[Stereotactic radiation therapy for liver tumours]. / Radiothérapie stéréotaxique hépatique.

Liver lesions are common in oncology, and various focal treatments can be used, such as surgery, chemoembolization, radiofrequency, and systemic treatment. However, these treatments are often not feasible for a number of reasons, including the patient's general health or the characteristics of the lesion itself. Additionally, localized relapses may occur after focal treatments. In the past, liver radiotherapy was limited by the toxicities it caused and was mainly used in palliative situations or specific pre-transplant management. However, advancements in high-precision radiotherapy, like hypofractionated radiotherapy in stereotactic conditions, have allowed to treat the lesions with minimal margins, delivering higher doses while reducing the healthy liver's exposure. Increasingly, retrospective and prospective studies have demonstrated the effectiveness and safety of hypofractionation for both primary and secondary liver lesions. This review discusses the indications, results, and techniques of this type of treatment.

Les lésions hépatiques primitives ou secondaires sont une situation fréquente en oncologie. Plusieurs types de traitements focaux peuvent être appliqués : chirurgie, chimio-embolisation, radio-fréquence, traitement systémique. Néanmoins, les traitements focaux sont régulièrement contre-indiqués, soit par l'état général et les antécédents du patient, soit par la lésion en elle-même (volume, situation). De plus, il peut y avoir des patients qui présentent des rechutes localisées après ce type de prise en charge. Le foie est un organe très radiosensible, et la radiothérapie hépatique a longtemps été limitée par les toxicités qu'elle engendrait. La radiothérapie est le plus souvent utilisée dans les situations très palliatives (irradiation hépatique en totalité) ou dans certains schémas de prise en charge avant greffe. Pourtant, l'avènement de la radiothérapie de haute précision, telle que la radiothérapie hypofractionnée en condition stéréotaxique, permet de traiter les lésions avec des marges minimes et donc, d'augmenter la dose délivrée en diminuant le volume de foie sain irradié. On retrouve aujourd'hui un nombre de plus en plus important de séries rétrospectives et prospectives qui décrivent son efficacité et sa tolérance tant pour les lésions primitives que secondaires. Nous faisons ici un point sur les indications, les résultats et les modalités de ce type de traitement.

Extreme hypofractionated stereotactic radiotherapy for localized prostate Cancer: Efficacy and late urinary toxicity according to transurethral resection of the prostate history.

Background and purpose: Extreme hypofractionated stereotactic body radiotherapy (SBRT) is a therapeutic alternative for localized low- or intermediate-risk prostate cancer. Despite the availability of several studies, the toxicity profile of SBRT has not been comprehensively described. This real-world evidence study assessed the efficacy and toxicities associated with this regimen, and potential prognosis factors for genitourinary toxicities. Materials and methods: This retrospective study included 141 consecutive patients with localized prostatic adenocarcinoma treated with CyberKnife™ SBRT, as primary irradiation, at the Oscar Lambret Center between 2010 and 2020. The prescribed dose was 36.25 Gy in 5 fractions. Acute and late toxicities were graded according to the CTCAE (version 5.0). Biochemical recurrence-free survival (bRFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The cumulative incidence of biochemical recurrence (cBR) was estimated using the Kalbfleisch-Prentice method. Results: Among the included patients, 13.5 % had a history of transurethral resection of the prostate (TURP). The median follow-up was 48 months. At 5 years, bRFS, cBR, and OS were 72 % (95 %CI: 61-81), 7 % (95 %CI: 3-14), and 82 % (95 %CI: 73-89), respectively. Twenty-nine patients experienced at least one late toxicity of grade ≥ 2; genitourinary (N = 29), including 3 cases of chronic hematuria, and/or gastrointestinal (N = 1). The cumulative incidence of late urinary toxicity of grade ≥ 2 was 20.6 % at 5 years (95 %CI: 13.9-28.1). Multivariate analysis revealed that a history of TURP was significantly associated with late urinary toxicity of grade ≥ 2, after adjusting for clinical target volume (Odds Ratio = 3.06; 95%CI: 1.05-8.86; P = 0.04). Conclusion: Extreme hypofractionated SBRT is effective for localized prostate cancer with a low risk of late toxicity. A history of TURP is associated with a higher risk of late urinary toxicity. These findings may contribute to the optimal management of patients treated with this regimen, particularly those with a history of TURP.

Studies of Intra-Fraction Prostate Motion During Stereotactic Irradiation in First Irradiation and Re-Irradiation.

BACKGROUND: Understanding intra-fractional prostate motions is crucial for stereotactic body radiation therapy (SBRT). No studies have focused on the intra-fractional prostate motions during re-irradiation with SBRT. The objective was to evaluate these translational and rotational motions in primary treated patients and in the context of re-irradiation. METHODS: From January 2011 to March 2020, 162 patients with histologically proven prostate cancer underwent prostate SBRT, including 58 as part of a re-irradiation treatment. We used the continuous coordinates of the fiducial markers collected by an orthogonal X-ray dual-image monitoring system. The translations and rotations of the prostate were calculated. Prostate deviations representing overall movement was defined as the length of the 3D-vectors. RESULTS: A total of 858 data files were analyzed. The deviations over time in the group of primary treated patients were significantly larger than that of the group of re-irradiation, leading to a mean deviation of 2.73 mm (SD =1.00) versus 1.90 mm (SD =0.79), P<0.001. In the re-irradiation group, we identified displacements of -0.05 mm (SD =1.53), 0.20 mm (SD =1.46); and 0.42 mm (SD =1.24) in the left-right, superior-inferior and anterior-posterior planes. Overall, we observed increasing deviations over the first 30 min followed by a stabilization related to movements in the three translational axes. CONCLUSION: This is the first study to focus on intrafraction prostate motions in the context of re-irradiation. We observed that intra-fraction prostate motions persisted in the setting of re-irradiation, although they showed a significant reduction when compared with the first irradiation. These results will help to better estimate random errors during SBRT treatment of intra-prostatic recurrence after irradiation.