

A Retrospective Comparison of Toxicity, Response and Survival of Intensity-Modulated Radiotherapy Versus Three-Dimensional Conformal Radiation Therapy in the Treatment of Rectal Carcinoma

INTRODUCTION

The main target of neoadjuvant treatment in rectal cancer is to downstage and downsize large tumours to increase the chance of complete surgical resection, and therefore decrease the chances of local recurrence. With or without the addition of chemotherapy, until recently, three-dimensional conformal radiotherapy (3D-CRT) used to be the radiotherapy treatment modality of choice. However, intensity-modulated radiotherapy (IMRT) is being increasingly adopted by many radiotherapy centres as a more modern, conformal technique due to its ability to minimize radiation dose to nearby organs. The aim of our analysis was to assess the difference in toxicity, response to treatment, and survival between the patients treated with these two different treatment modalities in our institution.

METHODS

We performed a retrospective analysis of data and compared two groups of patients with locally advanced rectal cancer who were treated with either 3D-CRT or IMRT. The main outcomes were radiation toxicity and response to treatment. Overall survival was a secondary outcome.

RESULTS

One hundred and thirty-six patients were included in the study: 71 patients treated with 3D-CRT and 65 patients treated with IMRT. With regard to toxicity, there was no significant difference between the groups for bladder and skin toxicity, but there was a significant reduction in acute grade 2 bowel toxicity in patients treated with a long course of IMRT [3D-CRT 77% (48/62) vs IMRT 64% (30/47) p=0.042]. There was no statistically significant difference in the treatment response rates of these two radiotherapy treatment modalities, as well as in overall survival between the groups (p=0.604).  Conclusion: Our study showed that IMRT can significantly reduce acute bowel side effects for patients undergoing neoadjuvant radiotherapy for locally advanced rectal cancers. Further studies are needed to confirm the clinical advantage of IMRT in rectal carcinoma.

DOSE AND VOLUME DE-ESCALATION OF RADIOTHERAPY IN HEAD AND NECK CANCER

Radiotherapy plays a key role in the treatment of head and neck cancer. However, irradiation of the head and neck region is associated with high rates of acute and chronic toxicity. Technological advances have led to better visualisation of target volumes and critical structures and improved dose conformality in the treatment volume. Despite this, acute toxicity has not been substantially reduced and late toxicity has a significant impact on patients' quality of life. The greater radiosensitivity of tumours associated with the HPV and the development of new imaging techniques have encouraged research into new deintensified strategies to reduce the side effects of radiotherapy. The aim of this paper is to review the literature on the strategies of de-escalated treatment in dose and/or volume in head and neck cancer.

Quality of Life and Patient-Reported Outcomes Following Proton Therapy for Oropharyngeal Carcinoma: A Systematic Review

BACKGROUND

Complex anatomy surrounding the oropharynx makes proton therapy (PT), especially intensity-modulated PT (IMPT), a potentially attractive option due to its ability to reduce the volume of irradiated healthy tissues. Dosimetric improvement may not translate to clinically relevant benefits. As outcome data are emerging, we aimed to evaluate the evidence of the quality of life (QOL) and patient-reported outcomes (PROs) following PT for oropharyngeal carcinoma (OC).

MATERIALS AND METHODS

We searched PubMed and Scopus electronic databases (date: 15 February 2023) to identify original studies on QOL and PROs following PT for OC. We employed a fluid strategy in the search strategy by tracking citations of the initially selected studies. Reports were extracted for information on demographics, main results, and clinical and dose factor correlates. Quality assessment was performed using the NIH's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. The PRISMA guidelines were followed in the preparation of this report.

RESULTS

Seven reports were selected, including one from a recently published paper captured from citation tracking. Five compared PT and photon-based therapy, although none were randomized controlled trials. Most endpoints with significant differences favored PT, including xerostomia, cough, need for nutritional supplements, dysgeusia, food taste, appetite, and general symptoms. However, some endpoints favored photon-based therapy (sexual symptoms) or showed no significant difference (e.g., fatigue, pain, sleep, mouth sores). The PROs and QOL improve following PT but do not appear to return to baseline.

CONCLUSION

Evidence suggests that PT causes less QOL and PRO deterioration than photon-based therapy. Biases due to the non-randomized study design remain obstacles to a firm conclusion. Whether or not PT is cost-effective should be the subject of further investigation.

Advances in Proton Therapy for the Management of Head and Neck Tumors

Proton therapy (PBRT) is a form of external beam radiotherapy with several dosimetric advantages compared with conventional photon (x-ray) radiotherapy. Unlike x-rays, protons deposit most of their dose over a finite range, with no exit dose, in a pattern known as the Bragg peak. Clinically, this can be exploited to optimize dose to tumors while delivering a lower integral dose to normal tissues. However, the optimal role of PBRT is not as well-defined as advanced x-ray-based techniques such as intensity-modulated radiotherapy.