Purpose: This study quantifies tumor shape variability in head-and-neck cancer patients during radiation therapy using implanted markers.Methods and Materials: Twenty-seven patients with... Show morePurpose: This study quantifies tumor shape variability in head-and-neck cancer patients during radiation therapy using implanted markers.Methods and Materials: Twenty-seven patients with oropharyngeal tumors treated with (chemo) radiation were included. Helical gold markers (0.35 x 2 mm, 3-10/patient, average 6) were implanted around the tumor. Markers were identified on planning computed tomography (CT) and daily cone beam CT (CBCT). After bony anatomy registration, the daily vector length on CBCT in reference to the planning CT and daily marker movement perpendicular to the gross tumor volume (GTV) surface at planning CT (d(normal)) of each marker were analyzed. Time trends were assessed with linear regression of the (markers). In 2 patients, 2 markers were implanted in normal tissue to evaluate migration by measuring intermarker distances.Results: Marker implantation was feasible without complications. Three-dimensional vectors (4827 measurements, mean 0.23 cm, interquartile ratio 0.24 cm) were highest in base of tongue sublocalization (P<.001) and bulky tumors (vectors exceeded 0.5 cm in 5.7% [0-20 mL], 12.0% [21-40 mL], and 21.7% [>= 41 mL], respectively [P<.001] of measurements). The measured inward time trend in 11/27 patients correlated with the visual observed marker pattern. In patients with an outward trend (5/27) or no trend (11/27), visual observation showed predominantly an inhomogeneous pattern. Remarkably, in 6 patients, outward marker movement was observed in the posterior pharyngeal wall. The difference in distance between normal tissue markers (1 SD) was 0.05-0.06 cm without time trend, indicating that implanted markers did not migrate.Conclusions: During head-and-neck radiation therapy, normal tissue markers remained stable. Changes in position of tumor markers depended on sublocalization and tumor volume. Large differences in marker patterns between patients as well as within patients were observed. Based on our study, the cranial and caudal border in the posterior pharyngeal wall are at highest risk to be covered insufficiently. Furthermore, implanted markers could help identify patients with an actual shrinkage of the GTV who might benefit from mid-radiation therapy redelineation to reduce toxicity. (C) 2012 Elsevier Inc. Show less
Hoebers, F.; Heemsbergen, W.; Moor, S.; Lopez, M.; Klop, M.; Tesselaar, M.; Rasch, C. 2011
Purpose: To analyze the effectiveness and toxicity of reirradiation (re-RT) for head-and-neck cancer.Methods and Materials: A retrospective data analysis was performed of 58 patients who underwent... Show morePurpose: To analyze the effectiveness and toxicity of reirradiation (re-RT) for head-and-neck cancer.Methods and Materials: A retrospective data analysis was performed of 58 patients who underwent re-RT with curative intent. Re-RT was given as definitive treatment in 53% of patients, whereas salvage surgery preceded reirradiation in 47%. The median cumulative RT dose was 119 Gy (range, 76-140). Concurrent chemotherapy was administered with re-RT (CRT) in 57% of patients. Event-free survival was defined as survival without recurrence and without serious toxicity (>= Grade 3).Results: Median follow-up was 57 months (range, 9-140). Locoregional (LR) control was 50% at 2 and 5 years. The 2-year and 5-year overall survival (OS) was 42% and 34%. The following factors were associated with improved OS: postoperative re-RT (vs. primary re-RT), treatment with RT only (vs. CRT) and interval >3 years between previous RT and re-RT. For patients treated with postoperative re-RT and definitive re-RT, the 5-year OS was 49% and 20%, respectively. Patients treated with CRT had a 5-year OS of 13%. Serious (late) toxicity >= Grade 3 was observed in 20 of 47 evaluable patients (43%). Three cases of treatment-related death were recorded. The 2-and 5-year serious toxicity-free interval was 59% and 55%, respectively. Associated with increased risk of serious toxicity were CRT and higher re-RT dose. The event-free survival rates at 2 and 5 years were 34% and 31%, respectively.Conclusions: Re-RT in head-and-neck cancer is associated with poor survival rates of 13-20% in patients with inoperable disease treated with primary (chemo-) re-RT. For this subgroup, however, no other curative options are available. Long-term disease control and survival can be achieved in patients who receive re-RT as an adjunct to surgical resection. The rates of serious toxicity after re-RT are high, with an incidence of approximately 45% at 5 years. Approximately 1 in 3 patients survived re-RT without recurrence and severe complications. (c) 2011 Elsevier Inc. Show less
Lamers-Kuijper, E.; Heemsbergen, W.; Mourik, A. van; Rasch, C. 2011
Purpose: To find parameters that predict which head and neck patients benefit from a sequentially delivered boost treatment plan compared to a simultaneously delivered plan, with the aim to spare... Show morePurpose: To find parameters that predict which head and neck patients benefit from a sequentially delivered boost treatment plan compared to a simultaneously delivered plan, with the aim to spare the salivary glands.Methods and materials: We evaluated 50 recently treated head and neck cancer patients. Apart from the clinical plan with a sequentially (SEQ) given boost using an Intensity Modulated Radiotherapy Technique (IMRT), a simultaneous integrated boost (SIB) technique plan was constructed with the same beam setup. The mean dose to the parotid glands was calculated and compared. The elective nodal areas were bilateral in all cases, with a boost on either one side or both sides of the neck.Results: When the parotid gland volume and the Planning Target Volume (PTV) for the boost overlap there is on average a lower dose to the parotid gland with a SIB technique (-1.2 Gy), which is, however, not significant (p = 0.08).For all parotid glands with no boost PTV overlap, there is a benefit from a SEQ technique compared to a SIB technique for the gland evaluated (on average a 2.5 Gy lower dose to the parotid gland, p < 0.001). When the distance between gland and PTV is 0-1 cm, this difference is on average 0.8 Gy, for 1-2 cm distance 2.9 Gy and for glands with a distance greater than 2 cm, 3.3 Gy. When the lymph nodes on the evaluated side are also included in the boost PTV, however, this relationship between the distance and the gain of a SEQ seems less clear.Conclusions: A sequentially delivered boost technique results in a better treatment plan for most cases, compared to a simultaneous integrated boost IMRT technique, if the boost PTV is more than 1 cm away from at least one parotid gland. (C) 2010 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 98 (2011) 51-56 Show less
