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

Abstract

BackgroundProton 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 methodsWe 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.ResultsTwelve 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.ConclusionPBT 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.

Hybrid Treatment Planning for Chest Wall Irradiation Utilizing Three-Dimensional Conformal Radiotherapy (3DCRT), Intensity-Modulated Radiation Therapy (IMRT), and Volumetric Modulated Arc Therapy (VMAT): A Systematic Review

“…Furthermore, it has been observed that the incidence of coronary events increases by 7.4 per 1 Gy increase in the mean heart dose [33]. In most studies, hybrid techniques (H-VMAT, H-IMRT) had lower heart doses than VMAT or IMRT [13][14][15][16][17][18]20], but some studies reported no statistically significant difference [25,27]. However, these latter studies included both breast and chest wall patients, which could affect the final result.…”

“…The search was conducted in the PubMed and Scopus databases using the population, intervention, control, and outcomes (PICO) framework to establish the search terms (Table 1, Appendix). This type of review is widely used to expand upon the current knowledge base to drive the development of healthcare practice [16][17][18]. Boolean search phrase combinations were used to guarantee that all pertinent articles were found (Supplementary A).…”

More than Five Decades of Proton Therapy: A Bibliometric Overview of the Scientific Literature

“…For instance, the peculiar dose distribution of protons leads to a significant reduction in the low "dose bath" absorbed by surrounding healthy tissues that are typically seen in photon-based techniques like intensity-modulated radiotherapy (IMRT). This could result in several advantages, like reducing (1) acute and late treatment-related side effects, (2) radiationinduced secondary-cancer risk (mainly in young patients), and (3) immune system depression (thanks to the lower exposure of circulating lymphocytes and immune organs like lymph nodes) [5][6][7][8][9][10][11][12]. Moreover, technological advances have allowed the transition from passive scattering to pencil-beam scanning (PBS), with even higher conformity of the dose distribution-a technique routinely introduced by the Paul Scherrer Institute (Villigen, Switzerland) in the late 1990s.…”

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

“…Proton therapy (PT) offers several advantages over photon therapy, including the elimination of exit dose and the possibility to tailor the dose resulting from the physical characteristics of the beams with Bragg peaks [ 10 ]. Several dose comparisons and clinical studies have shown significant normal tissue dose reductions favoring PT [ 11 , 12 , 13 ].…”