Helical tomotherapy for cancer treatment: a rapid health technology assessment

Radiation in Gastroenterology

The benefit of radiation is immense in the field of gastroenterology. Radiation is used daily in different gastrointestinal imaging and diagnostic and therapeutic interventional procedures. Radiotherapy is one of the primary modalities of treatment of gastrointestinal malignancies. There are various modalities of radiotherapy. Radiotherapy can injure malignant cells by directly damaging DNA, RNA, proteins, and lipids and indirectly by forming free radicals. External beam radiation, internal beam radiation and radio-isotope therapy are the major ways of delivering radiation to the malignant tissue. Radiation can also cause inflammation, fibrosis, organ dysfunction, and malignancy. Patients with repeated exposure to radiation for diagnostic imaging and therapeutic procedures are at slightly increased risk of malignancy. Gastrointestinal endoscopists performing fluoroscopy-guided procedures are also at increased risk of malignancy and cataract formation. The radiological protection society recommends certain preventive and protective measures to avoid side effects of radiation. Gastrointestinal complications related to radiation therapy for oncologic processes, and exposure risks for patients and health care providers involved in diagnostic or therapeutic imaging will be discussed in this review.

Evidence Mapping of Proton Therapy, Heavy Ion Therapy, and Helical Tomotherapy for Gastric Cancer

PURPOSE

This study aimed to systematically present application situation and therapeutic effect of proton therapy (PT), heavy ion therapy, and helical tomotherapy (TOMO) for gastric cancer (GC), and to find gaps of existing studies.

METHODS

PubMed, EMBASE, the Cochrane Library, Web of Science, and Chinese Biological Medical Database were searched. Tables, bubble plot, and heat map were conducted to display results.

RESULTS

Fourteen studies were included. About PT, 7 single-arm studies showed median overall survival (OS) within 2-66 months and 1 study reported 40% of patients happened moderate degree of radiation gastritis. About TOMO, 1 study reported longer median OS and progression-free survival, lower occurrence of Grade III toxicity, and late toxicity compared to 3D-CRT, while another study remained neutral. About heavy ion therapy, there was no clinical study was found.

CONCLUSIONS

Existing studies presented good clinic treatment effect about PT and TOMO for GC, and furthermore clinical studies are needed.

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

OBJECTIVE

This study used a population-based propensity score (PS)-matched analysis to compare the effectiveness of tomotherapy-based image-guided intensity-modulated radiotherapy (referred to as T-IMRT) with that of linear accelerator based (referred to as L-IMRT) for clinically localized pharyngeal cancer (LPC, divided into nasopharyngeal cancer and non-nasopharyngeal cancer) with definitive concurrent chemoradiotherapy (CCRT).

METHODS

Eligible LPC patients diagnosed between 2007 and 2014 were identified among all citizens in Taiwan from the Health and Welfare Data Science Center database. A PS-matched sample based on the PS estimated from the covariables of interest was constructed to compare the effectiveness of T-IMRT with L-IMRT. In the primary analysis, overall survival (OS) was compared for assessment of effectiveness. We also evaluated freedom from local regional recurrence and pharyngeal cancer-specific survival and performed supplementary analyses.

RESULTS

The study population included 960 patients equally divided into two groups. OS did not differ significantly between the T-IMRT and L-IMRT groups (hazard ratio for death: 0.82, p = 0.15, 5-year OS rate: 79 and 74% for T-IMRT and L-IMRT, respectively), and there were no significant differences in the other endpoints or supplementary analyses.

CONCLUSION

For LPC patients treated with definitive CCRT, we found no significant difference in disease control or survival between the T-IMRT and L-IMRT groups. However, further studies, especially randomized trials or studies focusing on other dimensions, such as quality of life, are needed. Advances in knowledge: We provide the first population-based study, as well as the largest study, on the clinical effectiveness of T-IMRT compared with L-IMRT in conjunction with CCRT in LPC patients.