Radiation therapy for cT1-2 carcinoma of the palatine tonsil diagnosed via a simple tonsillectomy: Dosimetry and patterns of care in the IMRT era

OBJECTIVE

Small carcinomas of the palatine tonsil are often diagnosed via simple tonsillectomy, a maneuver with non-therapeutic intent. Herein, practice patterns for this unique situation are evaluated.

PATIENTS AND METHODS

A retrospective review was performed across 10 facilities to identify patients with cT1-2 squamous carcinomas of the tonsil diagnosed by simple tonsillectomy between 2010 and 2018. Patients who received curative-intent intensity modulated radiotherapy (IMRT) without additional surgery were included. Target volumes were reviewed, and cumulative incidences of local failure and severe late dysphagia were calculated.

RESULTS

From 638 oropharyngeal patients, 91 were diagnosed via simple tonsillectomy. Definitive IMRT with no additional surgery to the primary site was utilized in 57, and three with gross residual disease were excluded, leaving 54 for analysis. Margins were negative in 13%, close (<5 mm) in 13%, microscopically positive in 61%, and not reported in 13%. Doses typically delivered to gross disease (68-70.2 Gy in 33-35 fx or 66 Gy/30 fx) were prescribed to the tonsil bed in 37 (69%). Sixteen patients (29%) received doses from 60 to 66 Gy (≤2 Gy/fx) and one received 50 Gy (2 Gy/fx). No local failures were observed. One late oropharyngeal soft tissue ulcer occurred, treated conservatively (grade 2). At five years, the cumulative incidence of severe late dysphagia was 17.4% (95% CI 6.1-28.8%).

CONCLUSION

Small tonsil carcinomas diagnosed by simple tonsillectomy represent a niche subset with favorable oncologic outcomes. Regardless, radiation oncologists tend to deliver full-dose to the tonsil bed. The necessity of this routine could be questioned in the modern era.

Dosimetric Benefits of Omitting Primary Tumor Beds in Postoperative Radiotherapy After Transoral Robotic Surgery Using the Auto-Planning Technique

Introduction: It has been suggested that post-transoral robotic surgery (post-TORS) radiotherapy (RT) might reduce the dose to organs at risk (OARs) adjacent to the primary tumor bed; however, the evidence supporting this has yet to be sufficient. This study examined the radiation dose reduction to OARs by omitting the primary tumor bed through the use of an Auto-Planning (AP)-based workflow.

Methods: Twelve patients were identified who underwent post-TORS RT to the primary tumor bed and the unilateral/bilateral neck lymph nodes. In each patient, two treatment plans were designed: a Comprehensive (Comp)-plan treating the original planning target volume (PTV) including both the primary tumor bed and the lymph nodes, and a Neck-plan treating only the lymph nodes and omitting the primary tumor bed. Both plans were optimized using AP to ensure plan quality consistency. We compared the doses received by 95% of the primary tumor beds and lymph nodes (D95%) and our institutional dose constraints for the OARs between the Comp- and Neck-plans. Statistical analysis was performed using R Statistical Software (R Foundation for Statistical Computing, Vienna, Austria) with a two-tailed paired Wilcoxon signed-rank test.

Results: All plans met target dose coverage requirements with at least 95% of the PTVs covered with the corresponding prescription doses. The primary tumor bed in the Neck-plans was spared with a significantly lower mean D95% (25.9 Gy vs. 60.0 Gy; p < 0.01; Wilcoxon test). The mean dose to the oral cavity (20.9 Gy vs. 28.1 Gy; p < 0.01) and the supraglottis (36.9 Gy vs. 28.2 Gy; p < 0.01) was significantly lower in the Neck-plans.

Conclusion: This study suggests that sparing the primary tumor bed during post-TORS RT offers dosimetric benefits to nearby OARs with significant dose reductions to the oral cavity and supraglottis. Further study of the clinical risks and benefits afforded by this strategy is needed.

Prognostic factor analysis and long-term results of the TAX 323 (EORTC 24971) study in unresectable head and neck cancer patients

BACKGROUND

In the TAX 323 (EORTC 24971) phase III trial enrolling patients with unresectable locoregionally advanced squamous cell carcinoma of the head and neck (LA-SCCHN), the addition of docetaxel (T) to cisplatin and 5-fluorouracil (PF)-based induction chemotherapy prior to definite radiotherapy significantly improved progression-free survival (PFS) and overall survival (OS).

METHODS

The data were updated for PFS, OS and treatment-related long-term side-effects. Baseline clinical and laboratory data of 17 variables were collected and subjected to univariate and multivariate prognostic factor analyses for OS.

RESULTS

All 358 patients randomised between 1999 and 2002 were included in the long-term analysis with a median follow-up of 8.6 years. The primary end-point of PFS remained significantly improved with TPF compared with PF (adjusted hazard ratio [HR], 0.70; 95% CI, 0.56-0.88, p = 0.002), translating into a persisting benefit in OS (adjusted HR, 0.75; 95% CI, 0.60-0.95, p = 0.015). Long-term side-effects in the TPF/PF arms comprised tracheostomy (7%/5%), feeding tube dependency (3%/6%) and gastrostomy (11%/11%). Second malignancy occurred in 8%/3%, respectively. Out of 177 patients randomised to the TPF arm, 160 were included in the multivariate analysis. Grade 2 or more dysphagia (p = 0.002) and grade 2 or more pain (p = 0.004) at baseline were identified as independent negative prognostic factors. In addition, OS differed across primary tumour sites (p = 0.027) and was worse in patients with a higher N-stage (p = 0.025).

CONCLUSIONS

In LA-SCCHN patients treated with sequential chemoradiotherapy, TPF induction chemotherapy demonstrated long-lasting efficacy, superior to the PF regimen. Higher-grade dysphagia and pain are unfavourable prognosticators.

Gastrostomy tube dependence and patient-reported quality of life outcomes based on type of treatment for human papillomavirus-associated oropharyngeal cancer: Systematic review and meta-analysis

We examined the impact of treatment modality on gastrostomy tube dependence and patient-reported outcomes in human papillomavirus-associated oropharyngeal cancer (HPV-OPSCC). We performed systematic review and meta-analysis of functional outcomes 1-3 years after treatment. Twenty-three studies were included, reporting on 3127 patients treated for HPV-OPSCC. Gastrostomy tube dependence failed to show statistically significant difference between surgery with adjuvant therapy and chemoradiotherapy with cisplatin at 12 months (8.3% [95% CI: 3.1-15.9] vs. 4.2% [1.1-9.2], p = 0.37) and 24-36 months (10.5% [95% CI: 3.2-21.5] vs. 3.3% [2.0-4.9], p = 0.06). Surgery with adjuvant therapy was associated with worse University of Washington Quality of Life (UW-QOL) Swallowing (84 [95% CI: 80-88] vs. 89 [87-90], p = 0.03) and UW-QOL Overall scores (76 [95% CI: 72-80] vs. 84 [81-86], p = 0.001) compared to chemoradiotherapy with cisplatin at 12 months. Surgery with adjuvant therapy was associated with worse performance on certain measures of patient-reported swallow and overall function compared to chemoradiotherapy with cisplatin. Further randomized controlled trials are needed to directly compare functional outcomes after treatment for HPV-OPSCC.

In vivo assessment of the safety of standard fractionation Temporally Feathered Radiation Therapy (TFRT) for head and neck squamous cell carcinoma: An R-IDEAL Stage 1/2a first-in-humans/feasibility demonstration of new technology implementation

INTRODUCTION

Prior in silico simulations of studies of Temporally Feathered Radiation Therapy (TFRT) have demonstrated potential reduction in normal tissue toxicity. This R-IDEAL Stage 1/2A study seeks to demonstrate the first-in-human implementation of TFRT in treating patients with head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

Patients with HNSCC treated with definitive radiation therapy were eligible (70 Gy in 35 fractions) were eligible. The primary endpoint was feasibility of TFRT planning as defined by radiation start within 15 business days of CT simulation. Secondary endpoints included estimates of acute grade 3-5 toxicity.

RESULTS

The study met its accrual goal of 5 patients. TFRT plans were generated in four of the five patients within 15 business days of CT simulation, therefore meeting the primary endpoint. One patient was not treated with TFRT at the physician's discretion, though the TFRT plan had been generated within sufficient time from the CT simulation. For patients who received TFRT, the median time from CT simulation to radiation start was 10 business days (range 8-15). The average time required for radiation planning was 6 business days. In all patients receiving TFRT, each subplan and every daily fraction was delivered in the correct sequence without error. The OARs feathered included: oral cavity, each submandibular gland, each parotid gland, supraglottis, and posterior pharyngeal wall (OAR pharynx). Prescription dose PTV coverage (>95%) was ensured in each TFRT subplan and the composite TFRT plan. One of five patients developed an acute grade 3 toxicity.

CONCLUSIONS

This study demonstrates the first-in-human implementation of TFRT (R-IDEAL Stage 1), proving its feasibility in the modern clinical workflow. Additionally, assessments of acute toxicities and dosimetric comparisons to a standard radiotherapy plan were described (R-IDEAL Stage 2a).

Technical Note: A step-by-step guide to Temporally Feathered Radiation Therapy planning for head and neck cancer

Purpose

Prior in silico simulations propose that Temporally Feathered Radiation Therapy (TFRT) may reduce toxicity related to head and neck radiation therapy. In this study we demonstrate a step‐by‐step guide to TFRT planning with modern treatment planning systems.

Methods

One patient with oropharyngeal cancer planned for definitive radiation therapy using intensity‐modulated radiation therapy (IMRT) techniques was replanned using the TFRT technique. Five organs at risk (OAR) were identified to be feathered. A “base plan” was first created based on desired planning target volumes (PTV) coverage, plan conformality, and OAR constraints. The base plan was then re‐optimized by modifying planning objectives, to generate five subplans. All beams from each subplan were imported onto one trial to create the composite TFRT plan. The composite TFRT plan was directly compared with the non‐TFRT IMRT plan. During plan assessment, the composite TFRT was first evaluated followed by each subplan to meet preset compliance criteria.

Results

The following organs were feathered: oral cavity, right submandibular gland, left submandibular gland, supraglottis, and OAR Pharynx. Prescription dose PTV coverage (>95%) was met in each subplan and the composite TFRT plan. Expected small variations in dose were observed among the plans. The percent variation between the high fractional dose and average low fractional dose was 29%, 28%, 24%, 19%, and 10% for the oral cavity, right submandibular, left submandibular, supraglottis, and OAR pharynx nonoverlapping with the PTV.

Conclusions

Temporally Feathered Radiation Therapy planning is possible with modern treatment planning systems. Modest dosimetric changes are observed with TFRT planning compared with non‐TFRT IMRT planning. We await the results of the current prospective trial to seeking to demonstrate the feasibility of TFRT in the modern clinical workflow (NCT03768856). Further studies will be required to demonstrate the potential benefit of TFRT over non‐TFRT IMRT Planning.

Follow-Up of Head and Neck Cancer Survivors: Tipping the Balance of Intensity

The traditional concept of post-treatment surveillance in head and neck cancer patients relies on examinations directed at early detection of disease recurrence and/or second primary tumors. They are usually provided by ear, nose and throat specialists with complementary input from radiation oncologists and medical oncologists. Emerging evidence underscores the importance of monitoring and effective management of late adverse events. One of the major drawbacks is a lack of prospective controlled data. As a result, local institutional policies differ, and practice recommendations are subject to continuing debate. Due to the economic burden and impact on emotional comfort of patients, intensity and content of follow-up visits are a particularly conflicting topic. According to the current evidence-based medicine, follow-up of head and neck cancer patients does not prolong survival but can improve quality of life. Therefore, an approach giving priority to a multidisciplinary care involving a speech and swallowing expert, dietician, dentist, and psychologist may indeed be more relevant. Moreover, on a case-by-case basis, some patients need more frequent consultations supplemented by imaging modalities. Human papillomavirus positive oropharyngeal cancer tends to develop late failures at distant sites, and asymptomatic oligometastatic disease, especially in the lungs, can be successfully salvaged by local ablation, either surgically or by radiation. The deep structures of the skull base related to the nasopharynx are inaccessible to routine clinical examination, advocating periodic imaging supplemented by nasofibroscopy as indicated. Anamnesis of heavy smoking justifies annual low-dose computed tomography screening of the thorax and intensive smoking cessation counseling. Finally, some cancer survivors feel more comfortable with regular imaging, and their voice should be taken into consideration. Future development of surveillance strategies will depend on several variables including identification of reliable predictive factors to select those who could derive the most benefit from follow-up visits, the availability of long-term follow-up data, the results of the first randomized trials, resource allocation patterns, infrastructure density, and the therapeutic landscape of locally advanced and recurrent and/or metastatic disease, which is rapidly changing with the advent of immune checkpoint inhibitors and better utilization of local approaches.

Benefit from surgery with additional radiotherapy in N1 head and neck cancer at the time of IMRT: A population-based study on recent developments

BACKGROUND

Currently, the role of adjuvant irradiation in head and neck cancer (HNC) patients with N1-lymph node status is not clarified.

OBJECTIVES

To assess the population-based effect of recent developments in radiotherapy such as intensity-modulated radiotherapy (IMRT) in relation to overall survival (OS) together with surgery in N1 HNC patients.

MATERIALS AND METHODS

We used 9,318 HNC cases with pT1/2 N0/1 disease from German cancer registries. Time of diagnosis ranged from January 2000 to December 2014, which we divided into three periods: (low [LIA] vs intermediate [IA] vs high [HIA] IMRT availability period) based on usage of IMRT in Germany. For each period, we examined a possible association between treatment (surgery vs. surgery and radiotherapy) in terms of OS. Statistical analyses included Kaplan-Meier and multivariate Cox regression (models adjusted for HPV-related cancer site).

RESULTS

Temporal analysis revealed increasing usage of IMRT in Germany. In patients with N1 tumours, a comparison of patients treated with and without radiotherapy during the HIA period showed a superiority of the combined treatment as opposed to surgery alone (HR 0.54, 95%CI: 0.35-0.85, p = 0.003). The survival analyses related to treatments in terms of period underlined the superiority of surgery plus radiotherapy between periods IA and HIA (p = 0.03).

CONCLUSION

The advent of IMRT, additional radiotherapy may present a survival advantage in patients with N1 HNC when combined with surgery.

Long-term outcomes following stereotactic body radiotherapy boost for oropharyngeal squamous cell carcinoma

Background/purpose: To determine the efficacy and toxicity profile of a stereotactic body radiotherapy (SBRT) boost as a first line treatment in patients with oropharyngeal squamous cell carcinoma (OPSCC). Materials and methods: We performed a retrospective cohort study in 195 consecutive OPSCC patients with T1-small T3 disease, treated at Erasmus MC between 2009 and 2016 with a SBRT (3 × 5.5 Gy) boost after 46 Gy IMRT. Primary endpoints were disease-specific survival (DSS) and Grade ≥3 toxicity (Common Terminology Criteria). The Kaplan-Meier method and Cox regression model were applied to determine rates and risk factors. Results: The median follow-up was 4.3 years. Treatment compliance was high (100%). Rates of 5-year DSS and late grade ≥3 toxicity were 85% and 28%, respectively. Five-year overall survival was 67%. The most frequently observed toxicities were mucosal ulceration or soft tissue necrosis (n = 30, 5 year 18%), dysphagia or weight loss (n = 18, 5 year 12%) and osteoradionecrosis (n = 11, 5 year 9%). Current smoker status (hazard ratio [HR] = 2.9, p = .001) and Charlson Comorbidity Index ≥2 (HR = 1.9, p = .03) were was associated with increased toxicity risk. Tooth extraction prior to RT was associated with increased osteoradionecrosis risk (HR = 6.4, p = .006). Conclusion: We reported on outcomes in the largest patient series to date treated with a hypofractionated boost for OPSCC. Efficacy was good with survival rates comparable to conventionally fractionated (chemo)radiotherapy. Grade ≥3 toxicity profiles showed high rates of soft tissue necrosis and osteoradionecrosis. Strategies to mitigate severe toxicity risks are under investigation to improve the tolerability of the SBRT boost.

Low-Dose vs. High-Dose Cisplatin: Lessons Learned From 59 Chemoradiotherapy Trials in Head and Neck Cancer

In locally advanced squamous cell carcinomas of the head and neck (LA-SCCHN), concurrent chemoradiotherapy is an integral part of multimodality management both in the adjuvant and in the definitive settings. Although de-intensification strategies have been propelled to the forefront of clinical research in human papillomavirus (HPV) positive oropharyngeal cancer, three cycles of 100 mg/m² cisplatin given every 3 weeks concurrently with conventionally fractionated external beam radiotherapy represent a cost-effective and globally accessible treatment option for the majority of LA-SCCHN cases. Based on four large randomized trials, this regimen has become the non-surgical standard of care for cisplatin-eligible patients. Nevertheless, the outcomes in terms of efficacy, toxicity, and compliance have been rather disappointing. Therefore, there is an unmet need to find a better alternative. With limited support from randomized trials, weekly low-dose cisplatin regimens have replaced the standard high-dose schedule at some institutions. Four prospective trials exploring radiotherapy with and without weekly low-dose cisplatin have been published. Two of them were conducted in the 1980s, one of which had a negative outcome, the third study provided insufficient information on toxicity, and the fourth trial had to be prematurely terminated due to poor accrual. Moreover, the findings of two phase III trials comparing the two concurrent cisplatin regimens favored the high-dose protocol. We performed a composite meta-analysis of 59 prospective trials enrolling a total of 5,582 patients. The primary endpoint was overall survival. Reflecting different radiotherapy fractionation schemes and treatment intents, three meta-analyses were carried out, one for postoperative conventional chemoradiotherapy, one for definitive conventional chemoradiotherapy, and one for definitive altered fractionation chemoradiotherapy. In the former two settings, both high- and low-dose regimens yielded similar survival outcomes, thus, the primary objective was not met. When given concurrently with altered fractionation radiotherapy, patients treated with high-dose cisplatin had significantly longer overall survival than those who received low-dose cisplatin. In this article we provide a synthetic view of the results, discuss the issue of cumulative dose, compare two vs. three cycles of high-dose cisplatin, and present our three-step recommendations for use of the current standard of care, high-dose cisplatin, in clinical practice.

Correlation between plan quality improvements and reduced acute dysphagia and xerostomia in the definitive treatment of oropharyngeal squamous cell carcinoma

BACKGROUND

To evaluate plan quality using volumetric-modulated arc therapy (VMAT) and step-and-shoot intensity-modulated radiation therapy (SS-IMRT) techniques and for patients treated for oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

Treatment plans for patients treated definitively for stages I-IVb, OPSCC between December 2009 and August 2015 were retrospectively reviewed. Dosimetric endpoints of involved organs-at-risk (OARs) were retrieved from clinical plans. Common Terminology Criteria for Adverse Events scores of acute toxicities were compared.

RESULTS

Two-hundred twenty-two patients were identified with 134 and 88 receiving SS-IMRT and VMAT with median follow-up time of 23.0 and 7.9 months, respectively. The dosimetric endpoints of the OARs were significantly improved in VMAT cohort, which translated into significantly lower rates of grade 2 or higher acute dysphagia and xerostomia.

CONCLUSION

Improvements in stages I-IVb, oropharyngeal cancer plan quality are associated with reduced grade ≥ 2 acute dysphagia and xerostomia.

Design and fabrication of a 3D-printed oral stent for head and neck radiotherapy from routine diagnostic imaging

Background

Oral stents have been shown to reduce the deleterious effects of head and neck radiotherapy through the displacement of normal tissues away from the areas of high dose irradiation. While these stents are commonly used in the treatment of patients with head and neck cancer at many large academic cancer centers, their use is much more limited outside of these institutions due to the time and expertise required for their fabrication.

Results

In the study, we describe a novel method to design and manufacture oral stents from routine computed tomography (CT) imaging studies through the use of 3D printing technologies.

Conclusion

Our proposed method may help to greatly expand access to these beneficial devices for patients undergoing radiation treatment at centers without access to dental and oral/maxillofacial specialists.

Functional Outcomes After De-escalated Chemoradiation Therapy for Human Papillomavirus-Positive Oropharyngeal Cancer: Secondary Analysis of a Phase 2 Trial

PURPOSE

To analyze functional outcomes for patients treated on a phase 2 trial of de-escalated chemoradiation therapy for human papillomavirus-positive oropharyngeal cancer.

METHODS AND MATERIALS

Patient eligibility included p16-positive, stage III or IV oropharyngeal squamous cell carcinoma and a Zubrod performance status of 0 to 1. Treatment was induction chemotherapy with paclitaxel, 175 mg/m², and carboplatin, area under the curve (AUC) of 6 mg/ml/min, for 2 cycles every 21 days, followed by concurrent paclitaxel, 30 mg/m², every 7 days with dose-reduced radiation therapy of 54 or 60 Gy. Trends in body weight and body mass index (BMI) were analyzed with gastrostomy tube and narcotic use rates. Functional outcomes were assessed using the University of Washington Quality of Life Scale and the Functional Assessment of Cancer Therapy-Head and Neck Scale.

RESULTS

Forty-five patients were registered, of whom 40 were evaluable. Only 1 patient had a BMI deemed unhealthy at the completion of treatment. For the 15 patients (38%) with a normal BMI (18-25 kg/m²) before treatment, recovery back to baseline occurred at approximately 18 months (average BMI, 23.2 kg/m² vs 22.3 kg/m²; P=.09). In 2 patients (5%), gastrostomy tubes were placed during treatment. No patient was enteral feeding tube-dependent at 6 months after treatment. Ninety-five percent of patients tolerated a normal regular diet at last follow-up.

CONCLUSIONS

De-escalated chemoradiation therapy may improve functional outcomes as indicated by the relatively low incidence of gastrostomy tube placement and long-term dysphagia. In patients with a normal BMI prior to chemoradiation therapy, BMI recovered to baseline levels.

Patient-reported quality-of-life outcomes after de-escalated chemoradiation for human papillomavirus-positive oropharyngeal carcinoma: Findings from a phase 2 trial

BACKGROUND

The current study represents a subset analysis of quality-of-life (QOL) outcomes among patients treated on a phase 2 trial of de-escalated chemoradiation for human papillomavirus (HPV)-associated oropharyngeal cancer.

METHODS

Eligibility included newly diagnosed, (American Joint Committee on Cancer, 7th edition) stage III or IV oropharyngeal squamous cell carcinoma, p16 positivity, age ≥ 18 years, and a Zubrod performance status of 0 to 1. Treatment was induction paclitaxel at a dose of 175 mg/m² and carboplatin at an area under the curve of 6 for 2 cycles followed by response-adapted, dose-reduced radiation of 54 Gy or 60 Gy with weekly concurrent paclitaxel at a dose of 30 mg/m² . The University of Washington Quality of Life (UW-QOL) and the Functional Assessment of Cancer Therapy-Head and Neck questionnaires were used to assess patient-reported QOL as a secondary endpoint.

RESULTS

A total of 45 patients were registered, 40 of whom completed QOL surveys and were evaluable. Nadirs for overall UW-QOL and Functional Assessment of Cancer Therapy-Head and Neck scores were reached at 4 weeks after treatment but returned to baseline at 3 months. Nearly all functional indices returned to baseline levels by 6 to 9 months. The mean overall UW-QOL score was 71.6 at baseline compared with 70.8, 73.0, 83.3, and 81.1, respectively, at 3 months, 6 months, 1 year, and 2 years after therapy. The percentage of patients rating their overall QOL as "very good" or "outstanding" at 6 months, 1 year, and 2 years using the UW-QOL was 50%, 77%, and 84%, respectively.

CONCLUSIONS

This de-escalation regimen achieved QOL outcomes that were favorable compared with historical controls. These results serve as powerful evidence that ongoing de-escalation efforts lead to tangible gains in function and QOL. Cancer 2018;124:521-9. © 2017 American Cancer Society.