Simple Summary: Hearing loss (HL) can be a side effect of paediatric cancer treatment and can be caused by chemotherapy but also local therapies such as radiotherapy and/or surgery of the head and... Show moreSimple Summary: Hearing loss (HL) can be a side effect of paediatric cancer treatment and can be caused by chemotherapy but also local therapies such as radiotherapy and/or surgery of the head and neck region. In this study, the frequency and patterns of HL were assessed in survivors of head and neck rhabdomyosarcoma (HNRMS). Our secondary aim was to look into the dose-effect relationship between radiotherapy dose on the cochlea and the presence of HL. Forty-nine survivors of HNRMS were included in this study, forty-two of them underwent audiological evaluation. HL was found in up to 19% of the survivors. Four survivors had low frequencies HL with normal hearing or milder HL in the higher frequencies. In our series, HL (>= Muenster 2b) was significantly associated with the maximum cochlear irradiation dose (p = 0.047). More research is needed on HL patterns in HNRMS survivors and on the radiotherapy dose-effect relationship. Purpose: The frequency and patterns of HL in a HNRMS survivor cohort were investigated. A dose-effect relationship between the dose to the cochlea and HL was explored. Methods: Dutch survivors treated for HNRMS between 1993 and 2017 with no relapse and at least two years after the end of treatment were eligible for inclusion. The survivors were evaluated for HL with pure-tone audiometry. HL was graded according to the Muenster, Common Terminology Criteria for Adverse Events (CTCAE) v4.03 and International Society for Paediatric Oncology (SIOP) classification. We defined deleterious HL as Muenster >= 2b, CTCAE >= 2, and SIOP >= 2. Mixed-effects logistic regression was used to search for the dose-effect relationship between the irradiation dose to the cochlea and the occurrence of HL. Results: Forty-two HNRMS survivors underwent pure-tone audiometry. The Muenster, CTCAE and SIOP classification showed that 19.0% (n = 8), 14.2% (n = 6) and 11.9% (n = 5) of survivors suffered from HL, respectively. A low-frequency HL pattern with normal hearing or milder hearing loss in the higher frequencies was seen in four survivors. The maximum cochlear irradiation dose was significantly associated with HL (>= Muenster 2b) (p = 0.047). In our series, HL (>= Muenster 2b) was especially observed when the maximum dose to the cochlea exceeded 19 Gy. Conclusion: HL occurred in up to 19% of survivors of HNRMS. More research is needed on HL patterns in HNRMS survivors and on radiotherapy dose-effect relationships. Show less
Dijk, I.W.E.M. van; Huijskens, S.C.; Jong, R. de; Visser, J.; Fajardo, R.D.; Rasch, C.R.N.; ... ; Bel, A. 2017
Background: Pediatric safety margins are generally based on data from adult studies; however, adult-based margins might be too large for children. The aim of this study was to quantify and compare... Show moreBackground: Pediatric safety margins are generally based on data from adult studies; however, adult-based margins might be too large for children. The aim of this study was to quantify and compare interfractional organ position variation in children and adults.Material and methods: For 35 children and 35 adults treated with thoracic/abdominal irradiation, 850 (range 5-30 per patient) retrospectively collected cone beam CT images were registered to the reference CT that was used for radiation treatment planning purposes. Renal position variation was assessed in three orthogonal directions and summarized as 3D vector lengths. Diaphragmatic position variation was assessed in the cranio-caudal (CC) direction only. We calculated means and SDs to estimate group systematic (sigma) and random errors (sigma) of organ position variation. Finally, we investigated possible correlations between organ position variation and patients' height.Results: Interfractional organ position variation was different in children and adults. Median 3D right and left kidney vector lengths were significantly smaller in children than in adults (2.8, 2.9mm vs. 5.6, 5.2mm, respectively; p<.05). Generally, the pediatric sigma and sigma were significantly smaller than in adults (p<.007). Overall and within both subgroups, organ position variation and patients' height were only negligibly correlated.Conclusions: Interfractional renal and diaphragmatic position variation in children is smaller than in adults indicating that pediatric margins should be defined differently from adult margins. Underlying mechanisms and other components of geometrical uncertainties need further investigation to explain differences and to appropriately define pediatric safety margins. Show less
Huijskens, S.C.; Dijk, I.W.E.M. van; Jong, R. de; Visser, J.; Fajardo, R.D.; Ronckers, C.M.; ... ; Bel, A. 2015
Background and purpose: To quantify renal and diaphragmatic interfractional motion in order to estimate systematic and random errors, and to investigate the correlation between interfractional... Show moreBackground and purpose: To quantify renal and diaphragmatic interfractional motion in order to estimate systematic and random errors, and to investigate the correlation between interfractional motion and patient-specific factors.Material and methods: We used 527 retrospective abdominal-thoracic cone beam CT scans of 39 childhood cancer patients (<18 years) to quantify renal motion relative to bony anatomy in the left-right (LR), cranio-caudal (CC) and anterior-posterior (AP) directions, and diaphragmatic motion in the CC direction only. Interfractional motion was quantified by distributions of systematic and random errors in each direction (standard deviations Sigma and sigma, respectively). Also, correlation between organ motion and height was analyzed.Results: Inter-patient organ motion varied widely, with the largest movements in the CC direction. Values of Sigma in LR, CC, and AP directions were 1.1, 3.8, 2.1 mm for the right, and 1.3, 3.0, 1.5 mm for the left kidney, respectively. The sigma in these three directions was 1.1, 3.1, 1.7 mm for the right, and 1.2, 2.9, 2.1 mm for the left kidney, respectively. For the diaphragm we estimated Sigma = 5.2 mm and sigma = 4.0 mm. No correlations were found between organ motion and height.Conclusions: The large inter-patient organ motion variations and the lack of correlation between motion and patient-related factors, suggest that individualized margin approaches might be required. (C) 2015 Elsevier Ireland Ltd. All rights reserved. Show less
Pulsed dose rate (PDR) brachytherapy is a treatment modality that combines physical advantages of high dose rate (HDR) brachytherapy with the radiobiological advantages of low dose rate... Show morePulsed dose rate (PDR) brachytherapy is a treatment modality that combines physical advantages of high dose rate (HDR) brachytherapy with the radiobiological advantages of low dose rate brachytherapy. The aim of this review was to describe the effective clinical use of PDR brachytherapy worldwide in different tumour locations. We found 66 articles reporting on clinical PDR brachytherapy including the treatment procedure and outcome. Moreover, PDR brachytherapy has been applied in almost all tumour sites for which brachytherapy is indicated and with good local control and low toxicity. The main advantage of PDR is, because of the small pulse sizes used, the ability to spare normal tissue. In certain cases, HDR resembles PDR brachytherapy by the use of multifractionated low-fraction dose. Show less
Objective. The aim of this study is to investigate the impact of treatment policy changes in cervical cancer patients treated with adjuvant (chemo) radiotherapy.Methods. Between 1970 and 2007, 292... Show moreObjective. The aim of this study is to investigate the impact of treatment policy changes in cervical cancer patients treated with adjuvant (chemo) radiotherapy.Methods. Between 1970 and 2007, 292 patients received adjuvant radiotherapy after a radical hysterectomy with pelvic lymphadenectomy for early stage cervical carcinoma. All patients received pelvic radiotherapy (40 Gy-46 Gy in 1.8 Gy-2 Gy/fraction). Vaginal vault brachytherapy boost (10-14 Gy) was increasingly used for patients with high-risk factors, and since 1993 systematically applied in patients with at least 2 of the 3 risk factors: adenocarcinoma, nodal involvement and parametrial invasion. Cisplatin-based chemotherapy was introduced in this group of patients from 2000.Results. The 5-year cumulative risk of local recurrence (CRLR) was 13% (95%CI 9%-17%), resulting in an overall 5-year survival (OS) of 78% (95%CI 83%-73%). Since 1970, the OR for the 5-year locoregional recurrence risk (LRR) decreased from 2.5 to 1.15 (linear-OR = -0.02/year). The OR for the 5-year mortality risk reduced from 2.2 in 1970 to 1.0 in 2007 (linear-OR = -0.03/year). The largest risk reductions were observed before 1990 with a minor rise after 2002. The risk of severe late toxicity reduced from 1.8% to 1.5% (linear-OR = -0.03/year). The addition of concomitant adjuvant chemotherapy since 2000 may have benefited a subgroup of patients with squamous cell carcinoma, but not the patients with adenocarcinoma, and after introduction of chemotherapy the risk of severe late toxicity tripled from 2% to 7%.Conclusion. Since 1970, tumour recurrence risk and mortality have decreased, as radiation dose increased. The potential benefit of concomitant adjuvant chemotherapy could not be demonstrated in this nonrandomized study. (C) 2014 Elsevier Inc. All rights reserved. Show less
