Effectiveness of tomotherapy vs linear accelerator image-guided intensity-modulated radiotherapy for localized pharyngeal cancer treated with definitive concurrent chemoradiotherapy: a Taiwanese population-based propensity score-matched analysis

Helical tomotherapy and two types of volumetric modulated arc therapy: dosimetric and clinical comparison for several cancer sites

Radiotherapy accelerators have undergone continuous technological developments. We investigated the differences between Radixact™ and VMAT treatment plans. Sixty patients were included in this study. Dosimetric comparison between the Radixact™ and VMAT plans was performed for six cancer sites: whole-brain, head and neck, lymphoma, lung, prostate, and rectum. The VMAT plans were generated with two Elekta linear accelerators (Synergy^® and Versa HD™). The planning target volume (PTV) coverage, organs-at-risk dose constraints, and four dosimetric indexes were considered. The deliverability of the plans was assessed using quality assurance (gamma index evaluation) measurements; clinical judgment was included in the assessment. The mean AAPM TG218 (3%-2 mm, global normalization) gamma index values were 99.4%, 97.8%, and 96.6% for Radixact™, Versa HD™, and Synergy®, respectively. Radixact™ performed better than Versa HD™ in terms of dosimetric indexes, hippocampi D_100%, spinal cord D_max, rectum V_{38.4  Gy}, bladder V_{30 Gy}, and V_{40 Gy}. Versa HD™ saved more of the (lungs-PTV) V_{5 Gy} and (lungs-PTV) D_mean, heart D_mean, breasts V_{4 Gy}, and bowel V_{45 Gy}. Regarding Synergy^®, the head and neck Radixact™ plan saved more of the parotid gland, oral cavity, and supraglottic larynx. From a clinical point of view, for the head and neck, prostate, and rectal sites, the Radixact™ and Versa HD™ plans were similar; Radixact™ plans were preferable for the head and neck and rectum to Synergy^® plans. The quality of linac plans has improved, and differences with tomotherapy have decreased. However, tomotherapy continues to be an essential add-on in multi-machine departments.

Age Alone Is Not a Barrier to Concurrent Chemoradiotherapy for Advanced Head and Neck Cancer

BACKGROUND

Head and Neck Cancer (HNC) is associated with significant morbidity and mortality, especially when high stage disease is present. There exists a range of options for the management of locoregionally advanced HNC, though doubt remains as to the optimal strategy in the elderly population.

AIMS

To evaluate the benefits imparted by concurrent chemoradiotherapy (CCRT) to the elderly population of HNC patients in Ireland.

METHODS

A retrospective cohort study was conducted using 20 years of cancer registry data provided by the National Cancer Registry of Ireland. Cox multivariate regression analysis was applied to test for the benefits of CCRT in HNC.

RESULTS

Survival analysis showed an overall benefit to the use of CCRT in patients with advanced disease over 70 years, particularly when used for hypopharyngeal, oropharyngeal, and laryngeal malignancy. There was a benefit to cancer-specific but not all-cause mortality in those over 75 years, and no benefit was observed to the addition of chemotherapy in those over 80 years; only 8 patients over 80 received CCRT. There was no statistically significant difference in the benefits derived by those over 70 years relative to those under 70 years.

CONCLUSION

CCRT confers significant survival benefits to appropriately selected elderly HNC patients and should therefore not be withheld solely on the basis of age.

Comparative effectiveness of simultaneous integrated boost vs sequential intensity-modulated radiotherapy for oropharyngeal or hypopharyngeal cancer patients: A population-based propensity score-matched analysis

There were 2 common radiotherapy dose fractionation strategies in head-and-neck cancer patients (such as oropharyngeal cancer [OPC] or hypopharyngeal cancer [HPC]) treated with radiotherapy: intensity-modulated radiotherapy using simultaneous integrated boost (IMRT-SIB) and sequential IMRT (IMRT-SEQ). There is a lack of high-level clinical evidence to compare IMRT-SIB vs IMRT-SEQ specifically for OPC or HPC patients. The present study investigated the survival outcomes of OPC or HPC patients receiving definite concurrent chemoradiotherapy (CCRT) with either IMRT-SIB or IMRT-SEQ via a population-based propensity score (PS)-based analysis.The localized stage OPC or HPC patients diagnosed between 2011 and 2015 were identified based on the Health and Welfare Data Science Center database in Taiwan. These patients received definitive CCRT with either IMRT-SIB or IMRT-SEQ. We constructed a PS-matched cohort (1:1 for IMRT-SIB vs IMRT-SEQ) to balance observable potential confounders. We compared the hazard ratio (HR) of death between IMRT-SIB and IMRT-SEQ during the entire follow-up period. We also evaluated other disease outcome or subgroups.Our study population constituted 200 patients with well balance in observed covariables. The HR of death when IMRT-SIB was compared to IMRT-SEQ was 1.23 (95% confidence interval 0.84-1.80, P = .29). The results were similar for other disease outcome or subgroups.We found the survival outcome might be comparable for those treated with IMRT-SIB vs those treated with IMRT-SEQ.

Effectiveness of image-guided radiotherapy for rectal cancer patients treated with neoadjuvant concurrent chemoradiotherapy: A population-based propensity score-matched analysis

AIM

The effects of image-guided radiotherapy (IGRT, an advanced RT technology) have been debated in the literature. We compared the outcomes of locally advanced rectal cancer (LARC) patients treated with neoadjuvant concurrent chemoradiotherapy (NCCRT; with vs without IGRT) in a large population-based propensity score (PS)-matched analysis.

METHODS

We identified LARC patients diagnosed between 2007 and 2015 via the Taiwan cancer registry (TCR) and constructed a PS-matched cohort to balance observable potential confounders. Outcomes (R0 resection, overall survival, incidence of local regional recurrence [ILRR], rectal cancer mortality [IRCM], other cancer mortality [IOCM] and cardiovascular mortality [ICVM]) were obtained from TCR and the national death registry. We compared the hazard ratio (HR) of death and other endpoints between IGRT and non-IGRT groups. We performed supplementary analysis (SA) to evaluate the robustness of these results in a subgroup, taking an additional potential confounder into account.

RESULTS

Our study population comprised of 586 patients that were balanced with regard to observed covariables. There was no significant difference in HR for death (0.99; 95% confidence interval 0.70-1.39; P = 0.94) between IGRT and non-IGRT groups. There were also no significant differences in R0 resection, ILRR, IRCM, IOCM or ICVM. The results of our SA were consistent with these findings.

CONCLUSION

For LARC patients treated with NCCRT, the treatment outcome was not significantly different among patients treated with and without IGRT. Further study is needed to clarify these results with consideration to additional potential confounding factors and toxicity profiles at endpoints.