Hyperbaric oxygen therapy for late radiation-associated tissue necroses: is it safe in patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers?

A radiomics model for predicting the response to methylprednisolone in brain necrosis after radiotherapy for nasopharyngeal carcinoma

BACKGROUND

Methylprednisolone is recommended as the front-line therapy for radiation-induced brain necrosis (RN) after radiotherapy for nasopharyngeal carcinoma. However, some patients fail to benefit from methylprednisolone or even progress. This study aimed to develop and validate a radiomic model to predict the response to methylprednisolone in RN.

METHODS

Sixty-six patients receiving methylprednisolone were enrolled. In total, 961 radiomic features were extracted from the pre-treatment magnetic resonance imagings of the brain. Least absolute shrinkage and selection operator regression was then applied to construct the radiomics signature. Combined with independent clinical predictors, a radiomics model was built with multivariate logistic regression analysis. Discrimination, calibration and clinical usefulness of the model were assessed. The model was internally validated using 10-fold cross-validation.

RESULTS

The radiomics signature consisted of 16 selected features and achieved favorable discrimination performance. The radiomics model incorporating the radiomics signature and the duration between radiotherapy and RN diagnosis, yielded an AUC of 0.966 and an optimism-corrected AUC of 0.967 via 10-fold cross-validation, which also revealed good discrimination. Calibration curves showed good agreement. Decision curve analysis confirmed the clinical utility of the model.

CONCLUSIONS

The presented radiomics model can be conveniently used to facilitate individualized prediction of the response to methylprednisolone in patients with RN.

Comparison between high-dose and low-dose intravenous methylprednisolone therapy in patients with brain necrosis after radiotherapy for nasopharyngeal carcinoma

BACKGROUND

Radiotherapy is the standard radical treatment for nasopharyngeal carcinoma (NPC) and may cause radiation-induced brain necrosis (RN). Intravenous steroids have been considered as an effective treatment for RN. However, evidence concerning the efficacy of different doses of intravenous steroid therapy remains insufficient to establish the optimal regimen for NPC patients with RN.

METHODS

We retrospectively reviewed charts of 169 patients who were diagnosed with RN after radiotherapy for NPC, treated with low-dose or high-dose intravenous methylprednisolone (IVMP) and followed up for 12 months. We collected the clinical data, including the Late Effects of Normal Tissue (LENT)/Subjective, Objective, Management, Analytic (SOMA) scales score and Montreal Cognitive Assessment (MoCA) score. Magnetic resonance imaging (MRI) was performed pre- and post-treatment to define the radiographic response.

RESULTS

There were no significant differences in the treatment response based on MRI, or changes in clinical symptoms and cognitive function between low and high-dose groups. Thirty of 93 low-dose patients (32.3%) and 21 of 76 high-dose patients (27.6%) presented effective response in MRI, with no significant differences between groups (P = 0.515). Neither group showed a significant difference in the effective rate based on the MoCA total score and LENT/SOMA score. The most commonly reported grade 3 adverse events in the high-dose group (n = 76) were infections and infestations (3 [3.9%] vs. none for low-dose group).

CONCLUSIONS

We found low-dose IVMP was not inferior to high-dose IVMP for NPC patients with RN. In addition, treatment-related infections and infestations were likewise more common with high-dose steroid than low-dose steroid.

Effect of hyperbaric oxygen therapy on a murine squamous cell carcinoma model

BACKGROUND

Hyperbaric oxygen (HBO) therapy is sometimes used to assist in wound healing after major head and neck cancer surgery. However, there is concern that HBO treatments might enhance the growth of any residual microscopic disease. This was studied in a mouse model of squamous cell carcinoma (SCC).

METHODS

SCC-VII/SF tumor cells were cultured, and then injected (3 × 10(3) cells) into C3H/HeJ mice in 5 groups: subcutaneous (SQ) control (n = 13), SQ-immediate (n = 12), SQ-delayed (n = 13), tail vein control (n = 8), and tail vein immediate (n = 9). The 3 experimental groups were subjected to HBO therapy, 2.4 atm for 90 minutes, 5 days per week for 4 weeks, starting on postinjection day 3 ("immediate") or 10 ("delayed"). Tumors in the SQ mice were measured 3 times per week. Lung metastases in the tail vein mice were counted at necropsy.

RESULTS

At postimplantation day 28, when the immediate group completed its HBO therapy, the tumor volume in the SQ-immediate group was 49.1% higher than the control group, and the SQ-delayed group was 105.1% higher than controls (p < .05). Two weeks later, the SQ-immediate group and SQ-delayed group tumor volumes were still significantly higher than controls, but the difference was smaller (18.4% and 43.8%, respectively; p < .05 only for the delayed group). The tail vein groups had similar numbers of lung metastases, with a mean of 8.7 metastases in the control group and 9.0 metastases in the HBO group (not significant [NS]).

CONCLUSION

This study suggests that HBO therapy does accelerate the growth of microscopic foci of SCCs. This finding differs from some earlier studies and warrants further study.

Hyperbaric oxygen therapy for late radiation tissue injury in gynecologic malignancies

BACKGROUND

Late radiation tissue injury is a serious complication of radiotherapy for patients with gynecologic malignancies. Strategies for managing pain and other clinical features have limited efficacy; however, hyperbaric oxygen therapy (HBO(2)) may be an effective option for some patients.

METHODS

In a systematic review of the literature, the Ovid medline, embase, Cochrane Library, National Guidelines Clearinghouse, and Canadian Medical Association Infobase databases were searched to June 2009 for clinical practice guidelines, systematic reviews, randomized controlled trials, or other relevant evidence. Studies that did not evaluate soft tissue necrosis, cystitis, proctitis, bone necrosis, and other complications were excluded.

RESULTS

Two randomized trials, eleven nonrandomized studies, and five supporting documents comprise the evidence base. In addition, information on the harms and safety of treatment with HBO(2) were reported in three additional sources. There is modest direct evidence and emerging indirect evidence that the use of HBO(2) is broadly effective for late radiation tissue injury of the pelvis in women treated for gynecologic malignancies.

CONCLUSIONS

Based on the evidence and expert consensus opinion, HBO(2) is likely effective for late radiation tissue injury of the pelvis, with demonstrated efficacy specifically for radiation damage to the anus and rectum;the main indication for HBO(2) therapy in gynecologic oncology is in the management of otherwise refractory chronic radiation injury;HBO(2) may provide symptomatic benefit in certain clinical settings (for example, cystitis, soft-tissue necrosis, and osteonecrosis); andHBO(2) may reduce the complications of gynecologic surgery in patients undergoing surgical removal of necrosis.

Radiation induced temporal lobe necrosis in patients with nasopharyngeal carcinoma: a review of new avenues in its management

Temporal lobe necrosis (TLN) is the most debilitating late-stage complication after radiation therapy in patients with nasopharyngeal cancer (NPC). The bilateral temporal lobes are inevitably encompassed in the radiation field and are thus prone to radiation induced necrosis. The wide use of 3D conformal and intensity-modulated radiation therapy (IMRT) in the treatment of NPC has led to a dwindling incidence of TLN. Yet, it still holds great significance due to its incapacitating feature and the difficulties faced clinically and radiologically in distinguishing it from a malignancy. In this review, we highlight the evolution of different imaging modalities and therapeutic options. FDG PET, SPECT and Magnetic Spectroscopy are among the latest imaging tools that have been considered. In terms of treatment, Bevacizumab remains the latest promising breakthrough due to its ability to reverse the pathogenesis unlike conventional treatment options including large doses of steroids, anticoagulants, vitamins, hyperbaric oxygen and surgery.