Reirradiation for diffuse intrinsic pontine glioma: a systematic review and meta-analysis.

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) is a pediatric brain tumor with dismal prognosis despite initial radiation therapy (RT). The clinical consequences of attempting reirradiation (reRT) in these patients to alleviate both symptomatology and improve prognosis are currently unclear. Thus, the aim of this systematic review and meta-analysis was to clarify the efficacy and safety of reRT in DIPG. METHODS: Searches of seven electronic databases from inception to January 2019 were conducted following the appropriate guidelines. Articles were screened against prespecified criteria. The incidence and duration of clinical outcomes were then extracted and pooled by means of meta-analysis from the included studies. RESULTS: A total of 7 studies satisfied all criteria, describing 90 cases of DIPG in which reRT was attempted 11.8-14 months after initial RT. Based on a random-effects model, the incidences of clinical improvement and radiologic response following reRT were 87% (95% CI, 78-95%) and 69% (95% CI, 52-84%), respectively. The incidence of acute serious toxicity was 0% (95% CI, 0-4%). Pooled overall survivals from initial diagnosis and time of reRT were 18.0 months (95% CI, 14.2-21.7) and 6.2 months (95% CI, 5.5-7.0), respectively. CONCLUSIONS: Based on these results, the clinical consequences of reRT for DIPG when administered appropriately and safely at first progression appear acceptable, and potentially favorable, based on the limited evidence in the current literature. Concerns regarding acute serious toxicity were not realized. It is likely that a subcohort of all DIPG diagnoses will be most amenable to improve prognosis with reRT, and greater investigation is required to identify their characteristics.

Reirradiation for locally recurrent breast cancer.

The aim of this study is to review the current status of reirradiation therapy (Re-RT) for locally recurrent breast cancer. The overall outcome of breast/chest wall Re-RT is difficult to assess because of the wide range of different treatments that a patient may have undergone and the patient's individual features. The local control and complete response rates were reported to be 43-96% and 41-71%, respectively. The combination of Re-RT and hyperthermia seems to be related to improved outcomes. Toxicity rates vary between studies, and Re-RT is generally well tolerated. Re-RT may be considered an option for patients with breast cancer relapse after prior irradiation. Further studies are needed to determine the best irradiation volume and treatment modality for patients with locally recurrent disease.

A surveillance study of the current status of reirradiation and patterns of practice.

The aim of this study was to survey the current status of reirradiation (Re-RT) and patterns of practice in Japan. An email questionnaire was sent to Kansai Cancer Therapist Group partner institutions, using questions similar to those in the Canadian radiation oncologist (RO) survey (2008). A total of 34 ROs from 28 institutions returned the survey. All 28 institutions experienced Re-RT cases in 2014. However, 26 of the 28 institutions (93%) reported difficulty in obtaining Re-RT case information from their respective databases. Responses from 19 institutions included the number of Re-RT cases; this rose from 183 in the period 2005-2009 (institution median = 4; 2-12.9) to 562 in the period 2010-2014 (institution median = 26; 2-225). Important considerations for indication of Re-RT were age (65%), performance status (83%), life expectancy (70%), absence of distant metastases (67%), and interval since previous treatment (73%). Previous total radiation dose (48%), volume of tissue irradiated (72%), and the biologically equivalent dose (BED; 68.5%) were taken into account during Re-RT planning. These factors were similar to those considered in the Canadian survey; however, the present study did not consider age. In eight site-specific scenarios, barring central nervous system recurrence, more than 90% of ROs agreed to perform Re-RT, which was higher than the percentage observed in the Canadian survey. Re-RT cases have increased in number and aroused interest among ROs in this decade of advanced technology. However, consensus building to establish guidelines for the practice and prospective evaluation of Re-RT is required.