Carbon ion radiotherapy for locally advanced squamous cell carcinoma of the external auditory canal and middle ear

[Current status of the diagnosis and treatment of temporal bone squamous cell carcinoma]

Temporal bone squamous cell carcinoma, which is rare in the clinical setting, is the most common type of temporal bone malignancy. Its rarity makes the staging, the way of temporal bone resection, the management of parotid gland and cervical lymph node, and the application of radiotherapy and chemotherapy still controversial.There is no unanimous consensus and guideline about it to date at home and abroad.This paper reviewed the recent advance in the diagnosis and treatment of temporal bone squamous cell carcinoma in the hope of providing some help and reference for the management of the disease.

Normal Tissue Complication Probability Model for Acute Radiation Dermatitis in Patients with Head and Neck Cancer Treated with Carbon Ion Radiotherapy

PURPOSE

This study aimed to explore the prognostic factors associated with acute radiation dermatitis (ARD). A normal tissue complication probability (NTCP) model for ARD in patients with head and neck cancer (HNC) treated with carbon ion radiotherapy (CIRT) was developed.

MATERIALS AND METHODS

A total of 187 patients were included in the analysis, and the endpoint was ≥grade 2 ARD. The biological and physical dose-surface parameters associated with ARD were used in the logistic regression model. The mean areas under the receiver operating characteristic curve (AUC) in the internal cross-validation and Akaike's corrected Information Criterion (AICc) were examined for model evaluation and selection. The multivariate logistic regression NTCP models were established based on factors with weak correlation.

RESULTS

Tumour volume, planning target volume to the skin, radiation technique and all dose-surface parameters were significantly associated with ARD (P < 0.05). Models with high performance for grade 2-3 ARD were constructed. The most significant prognostic predictors were S_{40 Gy (relative biological effectiveness, RBE)} and S_{20 Gy} [absolute surface area receiving RBE-weighted dose of 40 Gy (RBE) or physical dose of 20 Gy]. The internal cross-validation-based AUCs for models with S_{40 Gy (RBE)} and S_{20 Gy} were 0.78 and 0.77, respectively. The biological and physical dose-surface parameters had similar performance at various dose levels. However, the performance of the multivariate NTCP models based on two factors was not better than that of the univariate models.

CONCLUSIONS

NTCP models for ARD may provide a basis for the development of individualised treatment strategies and reduce the incidence of severe ARD in patients with HNC receiving CIRT. Furthermore, biological and physical dose-surface parameter-based models are comparable. However, further validation with more evaluation parameters is warranted.

Treatment Strategies for Malignancies of the External Auditory Canal

Malignant tumors of the external auditory canal (EAC) are rare tumors in the head and neck. Delayed diagnosis is not uncommon because the symptoms of early tumors are nonspecific. Various surgical and oncological treatment modalities have been reported. Decision-making depends on pathological feature and stage of the lesions, patient’s general condition and preference, and physician’s experience and skill. Radical surgery is widely accepted as the primary treatment of choice. Postoperative radiotherapy is used more often to improve local and regional control of the disease. Chemotherapy is usually recommended for advanced disease, residual disease, and metastasis. Prognosis is affected by multiple factors such as TNM stage, surgical margin, pathological type and differentiation of tumor, involvement of facial nerve, and so on. Although the survival rate is improved significantly over the past several decades with the development of skull base surgery, neuroradiology, anesthesiology, and oncology, it remains challenging to diagnose and treat EAC malignancies due to the rarity, the local anatomical complexity of temporal bone, and the lack of standard TNM staging system.

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.

A retrospective multicenter study of carbon-ion radiotherapy for external auditory canal and middle ear carcinomas

Background

We conducted a retrospective multicenter study to assess the clinical outcomes of carbon‐ion radiotherapy (CIRT) for head and neck malignancies (Japan Carbon‐Ion Radiation Oncology Study Group [J‐CROS] study: 1402 HN). We aimed to evaluate the safety and efficacy of CIRT in patients with external auditory canal (EAC) and middle ear (ME) carcinomas.

Methods

Thirty‐one patients treated with CIRT at four Japanese institutions were analyzed. Fourteen patients (45.2%) had squamous cell carcinomas, 13 (41.9%) had adenoid cystic carcinomas, and four (12.9%) had other types. Nineteen (61.3%), six (19.4%), three (9.7%), and three (9.7%) patients had T4, T3, T2, and T1 disease, respectively. All patients had N0M0 status. The median radiation dose was 64 Gy (relative biological effectiveness) in 16 fractions. The median gross tumor volume was 33.3 mL.

Results

The median follow‐up period was 18.4 months (range, 5.1‐85.6). The 1‐ and 3‐year local control and overall survival rates were 75.0% and 55.0% and 79.3% and 58.7%, respectively. Regarding grade 3 or higher toxicities, three patients (9.7%) had grade 3 dermatitis, one (3.2%) had grade 3 mucositis, and two (6.5%) had grade 3 central nervous necrosis (ie, radiation‐induced brain necrosis). No grade 4 or worse reactions were observed.

Conclusion

CIRT was effective for EAC and ME carcinomas.

Treatment and Outcomes of Carcinoma of the External and Middle Ear: The Validity of En Bloc Resection for Advanced Tumor

Carcinoma of the external and middle ear is a very rare disease. Despite the various treatment modalities available, its prognosis is still poor. We aimed to analyze the treatment modalities, outcomes, and validity of surgical approaches, especially in advanced tumors in the ear. Twenty-five patients with carcinoma of the external and middle ear were retrospectively analyzed. The modified Pittsburgh staging system was used for staging of the patients. Overall and disease-free survival was estimated using of Kaplan-Meier method. In our cohort of 25 patients, the majority (76%) had tumor located in external auditory meatus. The most common histologic subtype was squamous cell carcinoma (80%). More than half of patients (56%) had tumor stage IV. In the stage IV group, five patients underwent subtotal temporal bone resection and ipsilateral neck dissection. Seven patients underwent definitive radiotherapy. The remaining two patients underwent palliative chemotherapy. The 2-year overall and disease-free survival for patients with tumor stage IV was 67.7% and 57.8%, respectively. In patients with tumor stage IV, the 2-year overall survival for patients who underwent surgery was 80.0% versus 53.6% for those who underwent radiotherapy (P = 0.16). The 2-year disease-free survival for patients who underwent surgery was 80.0% versus 28.6% for those who underwent radiotherapy (P = 0.15). In the present study, the outcome of patients who received surgical treatment tended to be better than that of patients who received radiation therapy. Our results suggest that en bloc resection could be the first choice even in the advanced disease stage.

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.

Carbon Ion Radiotherapy: A Review of Clinical Experiences and Preclinical Research, with an Emphasis on DNA Damage/Repair

Compared to conventional photon-based external beam radiation (PhXRT), carbon ion radiotherapy (CIRT) has superior dose distribution, higher linear energy transfer (LET), and a higher relative biological effectiveness (RBE). This enhanced RBE is driven by a unique DNA damage signature characterized by clustered lesions that overwhelm the DNA repair capacity of malignant cells. These physical and radiobiological characteristics imbue heavy ions with potent tumoricidal capacity, while having the potential for simultaneously maximally sparing normal tissues. Thus, CIRT could potentially be used to treat some of the most difficult to treat tumors, including those that are hypoxic, radio-resistant, or deep-seated. Clinical data, mostly from Japan and Germany, are promising, with favorable oncologic outcomes and acceptable toxicity. In this manuscript, we review the physical and biological rationales for CIRT, with an emphasis on DNA damage and repair, as well as providing a comprehensive overview of the translational and clinical data using CIRT.

Hypofractionated Stereotactic Radiotherapy for Auditory Canal or Middle Ear Cancer

BACKGROUND

Stereotactic radiotherapy (SRT) may represent a new treatment option for individuals with auditory canal or middle ear cancer.

METHODS

Study participants with pathologically proven ear cancer were treated with SRT (35 Gy for 3 fractions or 40 Gy for 5 fractions) as first-line therapy. When local tumor recurrence developed following SRT, subtotal temporal bone resection and postoperative chemoradiotherapy were performed as salvage treatment. Boluses were used for the initial 14 study patients.

RESULTS

Twenty-nine study participants were enrolled and staged with T1 (n = 3), T2 (n = 7), T3 (n = 14), or T4 disease (n = 5). Three-year overall survival rates were 69% for T1/2 disease, 79% for T3 disease, and 0% for T4 disease. Three-year local control rates were 70% for T1/2 disease, 50% for T3 disease, and 20% for T4 disease. Grade 2 or higher dermatitis or soft-tissue necrosis occurred more frequently in study patients treated with boluses (8/14 vs 2/15; P = .02). Salvage treatment was safely performed for 12 recurrent cases.

CONCLUSIONS

These results suggest that SRT outcomes are promising for patients with ear cancer (? T3 disease). The rate of toxicity was acceptable in the study patients treated without boluses. Outcomes of salvage surgery and postoperative radiotherapy following SRT were also encouraging.

Multicenter experiences in temporal bone cancer surgery based on 89 cases

OBJECTIVE

To present outcomes of extensive surgery: lateral, subtotal, total petrosectomies in patients with temporal bone invasion resulting from specific primary cancers.

STUDY DESIGN

Retrospective case review.

SETTING

Four tertiary referral centers.

MATERIAL

89 patients with cancer of the temporal bone treated between January 2006 and December 2010.

INTERVENTION

Multidisciplinary team approach including surgical resection, reconstruction, and postoperative radiotherapy.

MAIN OUTCOME MEASURE

Disease-specific survival, overall survival.

RESULTS

In 27.0% of the patients, relapse was reported, with an average of 6.3 months after surgery; 31 patients (34.8%) died during the follow-up. The average mortality was 22.1 months. Fifty-four patients (58.7%) stayed alive during the time of observation. The average survival time was 42.0 months. The median time of survival with relapse was 12 months (range: 1-51 months). The three-year disease-free rate was 38.0% and the overall survival rate was 58.7%.

CONCLUSIONS

Petrosectomy is an effective treatment for malignant temporal bone invasion. The probability of a good outcome was statistically decreased with a high T grade, positive margins, and salvage surgery. Younger age is connected with better prognosis. One of the major tasks remains to improve detection and to shorten the time to diagnosis, keeping in mind that symptoms are insidious and in younger people, the time before diagnosis was longer.

The contribution of CT and MRI in staging, treatment planning and prognosis prediction of malignant tumors of external auditory canal

Carcinomas of external auditory canal (EAC) are rare. Radiological imaging particular in computed tomography (CT) and magnetic resonance imaging (MRI) plays an important role in the staging, treatment planning and follow up of the patients with malignant EAC tumor. This article aims to review the role of CT and MRI in the describing different tumor growth pattern, tumor staging, treatment planning, follow up and predicting the prognosis of malignant tumors of EAC.

Tumor Stage-Related Role of Radiotherapy in Patients with an External Auditory Canal and Middle Ear Carcinoma

PURPOSE

The purpose of this study was to evaluate the clinical outcomes of patients treated with radiotherapy (RT) for a carcinoma of the external auditory canal (EAC) and middle ear.

MATERIALS AND METHODS

The records of 32 patients who received RT from 1990 to 2013 were reviewed retrospectively. The Pittsburgh classification was used to stage all the cancers (early stage, T1/T2 [n=12]; advanced stage, T3/T4 or N positive [n=20]). Twenty-one patients (65.6%) were treated with postoperative RT and 11 patients (34.4%) were treated with definitive RT. The median radiation doses for postoperative and definitive RT were 60 Gy and 64.8 Gy, respectively. Chemotherapy was administered to seven patients (21.9%).

RESULTS

The 5-year overall survival and disease-free survival rates for all patients were 57% and 52%, respectively. The disease control rates for the patients with early stage versus advanced stage carcinomawere 55.6% (5/9) and 50% (6/12) in the postoperative RT group and 66.7% (2/3) and 37.5% (3/8) in the definitive RT group, respectively. Overall, 15 cases (14 patients, 46.7%) experienced treatment failure; these failures were classified as local in four cases, regional in one case, and distant in 10 cases. The median follow-up period after RT was 51 months (range, 7 to 286 months).

CONCLUSION

Patients with early stage carcinoma achieved better outcomes when definitive RT was used. Advanced stage carcinoma patients experienced better outcomes with postoperative RT. The high rate of distant failure after RT, with or without surgery, reflected the lack of a consensus regarding the best therapeutic approach for treating carcinoma of the EAC and middle ear.