Role of diffusion-weighted MRI in recurrent rectal cancer treated with carbon ion radiotherapy.

Aim: To evaluate the association between pretreatment diffusion-weighted MRI (DW-MRI) and 12-month radiological response in locally recurrent rectal cancer treated with carbon ion radiotherapy. Methods: Histogram analysis was performed on pretreatment DW-MRI for patients re-irradiated with carbon ion radiotherapy for local recurrence of rectal cancer. Results: A total of 17 patients were enrolled in the study. Pretreatment DW-MRI b-value of 1000 s/mm2 (b1000) and apparent diffusion coefficient (ADC) lesion median values for 1-year nonresponders (six patients) and responders (11 patients) demonstrated a median (interquartile of median values) of 62.5 (23.9) and 34.0 (13.0) and 953.0 (277.0) and 942.5 (339.0) µm2/s, respectively. All b1000 histogram features (h-features) and ADC h-kurtosis showed statistically significant differences, whereas only b1000 h-median, b1000 h-interquartile range and ADC h-kurtosis demonstrated remarkable diagnostic accuracy. Conclusion: DW-MRI showed promising results in predicting carbon ion radiotherapy outcome in local recurrence of rectal cancer, particularly with regard to b1000 h-median, b1000 h-interquartile range and ADC h-kurtosis.

Carbon ion radiotherapy is a form of advanced radiotherapy that is especially suitable for radioresistant and/or difficult-to-irradiate tumors. In case of recurrence of rectal cancer after pelvic photon beam radiotherapy, carbon ion radiotherapy may be an option. In this study, the authors looked at the potential role of specific MRI sequences performed before treatment to predict response to carbon ion radiotherapy. If confirmed in a larger prospective cohort, the findings of this study may drive clinical decisions toward a more tumor- and patient-tailored therapeutic approach.

Carotid blowout syndrome after reirradiation for head and neck malignancies: a comprehensive systematic review for a pragmatic multidisciplinary approach.

AIM: To provide a literature review on risk factors and strategies to prevent acute carotid blowout (CBO) syndrome in patients who underwent reirradiation (reRT) for recurrent head and neck (HN) malignancies. PATIENTS AND METHODS: Inclusion criteria were: 1) CBO following reRT in the HN region, 2) description on patient-, tumor- or treatment-related risk factors, 3) clinical or radiological signs of threatened or impending CBO, and 4) CBO prevention strategies. RESULTS: Thirty-five studies were selected for the analysis from five hundred seventy-seven records. Results provided indications on clinical, radiological and dosimetric parameters possibly associated with higher risk of CBO. Endovascular procedures (artery occlusion and stenting) to prevent acute massive hemorrhage in high risk patients were discussed. CONCLUSION: Literature data are still scarce with a low level of evidence. Nevertheless, the present work provides a comprehensive review useful for clinicians as a multidisciplinary pragmatic tool in their clinical practice.