40 research outputs found
Postoperative Radiotherapy in Stage I-III Merkel Cell Carcinoma
BACKGROUND: Postoperative radiotherapy (PORT) is currently recommended for the treatment of Merkel cell carcinoma. Nevertheless, deviations occur frequently due to the generally elderly and frail patient population. We aimed to evaluate the influence of PORT on survival in stage I-III MCC patients treated in the Netherlands. METHODS: Patients were included retrospectively between 2013 and 2018. Fine-Gray method was used for cumulative incidence of recurrence and MCC-related survival, cox regression was performed for overall survival (OS). Analyses were performed in patients with clinical (sentinel node biopsy [SN] not performed) stage I/II (c-I/II-MCC), pathologic (SN negative) stage I/II (p-I/II-MCC) and stage III MCC (III-MCC), separately. Propensity score matching (PSM) was performed to assess confounding by indication. RESULTS: In total 182 patients were included, 35 had p-I/II-MCC, 69 had c-I/II-MCC and 78 had III-MCC. Median follow up time was 53.5 (IQR 33.4-67.4), 30.5 (13.0-43.6) and 29.3 (19.3-51.0) months, respectively. Multivariable analysis showed PORT to be associated with less recurrences and improved OS, but not with MCC-related survival. In stage III-MCC, extracapsular extension (sub-distribution hazard [SDH] 4.09, p=0.012) and PORT (SDH 0.45, p=0.044) were associated with recurrence, and ≥4 positive lymph nodes (SDH 3.24, p=0.024) were associated with MCC-related survival. CONCLUSIONS: PORT was associated with less recurrences and improved OS in patients with stage I-III MCC, but not with improved MCC-related survival. Trends in OS benefit are likely to be caused by selection bias suggesting further refinement of criteria for PORT is warranted, for instance by taking life expectancy into account
National Protocol for Model-Based Selection for Proton Therapy in Head and Neck Cancer
In the Netherlands, the model-based approach is used to identify patients with head and neck cancer who may benefit most from proton therapy in terms of prevention of late radiation-induced side effects in comparison with photon therapy. To this purpose, a National Indication Protocol Proton therapy for Head and Neck Cancer patients (NIPP-HNC) was developed, which has been approved by the health care authorities. When patients qualify according to the guidelines of the NIPP-HNC, proton therapy is fully reimbursed. This article describes the procedures that were followed to develop this NIPP-HNC and provides all necessary information to introduce model-based selection for patients with head and neck cancer into routine clinical practice.</p
Primary treatment results of Nasopharyngeal Carcinoma (NPC) in Yogyakarta, Indonesia
INTRODUCTION Nasopharyngeal Carcinoma (NPC) is a major health problem in southern and eastern Asia. In Indonesia NPC is the most frequent cancer in the head and neck area. NPC is very sensitive to radiotherapy resulting in 3-year disease-free and overall survival of approximately 70% and 80%, respectively. Here we present routine treatment results in a prospective study on NPC in a top referral; university hospital in Indonesia. METHODS All NPC patients presenting from September 2008 till January 2011 at the ear, nose and throat (ENT) department of the Dr. Sardjito General Hospital, Universitas Gadjah Mada, Yogyakarta, Indonesia, were possible candidates. Patients were included if the biopsy was a histological proven NPC without distant metastasis and were assessed during counselling sessions prior to treatment, as being able to complete the entire treatment. RESULTS In total 78 patients were included for treatment analysis. The median time between diagnosis and start of radiotherapy is 120 days. Forty-eight (62%) patients eventually finished all fractions of radiotherapy. The median duration of the radiotherapy is 62 days for 66 Gy. Median overall survival is 21 months (95% CI 18–35) from day of diagnosis. CONCLUSION The results presented here reveal that currently the treatment of NPC at an Indonesian hospital is not sufficient and cannot be compared to the treatment results in literature. Main reasons for these poor treatment results are (1) a long waiting time prior to the start of radiotherapy, (2) the extended overall duration of radiotherapy and (3) the advanced stage of disease at presentation.Maarten A. Wildeman, Renske Fles, Camelia Herdini, Rai S. Indrasari, Andrew D. Vincent, Maesadji Tjokronagoro, Sharon Stoker, Johan Kurnianda, Baris Karakullukcu, Kartika W. Taroeno- Hariadi, Olga Hamming-Vrieze, Jaap M. Middeldorp, Bambang Hariwiyanto, Sofia M. Haryana, I. Bing Ta
Deterioration of Intended Target Volume Radiation Dose Due to Anatomical Changes in Patients with Head-and-Neck Cancer
Delivered radiation dose can differ from intended dose. This study quantifies dose deterioration in targets, identifies predictive factors, and compares dosimetric to clinical patient selection for adaptive radiotherapy in head-and-neck cancer patients. One hundred and eighty-eight consecutive head-and-neck cancer patients treated up to 70 Gy were analyzed. Daily delivered dose was calculated, accumulated, and compared to the planned dose. Cutoff values (1 Gy/2 Gy) were used to assess plan deterioration in the highest/lowest dose percentile (D1/D99). Differences in clinical factors between patients with/without dosimetric deterioration were statistically tested. Dosimetric deterioration was evaluated in clinically selected patients for adaptive radiotherapy with CBCT. Respectively, 16% and 4% of patients had deterioration over 1 Gy in D99 and D1 in any of the targets, this was 5% (D99) and 2% (D1) over 2 Gy. Factors associated with deterioration of D99 were higher baseline weight/BMI, weight gain early in treatment, and smaller PTV margins. The sensitivity of visual patient selection with CBCT was 22% for detection of dosimetric changes over 1 Gy. Large dose deteriorations in targets occur in a minority of patients. Clinical prediction based on patient characteristics or CBCT is challenging and dosimetric selection tools seem warranted to identify patients in need for ART, especially in treatment with small PTV margins
Regional control of melanoma neck node metastasis after selective neck dissection with or without adjuvant radiotherapy
Objective: To examine the effect of adjuvant radiotherapy on regional control of melanoma neck node metastasis. Design: A single-institution retrospective study. Setting: Tertiary care cancer center. Patients: The study included 64 patients with melanoma neck node metastasis who were treated with neck dissection between 1989 and 2004 in The Netherlands Cancer Institute, Amsterdam. Twenty-four patients were treated with surgery only (15 modified radical neck dissections [MRNDs] and 9 selective neck dissections [SNDs]) (S group), and 40 patients underwent surgery (28 MRNDs and 12 SNDs) and adjuvant radiotherapy (S+RT group). Results: Prognostic factors, ie, number of nodes, size of nodes, and extracapsular extension, were worse in the S+RT group. With a median follow-up of 2.5 years, the 2-year ipsilateral regional recurrence (RR) rate was 18% in the S+RT group and 46% in the S group. This 28% difference in RR was not statistically significant (P=.16). However, evaluation of the effect of adjuvant RT in multivariate analysis revealed a significant reduction of the RR rate after correction for the number of involved nodes (P=.04). In the S group, SND was associated with a trend toward worse RR rate compared with MRND but was not statistically significant in univariate analysis (P=.08). The type of neck dissection did not influence the RR rate in the S+RT group (P=.60). Three of the 4 RRs occurred outside the dissected volume after SND in the S group. Conclusions: Based on our findings, we conclude that, compared with extended neck dissection, SND leads to inferior regional control in patients with melanoma neck node metastasis who are not treated with RT, even those with low-risk neck disease. Furthermore, our results suggest that adjuvant RT improves regional control in patients with 2 or more involved nodes.</p
Regional control of melanoma neck node metastasis after selective neck dissection with or without adjuvant radiotherapy
Objective: To examine the effect of adjuvant radiotherapy on regional control of melanoma neck node metastasis. Design: A single-institution retrospective study. Setting: Tertiary care cancer center. Patients: The study included 64 patients with melanoma neck node metastasis who were treated with neck dissection between 1989 and 2004 in The Netherlands Cancer Institute, Amsterdam. Twenty-four patients were treated with surgery only (15 modified radical neck dissections [MRNDs] and 9 selective neck dissections [SNDs]) (S group), and 40 patients underwent surgery (28 MRNDs and 12 SNDs) and adjuvant radiotherapy (S+RT group). Results: Prognostic factors, ie, number of nodes, size of nodes, and extracapsular extension, were worse in the S+RT group. With a median follow-up of 2.5 years, the 2-year ipsilateral regional recurrence (RR) rate was 18% in the S+RT group and 46% in the S group. This 28% difference in RR was not statistically significant (P=.16). However, evaluation of the effect of adjuvant RT in multivariate analysis revealed a significant reduction of the RR rate after correction for the number of involved nodes (P=.04). In the S group, SND was associated with a trend toward worse RR rate compared with MRND but was not statistically significant in univariate analysis (P=.08). The type of neck dissection did not influence the RR rate in the S+RT group (P=.60). Three of the 4 RRs occurred outside the dissected volume after SND in the S group. Conclusions: Based on our findings, we conclude that, compared with extended neck dissection, SND leads to inferior regional control in patients with melanoma neck node metastasis who are not treated with RT, even those with low-risk neck disease. Furthermore, our results suggest that adjuvant RT improves regional control in patients with 2 or more involved nodes.</p
Head and Neck Margin Reduction With Adaptive Radiation Therapy: Robustness of Treatment Plans Against Anatomy Changes
We set out to investigate loss of target coverage from anatomy changes in head and neck cancer patients as a function of applied safety margins and to verify a cone beam computed tomography (CBCT)-based adaptive strategy with an average patient anatomy to overcome possible target underdosage. For 19 oropharyngeal cancer patients, volumetric modulated arc therapy treatment plans (2 arcs; simultaneous integrated boost, 70 and 54.25 Gy; 35 fractions) were automatically optimized with uniform clinical target volume (CTV)-to-planning target volume margins of 5, 3, and 0 mm. We applied b-spline CBCT-to-computed tomography (CT) deformable registration to allow recalculation of the dose on modified CT scans (planning CT deformed to daily CBCT following online positioning) and dose accumulation in the planning CT scan. Patients with deviations in primary or elective CTV coverage >2 Gy were identified as candidates for adaptive replanning. For these patients, a single adaptive intervention was simulated with an average anatomy from the first 10 fractions. Margin reduction from 5 mm to 3 mm to 0 mm generally led to an organ-at-risk (OAR) mean dose (Dmean) sparing of approximately 1 Gy/mm. CTV shrinkage was mainly seen in the elective volumes (up to 10%), likely related to weight loss. Despite online repositioning, substantial systematic errors were present (>3 mm) in lymph node CTV, the parotid glands, and the larynx. Nevertheless, the average increase in OAR dose was small: maximum of 1.2 Gy (parotid glands, Dmean) for all applied margins. Loss of CTV coverage >2 Gy was found in 1, 3, and 7 of 73 CTVs, respectively. Adaptive intervention in 0-mm plans substantially improved coverage: in 5 of 7 CTVs (in 6 patients) to <2 Gy of initially planned. Volumetric modulated arc therapy head and neck cancer treatment plans with 5-mm margins are robust for anatomy changes and show a modest increase in OAR dose. Margin reduction improves OAR sparing with approximately 1 Gy/mm at the expense of target coverage in a subgroup of patients. Patients at risk of CTV underdosage >2 Gy in 0-mm plans may be identified early in treatment using dose accumulation. A single intervention with an average anatomy derived from CBCT effectively mitigates discrepancie
Impact of daily anatomical changes on EPID-based in vivo dosimetry of VMAT treatments of head-and-neck cancer.
Background and purpose: Target dose verification for VMAT treatments of head-and-neck (H&N) cancer using 3D in vivo EPID dosimetry is expected to be affected by daily anatomical changes. By including these anatomical changes through cone-beam CT (CBCT) information, the magnitude of this effect is investigated. Materials and methods: For 20 VMAT-treated H&N cancer patients, all plan-CTs (pCTs), 633 CBCTs and 1266 EPID movies were used to compare four dose distributions per fraction: treatment planning system (TPS) calculated dose and EPID reconstructed in vivo dose, both determined using the pCT and using the CBCT. D2, D50 and D98 of the planning target volume (PTV) were determined per dose distribution. Results: When including daily anatomical information, D2, D50 and D98 of the PTV change on average by 0.0 +/- 0.4% according to TPS calculations; the standard deviation of the difference between EPID and TPS target dose changes from 2.5% (pCT) to 2.1% (CBCT). Small time trends are seen for both TPS and EPID dose distributions when using the pCT, which disappear when including CBCT information. Conclusions: Daily anatomical changes hardly influence the target dose distribution for H&N VMAT treatments according to TPS recalculations. Including CBCT information in EPID dose reconstructions slightly improves the agreement with TPS calculations. (C) 2015 Elsevier Ireland Ltd. All rights reserve