Clinical and Translational Radiation Oncology最新文献

Background

Current segmentation approaches for radiation treatment planning in head and neck cancer patients (HNCP) typically consider the entire mandible as an organ at risk, whereas segmentation of the maxilla remains uncommon. Accurate risk assessment for osteoradionecrosis (ORN) or implant-based dental rehabilitation after radiation therapy may require a nuanced analysis of dose distribution in specific mandibular and maxillary segments. Manual segmentation is time-consuming and inconsistent, and there is no definition of jaw subsections.

Materials and methods

The mandible and maxilla were divided into 12 substructures. The model was developed from 82 computed tomography (CT) scans of HNCP and adopts an encoder-decoder three-dimensional (3D) U-Net structure. The efficiency and accuracy of the automated method were compared against manual segmentation on an additional set of 20 independent CT scans. The evaluation metrics used were the Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and surface DSC (sDSC).

Results

Automated segmentations were performed in a median of 86 s, compared to manual segmentations, which took a median of 53.5 min. The median DSC per substructure ranged from 0.81 to 0.91, and the median HD95 ranged from 1.61 to 4.22. The number of artifacts did not affect these scores. The maxillary substructures showed lower metrics than the mandibular substructures.

Conclusions

The jaw substructure segmentation demonstrated high accuracy, time efficiency, and promising results in CT scans with and without metal artifacts. This novel model could provide further investigation into dose relationships with ORN or dental implant failure in normal tissue complication prediction models.

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.

Background and purpose

To assess feasibility, toxicity and outcome of moderately hypofractionated radiotherapy concomitant to capecitabine after induction chemotherapy for advanced pancreatic cancer.

Materials and methods

Patients with advanced pancreatic cancer without distant progression after induction chemotherapy (CHT) were considered. Radiochemotherapy (RCT) consisted of 44.25 Gy in 15 fractions to the tumor and involved lymph-nodes concomitant to capecitabine 1250 mg/m²/day. Feasibility and toxicity were evaluated in all pts. Overall survival (OS), progression free survival (PFS), distant PFS (DPFS) and local PFS (LPFS) were assessed only in stage III patients.

Results

254 patients, 220 stage III, 34 stage IV, were treated. Median follow up was 19 months. Induction CHT consisted of Gemcitabine (35 patients), or drug combination (219 patients); median duration was 6 months.

Four patients (1.6 %) did not complete RT (1 early progression, 3 toxicity), median duration of RT was 20 days, 209 patients (82 %) received ≥ 75 % of capecitabine dose.

During RCT G3 gastrointestinal toxicity occurred in 3.2% of patients, G3-G4 hematologic toxicity in 5.4% of patients. Subsequently, G3, G4, G5 gastric or duodenal lesions occurred in 10 (4%), 2 (0.8%) and 1 patients (0.4%), respectively.

Median PFS, LPFS, and DPFS were 11.9 months (95 % CI:11.4–13), 16 months (95 % CI:14.2–17.3) and 14.0 months (95 % CI:12.6–146.5), respectively.

Median OS was 19.5 months (95 % CL:18.1–21.3). One- and two-year survival were 85.2 % and 36 %, respectively.

Conclusions

The present schedule of hypofractionated RT after induction CHT is feasible with acceptable toxicity rate and provides an outcome comparable with that achievable with standard doses and fractionation.

Objective

As craniospinal irradiation (CSI) is delivered more frequently by helical tomotherapy (HT) with few reports about late effects, we analysed all patients treated in our centre over an 11-year period.

Methods and materials

Our study included all patients that underwent CSI by HT, between September 2009 and January 2020, in the Department of Radiation Oncology of the Toulouse Cancer Institute. Acute radiotherapy toxicities were reported and medium- to long-term outcomes analysed.

Results

Among the 79 patients included, 70.9 % were younger than 18 years at diagnosis, the median age was 13 (range: 1–52) at the time of radiation therapy, 67.1 % of patients had medulloblastoma. Half of them (49.4 %) had a metastatic disease at diagnosis. The median dose of CSI was 36 Gy (range, 18–36). Seventy-seven patients received a radiation boost to the original location of the primary tumour (97.5 %), 32 patients also received a boost to their metastatic sites (40.5 %). Median follow-up was 55.5 months (95 %CI = [41.2; 71.8]). The 3-year event-free survival rate was 66.3 % (95 %CI = [54.2; 75.9]). Most patients presented with acute haematological toxicities during CSI (85.9 %), predominantly severe thrombocytopenia (39.7 %). Among the 64 patients assessed for medium- and long-term outcomes, 52 survived and 47 were alive and disease-free at the latest follow-up visit on record. There were 3.8 % secondary tumours: two meningiomas and one diffuse intrinsic pontine glioma. Adult and paediatric patients respectively presented with secondary cataract (4.3 % vs 22.0 %), persistent hearing disorders (26.1 % vs 29.3 %), pulmonary or cardiac late effects (4.3 % vs 2.4 %), hormonal pituitary gland deficiencies (30.0 % vs 56.8 %) and psycho-cognitive disorders (56.5 % vs 53.7 %).

Conclusion

CSI dispensed by HT, did not result in any additional acute or late toxicities when compared to 3D-CSI. There was no increase in the secondary tumour rate compared to that reported in the literature.

This is a response to the letter to the editor from Dr. Ali et al. from Aga Khan University, Karachi, Pakistan.

Introduction

Patients with failure after primary radiotherapy (RT) for head and neck squamous cell carcinoma (HNSCC) have a poor prognosis. This study investigates pattern of failure after primary curatively intended IMRT in a randomized controlled trial in relation to HPV/p16 status.

Material and methods

Patients with HNSCC of the oral cavity, oropharynx (OPSCC), hypopharynx or larynx were treated with primary curative IMRT (+/-cisplatin) and concomitant nimorazole between 2007 and 12. Of 608 patients, 151 had loco-regional failure within five years, from whom 130 pairs of scans (planning-CT and diagnostic failure scan) were collected and deformably co-registered. Point of origin-based pattern of failure analysis was conducted, including distance to CTV1 and GTV, and estimated dose coverage of the point of origin.

Results

Of 130 patients with pairs of scans, 104 (80 %) had at least one local or regional failure site covered by 95 % of prescribed dose and 87 (67 %) of the failures had point of origin within the high-dose CTV (CTV1). Of failures from primary p16 + OPSCC, the majority of both mucosal (84 %) and nodal (61 %) failures were covered by curative doses. For p16− tumors (oral cavity, OPSCC p16neg, hypopharynx and larynx), 75 % of mucosal and 66 % of nodal failures were high-dose failures.

Conclusion

Radioresistance is the primary cause of failure after RT for HNSCC irrespective of HPV/p16 status. Thus, focus on predictors for the response to RT is warranted to identify patients with higher risk of high-dose failure that might benefit from intensified treatment regimens.

This series introduces the clinical management of difficult-to-treat non-melanoma skin cancers (NMSCs) through a multidisciplinary approach, emphasizing the integration of dermoscopy and Ultra high-frequency ultrasound (UHFUS) for accurate diagnosis and treatment planning, particularly in cases referred for radiotherapy (RT). Dermoscopy aids in diagnosing both pigmented and non-pigmented skin lesions, guiding treatment margins and reducing the benign-to-malignant biopsy ratio. UHFUS provides valuable insights into tumor size, depth, and vascularity, complementing clinical evaluations and assisting in RT planning. Three challenging cases are presented, highlighting the pivotal role of dermoscopy and UHFUS in decision-making and treatment optimization. Collaboration between dermatologists, radiation oncologists, and radiologists enhances diagnostic accuracy, tailoring treatment plans to individual patient needs and preferences, ultimately improving patient outcomes and experience. The integration of these imaging techniques holds promise for optimizing non-surgical treatments like RT and monitoring treatment progress, offering a personalized approach to NMSC management.

Purpose

To assess radiation-induced fibrosis (RIF) using shear-wave elastography (SWE) in patients with breast cancer who received radiotherapy (RT) after breast conserving surgery.

Methods

Forty-one patients were enrolled in a prospective study before RT. SWE and B-mode ultrasonography were performed to measure elasticity. For quantitative measurement, the maximum elasticity value was measured in the tumor bed and non-tumor bed of the treated breast, and contralateral breast before RT and at 3, and 12 months after RT. and RIF was recorded using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

Results

The mean ± standard deviation elasticity values for the tumor bed, non-tumor bed, and contralateral breast were 71.2 ± 74.9 kPa, 19.4 ± 9.8 kPa and 20.3 ± 10.0 kPa before RT; 28.7 ± 26.3 kPa, 15.1 ± 7.0 kPa, and 14.7 ± 6.3 kPa at 12 months after RT, respectively. The elasticity values for all three measurement areas before and 12 months after RT were significantly different (p < 0.001 for tumor bed, p = 0.002 for non-tumor bed, p = 0.001 for contralateral breast). At 12 months follow-up, the distribution of grades of RIF evaluated by CTCAE grade was grade 0 in 43.9 %, grade 1 in 48.8 %, and grade 2 in 7.3 %.

Conclusion

We demonstrated that SWE enables the evaluation of tissue stiffness to provide quantified information for the RIF of breast cancer. Further studies with long-term follow-up should provide more quantitative data.

Introduction

Although stereotactic ablative radiotherapy (SABR) has advance to standard-of-care for many different indications like lung and liver malignancies, it still remains in its infancy for treating head and neck cancer. Nevertheless there is a growing body of experience and evidence, which is summarized in this review Methods A thorough search of the literature was performed and critically reviewed both for SABR as a primary treatment as well as for treating locoregionally recurrent disease in a pre-irradiated field.

Results

There exist only few prospective data published so far for treating head and neck cancer with SABR. In the primary situation especially implementing SABR as a boost after definitive radiotherapy or a single-modality for locally limited, small glottic cancer appear promising. On the other hand, SABR can be a useful modality for treating local recurrence in a pre-irradiated field. However, caution is needed in the case of proximity to a pre-irradiated carotid artery or other serial organs at risk. Usually only limited gross volumes are treated with 3-6 fractions every other day and a cumulative dose of 24-44 Gy in dedicated radiosurgery platforms or modern linacs with the possibility of online image-guidance and adequate immobilsation.

Conclusions

SABR is an innovative, effective and promising treatment modality for small targets, especially in near proximity to organs at risk or in a pre-irradiated region. Prospective trials are further needed for this technique to become standard-of care.