[Risk of radionecrosis after hypofractionated stereotactic radiotherapy targeting the postoperative resection cavity of brain metastases]

PURPOSE

To investigate the factors that potentially lead to brain radionecrosis after hypofractionated stereotactic radiotherapy targeting the postoperative resection cavity of brain metastases.

METHODS AND MATERIALS

A retrospective analysis conducted in two French centres, was performed in patients treated with trifractionated stereotactic radiotherapy (3×7.7Gy prescribed to the 70% isodose line) for resected brain metastases. Patients with previous whole-brain irradiation were excluded of the analysis. Radionecrosis was diagnosed according to a combination of criteria including clinical, serial imaging or, in some cases, histology. Univariate and multivariate analyses were performed to determine the predictive factors of radionecrosis including clinical and dosimetric variables such as volume of brain receiving a specific dose (V_8Gy-V_22Gy).

RESULTS

One hundred eighty-one patients, with a total of 189 cavities were treated between March 2008 and February 2015. Thirty-five patients (18.5%) developed radionecrosis after a median follow-up of 15 months (range: 3-38 months) after hypofractionated stereotactic radiotherapy. One third of patients with radionecrosis were symptomatic. Multivariate analysis showed that infra-tentorial location was predictive of radionecrosis (hazard ratio [HR]: 2.97; 95% confidence interval [95% CI]: 1.47-6.01; P=0.0025). None V_8Gy-V_22Gy was associated with appearance of radionecrosis, even if V_14Gy trended toward significance (P=0.059).

CONCLUSION

Analysis of patients and treatment variables revealed that infratentorial location of brain metastases was predictive for radionecrosis after hypofractionated stereotactic radiotherapy for postoperative resection cavities.

Stereotactic radiation therapy of brain metastases from colorectal cancer: A single institution cohort

PURPOSE

The brain remains an uncommon site of colorectal cancer metastases. Due to the improvement of overall colorectal cancer patient survival, the incidence of brain metastases will likely rise. We report the efficacy and safety of hypofractionnated stereotactic radiation therapy and stereotactic radiosurgery, and its role in colorectal cancer brain metastasis management.

METHODS AND MATERIAL

Between June 2010 and December 2014, fifteen consecutive patients received hypofractionnated stereotactic radiation therapy or stereotactic radiosurgery as first local therapy or following surgical removal for colorectal cancer brain metastases. The primary endpoint was overall survival. Secondary endpoints were brain progression free survival, in field control rates and safety.

RESULTS

Median follow-up was 41 months (95% confidence interval [CI]: [8.9-73.1 months]), median overall survival was 8 months (95% CI [4.7-11.3 months]), and median brain progression-free survival was 5 months (95% CI [3.9-6.1 months]). Five in field recurrences were observed, which makes a control rate per metastases at 6 and 12 months of 77.8% (95% CI [74.34%-81.26%]), 51.9% (95% CI [44.21%-59.59%]) respectively. Over the 19 treatment sequences, five in field recurences were observed: 6, 12 and 18 months control rate per treatment sequence were 93.3% (95% CI [90.42%-96.18%]), 68.1% (95% CI [62.03%-74.17%]) and 45.4% (95% CI [36.14%-54.66%]) respectively. Immediate tolerance was good with no toxicity grade III or more. Long-term toxicity included two radionecrosis among which, one was symptomatic.

DISCUSSION

The results of this retrospective analysis suggest that hypofractionnated stereotactic radiation therapy and stereotactic radiosurgery are effective and safe treatment modalities for single and multiple small brain metastases from colorectal cancer. However, results need to be confirmed by multicenter, collected data.

[Choroidal metastasis from a lung adenocarcinoma treated by intravitreal injection of anti-VEGF and external beam radiotherapy: A case report]

Choroidal metastases of lung cancer are very uncommon. This localization should be suspected on blurred vision and confirmed with an ophthalmological examination. Its treatment is not entirely codified. We report a case of blurred vision secondary to bilateral choroidal metastasis in a patient with choroidal metastases from a lung adenocarcinoma, treated by intravitreal anti-vascular endothelial growth factor (VEGF) injection and external beam radiotherapy. According to a literature review, we analyzed the place of the targeted treatments used alone or combined with the radiotherapy.

[Radiotherapy and targeted therapy/immunotherapy]

Thanks to recent advances achieved in oncologic systemic and local ablative treatment, the treatments become more and more efficient in term of local control and overall survival. Thus, the targeted therapies, immunotherapy or stereotactic radiotherapy have modified the management of patients, especially in case of oligometastatic disease. Many questions are raised by these innovations, particularly the diagnosis and management of new side effects or that of the combination of these different treatments, depending on the type of primary tumor. Fundamental data are available, while clinical data are still limited. Ongoing trials should help to clarify the clinical management protocols. This manuscript is a review of the combination of radiotherapy and targeted therapy/immunotherapy.

[Proton therapy]

Proton therapy is an optimized radiotherapy technique. Today, the technical improvement provides reliable machines. The therapeutic indications are clearer even though therapeutic trials should confirm the current guidelines. A better knowledge in radiobiology could be useful if it is integrated in the treatment planning system. A new organization of care will definitively stabilize the number of patients for which treatment will be relevant. This organization will prepare the future expansion of this technique.

[Consequences of prosthesis on quality of the radiation therapy]

Dose prescription, delineation and dose calculation are clearly complicated when a patient have been operated on with insertion of prosthesis. Knowledge of the physical and material characteristics is needed to decrease incertitude of calculations. Recommendations for each step of treatments are proposed in this article allowing to optimization of the treatment safety.

[Guidelines for the radiotherapy of gliomas]

Gliomas are the most frequent primary brain tumours. Treating these tumours is difficult because of the proximity of organs at risk, infiltrating nature, and radioresistance. Clinical prognostic factors such as age, Karnofsky performance status, tumour location, and treatments such as surgery, radiation therapy, and chemotherapy have long been recognized in the management of patients with gliomas. Molecular biomarkers are increasingly evolving as additional factors that facilitate diagnosis and therapeutic decision-making. These practice guidelines aim at helping in choosing the best treatment, in particular radiation therapy.

[Pediatric medulloblastoma: Retrospective series of 52 patients]

PURPOSE

Retrospective analysis of the results of 52 children irradiated for a medulloblastoma.

PATIENTS AND METHODS

Between 1974 and 2012, 52 children with an average age of 6 years and a half (11 months-17 years and a half) were treated with surgery then with radiotherapy at the Comprehensive Cancer Centre of Strasbourg (France). For 44 children, the treatment consisted of a chemotherapy.

RESULTS

After a mean follow-up of 106.6 months (7-446 months), 13 relapses and 24 deaths were observed. Overall survival at 5 years and 10 years were 62% and 57%, respectively. Disease-free survival at 5 years and 10 years were 80% and 63%, respectively. Univariate analysis found the following adverse prognostic factors: the existence of a postoperative residue, the positivity of the cerebrospinal fluid, the metastatic status and medulloblastoma of high-risk. Positivity of the cerebrospinal fluid remains a negative factor in multivariate analysis.

CONCLUSION

These results confirm the survival rate obtained by a conventional approach (surgery then irradiation). Insufficiency of results and rarity of medulloblastoma require the establishment of international protocols.