Postsurgical geometrical variations of tumor bed and brainstem during photon and proton therapy for pediatric tumors of the posterior fossa: dosimetric impact and predictive factors.

PURPOSE: Brainstem radionecrosis is an important issue during the irradiation of tumors of the posterior fossa. The aim of the present study is to analyze postsurgical geometrical variations of tumor bed (TB) and brainstem (BS) and their impact on dosimetry. METHODS: Retrospective collection of data from pediatric patients treated at a single institution. Availability of presurgical magnetic resonance imaging (MRI) was verified; availability of at least two postsurgical MRIs was considered a further inclusion criterion. The following metrics were analyzed: total volume, Dice similarity coefficient (DSC), and Haudsdorff distances (HD). RESULTS: Fourteen patients were available for the quantification of major postsurgical geometrical variations of TB. DSC, HD max, and HD average values were 0.47 (range: 0.08;0.76), 11.3 mm (7.7;24.5), and 2.6 mm (0.7;6.7) between the first and the second postoperative MRI, respectively. Postsurgical geometrical variations of the BS were also observed. Coverage to the TB was reduced in one patient (D95: -2.9 Gy), while D2 to the BS was increased for the majority of patients. Overall, predictive factors for significant geometrical changes were presurgical gross tumor volume (GTV) > 33 mL, hydrocephaly at diagnosis, Luschka foramen involvement, and younger age (≤ 8 years). CONCLUSION: Major volume changes were observed in this cohort, with some dosimetric impact. The use of a recent co-registration MRI is advised. The 2-3 mm HD average observed should be considered in the planning target volume/planning organ at risk volume (PTV/PRV) margin and/or robust optimization planning. Results from wider efforts are needed to verify our findings.

Author Correction: VEGFC negatively regulates the growth and aggressiveness of medulloblastoma cells.

A Correction to this paper has been published: https://doi.org/10.1038/s42003-020-01502-2.

VEGFC negatively regulates the growth and aggressiveness of medulloblastoma cells.

Medulloblastoma (MB), the most common brain pediatric tumor, is a pathology composed of four molecular subgroups. Despite a multimodal treatment, 30% of the patients eventually relapse, with the fatal appearance of metastases within 5 years. The major actors of metastatic dissemination are the lymphatic vessel growth factor, VEGFC, and its receptors/co-receptors. Here, we show that VEGFC is inversely correlated to cell aggressiveness. Indeed, VEGFC decreases MB cell proliferation and migration, and their ability to form pseudo-vessel in vitro. Irradiation resistant-cells, which present high levels of VEGFC, lose the ability to migrate and to form vessel-like structures. Thus, irradiation reduces MB cell aggressiveness via a VEGFC-dependent process. Cells intrinsically or ectopically overexpressing VEGFC and irradiation-resistant cells form smaller experimental tumors in nude mice. Opposite to the common dogma, our results give strong arguments in favor of VEGFC as a negative regulator of MB growth.

Early Toxicities After High Dose Rate Proton Therapy in Cancer Treatments.

BACKGROUND: The conventional dose rate of radiation therapy is 0.01-0.05 Gy per second. According to preclinical studies, an increased dose rate may offer similar anti-tumoral effect while dramatically improving normal tissue protection. This study aims at evaluating the early toxicities for patients irradiated with high dose rate pulsed proton therapy (PT). MATERIALS AND METHODS: A single institution retrospective chart review was performed for patients treated with high dose rate (10 Gy per second) pulsed proton therapy, from September 2016 to April 2020. This included both benign and malignant tumors with ≥3 months follow-up, evaluated for acute (≤2 months) and subacute (>2 months) toxicity after the completion of PT. RESULTS: There were 127 patients identified, with a median follow up of 14.8 months (3-42.9 months). The median age was 55 years (1.6-89). The cohort most commonly consisted of benign disease (55.1%), cranial targets (95.1%), and were treated with surgery prior to PT (56.7%). There was a median total PT dose of 56 Gy (30-74 Gy), dose per fraction of 2 Gy (1-3 Gy), and CTV size of 47.6 ml (5.6-2,106.1 ml). Maximum acute grade ≥2 toxicity were observed in 49 (38.6%) patients, of which 8 (6.3%) experienced grade 3 toxicity. No acute grade 4 or 5 toxicity was observed. Maximum subacute grade 2, 3, and 4 toxicity were discovered in 25 (19.7%), 12 (9.4%), and 1 (0.8%) patient(s), respectively. CONCLUSION: In this cohort, utilizing high dose rate proton therapy (10 Gy per second) did not result in a major decrease in acute and subacute toxicity. Longer follow-up and comparative studies with conventional dose rate are required to evaluate whether this approach offers a toxicity benefit.

Oncologic and visual outcomes after postoperative proton therapy of localized conjunctival melanomas.

INTRODUCTION: conjunctival melanomas have high local relapse rates. Oncologic and visual outcomes can be improved with proton therapy and no-touch surgery. MATERIAL AND METHODS: a monocentric retrospective study of consecutive patients treated with surgery and proton therapy for conjunctival melanoma was conducted. Proton therapy was performed to a total dose of 45 Grays physical dose delivered in eight fractions over two weeks. RESULTS: Ninety-two patients were included. The mean age was 63-year-old. 65.2% of patients had primary acquired melanosis. The mean tumor thickness and diameter was 2.5 mm and 7.0 mm respectively. The clinical stage was T1 in 71.6% of cases, with a quadrangular involvement of more than 90° in 69% of cases. Conjunctival melanomas were of epithelioid cell-type in 40% of cases. Mean follow-up was 4.7 years. Five-year local failure rate was 33.2%. Of 25 local recurrences, 14 were marginal/out-of-field, 4 in-field, others were undetermined. First surgery at expert center resulted in 24.3% of local failure at 5 years versus 38.7% if performed elsewhere (p = 0.41). Salvage exenteration was performed in 13 patients. Tumor stage and quadrangular involvement were significant factors for local failure. Five-year progression-free survival and cause-specific death rates were 61.5 and 3.6%. Stage and epithelioid type were associated with poorer progression-free survival. Trophic toxicity occurred in 22.9% of patients and was treated locally, with grafts in 7 patients. Glaucoma and cataract occurred in 13 and 22 patients respectively. Prognostic factors for visual deterioration were age, tumor extent (multifocality, quadrangular involvement > 180°) and cryotherapy. CONCLUSIONS: 5-year local failure rate after postoperative proton therapy for conjunctival melanoma was of 33.2%. Radiation-induced complications were overall manageable.

Adapted strategy to tumor response in childhood nasopharyngeal carcinoma: the French experience.

PURPOSE: The aim of this study was to retrospectively study survival and long-term morbidities of children with nasopharyngeal carcinoma (NPC) treated by induction chemotherapy and concurrent chemoradiation (CRT). The total dose of radiation was adapted to the response following neoadjuvant chemotherapy. METHODS: Children with non-metastatic NPC treated in France between 1999 and 2015 were retrospectively included in the study. The strategy combined neoadjuvant platinum-based chemotherapy, followed by adapted CRT to tumor response. RESULTS: In total, 95 patients (median age 15 years [range, 7-23 years], male-to-female ratio 1.8) with undifferentiated NPC were included; 59% of patients had TNM stage IV. Intensity-modulated radiotherapy (IMRT) was delivered to 57 patients (60%), while the other patients were treated with conformal RT (3D-RT). After a median follow-up of 4.5 years [range, 3.6-5.5 years], 13 relapses and seven deaths had occurred. The 3­year overall and relapse-free survival (RFS) were 94% [95% CI, 85-97%] and 86% [77-92%], respectively. The locoregional failure rate was 6% [95% CI, 2-14]. Long-term treatment-related sequelae of grade 2+ were reported by 37 (50%) patients; odynophagia was significantly reduced treated by IMRT vs. conventional 3D-RT (7% vs. 55%, p = 0.015). Using a reduction dose of 59.4 Gy, 54 Gy, and 45 Gy, respectively, to the primary, involved, and uninvolved neck nodes, after a favorable tumor response, was not associated with an increased locoregional failure rate. CONCLUSIONS: The survival rates for NPC have been considerably improved by means of multimodal therapy, but long-term locoregional morbidity remains common. Use of IMRT may induce less residual odynophagia. Radiation dose reduction adapted to chemotherapy response does not have a negative impact on outcome. These findings support the use of an RT protocol adapted to the tumor response to neoadjuvant chemotherapy for a long-lasting improvement in the patient's quality of life.

[Proton therapy in soft tissue and bone sarcomas]. / La protonthérapie comme modalité d'irradiation dans les sarcomes des os ou cartilage et des tissus mous, état des lieux en 2018.

Sarcomas are a common type of tumor within the pediatric population. The utilization of proton therapy as a primary attribute the ability to spare adjacent healthy tissue, therefore, proton therapy has become a preferential indication in pediatrics compared to other photon irradiation modalities. Proton therapy is also a proven and historically validated irradiation technique in the treatment of chondrosarcomas and chordomas of the skull base and spine. Additionally, proton therapy can potentially limit irradiated healthy tissue volumes in adults and limit the risk of acute and late toxicities. The evaluation of the effectiveness of proton therapy in sarcomas is underway in many clinical situations in prospective trials, some of which are randomized.

CXCL7 is a predictive marker of sunitinib efficacy in clear cell renal cell carcinomas.

BACKGROUND: Sunitinib is one of the first-line standard treatments for metastatic clear cell renal cell carcinoma (ccRCC) with a median time to progression shorter than 1 year. The objective is to discover predictive markers of response to adapt the treatment at diagnosis. METHODS: Prospective phase 2 multi-centre trials were conducted in ccRCC patients initiating sunitinib (54 patients) or bevacizumab (45 patients) in the first-line metastatic setting (SUVEGIL and TORAVA trials). The plasmatic level of CXCL7 at baseline was correlated with progression-free survival (PFS). RESULTS: The cut-off value of CXCL7 for PFS was 250 ng ml-1. Patients with CXCL7 plasmatic levels above the cut-off at baseline (250 ng ml-1) had a significantly longer PFS (hazard ratio 0.323 (95% confidence interval 0.147-0.707), P=0.001). These results were confirmed in a retrospective validation cohort. The levels of CXCL7 did not influence PFS of the bevacizumab-treated patients. CONCLUSIONS: CXCL7 may be considered as a predictive marker of sunitinib efficacy for ccRCC patients.

Sunitinib Stimulates Expression of VEGFC by Tumor Cells and Promotes Lymphangiogenesis in Clear Cell Renal Cell Carcinomas.

Sunitinib is an antiangiogenic therapy given as a first-line treatment for renal cell carcinoma (RCC). While treatment improves progression-free survival, most patients relapse. We hypothesized that patient relapse can stem from the development of a lymphatic network driven by the production of the main growth factor for lymphatic endothelial cells, VEGFC. In this study, we found that sunitinib can stimulate vegfc gene transcription and increase VEGFC mRNA half-life. In addition, sunitinib activated p38 MAPK, which resulted in the upregulation/activity of HuR and inactivation of tristetraprolin, two AU-rich element-binding proteins. Sunitinib stimulated a VEGFC-dependent development of lymphatic vessels in experimental tumors. This may explain our findings of increased lymph node invasion and new metastatic sites in 30% of sunitinib-treated patients and increased lymphatic vessels found in 70% of neoadjuvant treated patients. In summary, a therapy dedicated to destroying tumor blood vessels induced the development of lymphatic vessels, which may have contributed to the treatment failure. Cancer Res; 77(5); 1212-26. ©2017 AACR.

Second salvage treatment for local recurrence of prostate cancer using high-dose-rate brachytherapy: a case report.

PURPOSE: Currently, there are no recommendations for the management of a second local recurrence of prostate adenocarcinoma except for the introduction of androgen deprivation therapy (ADT). CASE REPORT: A 69-year-old man underwent a third salvage local treatment with high-dose-rate brachytherapy (HDRB), for a second biochemical relapse for local recurrence. Thirty-five Grays in 5 fractions were delivered on the whole prostate extended to the proximal part of left seminal vesicle. Given the availability of new treatment techniques in our radiation therapy department, a dosimetric comparison between HDRB and stereoatactic radiosurgery (SRS) was performed. RESULTS: Immediate tolerance of HDRB was acceptable with achievement of prostate specific antigen (PSA) nadir in 24 months (0.03 ng/ml). Observed late toxicities were only grade 2 urinary incontinence. Dosimetric comparison showed a slight advantage on clinical target volume coverage and rectum protection for the SRS. The HDRB showed an advantage on bone irradiation including femoral heads and the volume receiving 0.5 Gy (EQD2 = 1 Gy with α/ß = 3). CONCLUSIONS: A third local treatment with good tolerance could be a therapeutic option in case of a second local prostate cancer recurrence in order to delay, as long as possible, the chemical castration. Both techniques (HDRB and SRS) seem valid and should be chosen based on the availability and experience in a treatment center.

Interstitial high-dose rate brachytherapy as boost for anal canal cancer.

AIM: To assess clinical outcomes of patients treated with a high-dose rate brachytherapy boost for anal canal cancer (ACC). METHODS: From August 2005 to February 2013, 28 patients presenting an ACC treated by split-course external beam radiotherapy (EBRT) and HDR brachytherapy with or without chemotherapy in a French regional cancer center in Nice were retrospectively analyzed. RESULTS: Median age was 60.6 years [34 - 83], 25 patients presented a squamous cell carcinoma and 3 an adenocarcinoma; 21 received chemotherapy. Median dose of EBRT was 45 Gy [43.2 - 52]. Median dose of HDR brachytherapy was 12 Gy [10 - 15] with a median duration of 2 days. Median overall treatment time was 63 days and median delay between EBRT and brachytherapy was 20 days. Two-year local relapse free, metastatic free, disease free and overall survivals were 83%, 81.9%, 71.8% and 87.7% respectively. Acute toxicities were frequent but not severe with mostly grade 1 toxicities: 37% of genito-urinary, 40.7% of gastro-intestinal and 3.7% of cutaneous toxicities. Late toxicities were mainly G1 (43.1%) and G2 (22%). Two-year colostomy-free survival was 75.1%, one patient had a definitive sphincter amputation. CONCLUSION: High-dose rate brachytherapy for anal canal carcinoma as boost represents a feasible technique compared to low or pulsed-dose rate brachytherapy. This technique remains an excellent approach to precisely boost the tumor in reducing the overall treatment time.

Results of age-dependent anal canal cancer treatment: a single centre retrospective study.

BACKGROUND: Information concerning management of anal canal cancer among the elderly is scarce and much less abundant than for younger subjects. POPULATION AND METHODS: We retrospectively analysed 115 patients treated for anal epidermoid cancer between 2000 and 2010. The population was divided according to age (<70 years and ≥70 years). RESULTS: Of the 115 patients, 81 (70.4%) were <70 years old and 34 were ≥70 years (29.6%). Tumour characteristics were identical between the two groups and median follow-up was 62 months. Elderly patients had a less favourable performance status (p=0.001) and fewer had received radiochemotherapy (61.8% vs 82.5%, p=0.004). Treatment-related grade 3 and 4 hematologic toxicity was observed more often among elderly subjects. The results at 5 years were less favourable for overall, disease-specific, and disease-free survival (respectively p=0.002, p=0.001, and p=0.001). For patients treated with a curative intent, at 5 years there was no difference between the two groups in terms of overall survival (p=0.2). However, there was a statistically significant difference in favour of the younger group for disease-free survival and metastasis-free survival. CONCLUSION: If radiochemotherapy can be delivered to elderly subjects with a good general status, the effects appear less favourable than in younger patients.