Surface-guided radiotherapy overview: Technical aspects and clinical applications.

In radiotherapy, patient positioning has long been ensured by ionizing imaging (kV or MV). Over the past ten years, surface-guided radiotherapy has appeared in radiotherapy departments. It is a continuous three-dimensional acquisition of the surface of the patient, based on the use of several optical cameras. The acquired surface is compared to an expected surface (usually taken from the planning scanner). Operators can constantly appreciate poor position, anatomical deformity or patient shift. Thus, the system allows an aid to the positioning of the patient, possibly without tattooing, but also a follow-up of the patient during the duration of the session. The most obvious contribution of the system concerns the treatment of the breast. In fact, for this location, the bone registration is not ideal and the target is visible in surface-guided radiotherapy. These systems also make it possible to treat in deep inspiration breath hold. But several other locations can benefit from it (pelvis, thorax, etc.).

Interactions of radiation therapy with common and innovative systemic treatments: Antidiabetic treatments, antihypertensives, lipid-lowering medications, immunosuppressive medications and other radiosensitizing methods.

The invention and approval of innovative anticancer therapies in the last decade have revolutionized oncology treatment. Radiotherapy is one of the three traditional pillars in oncology treatment with surgery and systemic therapies. Some standard-of-care combinations of chemoradiotherapy widened the therapeutic window of radiation, while some other chemotherapies such as gemcitabine caused unacceptable toxicities when combined with radiation in lung cancers. Fast-paced progress are specially focused on immunotherapies, targeted-therapies, anti-angiogenic treatment, DNA repair inhibitors, hormonotherapy and cell cycle inhibitors. New anticancer therapeutic arsenals provided new possibilities of combined oncological treatments. The interactions of the radiotherapy with other systemic treatments, such as non-anticancer immunomodulatory/immunosuppressive medications are sometimes overlooked even though they could offer a real therapeutic benefit. In this review, we summarize the new opportunities and the risks of historical and novel combined therapies with radiation: non-anticancer immunomodulatory/immunosuppressive drugs, systemic reoxygenation, new therapies such as nanoparticles and SMAC mimetics. Key biological mechanisms, pre-clinical and available clinical data will be provided to demonstrate the promising opportunities in the years to come.

[Why is brachytherapy still essential in 2017?] / Pourquoi la curiethérapie reste-t-elle indispensable en 2017 ?

These recent years, brachytherapy has benefited from imaging modalities advances. A more systematic use of tomodensitometric, ultrasonographic and MRI images during brachytherapy procedures has allowed an improvement in target and organs at risk assessment as well as their relationship with the applicators. New concepts integrating tumor regression during treatment have been defined and have been clinically validated. New applicators have been developed and are commercially available. Optimization processes have been developed, integrating hypofractionation modalities leading to tumor control improvement. All these opportunities led to further development of brachytherapy, with indisputable ballistic advantages, especially compared to external irradiation.

[Repair and time-dose factor: The example of spinal cord irradiation]. / Réparation et facteur temps : l'exemple de l'irradiation médullaire.

The question whether a reirradiation is possible, with either curative of palliative intent, is a frequent issue and a true therapeutic challenge, in particular for a critical organ sensitive to cumulative dose, such as the spinal cord. Preclinical experimental data, based on debatable models that are hardly transferable to patients, suggest that there is a possibility of reirradiation, beyond the classical threshold for dose constraints, taking into account the "time-dose factor". Although the underlying biological mechanisms are however uncertain, scarce clinical data seem to confirm that the tolerance of spinal cord to reirradiation does exist, provided that a particular attention to total dose is given. In the context where modern stereotactic irradiation facilities expand therapeutic perspectives, we review the literature on possibilities of reirradiation, through the example of spinal cord reirradiation.

Pelvic radiotherapy in the setting of rheumatoid arthritis: Refining the paradigm.

PURPOSE: Conflicting results concerning the toxicity of radiotherapy in the setting of rheumatoid arthritis were reported in literature. This work describes the toxicity profiles of patients with rheumatoid arthritis undergoing pelvic radiotherapy for gynecologic malignancies at our institution. PATIENTS AND METHODS: Charts of patients with rheumatoid arthritis who underwent pelvic radiotherapy for cervical or endometrial cancer in a curative intent at the Gustave-Roussy Cancer Campus between 1990 and 2015 were reviewed for treatment-related toxicities. Acute and late effects were graded as per the Common Terminology Criteria for Adverse Events version 4.0 scoring system. RESULTS: Eight patients with cervical cancer and three with endometrial cancer were identified. Median follow-up was 56 months. Median external beam radiotherapy dose was 45Gy. All patients received a brachytherapy boost using either pulse- or low-dose rate technique. Concomitant chemotherapy was used in seven cases. Median time from rheumatoid arthritis diagnosis to external beam radiation therapy was 5 years. No severe acute gastrointestinal or genitourinary toxicity was reported. One patient had grade 3 dermatitis. Any late toxicity occurred in 7 /11 patients, and one patient experienced severe late toxicities. One patient with overt systemic rheumatoid arthritis symptoms at the time of external beam radiation therapy experienced late grade 3 ureteral stenosis, enterocolitis and lumbar myelitis. CONCLUSION: Pelvic radiotherapy, in the setting of rheumatoid arthritis, appears to be feasible, with potentially slight increase in low grade late events compared to other anatomic sites. Patients with overt systemic rheumatoid arthritis manifestation at the time of radiotherapy might be at risk of potential severe toxicities.

Brachytherapy as part of the conservative treatment for primary and recurrent vulvar carcinoma.

PURPOSE: There are only scarce data on the place of brachytherapy (BT) for treatment of vulvar carcinoma. Our institutional experience of interstitial BT for vulvar carcinoma patients is reported. METHODS AND MATERIALS: Clinical records of patients receiving low-dose-rate or pulsed-dose-rate BT as part of the primary treatment for primary/recurrent vulvar squamous cell carcinoma or as part of postoperative treatment between 2000 and 2015 were included. Patients, tumors, and treatment characteristics as well as clinical outcome were examined. RESULTS: A total of 26 patients treated with BT were identified. BT was delivered as part of primary intent treatment for locally advanced/recurrent cancer in 11 patients and as part of postoperative treatment in 15 patients. Median age at time of BT was 63 years (range, 41-88 years). Pulsed-dose-rate and low-dose-rate were used in 15 patients and 11 patients, respectively. BT was performed as a boost to the tumor bed following external beam radiotherapy (n = 13) or as the sole irradiation modality (n = 13). Total median dose at the level of primary tumor was 60 GyEQD2 (range, 55-60 GyEQD2). With mean followup of 41 months (range, 5 months-11.3 years), 11 patients experienced tumor relapse, and in two of them, site of relapse was only local. Three-year estimated disease-free survival and overall survival rates were 57% (95% confidence interval: 45-69%) and 81% (95% confidence interval: 72-90%), respectively. All toxicities were Grade 2 or less. CONCLUSIONS: Interstitial BT used as part of the primary or postoperative treatment of vulvar carcinoma is feasible with a satisfactory toxicity profile. Prognosis remains, however, dismal, with a high frequency of failures in patients with locally advanced tumors.

45 or 50 Gy, Which is the Optimal Radiotherapy Pelvic Dose in Locally Advanced Cervical Cancer in the Perspective of Reaching Magnetic Resonance Image-guided Adaptive Brachytherapy Planning Aims?

AIMS: In locally advanced cervical cancer, the dose delivered results from the sum of external beam radiotherapy and brachytherapy, and is limited by the surrounding organs at risk. The balance between both techniques influences the total dose delivered to the high-risk clinical target volume (HR-CTV). The aim of the present study was to compare the ability of reaching different planning aims after external beam radiotherapy pelvic doses of 45 Gy in 25 fractions or 50.4 Gy in 28 fractions, both considered as standard prescriptions. MATERIALS AND METHODS: The optimised plans of 120 patients treated with pelvic chemoradiation followed by magnetic resonance image-guided intracavitary brachytherapy were reviewed. The doses per pulse were calculated, and the number of pulses required to reach the planning aims, or a limiting dose constraint to organs at risk, was calculated. All doses were converted to 2-Gy equivalents. Three scenarios were applied consisting of different sets of planning aims: 85 and 60 Gy for the HR-CTV and the intermediate-risk CTV (IR-CTV) D90 (minimal dose received by 90% of the volume) in scenario 1, 90 and 60 Gy, respectively, for scenarios 2 and 3. For organs at risk, dose constraints were 90, 75 and 75 Gy to the bladder, rectum and sigmoid D2cm(3), respectively, in scenarios 1 and 2, and 80, 65 and 70 Gy in scenario 3. RESULTS: A similar HR-CTV D90 could have been reached in scenarios 1 and 2 according to both pelvic doses. In scenario 3, a higher mean HR-CTV could have been reached in the 45 Gy arm (83.5 ± 8.0 versus 82.4 ± 8.0, P < 0.0001). The mean D2cm(3) of organs at risk was systematically and significantly increased after a delivery of 50.4 Gy to the pelvis, from 0.9 to 2.89 Gy. The proportions of plans reaching planning aims were 85.8, 72.5 and 42.5% after 45 Gy and 85.5, 67.5 and 33.3% after 50.4 Gy according to scenarios 1, 2 and 3, respectively. According to scenario 3, 50.4 Gy, the reachable HR-CTV D90 was higher in 30% of the cases, by 2 Gy in two cases. Those cases were unpredictable and due to unfavourable organs at risk topography and poor response to external beam radiotherapy. CONCLUSION: The delivery of 45 Gy in 25 fractions to the pelvis before brachytherapy warrants a higher probability to reach brachytherapy planning aims, in comparison with 50.4 Gy in 28 fractions.

Interstitial pulsed-dose-rate brachytherapy for the treatment of squamous cell anal carcinoma: A retrospective single institution analysis.

OBJECTIVE: To examine the outcome of patients receiving interstitial pulsed-dose-rate brachytherapy (PDR-BT) after pelvic radiation therapy for treatment of an anal squamous cell carcinoma. METHODS AND MATERIALS: Twenty-one patients were identified: 13, six, and two with stages I, II, and III tumors, respectively. After receiving received pelvic irradiation +/- concurrent chemotherapy, patients were delivered a PDR-BT boost to the residual tumor, with intention to deliver a minimal total dose of 60 Gy. The greatest dimension of residual tumor at the time of brachytherapy procedure was 12.5 mm (range: 0-20 mm). Brachytherapy implantation was performed according to the Paris system, only one plane implant being used. RESULTS: Median dose delivered through BT was 20 Gy (range: 10-30 Gy). Median number of pulses was 48 (range: 20-80 pulses). Median treated volume was 9 cm(3) (range: 5-16 cm(3)). Median dose per pulse was 40 cGy (range: 37.5-50 cGy). No Grade 3 or more acute toxicity was reported. No Grade 3 or more delayed toxicity was seen among 18 patients with more than 6 months follow-up. Median followup was 47 months (range: 6-73 months). Twenty patients (95%) were alive at last follow-up. Tumor relapses were experienced in four patients (19%), including local relapse in three patients (14%). CONCLUSION: With almost 4 years median followup, this study confirms previous data suggesting that PDR-BT is effective and safe in this indication. Local control rate and toxicity were in the range of what was seen with continuous low-dose-rate BT.

Clinical Experience with Pulse Dose Rate Brachytherapy for Conservative Treatment of Penile Carcinoma and Comparison with Historical Data of Low Dose Rate Brachytherapy.

AIMS: To assess the efficacy of pulse dose rate (PDR) interstitial brachytherapy in the treatment of carcinoma of the penis and to compare with historical data of low dose rate (LDR) brachytherapy. MATERIALS AND METHODS: We reviewed the clinical records of 27 consecutive patients treated in our institution with exclusive PDR brachytherapy for a squamous cell carcinoma of the penis. The median tumour greatest diameter was 20 mm (range: 10-50 mm). Twenty-three patients (85%) had tumours limited to the glans and/or prepuce and four patients (15%) also had inguinal lymph node metastases. Implantations were carried out according to the Paris system and treatments were delivered with PDR brachytherapy. RESULTS: The median brachytherapy dose was 60 Gy (range: 60-70 Gy). The median treated volume was 28 cm(3) (range: 8-62 cm(3)). The median reference isodose rate was 0.4 Gy/pulse/h (range: 0.4-0.5 Gy/pulse/h). The median number of pulses was 150 (range: 120-175 pulses). With a median follow-up of 33 months (range: 6-64 months), tumour relapses in the penis were reported in four patients (15%). All patients with only local relapse (n = 3) were successfully salvaged with partial amputation. The estimated overall survival rate at 3 years was 95% (95% confidence interval: 83-100%). No grade 3 or more acute reaction was observed. Delayed ulcerations and stenoses requiring at least one meatal dilatation were reported in two (9%) and five (22%) patients without local relapse. The treated volume was significantly correlated to the risk of clinically relevant delayed toxicity. CONCLUSIONS: The efficacy/toxicity results of PDR brachytherapy for the treatment of penile carcinoma are comparable with those obtained with LDR brachytherapy in historical cohorts.

Volumetric evaluation of an alternative bladder point in brachytherapy for locally advanced cervical cancer.

PURPOSE: To evaluate an alternative dose point, so-called ALG (for Alain Gerbaulet), for the bladder in comparison to the International Commission on Radiation Units and Measurements (ICRU) point and D2cm(3) (minimal dose to maximally exposed 2 cm(3)) in a large cohort of patients with locally advanced cervical cancer treated with external beam radiotherapy followed by image-guided pulsed dose rate brachytherapy. METHODS AND MATERIALS: For each patient, the ALG point was constructed 1.5 cm above the ICRU bladder, parallel to the tandem (coronal and sagittal planes). The dosimetric data from 162 patients were reviewed. RESULTS: Average doses to ALG and bladder points were 19.40 Gy ± 7.93 and 17.14 ± 8.70, respectively (p=0.01). The 2 cm(3) bladder dose averaged 24.40 ± 6.77 Gy. Ratios between D2cm(3) and dose points were 1.37 ± 0.46 and 1.68 ± 0.74 (p<0.001) for ALG and ICRU points, respectively. Both dose points appeared correlated with D2cm(3) (p<0.001) with coefficients of determination (R(2)) of 0.331 and 0.399 respectively. The estimated dose to the ICRU point of the rectum was 12.77 ± 4.21 and 15.76 ± 5.94 for D2cm(3) (p<0.0001). Both values were significantly correlated (p<0.0001, R(2) = 0.485). CONCLUSION: The ALG point underestimates the D2cm(3), but its mean on a large cohort is closer to D2cm(3) than the dose to ICRU point. However, it shows great variability between cases and the weak strength of its correlation to D2cm(3) indicates that it is not a good surrogate for individual volumetric evaluation of the dose D2cm(3).

[Gated radiotherapy in breast cancer]. / Asservissement respiratoire en radiothérapie mammaire.

Postoperative radiotherapy is a cornerstone of the local treatment in breast cancer. It has been proved with high level of evidence that it decreases local relapse and improves survival of patients. However, radiotherapy comes with healthy tissue toxicity, heart and lung in particular. With constant improvement of radiation techniques, several methods have been developed to decrease the dose to the heart and the lungs. Sometimes, respiratory maneuvers can help, due to patient's anatomy: the radiotherapy is gated with patient's breath. The Deep Inspiration Breath Hold technique is the most popular and there are several ways to perform it. This note will describe the different systems with published data in order to help the radiation oncologist in the daily practice.