Prospective observational study of carbon-ion radiotherapy for non-squamous cell carcinoma of the head and neck

Machine learning model for diagnosing salivary gland adenoid cystic carcinoma based on clinical and ultrasound features

OBJECTIVE

To develop and validate machine learning (ML) models for diagnosing salivary gland adenoid cystic carcinoma (ACC) in the salivary glands based on clinical and ultrasound features.

METHODS

A total of 365 patients with ACC or non-ACC of the salivary glands treated at two centers were enrolled in training cohort, internal and external validation cohorts. Synthetic minority oversampling technique was used to address the class imbalance. The least absolute shrinkage and selection operator (LASSO) regression identified optimal features, which were subsequently utilized to construct predictive models employing five ML algorithms. The performance of the models was evaluated across a comprehensive array of learning metrics, prominently the area under the receiver operating characteristic curve (AUC).

RESULTS

Through LASSO regression analysis, six key features-sex, pain symptoms, number, cystic areas, rat tail sign, and polar vessel-were identified and subsequently utilized to develop five ML models. Among these models, the support vector machine (SVM) model demonstrated superior performance, achieving the highest AUCs of 0.899 and 0.913, accuracy of 90.54% and 91.53%, and F1 scores of 0.774 and 0.783 in both the internal and external validation cohorts, respectively. Decision curve analysis further revealed that the SVM model offered enhanced clinical utility compared to the other models.

CONCLUSIONS

The ML model based on clinical and US features provide an accurate and noninvasive method for distinguishing ACC from non-ACC.

CRITICAL RELEVANCE STATEMENT

This machine learning model, constructed based on clinical and ultrasound characteristics, serves as a valuable tool for the identification of salivary gland adenoid cystic carcinoma.

KEY POINTS

Rat tail sign and polar vessel on US predict adenoid cystic carcinoma (ACC). Machine learning models based on clinical and US features can identify ACC. The support vector machine model performed robustly and accurately.

Rebamipide gargle and benzydamine gargle in prevention and management of chemo-radiotherapy and radiotherapy-induced oral mucositis in head and neck cancer patients (randomized clinical trial)

OBJECTIVES

This study aimed to evaluate the preventive and therapeutic effects of rebamipide gargle in comparison with benzydamine in head and neck cancer patients undergoing radiotherapy with or without chemotherapy.

MATERIALS AND METHODS

Phase III randomized clinical trial was conducted from January 2021 till August 2022 on one hundred patients with head and neck cancer receiving high doses of radiotherapy. These patients were equally allocated into either rebamipide group or benzydamine group, The measured outcomes were the incidence of oral mucositis ≥ grade1, according to the WHO mucositis scale, in addition to the duration, and the onset of oral mucositis.

RESULTS

There was no statistically significant difference between the two groups, regarding the incidence of a severe grade of oral mucositis (WHO grades 3), as well as the onset and duration of oral mucositis. Both gargles succeeded to prevent the development of WHO grade 4 oral mucositis. Side effects reported were mainly burning sensation in benzydamine group and nausea in rebamipide group.

CONCLUSION

Rebamipide mouthwash was as beneficial as benzydamine mouthwash in minimizing the incidence of severe oral mucositis induced by treatment of head and neck cancer. However, rebamipide gargle proved to be superior to benzydamine in terms of reduction in the severity of the radiation-induced oral mucositis.

TRIAL REGISTRATION

The trial was registered in the protocol Registration and Result system of Clinical Trials (Registration ID: NCT04685395)0.28-12-2020.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Assessing the Impact of Charged Particle Radiation Therapy for Head and Neck Adenoid Cystic Carcinoma: A Systematic Review and Meta-Analysis

Purpose: Head and neck adenoid cystic carcinoma (HNACC) is a radioresistant tumor. Particle therapy, primarily proton beam therapy and carbon-ion radiation, is a potential radiotherapy treatment for radioresistant malignancies. This study aims to conduct a meta-analysis to evaluate the impact of charged particle radiation therapy on HNACC. Methods: A comprehensive search was conducted in Pubmed, Cochrane Library, Web of Science, Embase, and Medline until December 31, 2022. The primary endpoints were overall survival (OS), local control (LC), and progression-free survival (PFS), while secondary outcomes included treatment-related toxicity. Version 17.0 of STATA was used for all analyses. Results: A total of 14 studies, involving 1297 patients, were included in the analysis. The pooled 5-year OS and PFS rates for primary HNACC were 78% (95% confidence interval [CI] = 66-91%) and 62% (95% CI = 47-77%), respectively. For all patients included, the pooled 2-year and 5-year OS, LC, and PFS rates were as follows: 86.1% (95% CI = 95-100%) and 77% (95% CI = 73-82%), 92% (95% CI = 84-100%) and 73% (95% CI = 61-85%), and 76% (95% CI = 68-84%) and 55% (95% CI = 48-62%), respectively. The rates of grade 3 and above acute toxicity were 22% (95% CI = 13-32%), while late toxicity rates were 8% (95% CI = 3-13%). Conclusions: Particle therapy has the potential to improve treatment outcomes and raise the quality of life for HNACC patients. However, further research and optimization are needed due to the limited availability and cost considerations associated with this treatment modality.

Salivary gland cancers in elderly patients: challenges and therapeutic strategies

Salivary gland carcinomas (SGCs) are the most heterogeneous subgroup of head and neck malignant tumors, accounting for more than 20 subtypes. The median age of SGC diagnosis is expected to rise in the following decades, leading to crucial clinical challenges in geriatric oncology. Elderly patients, in comparison with patients aged below 65 years, are generally considered less amenable to receiving state-of-the-art curative treatments for localized disease, such as surgery and radiation/particle therapy. In the advanced setting, chemotherapy regimens are often dampened by the consideration of cardiovascular and renal comorbidities. Nevertheless, the elderly population encompasses a broad spectrum of functionalities. In the last decades, some screening tools (e.g. the G8 questionnaire) have been developed to identify those subjects who should receive a multidimensional geriatric assessment, to answer the question about the feasibility of complex treatments. In the present article, we discuss the most frequent SGC histologies diagnosed in the elderly population and the relative 5-years survival outcomes based on the most recent data from the Surveillance, Epidemiology, and End Results (SEER) Program. Moreover, we review the therapeutic strategies currently available for locoregionally advanced and metastatic disease, taking into account the recent advances in precision oncology. The synergy between the Multidisciplinary Tumor Board and the Geriatrician aims to shape the most appropriate treatment pathway for each elderly patient, focusing on global functionality instead of the sole chronological age.

Functional imaging-guided carbon ion irradiation with simultaneous integrated boost for localized prostate cancer: study protocol for a phase II randomized controlled clinical trial

Background

Due to the physical dose distribution characteristic of “Bragg peak” and the biological effect as a kind of high linear energy transfer ray, heavy ion therapy has advantages over conventional photon therapy in both efficacy and safety. Based on the evidence that prostate cancer lesions before treatment are the most common sites of tumor residual or recurrence after treatment, simultaneous integrated boost radiation therapy for prostate cancer has been proven to have the advantage of improving efficacy without increasing toxicities.

Methods

This study is a prospective phase II randomized controlled clinical trial evaluating the efficacy and safety of functional imaging-guided carbon ion irradiation with simultaneous integrated boost for localized prostate cancer. One hundred and forty patients with localized prostate cancer will be randomized into carbon ion radiotherapy group and simultaneous integrated boost carbon ion radiotherapy group at a 1:1 ratio. The primary endpoint is to compare the incidence of treatment-related grade 2 and higher acute toxicities between the two groups according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4.03. Secondary endpoints are late toxicities, biochemical relapse-free survival, overall survival, progression-free survival, and quality of life.

Discussion

This study adopts functional imaging-guided simultaneous integrated boost of carbon ion radiotherapy for localized prostate cancer, aiming to evaluate the differences in the severity and incidence of acute toxicities in patients with localized prostate cancer treated with carbon ion radiotherapy and simultaneous integrated boost carbon ion radiotherapy, in order to optimize the carbon ion treatment strategy for localized prostate cancer.

Trial registration

ClinicalTrials.gov NCT05010343. Retrospectively registered on 18 August 2021

A cross-sectional analysis of registered clinical trials on the use of particle beam radiation therapy in head and neck cancers

Background

To present and analyze the current status of registered clinical trials on particle beam (including proton and carbon ion beam) radiation therapy (PBRT) for head and neck (H&N) malignancies, and to provide insights for future clinical research, we designed the cross-sectional analysis.

Methods

We identified and analyzed all clinical trials of interest registered on ClinicalTrials.gov and PTCOG.ch until March 22, 2020.

Results

We identified 57 registered clinical trials related to the use of proton therapy or carbon ion radiation therapy (CIRT) in H&N malignancies. There were 20, 27, and 5 trials focused on CIRT, proton therapy, and both ions, respectively. The eligible trials were registered between 2007 and 2020, mainly focused on adenoid cystic carcinoma (ACC), squamous cell carcinoma (SCC), sinonasal malignancies (SNM), skull base tumors, locally advanced, and recurrent tumors. The nature of 23 (40%) trials were not stated and could not be identified. A total of 25 (44%) registered trials were phase II, including randomized controlled trials (RCTs). There were 14 RCTs (7 phase II, 2 phase II/III, 2 phase III, 1 phase I/II, and 2 phase not applicable), and 25 studies including RCTs were registered before the first enrolment. There were 11 completed clinical trials among the eligible trials, including 7 with published trial-related results.

Conclusions

Less than 10% of the countries with PBRT treatment facilities in operation have initiated clinical trials on H&N cancer. Furthermore, among all registered trials, less than 10% have been completed with results published. More clinical trials, especially high quality trials, are needed for optimizing and standardizing treatment techniques of PBRT for H&N malignancies.

Particle Therapy for Breast Cancer

Particle therapy has received increasing attention in the treatment of breast cancer due to its unique physical properties that may enhance patient quality of life and reduce the late effects of therapy. In this review, we will examine the rationale for the use of proton and carbon therapy in the treatment of breast cancer and highlight their potential for sparing normal tissue injury. We will discuss the early dosimetric and clinical studies that have been pursued to date in this domain before focusing on the remaining open questions limiting the widespread adoption of particle therapy.

Relationship between oral mucositis and the oral bacterial count in patients with head and neck cancer undergoing carbon ion radiotherapy: A prospective study

BACKGROUND AND PURPOSE

Acute adverse events, such as oral mucositis, can affect treatment success in patients undergoing head and neck radiotherapy. In this study, we aimed to identify the relationship between oral mucositis and oral bacterial counts during carbon ion radiotherapy (C-ion RT) in patients with head and neck cancer.

MATERIALS AND METHODS

This prospective study included patients with head and neck tumors treated with C-ion RT between 2017 and 2019. C-ion RT consisted of treatment at 57.6, 64.0, or 70.4 Gy (relative biological effectiveness) in 16 fractions. Bacterial counts in the saliva and the back of the tongue were measured using a rapid oral bacteria quantification system. The relationship between the oral bacterial count and oral mucositis was subsequently analyzed.

RESULTS

In total, 46 patients were included in the analysis. The bacterial count in the saliva gradually increased from the commencement of C-ion RT and peaked at 16 fractions. Bacterial counts at the back of the tongue were already high at the beginning of C-ion RT; however, they decreased with continued treatment, peaked at 16 fractions, and subsequently decreased again. Patients with bacterial counts exceeding the mean before C-ion RT (high-count group) did not experience more severe mucositis than those with counts below the mean (low-count group). However, patients in the high-count group tended to experience faster-onset mucositis and slower healing than those in the low-count group.

CONCLUSION

Bacterial counts may aid in the development of clinical strategies for C-ion RT-induced oral mucositis.

Physics and biomedical challenges of cancer therapy with accelerated heavy ions

Radiotherapy should have low toxicity in the entrance channel (normal tissue) and be very effective in cell killing in the target region (tumour). In this regard, ions heavier than protons have both physical and radiobiological advantages over conventional X-rays. Carbon ions represent an excellent combination of physical and biological advantages. There are a dozen carbon-ion clinical centres in Europe and Asia, and more under construction or at the planning stage, including the first in the USA. Clinical results from Japan and Germany are promising, but a heated debate on the cost-effectiveness is ongoing in the clinical community, owing to the larger footprint and greater expense of heavy ion facilities compared with proton therapy centres. We review here the physical basis and the clinical data with carbon ions and the use of different ions, such as helium and oxygen. Research towards smaller and cheaper machines with more effective beam delivery is necessary to make particle therapy affordable. The potential of heavy ions has not been fully exploited in clinics and, rather than there being a single 'silver bullet', different particles and their combination can provide a breakthrough in radiotherapy treatments in specific cases.

Comparison of Clinical Outcomes of Definitive and Postoperative Radiotherapy for Adenoid Cystic Carcinoma of the Head and Neck: Can Definitive Radiotherapy Be a Treatment Option?

Simple Summary

Adenoid cystic carcinoma of the head and neck is a rare malignant tumor; thus, it is difficult to establish an optimal treatment based on clinical trials with a large number of enrolled patients. Retrospective analyses of a small number of cases have revealed that the standard treatment is surgical resection followed by postoperative radiotherapy, while definitive radiotherapy is considered inadequate. Previous studies have used classical techniques for radiotherapy and did not evaluate the efficacy of current radiotherapy techniques, which may have underestimated the efficacy of definitive radiotherapy. We retrospectively analyzed 44 cases of adenoid cystic carcinoma of the head and neck treated with current radiotherapy techniques. Our results show that definitive radiotherapy is comparable to surgical resection followed by postoperative radiotherapy with respect to overall survival and local control. The results suggest that definitive radiotherapy can be an effective treatment option for adenoid cystic carcinoma of the head and neck.

Abstract

Background: The standard treatment for adenoid cystic carcinoma of the head and neck is surgical resection followed by postoperative radiotherapy (PORT). Currently, definitive radiotherapy (defRT) is considered an inadequate treatment; however, its data are based on studies using classical radiotherapy techniques. Therefore, the therapeutic effects of current radiotherapy techniques have not been adequately evaluated, and it may have underestimated the efficacy of defRT. Methods: We retrospectively analyzed 44 adenoid cystic carcinoma patients treated with radiotherapy based on modern treatment techniques from 1993 to 2017. Results: Twenty-four patients underwent PORT and 20 patients underwent defRT. The 5-year overall survival rates for patients treated with PORT and defRT were 85.3% and 79.7%, respectively. The 5-year local control rates were 82.5% and 83.1%, respectively. There were no statistically significant differences in the overall survival and local control of patients treated with PORT and defRT (p = 0.4392 and p = 0.0904, respectively). Conclusion: Our results show that defRT is comparable to surgical resection followed by PORT with respect to overall survival and local control. The results suggest that defRT can be an effective treatment option for adenoid cystic carcinoma of the head and neck.

Predicted probabilities of brain injury after carbon ion radiotherapy for head and neck and skull base tumors in long-term survivors

BACKGROUND AND PURPOSE

We aimed to determine the risk factors for radiation-induced brain injury (RIBI¹) after carbon ion radiotherapy (CIRT) to predict their probabilities in long-term survivors.

MATERIALS AND METHODS

We evaluated 104 patients with head, neck, and skull base tumors who underwent CIRT in a regimen of 32 fractions and were followed up for at least 24 months. RIBI was assessed using the Common Terminology Criteria for Adverse Events.

RESULTS

The median follow-up period was 45.5 months; 19 (18.3 %) patients developed grade ≥2 RIBI. The maximal absolute dose covering 5 mL of the brain (D5ml) was the only significant risk factor for grade ≥2 RIBI in the multivariate logistic regression analysis (p = 0.001). The tolerance doses of D5ml for the 5% and 50% probabilities of developing grade ≥2 RIBI were estimated to be 55.4 Gy (relative biological effectiveness [RBE]) and 68.4 Gy (RBE) by a logistic model, respectively.

CONCLUSION

D5ml was most significantly associated with grade ≥2 RIBI and may enable the prediction of its probability.

Dosimetric Parameters Predicting Tooth Loss after Carbon Ion Radiotherapy for Head and Neck Tumors

Background: Tooth loss reduces quality of life; however, little is known about tooth loss caused by carbon ion radiotherapy (CIRT). Here, we aimed to elucidate the incidence of tooth loss post-CIRT for head and neck tumors and to identify risk-predictive dosimetric parameters. Methods: This study enrolled 14 patients (i.e., 171 teeth in total) with head and neck non-squamous cell carcinoma. All patients received CIRT comprised of 57.6 or 64.0 Gy (relative biological effectiveness, RBE) in 16 fractions. Dose–volume analysis of the teeth was performed using receiver operating characteristic (ROC) curve analysis with VX (i.e., the volume irradiated with X Gy (RBE)). Results: The median follow-up period was 69.1 months. The median time of tooth loss was 38.6 months. The 5 year cumulative incidence of tooth loss was 13.3%. The volume of irradiated teeth was significantly greater for the lost teeth than for the remaining teeth throughout the dose range. Using the cut-offs calculated from ROC curve analysis, V30–V60 showed high accuracy (i.e., >94%) for predicting tooth loss, with V50 being the most accurate (cut-off, 58.1%; accuracy, 0.95). Conclusions: This is the first report to examine the incidence of tooth loss post-CIRT and to identify risk-predictive dosimetric parameters.

Clinical features and dosimetric evaluation of carbon ion radiation-induced osteoradionecrosis of mandible in head and neck tumors

BACKGROUND AND PURPOSE

Osteoradionecrosis (ORN) affects the patient's quality of life by making eating and maintaining oral hygiene painful. This study aimed to analyze carbon ion radiotherapy (C-ion RT)-induced ORN of the mandible.

MATERIALS AND METHODS

A retrospective study of 199 patients with head and neck tumors treated with C-ion RT was performed from 2010 to 2019. Only 11 patients with tumors located in the oropharynx and floor of the mouth were analyzed. C-ion RT consisted of 57.6 Gy or 64.0 Gy (relative biological effectiveness) in 16 fractions. The mandible was analyzed for magnetic resonance imaging (MRI) changes and bone exposure. The relationship between the radiation dose and ORN of the mandible was analyzed.

RESULTS

Five patients (45.5%) had ORN of the mandible. The median follow-up time was 68 months. The median onset times based on MRI changes and bone exposure were 9 and 15 months, respectively. Doses of 30 Gy (relative biological effectiveness) to the mandible and teeth showed the most significant effect, causing ORN at 29.5 ± 6.7 cc and 3.9 ± 1.8 cc, respectively, with cut-off values at 16.5 cc (p = 0.002) and 1.8 cc (p = 0.0059), respectively.

CONCLUSION

This is the first study reporting the incidence, onset time, and risk-predictive dosimetry parameters of C-ion RT-induced ORN of the mandible. Our study will be useful for establishing clinical strategies for C-ion RT to the head and neck near the mandible.

Prospective Evaluation of Quality of Life and Functional Outcomes after Carbon Ion Radiotherapy for Inoperable Bone and Soft Tissue Sarcomas

Simple Summary

Quality of life (QOL) and functional outcomes in patients with inoperable bone and soft tissue sarcoma treated with definitive carbon-ion radiotherapy (CIRT) were prospectively investigated. CIRT showed favorable clinical efficacy and safety, maintaining the physical component of QOL and functional outcomes, and improving the mental component of QOL. The physical component of QOL was positively correlated with functional outcomes. Poor performance status at diagnosis and female gender were independent predictors of the physical component of QOL and functional outcomes after CIRT.

Abstract

Carbon-ion radiotherapy (CIRT) represents a definitive treatment for inoperable bone and soft tissue sarcoma (BSTS). This prospective study analyzed 61 patients with inoperable BSTS who were treated with CIRT to evaluate QOL, functional outcomes, and predictive factors in patients with inoperable BSTS treated with definitive CIRT. The Musculoskeletal Tumor Society (MSTS) scoring system and the Short Form (SF)-8 questionnaire were completed before and at 1, 3, 6, 12, and 24 months after CIRT. The median follow-up period was 38 months. The main site of primary disease was the pelvis (70.5%), and the most common pathologic diagnosis was chordoma (45.9%). The 3-year overall survival and local control rates were 87.8% and 83.8%, respectively. The MSTS score and physical component score (PCS) of SF-8 did not change significantly between the baseline and subsequent values. The mental component score of SF-8 significantly improved after CIRT. Multivariate analysis showed that the normalized MSTS and normalized PCS of SF-8 at the final follow-up were significantly affected by performance status at diagnosis and sex. CIRT showed clinical efficacy, preserving the physical component of QOL and functional outcomes and improving the mental component of QOL, suggesting its potential value for the treatment of patients with inoperable BSTS.

Estimating the Number of Patients Eligible for Carbon Ion Radiotherapy in the United States

Purpose

Carbon ion radiotherapy (CIRT) is an emerging radiotherapy modality with potential advantages over conventional photon-based therapy, including exhibiting a Bragg peak and greater relative biological effectiveness, leading to a higher degree of cell kill. Currently, 13 centers are treating with CIRT, although there are no centers in the United States. We aimed to estimate the number of patients eligible for a CIRT center in the United States.

Materials and Methods

Using the National Cancer Database, we analyzed the incidence of cancers frequently treated with CIRT internationally (glioblastoma, hepatocellular carcinoma, cholangiocarcinoma, locally advanced pancreatic cancer, non-small cell lung cancer, localized prostate cancer, soft tissue sarcomas, and specific head and neck cancers) diagnosed in the United States in 2015. The percentage and number of patients likely benefiting from CIRT was estimated with inclusion criteria from clinical trials and retrospective studies, and that ratio was applied to 2019 cancer statistics. An adaption correction rate was applied to estimate the potential number of patients treated with CIRT. Given the high dependency on prostate and lung cancers and the uncertain adoption of CIRT in those diseases, the data were then reanalyzed excluding those diagnoses.

Results

Of the 1 127 455 new cases of cancer diagnosed in the United States in 2015, there were 213 073 patients (18.9%) eligible for treatment with CIRT based on inclusion criteria. When applying this rate and the adaption correction rate to the 2019 incidence data, an estimated 89 946 patients (42.2% of those fitting inclusion criteria) are eligible for CIRT. Excluding prostate and lung cancers, there were an estimated 8922 patients (10% of those eligible for CIRT) eligible for CIRT. The number of patients eligible for CIRT is estimated to increase by 25% to 27.7% by 2025.

Conclusion

Our analysis suggests a need for CIRT in the United States in 2019, with the number of patients possibly eligible to receive CIRT expected to increase during the coming 5 to 10 years.

Evaluation of Carbon Ion Radiation-Induced Trismus in Head and Neck Tumors Using Dose-Volume Histograms

Simple Summary

Patients who receive carbon ion radiotherapy (C-ion RT) for tumors near the temporomandibular joint are likely to experience trismus, a condition characterized by reduced jaw opening. However, the relationship between the dose of carbon ion and the onset of trismus remains unclear. Therefore, we conducted a subgroup analysis of a prospective observational study to understand the relationship between the dose of carbon ion and the occurrence of trismus. Of 35 patients included in the study, six developed grade 2 trismus, and the median onset time was 12 months. The affected muscles included masticatory muscles and the coronoid process. Our findings suggest better treatment planning, such as dose optimization, to minimize the occurrence of muscle-related adverse effects associated with C-ion RT.

Abstract

Carbon ion radiotherapy (C-ion RT) provides a highly localized deposition of energy that can increase radiation doses to tumors while minimizing irradiation of adjacent normal tissues. For tumors located near the temporomandibular joint, C-ion RT-induced trismus may occur. However, the relationship between the carbon ion dose and the onset of trismus is unclear. In this prospective observational study, we assessed the trismus/carbon ion dose relationship using dose−volume histograms in 35 patients who received C-ion RT in their head and neck regions between 2010 and 2014. Trismus was evaluated in patients according to the Common Terminology Criteria for Adverse Events, version 4.0. All patients were treated with 57.6 or 64.0 Gy (relative biological effectiveness (RBE)) in 16 fractions, and the median follow-up time was 57 months. Grade 2 trismus was observed in six patients. The median onset time was 12 months. At maximum radiation doses, all masticatory muscles and coronoid processes, particularly the masseter muscle, were significantly different (p = 0.003). The contouring of the masseter muscle and coronoid process requires different treatment planning. The maximum radiation doses of the coronoid process can be proposed as a guideline for treatment planning, considering the ease of contouring in C-ion RT.

Impact of oral mucositis on quality of life in patients undergoing oncological treatment: a systematic review

Oral mucositis (OM) is one of the most prominent side effects of cancer treatment and is believed to have a significant impact on the quality of life (QoL) of the affected patients. However, measurements for the investigation of OM is plagued by heterogeneity in symptoms that varies with the type of cancer or the treatment. We aimed to carry out a qualitative assessment of the current evidence on the impact of OM on QoL in patients undergoing oncologic treatment. A systematic search for studies evaluating the impact of OM on QoL was performed in MEDLINE and Embase databases from inception to December 2018 using the MeSH terms for the keywords “Antineoplastic”, “Stomatitis”, and “Quality of life”. Studies were initially assessed based on the selection criteria and underwent a selection process based on the title and abstract followed by a full text review. Data extraction was performed into a standardized data collection form to collect data pertaining to the author/year, study design, study characteristics, mucositis assessment, QoL assessment and results. A qualitative assessment was performed. A total of 459 articles were selected after removal of duplicates. Following the full text review, only ten articles qualified for the systematic review based on the selection criteria. Several studies have identified a correlation between the severity of mucositis and reduction in QoL. The impact of OM on QoL extend beyond the local oral complications and has been shown to affect the physical, emotional, and psychological functional domains. However, heterogeneity in the study parameters and evaluation (cancer types, treatment regimens, chosen time points (during or after therapy) and the instruments used for QoL measurements) does not permit a robust assessment of the impact of OM on QoL. A standardized approach to the measurement of oral mucositis and evaluation of QoL is required to enhance the utility of QoL data in patients afflicted with oral mucositis following cancer treatment.

Carbon Ion Therapy: A Modern Review of an Emerging Technology

Radiation therapy is one of the most widely used therapies for malignancies. The therapeutic use of heavy ions, such as carbon, has gained significant interest due to advantageous physical and radiobiologic properties compared to photon based therapy. By taking advantage of these unique properties, carbon ion radiotherapy may allow dose escalation to tumors while reducing radiation dose to adjacent normal tissues. There are currently 13 centers treating with carbon ion radiotherapy, with many of these centers publishing promising safety and efficacy data from the first cohorts of patients treated. To date, carbon ion radiotherapy has been studied for almost every type of malignancy, including intracranial malignancies, head and neck malignancies, primary and metastatic lung cancers, tumors of the gastrointestinal tract, prostate and genitourinary cancers, sarcomas, cutaneous malignancies, breast cancer, gynecologic malignancies, and pediatric cancers. Additionally, carbon ion radiotherapy has been studied extensively in the setting of recurrent disease. We aim to provide a comprehensive review of the studies of each of these disease sites, with a focus on the current trials using carbon ion radiotherapy.

Dosimetric parameters predictive of nasolacrimal duct obstruction after carbon-ion radiotherapy for head and neck carcinoma

BACKGROUND AND PURPOSE

Little information is available on the risk factors for nasolacrimal duct obstruction after radiotherapy for head and neck tumors. We investigated the incidence and predictive dosimetric parameters for nasolacrimal duct obstruction following carbon-ion radiotherapy for head and neck tumors.

MATERIALS AND METHODS

Twenty-eight patients with head and neck non-squamous cell carcinoma were analyzed in this single-institution prospective study. More than half of the tumors were located in the nasal cavity and maxillary sinus. Carbon-ion radiotherapy consisting of 57.6 or 64.0 Gy(relative biological effectiveness; RBE) in 16 fractions was administered. Nasolacrimal duct obstruction was recorded according to Common Terminology Criteria for Adverse Events version 4.0. Cutoff values were determined using receiver operating characteristic (ROC) curve analysis. VX indicates the volume irradiated with X Gy(RBE).

RESULTS

The median follow-up period was 60.3 months. Incidences of Grade 1 and 2 nasolacrimal duct obstructions were 46% (13/28) and 7% (2/28), respectively; no Grade 3 or greater toxicities were recorded. Throughout the dose range, the volumes of the irradiated nasolacrimal ducts were significantly higher in the obstruction-positive patients than in the obstruction-negative patients (p < 0.001 for V10, V20, V30, V40, V50, and V60). Cutoff values determined by the ROC curve analysis classified the obstruction-positive patients with an accuracy of >96% over the entire range of V10-V60.

CONCLUSION

The incidence and predictive dosimetric parameters for nasolacrimal duct obstruction after carbon-ion radiotherapy were demonstrated in a prospective cohort. These data should help optimize carbon-ion radiotherapy treatments for patients with head and neck tumors.

Prospective Observational Study of High-Dose Carbon-Ion Radiotherapy for Pelvic Recurrence of Rectal Cancer (GUNMA 0801)

Background and purpose: Favorable clinical outcomes of carbon-ion radiotherapy for pelvic recurrence of rectal cancer have been described by previous prospective phase I/II and II studies; however, these studies were performed at a single institution. Therefore, we conducted a prospective observational study aimed at exploring whether carbon-ion radiotherapy for post-operative pelvic recurrence of rectal cancer provides a less invasive local treatment strategy with higher cure rates than other anticancer treatments.

Materials and methods: Patients (1) with pelvic recurrence of rectal cancer, as confirmed by histology or diagnostic imaging; (2) without distant metastasis; (3) who had undergone curative resection of their primary disease and regional lymph nodes, without gross or microscopic residual disease; and (4) with radiographically measurable tumors were included in this study. The total carbon-ion radiotherapy dose for all patients was 73.6 Gy [relative biological effectiveness (RBE)] administered in 16 fractions once daily for 4 days a week (Tuesday to Friday).

Results: A total of 28 patients were enrolled between October 2011 and July 2017. The median follow-up duration was 38.9 months. The 3-year overall survival, local control, and progression-free survival rates were 92, 86, and 31%, respectively. At the time of the analysis, 4 patients had local recurrence, and 7 had died of rectal cancer. None of the patients developed grade 3 or higher acute toxicities. Late toxicities occurred in 2 and 7 patients who developed grade 3 pelvic infection and grade 2 peripheral neuropathy, respectively.

Conclusion: Carbon-ion radiotherapy for pelvic recurrence of rectal cancer showed favorable clinical outcomes and is a highly curative and less invasive local treatment.

Prospective Study of Isolated Recurrent Tumor Re-irradiation With Carbon-Ion Beams

Purpose: To perform a prospective study to evaluate the efficacy and safety of isolated recurrent tumor re-irradiation with carbon-ion radiotherapy (RT).

Methods and Materials: The inclusion criteria were clinically proven recurrent tumors, measurable by computed tomography or magnetic resonance imaging, patients ≥ 16 years old, performance status scores between 0 and 2, isolated tumor at a previously irradiated site, and a life expectancy > 6 months. The exclusion criteria were tumor invasion into the gastrointestinal tract or a major blood vessel, uncontrolled infection, early recurrence (<3 months), and severe concomitant diseases. The primary end-point was the local control rate, the secondary end-points including the overall survival rate, and adverse events.

Results: Between December 2013 and March 2016, 22 patients were enrolled in this prospective study. All patients were re-irradiated with carbon-ion RT with radical intent. Five patients had rectal cancer, 4 had sarcoma, 4 had lung cancer, 3 had hepatic cell carcinoma, and 6 had other tumors. The median follow-up time was 26 months. Eight patients developed local recurrence, and the 1- and 2-year local control rates were 71 and 60%, respectively. Eight patients died of their cancers and 2 died of other diseases. The 1- and 2-year overall survival rates were 76 and 67%, respectively. There were no grade 2 or higher acute adverse events and 4 patients (18%) developed grade 3 late adverse events. The group with the longer interval (>16 months) between the first RT and re-irradiation had significantly better outcomes than the shorter interval group (≤ 16 months).

Conclusions: Re-irradiation, using carbon-ion RT with radical intent, had favorable local control and overall survival rates without severe toxicities for selected patients. Re-irradiation has the potential to improve clinical outcomes for isolated, local, recurrent tumors; further investigations are required to confirm the therapeutic efficacy.

Results of a combination treatment with intensity modulated radiotherapy and active raster-scanning carbon ion boost for adenoid cystic carcinoma of the minor salivary glands of the nasopharynx

OBJECTIVES

We aimed to present the first clinical results for adenoid cystic carcinoma (ACC) of the nasopharynx after primary radiotherapy (RT) with the focus on local control (LC) and patterns of recurrence.

MATERIALS AND METHODS

We retrospectively analyzed 59 patients with ACC of the nasopharynx, who were treated with bimodal radiotherapy (RT) consisting of intensity modulated radiotherapy and carbon ion boost at the Heidelberg Ion-Beam Therapy Center between 2009 and 2018. The patients had predominantly inoperable (n = 42, 72%) or incompletely resected (n = 17, 29%) tumors. Kaplan-Meier estimates and the log-rank (Mantel-Cox) test were used for univariate and multivariate analyses.

RESULTS

The median follow-up was 32 months. At last follow-up, 67% of the patients were still alive (n = 39/58), of whom 74% were free of progression (n = 29/39). The 2-year LC, distant progression-free survival (DPFS) and overall survival (OS) were 83%, 81%, 87% and the estimated 5-year LC, DPFS and OS were 49%, 54%, 69%, respectively. LC was significantly inferior in patients with large tumor volumes (gross tumor volume, GTV > 100 cc, p = 0.020) and T4 tumors (p = 0.021). The majority of the recurrences occurred at the margin, where critical structures were spared (n = 11/19, 58%). Overall, grade 3 toxicity was moderate with 12% acute and 8% late side effects.

CONCLUSION

Bimodal RT including active raster-scanning carbon ion boost for nasopharyngeal ACC resulted in adequate LC and OS rates with moderate toxicity. T4 stage, large tumor volume and the necessary dose sparing in critical structures, i.e. optic nerves, brain stem and orbit, negatively affected LC.

Carbon-ion radiotherapy in accelerated hypofractionated active raster-scanning technique for malignant lacrimal gland tumors: feasibility and safety

Introduction

We evaluated treatment outcomes of CIRT in an active raster-scanning technique alone or in combination with IMRT for lacrimal gland tumors.

Methods

A total of 24 patients who received CIRT for a malignant lacrimal gland tumor at the HIT between 2009 and 2018 were analyzed retrospectively for LC, OS, and distant progression-free survival (DPFS) using Kaplan-Meier estimates. Toxicity was assessed according to the CTCAE version 5.

Results

Median follow-up was 30 months and overall median LC, OS, and DPFS 24 months, 36 months, and 31 months, respectively. Two-year LC, OS, and DPFS of 93%, 96%, and 87% with CIRT was achieved for all patients. Local failure occurred only in patients with ACC and after a median follow-up of 30 months after the completion of RT (n=5, 21%; P=0.09). We identified a significant negative impact of a macroscopic tumor disease, which was diagnosed on planning CT or MRI before RT, on LC (P=0.026). In contrast, perineural spread (P=0.661), T stage (P=0.552), and resection margins in operated patients (P=0.069) had no significant impact on LC. No grade ≥3 acute or grade >3 chronic toxicity occurred. Late grade 3 side effects were identified in form of a wound-healing disorder 3 months after RT in one patient and temporal lobe necrosis 6 months after RT in another (n=2, 8%).

Conclusion

Accelerated hypofractionated active raster-scanning CIRT for relative radio-resistant malignant lacrimal gland tumors results in adequate LC rates and moderate acute and late toxicity. Nevertheless, LC for ACC histology remains challenging and risk factors for local recurrence are still unclear. Further follow-up is necessary to evaluate long-term clinical outcome.

A multi-institutional retrospective study of carbon-ion radiotherapy for non-squamous cell malignant tumors of the nasopharynx: Subanalysis of Japan Carbon-Ion Radiation Oncology Study Group study 1402 HN

Background

This multi‐institutional retrospective study focused on the clinical outcome of carbon‐ion radiotherapy (C‐ion RT) for non‐squamous cell malignant tumors of the nasopharynx.

Methods

The Japan Carbon‐ion Radiation Oncology Study Group collected and analyzed data for 43 patients with non‐squamous cell malignant tumors of the nasopharynx treated with C‐ion RT at four institutions in Japan.

Results

Twenty‐nine patients had adenoid cystic carcinomas, seven had malignant melanomas, three had adenocarcinomas, two had mucoepidermoid carcinomas, and two had other pathologies. Twenty‐six of the 43 patients (61%) had T4 tumors. The most common dose‐fractionation schedule was 64 Gy (relative biological effectiveness) in 16 fractions. The median follow‐up period was 30 months. The 2‐year local control (LC) and overall survival (OS) rates were 88% and 84%, respectively. For late toxicity, one patient developed grade 4 optic nerve disorder and two developed grade 5 pharyngeal hemorrhage. Actual incidence of grade 3 or higher late adverse events was 19%, and included cranial nerve dysfunction, jaw bone necrosis, central nervous system necrosis, and ear inflammation.

Conclusions

C‐ion RT provided good LC and OS rates with acceptable toxicity for treatment of non‐squamous cell malignant tumors of the nasopharynx.

Accelerated Hypofractionated Active Raster-Scanned Carbon Ion Radiotherapy (CIRT) for Laryngeal Malignancies: Feasibility and Safety

(1) Background: The authors present the first results of active raster-scanned carbon ion radiotherapy (CIRT) for radioresistant laryngeal malignancies regarding efficacy and toxicity. (2) Methods: 15 patients with laryngeal adenoid cystic carcinoma (ACC; n = 8; 53.3%) or chondrosarcoma (CS; n = 7; 46.7%) who underwent radiotherapy with carbon ions (C12) at the Heidelberg Ion Beam Therapy Center (HIT) between 2013 and 2018 were identified retrospectively and analyzed for local control (LC), overall survival (OS), and distant progression-free survival using the Kaplan–Meier method. CIRT was applied either alone (n = 7, 46.7%) or in combination with intensity modulated radiotherapy (IMRT) (n = 8, 53.3%). The toxicity was assessed according to the Common Toxicity Terminology Criteria for Adverse Events (CTCAE) v4.03. (3). Results: the median follow-up was 24 months (range 5–61 months). Overall, the therapy was tolerated very well. No grade >3 acute and chronic toxicity could be identified. The most reported acute grade 3 side effects were acute dysphagia (n = 2; 13%) and acute odynophagia (n = 3; 20%), making supportive nutrition via gastric tube (n = 2; 13.3%) and via high caloric drinks (n = 1; 6.7%) necessary due to swallowing problems (n = 4; 27%). Overall, chronic grade 3 toxicity in the form of chronic hoarseness occurred in 7% of the patients (n = 1; 7%). At the last follow-up, all the patients were alive. No local or locoregional recurrence could be identified. Only one patient with laryngeal ACC developed lung metastases three years after the first diagnosis. (4) Conclusions: the accelerated hypofractionated active raster-scanned carbon ion radiotherapy for radioresistant laryngeal malignancies is feasible in practice with excellent local control rates and moderate acute and late toxicity. Further follow-ups are necessary to evaluate the long-term clinical outcome.

The 150 most important questions in cancer research and clinical oncology series: questions 67-75 : Edited by Chinese Journal of Cancer

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which sparkle diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, 9 more questions are presented as followed. Question 67. How could we overcome the resistance of hepatocellular carcinoma against chemotherapeutics? Question 68. Is pursuit of non-covalent small-molecule binders of RAS proteins viable as a strategy of cancer drug discovery? Question 69. In what oligomeric structures do RAS proteins signal? Question 70. How can we achieve non-invasive early detection and diagnosis of lung cancer? Question 71. Does genetic information influence the volatolome enabling diagnosis of lung cancer with genetic mutations via cell headspace or breath analysis? Question 72. Is heavy ion beam radiotherapy effective to kill cancer stem cells? Question 73. Is there any diversity among different types of cancer in terms of sensitivity to heavy ion beam radiotherapy? Question 74. Can targeted alpha-particle therapy augment the effect of carbon ion radiotherapy on malignancies? Question 75. How does chromosomal instability drive tumor progression?

Prospective observational study of carbon-ion radiotherapy for non-squamous cell carcinoma of the head and neck

To evaluate the efficacy and safety of carbon-ion radiotherapy for non-squamous cell carcinoma of the head and neck, 35 patients were enrolled in this prospective study. The primary end-point was the 3-year local control rate, and the secondary end-points included the 3-year overall survival rate and adverse events. Acute and late adverse events were evaluated according to the Common Terminology Criteria for Adverse Events, version 4.0. The median follow-up time for all patients was 39 months. Thirty-two and three patients received 64.0 Gy (relative biological effectiveness) and 57.6 Gy (relative biological effectiveness) in 16 fractions, respectively. Adenoid cystic carcinoma was dominant (60%). Four patients had local recurrence and five patients died. The 3-year local control and overall survival rates were 93% and 88%, respectively. Acute grade 2-3 radiation mucositis (65%) and dermatitis (31%) was common, which improved immediately with conservative therapy. Late mucositis of grade 2, grade 3, and grade 4 were observed in 11, one, and no patients, respectively. There were no adverse events of grade 5. Carbon-ion radiotherapy achieved excellent local control and overall survival rates for non-squamous cell carcinoma. However, the late mucosal adverse events were not rare, and meticulous treatment planning is required. Trial registration no. UMIN000007886.