Narrative review of the utility of magnetic resonance imaging in radiotherapy for cervical cancer.

BACKGROUND AND OBJECTIVE: In radiotherapy (RT) for locally advanced cervical cancer, high soft tissue contrast on magnetic resonance imaging (MRI) can ensure accurate delineation of target volumes (TVs) and optimal dose distribution to the RT target and organs at risk (OAR). MRI-guided adaptive RT (MRIgART) is a novel technology that revises RT plans according to anatomical changes occurring throughout the treatment to improve target coverage and minimise OAR toxicity. This review aims to assess the evidence and gaps of MRI use in RT planning and MRIgART in the treatment of cervical cancer, as well as challenges in its clinical implementation. METHODS: Ovid Medline and PubMed were searched using keywords for MRI in RT for cervical cancer. After applying the inclusion and exclusion criteria, the initial search was deduced to 32 studies. A total of 37 final studies were reviewed, including eight additional articles from references. KEY CONTENT AND FINDINGS: In the primary studies, TVs and organ motion were assessed before, during, and after treatment. MRI was used to investigate dose distribution and therapeutic response to the treatment in association with its outcome. Lastly, rationales for MRIgART were evaluated. CONCLUSIONS: It was concluded that MRI enables accurate target delineation, assessment of organ motion and interfraction changes, and monitoring of treatment response through dynamic parameters. Enhanced target coverage and reduced OAR irradiation through MRIgART can improve local control and the overall outcome, although its rationales against the logistical challenges need to be evaluated on further research.

Gynecological intrauterine brachytherapy training for radiation therapists: The development and implementation of a training program.

PURPOSE: Gynecological brachytherapy (GynBT) is an important part of gynecological cancer management. At Olivia Newton-John Cancer Wellness & Research Centre (ONJCWRC), Melbourne, Australia, radiation therapists (RTs) are integral to the MRI adaptive GynBT program workflow. However, there is limited GynBT training available for RTs in Australia. A GynBT training program has been developed at ONJCWRC to meet this need and support RTs in becoming competent, proficient and confident in the various roles in GynBT. This is a preliminary report on the development and implementation of a credentialing program, providing a structured approach to GynBT training of RTs. METHODS AND MATERIALS: A credentialing program was designed with modules and competency assessments to ensure efficiency and proficiency of RTs in the GynBT workflow. The program includes theoretical modules in anatomy, international GynBT guidelines, radiation safety and local protocols; and practical modules in equipment, ultrasound for GynBT, operating theatre procedures, MRI, contouring, applicator reconstruction, planning, quality assurance and treatment delivery. Learning strategies include self-directed learning, tutorials, practical sessions, and third-party courses. The program concludes with an exit examination assessing major competencies. RESULTS: The program was implemented in April 2018 with three RTs completing the program and passing the exit examination on first attempt. On post-program survey, the RTs felt the program was comprehensive, helping to build their confidence, and proficiency in GynBT. CONCLUSIONS: A GynBT RT credentialing program was successfully developed and implemented to improve the quality of training at ONJCWRC. This program is mandatory for RTs joining the GynBT team. This program can provide a framework for implementation of GynBT training in other centers.

To biopsy or not to biopsy? Outcomes following stereotactic body radiotherapy (SBRT) for biopsy-confirmed versus radiologically-diagnosed primary lung cancer in a single Australian institution.

INTRODUCTION: Obtaining tissue diagnosis for lung cancer can sometimes be difficult and unsafe. We evaluated outcomes of biopsy-confirmed versus radiologically-diagnosed lung cancer treated with stereotactic body radiotherapy (SBRT). METHODS: A single-institutional retrospective cohort of lung cancer patients treated with SBRT between February 2014 and October 2018. Outcomes of interest were: local failure (LF), distant failure (DF), and overall survival (OS). Probability of LF, DF, and OS were estimated using the Kaplan-Meier method. Differences in outcomes between biopsy-confirmed versus radiologically-diagnosed lung cancer were evaluated using the log-rank test. RESULTS: Sixty-five lung lesions in 61 patients were treated with SBRT. Mean age was 75.6 years. Twenty-seven patients (44.3%) were ECOG 2-3. Thirty-nine patients (64%) were radiologically-diagnosed. There were five cases of LF observed at median of 12.8 months post-SBRT and 12-month LF-free survival was 96% (95% CI, 86-99%), with no differences between groups (p = 0.1). Sixteen patients developed DF, with 12-month DF-free survival of 84% (95% CI, 71-91%), and no difference between groups (p = 0.06). Sixteen deaths were reported at a median of 12.5 months post-SBRT, with 12-month OS of 85% (95% CI, 73-92%), and no differences between study groups (p = 0.5). No grade 3 toxicities were reported. CONCLUSION: The oncological outcomes were similar in patients with early lung cancer treated with SBRT with or without biopsy-confirmation. In situations where tissue diagnosis is not feasible or unsafe, it is not unreasonable to offer SBRT based on clinical and radiological suspicion following multidisciplinary discussions.

Adjuvant radiotherapy for endometrial cancer with cervical stromal involvement: A patterns of practice survey in Australia and New Zealand.

INTRODUCTION: The purpose of this study is to describe the patterns of practice in Australia and New Zealand for post-operative radiotherapy in endometrial cancer with cervical stromal involvement. METHODS: A ten-item survey including five clinical case scenarios in endometrial cancer with cervical stromal invasion was emailed to Royal Australian and New Zealand College of Radiologists (RANZCR) radiation oncologists in 2018. Responses were analysed to determine relative frequency distributions and preferred adjuvant treatment modalities for the clinical case scenarios. RESULTS: A total of 65 respondents initiated the survey with 27 respondents treating more than 11 endometrial cancer cases annually. Only 31 respondents answered all five clinical case scenarios. Preferred adjuvant radiotherapy modalities varied for the Stage II cases between vault brachytherapy (VB), pelvic external beam radiotherapy (EBRT) or a combination. For the stage IIIA and IIIC1 cases, the majority recommended pelvic EBRT with or without VB boost (79% and 77%), and of these, most combined with chemotherapy (61% and 88%). For 4 of the 5 case scenarios, when pelvic EBRT was offered, most recommended a VB boost. CONCLUSION: This patterns of practice survey suggests variability in adjuvant radiotherapy recommendations in endometrial cancer with cervical involvement, particularly in cases where there is lack of randomised data and discrepancies in consensus guidelines.

Outcomes and relapse patterns following chemotherapy in advanced Hodgkin lymphoma in the positron emission tomography era.

BACKGROUND: This study evaluated relapse patterns and survival in advanced Hodgkin lymphoma (HL) patients treated with doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) with positron emission tomography (PET) used for staging and response assessment. PATIENTS AND METHODS: Patients aged 18 years or above with newly diagnosed histologically proven Stage III or IV HL treated with ABVD at Calvary Mater Newcastle from January 2005 to December 2012 were included in this study. All patients underwent pre-chemotherapy staging with 18F-fluorodeoxyglucose PET or PET/computed tomography and post-chemotherapy PET or PET/computed tomography for the assessment of response. RESULTS: Forty-three patients were included in the study. The 5-year disease-free survival, progression-free survival and overall survival were 88%, 74% and 86%, respectively. PET complete response was seen in 35 patients (81%), and the 5-year overall survival for this group was 94%. Relapse following a PET complete response was low (three patients) and occurred predominantly at the initial sites of disease. Four of five patients with bulky disease received consolidative radiotherapy and no in-field relapses were observed. CONCLUSION: Advanced stage HL with a PET complete response following ABVD is associated with an excellent prognosis.

Audiovisual biofeedback guided breath-hold improves lung tumor position reproducibility and volume consistency.

PURPOSE: Respiratory variation can increase the variability of tumor position and volume, accounting for larger treatment margins and longer treatment times. Audiovisual biofeedback as a breath-hold technique could be used to improve the reproducibility of lung tumor positions at inhalation and exhalation for the radiation therapy of mobile lung tumors. This study aimed to assess the impact of audiovisual biofeedback breath-hold (AVBH) on interfraction lung tumor position reproducibility and volume consistency for respiratory-gated lung cancer radiation therapy. METHODS: Lung tumor position and volume were investigated in 9 patients with lung cancer who underwent a breath-hold training session with AVBH before 2 magnetic resonance imaging (MRI) sessions. During the first MRI session (before treatment), inhalation and exhalation breath-hold 3-dimensional MRI scans with conventional breath-hold (CBH) using audio instructions alone and AVBH were acquired. The second MRI session (midtreatment) was repeated within 6 weeks after the first session. Gross tumor volumes (GTVs) were contoured on each dataset. CBH and AVBH were compared in terms of tumor position reproducibility as assessed by GTV centroid position and position range (defined as the distance of GTV centroid position between inhalation and exhalation) and tumor volume consistency as assessed by GTV between inhalation and exhalation. RESULTS: Compared with CBH, AVBH improved the reproducibility of interfraction GTV centroid position by 46% (P = .009) from 8.8 mm to 4.8 mm and GTV position range by 69% (P = .052) from 7.4 mm to 2.3 mm. Compared with CBH, AVBH also improved the consistency of intrafraction GTVs by 70% (P = .023) from 7.8 cm3 to 2.5 cm3. CONCLUSIONS: This study demonstrated that audiovisual biofeedback can be used to improve the reproducibility and consistency of breath-hold lung tumor position and volume, respectively. These results may provide a pathway to achieve more accurate lung cancer radiation treatment in addition to improving various medical imaging and treatments by using breath-hold procedures.

Stage IB cervix cancer with nodal involvement treated with primary surgery or primary radiotherapy: Patterns of failure and outcomes in a contemporary population.

INTRODUCTION: The purpose of this study is to evaluate patterns of failure, overall survival (OS), disease-free survival (DFS), prognostic factors and late toxicities in node positive International Federation of Gynaecology and Obstetrics (FIGO) stage IB cervix cancer treated with curative intent. METHODS: Patients with FIGO stage IB cervix cancer and positive nodes were identified from the Peter MacCallum Cancer Centre prospective gynaecology database. Patients were treated with primary surgery and adjuvant radiotherapy (S + RT) or primary radiotherapy (primary RT). Prognostic factors examined were tumour size, histology, grade, lymphovascular invasion or corpus uterine invasion, MRI tumour volume, number of nodes involved, highest site of nodal involvement, treatment modality, age and smoking. RESULTS: Of the 103 eligible patients, 43 patients had S + RT and 60 patients had primary RT. Tumours were significantly smaller in the S + RT group (mean 3.0 cm vs. 4.5 cm, P < 0.001). Five-year OS (95% confidence interval) and DFS (95% confidence interval) for the whole cohort was 67.6% (56.5-76.4%) and 66.1% (55.7-74.6%), respectively. Tumour diameter and number of positive nodes were significant prognostic factors for OS and DFS and smoking was related to DFS. Treatment modality was not a significant prognostic factor in OS and DFS. Of 33 patients that relapsed, 32 patients relapsed outside the pelvis. One patient failed in the pelvis only. CONCLUSIONS: Early stage cervix cancer with nodal involvement is associated with excellent pelvic disease control following curative intent treatment. Almost all relapses occurred beyond the pelvis and therefore more aggressive local treatment is unlikely to improve survival in these patients.

Dosimetric comparison of optimization methods for multichannel intracavitary brachytherapy for superficial vaginal tumors.

PURPOSE: Multichannel vaginal applicators allow treatment of a more conformal volume compared with a single, central vaginal channel. There are several optimization methods available for use with multichannel applicators, but no previous comparison of these has been performed in the treatment of superficial vaginal tumors. Accordingly, a feasibility study was completed to compare inverse planning by simulated annealing (IPSA), dose point optimization (DPO), and graphical optimization for high-dose-rate brachytherapy using a multichannel, intracavitary vaginal cylinder. METHODS AND MATERIALS: This comparative study used CT data sets from five patients with superficial vaginal recurrences of endometrial cancer treated with multichannel intracavitary high-dose-rate brachytherapy. Treatment plans were generated using DPO, graphical optimization, surface optimization with IPSA (surf IPSA), and two plans using volume optimization with IPSA. The plans were evaluated for target coverage, conformal index, dose homogeneity index, and dose to organs at risk. RESULTS: Best target coverage was achieved by volume optimization with IPSA 2 and surf IPSA with mean V100 values of 93.89% and 91.87%, respectively. Doses for the most exposed 2-cm(3) of the bladder (bladder D2cc) was within tolerance for all optimization methods. Rectal D2cc was above tolerance for one DPO plan. All volume optimization with IPSA plans resulted in higher vaginal mucosa doses for all patients. Greatest homogeneity within the target volume was seen with surf IPSA and DPO. Highest conformal indices were seen with surf IPSA and graphical optimization. CONCLUSIONS: Optimization with surf IPSA was user friendly for the generation of treatment plans and achieved good target coverage, conformity, and homogeneity with acceptable doses to organs at risk.

Radiotherapy and technetium-99m-labeled red blood cell scintigraphy for hemoptysis from chronic MRSA infection.

AIM: To discuss the application of external beam radiotherapy (EBRT) and technetium-99m-labeled red blood cell scintigraphy (LRBCS) in life-threatening hemoptysis from a non-malignant condition. MATERIALS AND METHODS: This case report presents a patient with persistent hemoptysis secondary to chronic Methicillin-resistant Staphylococcus aureus (MRSA) infection in whom conventional management failed to localize the site of pulmonary bleeding or to provide effective therapy. RESULTS: EBRT was successfully given for life-threatening hemoptysis with improvement in quality of life for nearly 1 year. LRBCS was used to localize the source of further bleeding and facilitate targeted therapy. CONCLUSION: EBRT can be an effective and well-tolerated modality in treating life-threatening hemoptysis refractory to conventional methods. LRBCS is a non-invasive diagnostic tool that can be used to detect the source of pulmonary bleeding.