Hyperbaric oxygen therapy for local late radiation toxicity in breast cancer patients: A systematic review.

PURPOSE: This systematic review aims to provide an overview of the literature on the effect of hyperbaric oxygen therapy (HBOT) on symptoms of local late radiation toxicity (LRT) in patients treated for breast cancer. METHODS: A systematic search was performed in September 2021. All studies with a sample size of ≥10 patients reporting the effect of HBOT for symptoms of LRT after radiotherapy of the breast and/or chest wall were included. The ROBINS-I tool was used for critical appraisal of methodological quality. The toxicity outcomes pain, fibrosis, lymphedema, necrosis/skin problems, arm and shoulder mobility, and breast and arm symptoms were evaluated. RESULTS: Nine studies concerning a total of 1308 patients were included in this review. Except for one study, sample sizes were small. Most studies had inadequate methodology with a substantial risk of bias. Post-HBOT, a significant reduction of pain was observed in 4/5 studies, of fibrosis in 1/2 studies, and of lymphedema of the breast and/or arm in 4/7 studies. Skin problems of the breast were significantly reduced in 1/2 studies, arm- and shoulder mobility significantly improved in 2/2 studies, and breast- and arm symptoms were significantly reduced in one study. CONCLUSION: This systematic review indicates that HBOT might be useful for reducing symptoms of LRT in breast cancer patients, however evidence is limited. A randomized controlled trial in a larger cohort of patients including a combination of patient- and clinician-reported outcome measures would be valuable to assess the effect of HBOT on symptoms of LRT.

Interrater agreement of contouring of the neurovascular bundles and internal pudendal arteries in neurovascular-sparing magnetic resonance-guided radiotherapy for localized prostate cancer.

BACKGROUND AND PURPOSE: Radiation damage to neural and vascular tissue, such as the neurovascular bundles (NVBs) and internal pudendal arteries (IPAs), during radiotherapy for prostate cancer (PCa) may cause erectile dysfunction. Neurovascular-sparing magnetic resonance-guided adaptive radiotherapy (MRgRT) aims to preserve erectile function after treatment. However, the NVBs and IPAs are not routinely contoured in current radiotherapy practice. Before neurovascular-sparing MRgRT for PCa can be implemented, the interrater agreement of the contouring of the NVBs and IPAs on pre-treatment MRI needs to be assessed. MATERIALS AND METHODS: Four radiation oncologists independently contoured the prostate, NVB, and IPA in an unselected consecutive series of 15 PCa patients, on pre-treatment MRI. Dice similarity coefficients (DSCs) for pairwise interrater agreement of contours were calculated. Additionally, the DCS of a subset of the inferior half of the NVB contours (i.e. approximately prostate midgland to apex level) was calculated. RESULTS: Median overall interrater DSC for the left and right NVB was 0.60 (IQR: 0.54 - 0.68) and 0.61 (IQR: 0.53 - 0.69) respectively and for the left and right IPA 0.59 (IQR: 0.53 - 0.64) and 0.59 (IQR: 0.52 - 0.64) respectively. Median overall interrater DSC for the inferior half of the left NVB was 0.67 (IQR: 0.58 - 0.74) and 0.67 (IQR: 0.61 - 0.71) for the right NVB. CONCLUSION: We found that the interrater agreement for the contouring of the NVB and IPA improved with enhancement of the MRI sequence as well as further training of the raters. The agreement was best in the subset of the inferior half of the NVB, where a good agreement is clinically most relevant for neurovascular-sparing MRgRT for PCa.

Assessing the effect of hyperbaric oxygen therapy in breast cancer patients with late radiation toxicity (HONEY trial): a trial protocol using a trial within a cohort design.

BACKGROUND: Breast cancer treatment with radiotherapy can induce late radiation toxicity, characterized by pain, fibrosis, edema, impaired arm mobility, and poor cosmetic outcome. Hyperbaric oxygen therapy (HBOT) has been proposed as treatment for late radiation toxicity; however, high-level evidence of effectiveness is lacking. As HBOT is standard treatment and reimbursed by insurers, performing classic randomized controlled trials is difficult. The "Hyperbaric OxygeN therapy on brEast cancer patients with late radiation toxicity" (HONEY) trial aims to evaluate the effectiveness of HBOT on late radiation toxicity in breast cancer patients using the trial within cohorts (TwiCs) design. METHODS: The HONEY trial will be conducted within the Utrecht cohort for Multiple BREast cancer intervention studies and Long-term evaluation (UMBRELLA). Within UMBRELLA, breast cancer patients referred for radiotherapy to the University Medical Centre Utrecht are eligible for inclusion. Patients consent to collection of clinical data and patient-reported outcomes and provide broad consent for randomization into future intervention studies. Patients who meet the HONEY in- and exclusion criteria (participation ≥ 12 months in UMBRELLA, moderate/severe breast or chest wall pain, completed primary breast cancer treatment except hormonal treatment, no prior treatment with HBOT, no contraindications for HBOT, no clinical signs of metastatic or recurrent disease) will be randomized to HBOT or control group on a 2:1 ratio (n = 120). Patients in the control group will not be informed about participation in the trial. Patients in the intervention arm will undergo 30-40 HBOT treatment sessions in a high pressure chamber (2.4 atmospheres absolute) where they inhale 100% oxygen through a mask. Cohort outcome measures (i.e., physical outcomes, quality of life, fatigue, and cosmetic satisfaction) of the HBOT group will be compared to the control group at 3 months follow-up. DISCUSSION: This pragmatic trial within the UMBELLA cohort was designed to evaluate the effectiveness of HBOT on late radiation toxicity in breast cancer patients using the TwiCs design. Use of the TwiCs design is expected to address issues encountered in classic randomized controlled trials, such as contamination (i.e., HBOT in the control group) and disappointment bias, and generate information about acceptability of HBOT. TRIAL REGISTRATION: ClinicalTrials.gov. NCT04193722 . Registered on 10 December 2019.

Redefining radiotherapy for early-stage breast cancer with single dose ablative treatment: a study protocol.

BACKGROUND: A shift towards less burdening and more patient friendly treatments for breast cancer is currently ongoing. In low-risk patients with early-stage disease, accelerated partial breast irradiation (APBI) is an alternative for whole breast irradiation following breast-conserving surgery. MRI-guided single dose ablative APBI has the potential to offer a minimally burdening, non-invasive treatment that could replace current breast-conserving therapy. METHODS: The ABLATIVE study is a prospective, single arm, multicenter study evaluating preoperative, single dose, ablative radiation treatment in patients with early-stage breast cancer. Patients with core biopsy proven non-lobular invasive breast cancer, (estrogen receptor positive, Her2 negative, maximum tumor size 3.0 cm on diagnostic MRI) and a negative sentinel node biopsy are eligible. Radiotherapy (RT) planning will be performed using a contrast enhanced (CE) planning CT-scan, co-registered with a CE-MRI, both in supine RT position. A total of twenty-five consecutive patients will be treated with a single ablative RT dose of 20 Gy to the tumor and 15 Gy to the tumorbed. Follow-up MRIs are scheduled within 1 week, 2, 4 and 6 months after single-dose RT. Breast-conserving surgery is scheduled at six months following RT. Primary study endpoint is pathological complete response. Secondary study endpoints are the radiological response and toxicity. Furthermore, patients will fill out questionnaires on quality of life and functional status. Cosmetic outcome will be evaluated by the treating radiation oncologist, patient and 'Breast Cancer Conservation Treatment cosmetic results' software. Recurrence and survival rates will be assessed. The patients will be followed up to 10 years after diagnosis. If patients give additional informed consent, a biopsy and a part of the irradiated specimen will be stored at the local Biobank and used for future research on radiotherapy response associated genotyping. DISCUSSION: The ABLATIVE study evaluates MRI-guided single dose ablative RT in patients with early-stage breast cancer, aiming at a less burdening and non-invasive alternative for current breast-conserving treatment. TRIAL REGISTRATION: ClinicalTrials.gov registration number NCT02316561 . The trial was registrated prospectively on October 10th 2014.