Brachytherapy: An emblematic example of extreme hypofractionated regimen.

In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3Gy), then ultra (dose/fraction: 5.2 to 6.1Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20Gy/fraction), the use of a single fraction of 19 to 23Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.

Stereotactic Pelvic Reirradiation for Locoregional Cancer Relapse.

AIMS: Up to 40% of patients who have received radiation for a pelvic malignancy will develop locoregional recurrence in the previously irradiated volume. Stereotactic body radiotherapy (SBRT) has been used in the oligometastatic setting, and provides an ablative approach ideal for reirradiation. The purpose of this study was to evaluate the outcomes after SBRT reirradiation of extraosseous recurrences in the pelvis. MATERIALS AND METHODS: This single institution retrospective study evaluated patients treated with SBRT reirradiation in the pelvis from January 2011 to February 2018. Patients with more than five oligometastatic lesions, >7 cm in size, and recurrence within the prostate were excluded. RESULTS: In total, 30 patients were treated with SBRT with a median follow-up of 29.4 months. The primary tumour sites were most commonly rectum (30.8%) and prostate (30.8%). The median time interval between irradiation for the primary and SBRT reirradiation was 48 months (3-245). The typical reirradiation treatment was 35 Gy in five fractions, the median gross tumour volume size was 10.2 (0.3-110.5) ml and the most common target was the iliac nodes (40%). There were three (10%) acute grade 3 toxicities and no late grade 3 or more toxicities. At 12/24 months, local relapse-free survival, metastasis-free survival, progression-free survival and overall survival were 67.7%/50.7%, 67%/41.7%, 34.8%/14.9% and 83.2%/62.5%, respectively. On univariate analysis, improved local control was associated with low gross tumour volume (<10 ml) (P = 0.003) and prostate primary (P = 0.02), but was no longer significant on multivariate analysis. The proximity of organ at risk to the target did not significantly correlate with worse toxicity (P = 0.14) or tumour coverage (gross tumour volume: P = 0.8, planning target volume: P = 0.4). CONCLUSION: SBRT pelvic reirradiation in oligometastatic patients is a safe and effective treatment modality. Careful consideration should be taken with larger tumour size, as it may be associated with worse oncological and toxicity outcome.

[Brachytherapy in France in 2020: State of the art and perspectives from the Groupe curiethérapie de la SFRO]. / Curiethérapie en France en 2020 : synthèse et perspectives du Groupe curiethérapie de la Société française de radiothérapie oncologique.

Because of its principle and its high proof level clinical results, brachytherapy represents a specific irradiation technique for the treatment of primary tumors as well as some local relapses in pre-irradiated area. After a glory period between the 80's and 90's, brachytherapy has progressively lost its attractiveness. In order to provide a practical solution to this deleterious situation, it is important that guardianships, health care payers, patient associations, specialist doctors and radiation oncologists understand the reasons leading to this harmful state as well as the risks concerned. A teaching judged insufficient, non-adapted value and an aging image of brachytherapy represent the three main reasons of this degradation and constitute the three most important challenges conditioning its maintain in the anticancer treatment arsenal. An adapted communication with radiation oncologists themselves but also with the other scientific societies remains crucial as well as with guardianship and patient associations. It is central that brachytherapy could be recognized in order to make it stronger and accessible for all the patients who could need it.

[Radiotherapy of benign intracranial tumors]. / Radiothérapie des tumeurs intracrâniennes bénignes.

Most of the benign intracranial tumors are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumors. Some of them grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumors are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumor, or a local relapse. Indications have to be discussed in polydisciplinary meetings, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumors, are commonly realized, to avoid as much a possible the occurrence of late side effects.

[Current situation and perspectives of proton therapy]. / État des lieux et perspectives de la protonthérapie.

Proton beam therapy is indicated as a treatment for some rare tumours and paediatric tumours because the technique allows a good local control with minimal toxicity; the growing number of centres that use proton beam therapy is associated with an increase of dosimetric and clinical data for other malignant tumours as well. This paper reviews potential indications of proton beam therapy. A systematic review on Medline was performed with the following keywords proton beam therapy, cancer, heavy particle, charged particle. No phase III trial has been published using proton beam therapy in comparison with the best photon therapy, but numerous retrospective and dosimetric studies have revealed an advantage of proton beam therapy compared to photons, above all in tumours next to parallel organs at risk (thoracic and abdominal tumours). This could be accompanied with a better safety profile and/or a better tumoural control; numerous phase 0, I, II, III and IV studies are ongoing to examine these hypotheses in more common cancers. Use of proton beam therapy is growing for common cancers within clinical trials but some indications could be applied sooner since in silico analysis showed major advantages with this technique.

[Salvage HIFU after radiotherapy and salvage radiotherapy after HIFU in locally recurrent prostate cancer: Retrospective analysis of morbidity]. / Traitements de rattrapage par HIFU après radiothérapie première et par radiothérapie après HIFU première dans la récidive locale du cancer de prostate: analyse rétrospective de la toxicité

OBJECTIVES: To evaluate the toxicity of therapeutic sequences High Intensity Focused Ultrasound (HIFU)-salvage radiotherapy (HIFU-RT) or radiotherapy-salvage HIFU (RT-HIFU) in case of locally recurrent prostate cancer. MATERIALS AND METHODS: Nineteen patients had a local recurrence of prostate cancer. Among them, 10 patients were treated by HIFU-RT and 9 patients by RT- HIFU (4 by external beam radiotherapy [EBR] and 5 by brachytherapy [BRACHY]). Urinary side effects were assessed using CTCAE v4. RESULTS: At the time of the initial management, the median age was 66.5 years (53-72), the median PSA was 10.8ng/mL (3.4-50) and the median initial Gleason score was 6.3 (5-8). Median follow-up after salvage treatment was 46.3 months (2-108). Thirty percent of the patients in the HIFU-RT group and 33.3 % of the patients in the RT-HIFU group, all belonging to the sub-group BRACHY-HIFU, had urinary complication greater than or equal to grade 2. Among all the patients, only 1 had grade 1 gastrointestinal toxicity. CONCLUSION: BRACHY-HIFU sequence seems to be purveyor of many significant urinary side effects. A larger database is needed to confirm this conclusion.

[Prostate cancer boost using high-dose-rate brachytherapy: impact of the learning curve on the dosimetry]. / Curiethérapie de haut débit de dose après radiothérapie externe d'un cancer de prostate : impact de la courbe d'apprentissage sur la dosimétrie.

PURPOSE: To analyse the influence of the learning curve on dosimetric data for high-dose-rate brachytherapy prostate cancer boost. PATIENTS AND METHODS: From February 2009 to May 2012, after a first course of external beam radiation therapy (46Gy/23 fractions), 124 patients underwent high-dose-rate brachytherapy boost using Plato™ (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden). The impact of the learning curve on the dosimetric quality of the prostate implant was assessed. The dosimetric data have been analysed: clinical target volume (CTV), D90 (dose to 90 % of CTV), D100, V100 (part on the CTV receiving 100 % of the dose), V150, V200 and DHI (dose non-homogeneity index). The doses delivered to 0.1, 1 and 2 cm(3) of the rectum and urethra were calculated. RESULTS: During the study period (39 months), a significant reduction of V150 (P<0.001), V200 (P<0.001), D0.1rectum (P<0.001), D1rectum (P<0.001), D2rectum (P<0.001), D0.1urethra (P<0.001), and D1urethra (P<0.002) was observed associated with a significant degradation of the D90 (P<0.001) but not significant for the V100 (P=0.29) and the D100 (P=0.3). CONCLUSION: This study confirms that the dosimetric quality of high-dose-rate brachytherapy prostate implant is significantly improved during the learning curve period.

[Brachytherapy of breast cancer]. / Curiethérapie du cancer du sein.

For breast cancer, interstitial brachytherapy remains an accurate irradiation technique for delivering a high dose (increasing the local control) in a small volume (decreasing the toxicity). In this article, we present the technical data related to the breast brachytherapy proceeding, from the implantation of the vectors to the treatment itself, including the planning. The different indications of breast brachytherapy include all the breast irradiations focusing on the initial tumour bed (partial irradiation of the breast), such as boost, accelerated and partial breast irradiation (APBI) and second conservative radiosurgical treatment in case of ipsilateral in-breast recurrence. The results in terms of efficacy and toxicity are presented for each indication. Interstitial breast brachytherapy, performed according with the standard rules, remains a major technique for breast cancer treatment.