Mixed Photon and Carbon-Ion Beam Radiotherapy in the Management of Non-Metastatic Nasopharyngeal Carcinoma

Toxicity profile of patients treated with proton and carbon-ion therapy for primary nasopharyngeal carcinoma: A systematic review and meta-analysis

BACKGROUND

Proton and carbon-ion therapy may spare normal tissues in regions with many critical structures surrounding the target volume. As toxicity outcome data are emerging, we aimed to synthesize the published data for the toxicity outcomes of proton or carbon-ion therapy (together known as particle beam therapy [PBT]) for primary nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

We searched PubMed and Scopus electronic databases to identify original studies reporting toxicity outcomes following PBT of primary NPC. Quality assessment was performed using NIH's Quality Assessment Tool. Reports were extracted for information on demographics, main results, and clinical and dose factors correlates. Meta-analysis was performed using the random-effects model.

RESULTS

Twelve studies were selected (six using mixed particle-photon beams, five performed comparisons to photon-based therapy). The pooled event rates for acute grade ≥2 toxicities mucositis, dermatitis, xerostomia weight loss are 46% (95% confidence interval [95% CI]-29%-64%, I2 = 87%), 47% (95% CI-28%-67%, I2 = 87%), 16% (95% CI-9%-29%, I2 = 76%), and 36% (95% CI-27%-47%, I2 = 45%), respectively. Only one late endpoint (xerostomia grade ≥2) has sufficient data for analysis with pooled event rate of 9% (95% CI-3%-29%, I2 = 77%), lower than intensity-modulated radiotherapy 27% (95% CI-10%-54%, I2 = 95%). For most endpoints with significant differences between the PBT and photon-based therapies, PBT resulted in better outcomes. In two studies where dose distribution was studied, doses to the organs at risk were independent risk factors for toxicities.

CONCLUSION

PBT may reduce the risk of acute toxicities for patients treated for primary NPC, likely due to dose reduction to critical structures. The pooled event rate for toxicities derived in this study can be a guide for patient counseling.

A qualitative exploration of fear of progression in patients with nasopharyngeal carcinoma treated with proton and heavy ion therapy

OBJECTIVE

To investigate fear of progression (FOP) in nasopharyngeal carcinoma (NPC) patients treated with proton and heavy ion therapy.

METHODS

Thirty NPC patients were selected for face-to-face semistructured interviews through purposive sampling while using the phenomenological approach in qualitative research. The interviews were transcribed, organized, and analyzed by applying Colaizzi's seven-step analysis.

RESULTS

Seven themes were summarized, namely, illness uncertainty, trapped into insecurity (including four categories: insecurity about the possibility of discrimination, insecurity about the possibility of the inability to tolerate the pain of retreatment, insecurity about the difficulty of retreatment after recurrence, and insecurity of waiting for test results), hopelessness, loss, guilt toward children, enhancing tolerance toward family, and self-emotional comfort.

CONCLUSION

We found that women with children and patients who experienced their first episode underwent significant FOP. Patients at the postgraduate level and above were more inclined to feel loss. The finding that respondents expressed is intense FOP while waiting for test results, which provides a reference for the analysis of the trajectory of FOP. Health care professions should be cognitively aware the importance of eliminating patients' uncertainty and insecurity about disease to enhance their positive experience in coping with cancer.

Current Radiotherapy Considerations for Nasopharyngeal Carcinoma

Radiotherapy is the primary treatment modality for nasopharyngeal carcinoma (NPC). Successful curative treatment requires optimal radiotherapy planning and precise beam delivery that maximizes locoregional control while minimizing treatment-related side effects. In this article, we highlight considerations in target delineation, radiation dose, and the adoption of technological advances with the aim of optimizing the benefits of radiotherapy in NPC patients.

Flourish of Proton and Carbon Ion Radiotherapy in China

Proton and heavy ion therapy offer superior relative biological effectiveness (RBE) in the treatment of deep-seated tumors compared with conventional photon radiotherapy due to its Bragg-peak feature of energy deposition in organs. Many proton and carbon ion therapy centers are active all over the world. At present, five particle radiotherapy institutes have been built and are receiving patient in China, mainly including Wanjie Proton Therapy Center (WPTC), Shanghai Proton Heavy Ion Center (SPHIC), Heavy Ion Cancer Treatment Center (HIMM), Chang Gung Memorial Hospital (CGMH), and Ruijin Hospital affiliated with Jiao Tong University. Many cancer patients have benefited from ion therapy, showing unique advantages over surgery and chemotherapy. By the end of 2020, nearly 8,000 patients had been treated with proton, carbon ion or carbon ion combined with proton therapy. So far, there is no systemic review for proton and carbon ion therapy facility and clinical outcome in China. We reviewed the development of proton and heavy ion therapy, as well as providing the representative clinical data and future directions for particle therapy in China. It has important guiding significance for the design and construction of new particle therapy center and patients’ choice of treatment equipment.