Henrik Hauswald

DYNAMIC JAWS AND DYNAMIC COUCH IN HELICAL TOMOTHERAPY

PURPOSE To investigate the next generation of helical tomotherapy delivery with dynamic jaw and dynamic couch movements. METHODS AND MATERIALS The new technique of dynamic jaw and dynamic couch movements is described, and a comparative planning study is performed. Ten nasopharyngeal cancer patients with skull base infiltration were chosen for this comparison of longitudinal dose profiles using regular tomotherapy delivery, running-start-stop treatment, and dynamic jaw and dynamic couch delivery. A multifocal simultaneous integrated boost concept was used (70.4Gy to the primary tumor and involved lymph nodes; 57.4Gy to the bilateral cervical lymphatic drainage pathways, 32 fractions). Target coverage, conformity, homogeneity, sparing of organs at risk, integral dose, and radiation delivery time were evaluated. RESULTS Mean parotid dose for all different deliveries was between 24.8 and 26.1Gy, without significant differences. The mean integral dose was lowered by 6.3% by using the dynamic technique, in comparison with a 2.5-cm-field width for regular delivery and 16.7% with 5-cm-field width for regular delivery. Dynamic jaw and couch movements reduced the calculated radiation time by 66% of the time required with regular 2.5-cm-field width delivery (199 sec vs. 595 sec, p < 0.001). CONCLUSIONS The current delivery mode of helical tomotherapy produces dose distributions with conformal avoidance of parotid glands, brain stem, and spinal cord. The new technology with dynamic jaw and couch movements improves the plan quality by reducing the dose penumbra and thereby reducing the integral dose. In addition, radiation time is reduced by 66% of the regular delivery time.

Long-term outcome and patterns of failure in patients with advanced head and neck cancer.

PurposeTo access the long-time outcome and patterns of failure in patients with advanced head and neck squamous cell carcinoma (HNSCC).Methods and materialsBetween 1992 and 2005 127 patients (median age 55 years, UICC stage III n = 6, stage IV n = 121) with primarily inoperable, advanced HNSCC were treated with definite platinum-based radiochemotherapy (median dose 66.4 Gy). Analysed end-points were overall survival (OS), disease-free survival (DFS), loco-regional progression-free survival (LPFS), development of distant metastases (DM), prognostic factors and causes of death.ResultsThe mean follow-up time was 34 months (range, 3-156 months), the 3-, 5- and 10-year OS rates were 39%, 28% and 14%, respectively. The median OS was 23 months. Forty-seven patients achieved a complete remission and 78 patients a partial remission. The median LPFS was 17 months, the 3-, 5- and 10-year LPFS rates were 41%, 33% and 30%, respectively. The LPFS was dependent on the nodal stage (p = 0.029). The median DFS was 11 months (range, 2-156 months), the 3-, 5- and 10-year DFS rates were 30%, 24% and 22%, respectively. Prognostic factors in univariate analyses were alcohol abuse (n = 102, p = 0.015), complete remission (n = 47, p < 0.001), local recurrence (n = 71, p < 0.001), development of DM (n = 45, p < 0.001; median OS 16 months) and borderline significance in nodal stage N2 versus N3 (p = 0.06). Median OS was 26 months with lung metastases (n = 17). Nodal stage was a predictive factor for the development of DM (p = 0.025). Cause of death was most commonly tumor progression.ConclusionsIn stage IV HNSCC long-term survival is rare and DM is a significant predictor for mortality. If patients developed DM, lung metastases had the most favourable prognosis, so intensified palliative treatment might be justified in DM limited to the lungs.

First experiences in treatment of low-grade glioma grade I and II with proton therapy.

BackgroundTo retrospectively assess feasibility and toxicity of proton therapy in patients with low-grade glioma (WHO °I/II).Patients and methodsProton beam therapy only administered in 19 patients (median age 29 years; 9 female, 10 male) for low-grade glioma between 2010 and 2011 was reviewed. In 6 cases proton therapy was performed due to tumor progression after biopsy, in 8 cases each due to tumor progression after (partial-) resection, and in 5 cases due to tumor progression after chemotherapy. Median total dose applied was 54 GyE (range, 48,6-54 GyE) in single fractions of median 1.8 GyE. Median clinical target volume was 99 cc (range, 6–463 cc) and treated using median 2 beams (range, 1–2).ResultsProton therapy was finished as planned in all cases. At end of proton therapy, 13 patients showed focal alopecia, 6 patients reported mild fatigue, one patient with temporal tumor localization concentration deficits and speech errors and one more patient deficits in short-term memory. Four patients did not report any side effects. During follow-up, one patient presented with pseudo-progression showing worsening of general condition and brain edema 1–2 months after last irradiation and restitution after 6 months. In the present MR imaging (median follow-up 5 months; range 0–22 months) 12 patients had stable disease, 2 (1) patients partial (complete) remission, one more patient pseudo-progression (differential diagnosis: tumor progression) 4 weeks after irradiation without having had further follow-up imaging so far, and one patient tumor progression approximately 9 months after irradiation.ConclusionRegarding early side effects, mild alopecia was the predominant finding. The rate of alopecia seems to be due to large treatment volumes as well as the anatomical locations of the target volumes and might be avoided by using multiple beams and the gantry in the future. Further evaluations including neuropsychological testing are in preparation.

Surgery with Complete Resection Improves Survival in Radiooncologically Treated Patients with Cervical Lymph Node Metastases from Cancer of Unknown Primary

Purpose:To assess long-term toxicity, outcome and prognostic factors after multimodal treatment of cervical lymph node metastases from cancer of unknown primary (CUP).Patients and Methods:In a retrospective study, the treatment results of 84 patients with CUP (median age 63 years, N1 n = 0, N2 n = 44, N3 n = 39, Nx n = 1), treated between 1971 and 2002 with radiotherapy (n = 84, median dose 60 Gy), platinum-based chemotherapy (n = 23) and surgery (n = 69, tonsillectomy [n = 40], neck dissection [n = 52], suprahyoid dissection [n = 18], lymph node excision [n = 14]), were analyzed.Results:After a mean follow-up time of 25 months (ranging from 0.1 to 260 months), the 3- and 5-year overall (disease-free) survival rates were 30% (39%) and 27% (34%), respectively. 75% of individuals achieved remission, whereas 23% showed no change or progression after treatment. The 3-, 5- and 10-year local control rates were 58%, 58% and 46%, respectively. 40% of patients suffered grade 3/4 late toxicity: severe skin contracture/induration (n = 2) and severe xerostomia (n = 32). Tonsillectomy (p = 0.003) and neck dissection (p = 0.037) performed before radiotherapy significantly improved outcome. Other prognostic factors were age (p = 0.0235), extracapsular spread (n = 63; p = 0.0045), incomplete resection (n = 24; p = 0.0026), nodal disease (p = 0.0034), and distant metastases (n = 17; p = 0.0002). After multivariate analysis only extracapsular spread (p = 0.004) and tonsillectomy (p = 0.01) showed impact on survival.Conclusion:Irradiation of cervical lymph node metastases from CUP is an effective treatment option with acceptable late toxicity. Complete tonsillectomy and neck dissection significantly improved survival in N2/N3 disease. Extracapsular spread was the best predictor for survival and local control. Prospective studies defining a standard treatment are needed.Ziel:Evaluation der Therapieergebnisse und Langzeittoxizität bei Patienten mit zervikalen Lymphknotenmetastasen bei unbekanntem Primärtumor (CUP).Patienten und Methodik:In einer retrospektiven Studie wurden die Ergebnisse von insgesamt 84 Patienten mit CUP (medianes Alter 63 Jahre, N1 n = 0, N2 n = 44, N3 n = 39, Nx n = 1), welche zwischen 1971 und 2002 mittels Radiotherapie (n = 84, mediane Dosis 60 Gy), platinbasierter Chemotherapie (n = 23) und chirurgischer Intervention (n = 69, Tonsillektomie [n = 40], Neck-Dissection [n = 52], suprahyoidale Ausräumung [n = 18], Lymphknotenexzision [n = 14]) behandelt wurden, ausgewertet.Ergebnisse:Nach einer mittleren Nachbeobachtungszeit von 25 Monaten (Range 0,1–260 Monate) betrug das 3- bzw. 5-Jahres- Gesamt- (krankheitsfreie) Überleben 30% (39%) und 27% (34%). 75% der Patienten erzielten eine Remission, während 23% nach Therapieabschluss keine Änderung oder einen Progress aufwiesen. Die 3-, 5- und 10-Jahres-Raten der lokalen Kontrolle betrugen 58%, 58% und 46%. 40% erlitten Grad-3- oder -4-Spättoxizität: schwere Kontrakturen oder Indurationen der Haut (n = 2) sowie schwere Xerostomie (n = 32). Sowohl eine Tonsillektomie (p = 0,003) als auch Neck-Dissection (p = 0,037) vor Bestrahlung verbesserten das Überleben signifikant. Weitere prognostische Faktoren waren Alter (p = 0,0235), extrakapsuläre Ausbreitung (n = 63; p = 0,0045), inkomplette Resektion (n = 24; p = 0,0026), Lymphknotenstatus (p = 0,0034) und Fernmetastasen (n = 17; p = 0,0002). Nach multivariater Analyse zeigten noch extrakapsuläre Ausbreitung (p = 0,004) und Tonsillektomie (p = 0,01) Einfluss auf das Überleben.Schlussfolgerung:Die Bestrahlung zervikaler Lymphknotenmetastasen bei CUP stellt eine effektive Behandlungsoption dar. Eine komplette operative Tumorentfernung und eine prophylaktische Tonsillektomie vor Radiotherapie verbesserten das Überleben von Patienten mit zervikalem CUP-Syndrom. Extrakapsuläre Tumorausbreitung war der beste Parameter des Überlebens und lokalen Kontrolle. Prospektive Studien zur Festlegung eines Standardtherapiekonzepts werden benötigt.

Total skin electron beam therapy as palliative treatment for cutaneous manifestations of advanced, therapy-refractory cutaneous lymphoma and leukemia

BackgroundTo retrospectively access the outcome and toxicity of a total skin electron beam therapy (TSEBT) in patients with cutaneous lymphoma (CL) or leukemia.Patients and methodsTreatment results of 25 patients (median age 63 years; 5 female, 20 male) with cutaneous manifestations of advanced and therapy-refractory CL (n = 21; T-cell lymphomas n = 18, B-cell lymphomas n = 3) stage IIB-IV or leukemia (n = 4; AML n = 2, CLL n = 1, PDC n = 1) treated between 1993 and 2010 were reviewed. All patients were symptomatic. The median total dose was 29Gy, applied in 29 fractions of median 1 Gy each.ResultsThe median follow-up was 10 months. Palliation was achieved in 23 patients (92%). A clinical complete response was documented in 13 (52%) and a partial response in 10 patients (40%). The median time to skin progression was 5 months (range 1–18 months) and the actuarial one-year progression-free survival 35%. The median overall survival (OS) after the initiation of TSEBT was 10 months (range 1–46 months) and the actuarial one-year OS 45%. TSEBT related acute adverse events (grade 1 or 2) were observed in all patients during the treatment period. An acute grade 3 epitheliolysis developed in eight patients (32%). Long-term adverse events as a hyperpigmentation of the skin (grade 1 or 2) were documented in 19 patients (76%), and a hypohidrosis in seven patients (28%).ConclusionFor palliation of symptomatic cutaneous manifestations of advanced cutaneous lymphoma or leukemia, total skin electron beam therapy is an efficient and well tolerated considerable treatment option.

Reirradiation with intensity-modulated radiotherapy in recurrent head and neck cancer

In this retrospective investigation we analyzed outcome and toxicity after intensity‐modulated reirradiation of recurrent head and neck cancer.

Spinal cord sparing reirradiation with helical tomotherapy.

The purpose of this study was to present planning, feasibility, toxicity, and outcome of helical tomotherapy for spinal cord‐sparing reirradiation of spinal metastases and tumors.

New multileaf collimator with a leaf width of 5 mm improves plan quality compared to 10 mm in step-and-shoot IMRT of HNC using integrated boost procedure

Purpose:To investigate whether a new multileaf collimator with a leaf width of 5 mm (MLC-5) over the entire field size of 40 × 40 cm2 improves plan quality compared to a leaf width of 10 mm (MLC-10) in intensity-modulated radiotherapy (IMRT) with integrated boost for head and neck cancer.Patients and Methods:A plan comparison was performed for ten patients with head and neck cancer. For each patient, seven plans were calculated: one plan with MLC-10 and nine beams, four plans with MLC-5 and nine beams (with different intensity levels and two-dimensional median filter sizes [2D-MFS]), and one seven-beam plan with MLC-5 and MLC-10, respectively. Isocenter, beam angles and planning constraints were not changed. Mean values of common plan parameters over all ten patients were estimated, and plan groups of MLC-5 and MLC-10 with nine and seven beams were compared.Results:The use of MLC-5 led to a significantly higher conformity index and an improvement of the 90% coverage of PTV1 (planning target volume) and PTV2 compared with MLC-10. This was noted in the nine- and seven-beam plans. Within the nine-beam group with MLC-5, a reduction of the segment number by up to 25% at reduced intensity levels and for increased 2D-MFS did not markedly worsen plan quality. Interestingly, a seven-beam IMRT with MLC-5 was inferior to a nine-beam IMRT with MLC-5, but superior to a nine-beam IMRT with MLC-10.Conclusion:The use of an MLC-5 has significant advantages over an MLC-10 with respect to target coverage and protection of normal tissues in step-and-shoot IMRT of head and neck cancer.Ziel:Gegenstand dieser Untersuchung war, ob bei der intensitätsmodulierten Radiotherapie (IMRT) von Kopf-Hals-Tumoren mit integriertem Boost ein neuer kommerzieller Multileafkollimator mit einer Lamellenblende von 5 mm (MLC-5) über eine Feldgröße von 40 × 40 cm2 zu einer Verbesserung der Planqualität im Vergleich zu einer Lamellenblende von 10 mm (MLC-10) führt.Patienten und Methodik:Der Planvergleich wurde an zehn Patienten mit Kopf-Hals-Tumoren durchgeführt. Für jeden Patienten wurden sieben Pläne berechnet: ein Plan mit MLC-10 und neun Feldern, vier Pläne mit MLC-5 und neun Feldern (mit verschiedenen Intensitätsleveln bzw. zweidimensionalen Medianfiltergrößen [2D-MFS]) und je ein Sieben-Felder-Plan mit MLC-5 und MLC-10. Isozentrum, Feldwinkel und Planungsbeschränkungen blieben unverändert. Es wurden Mittelwerte der üblichen Planparameter von allen zehn Patienten berechnet und die Plangruppen mit MLC-5 und MLC-10 bzw. neun und sieben Feldern miteinander verglichen.Ergebnisse:Der Einsatz eines MLC-5 führt im Vergleich zu einem MLC-10 zu einer signifikanten Verbesserung des Konformitätsindex und zu einer Erhöhung von V90 des PTV1 (Planungszielvolumen) und PTV2 (Tabellen 1–4, Abbildung 3). Dies konnte für Neun- und Sieben-Felder-Pläne gezeigt werden. Innerhalb der Neun-Felder-Plangruppen mit MLC-5 führte eine Verringerung der Segmentanzahl um 25% durch Reduktion der Intensitätslevel und/oder des 2D-MFS nicht zu einer Verschlechterung der Planqualität (Abbildung 2). Eine Sieben-Felder-IMRT mit MLC-5 war einer Neun-Felder-IMRT mit MLC-5 unterlegen, aber besser als eine Neun-Felder-IMRT mit MLC-10.Schlussfolgerung:Die Verwendung eines MLC-5 weist gegenüber einem MLC-10 signifikante Vorteile bezüglich der Zielvolumenabdeckung und der Normalgewebsschonung bei der „step-and-shoot“-IMRT von Kopf-Hals-Tumoren mit integrierter Boostapplikation auf.

Influence of Intravenous Contrast Agent on Dose Calculation in 3-D Treatment Planning for Radiosurgery of Cerebral Arteriovenous Malformations

Purpose:To investigate the influence of local density increase by i.v. contrast agent on dose calculation in linac-based radiosurgery (RS) of cerebral arteriovenous malformations (AVMs).Material and Methods:RS was performed after three-dimensional (3-D) treatment planning using a total number of nine to 14 beams. Mean target volume was 5.3 cm3 (range, 0.1–41.2 cm3). Mean maximum diameter was 23.2 mm (range, 8–51 mm). Dose deviation was estimated and calculated from the enhanced and unenhanced datasets of 30 patients. Dose calculation was performed using the same RS treatment plan on both datasets. Both plans were standardized to 1 Gy at isocenter with the same dose weight for all beams.Results:Mean difference of Hounsfield units (ΔHU) between enhanced and unenhanced CT was 152 HU (range, 50–350 HU). The estimated dose deviation was ≤ 1% in 80% of cases with a mean deviation of 0.67% and a maximum dose deviation of 1.8%. With increasing ΔHU and increasing maximum diameter dose deviation increased as well. The calculated overdosage in ten datasets of enhanced and unenhanced CT scans was 0.66% mean (range, 0.2–1.2%).Conclusion:The use of i.v. contrast agent in 3-D treatment planning for RS of cerebral AVMs may lead to an underestimation of actual applied dose. The effect on dose calculation is rather low with dose deviations < +1% in most of the cases. However, there are cases especially in large AVMs with high ΔHU located next to critical, radiosensitive structures in which an additional unenhanced CT scan is recommended for exact dose calculation to avoid side effects.Ziel:Untersuchung des Einflusses der lokalen Dichteerhöhung durch Röntgenkontrastmittel auf die Dosisberechnung bei der Radiochirurgie (RS) von zerebralen arteriovenösen Malformationen (AVM).Material und Methodik:Die RS erfolgte nach dreidimensionaler (3-D) Bestrahlungsplanung über 9 bis 14 Felder. Die mittlere Zielvolumengröße lag bei 5,3 cm3 (Spanne 0,1–41,2 cm3). Der mittlere maximale Durchmesser betrug 23,2 mm (Spanne 8–51 mm). Die potentielle Dosisabweichung wurde anhand eines nativen und eines kontrastmittelverstärkten Datensatzes von 30 Patienten bestimmt. Die Berechnung der Dosisverteilung zur RS erfolgte jeweils auf beiden Datensätzen. Beide Pläne wurden zum Vergleich auf 1 Gy im Isozentrum normiert, mit einer gleichmäßigen Dosisgewichtung über alle Felder.Ergebnisse:Die mittlere Differenz der Hounsfield-Einheiten (ΔHU) zwischen kontrastverstärktem und nativem CT lag bei 152 HU (Spanne 50–350 HU). Die geschätzte Dosisabweichung betrug in 80% der Fälle ≤ 1% mit einer mittleren Abweichung von 0,67% und einer maximalen Abweichung von 1,8%. Mit zunehmender ΔHU und zunehmendem maximalem Durchmesser nahm auch die Dosisabweichung im Sinne einer Überdosierung zu. Die berechnete mittlere Dosisabweichung lag bei zehn nativen und kontrastverstärkten Datensätzen bei 0,66% (Spanne 0,2–1,2%).Schlussfolgerung:Die Verwendung von Röntgenkontrastmittel zur 3-D-Bestrahlungsplanung kann zu einer Unterschätzung der tatsächlich applizierten Dosis bei der RS von zerebralen AVM führen. Der Effekt auf die Dosisberechnung ist eher gering, mit Dosisabweichungen < +1% in den meisten Fällen. Jedoch ist die Durchführung eines zusätzlichen nativen CT zur exakten Dosisberechnung, insbesondere bei großen AVM mit großem ΔHU in unmittelbarer Nähe zu kritischen, strahlenempfindlichen Organen, zur Vermeidung von Nebenwirkungen sinnvoll.

Potential of quantitative susceptibility mapping for detection of prostatic calcifications

To evaluate whether quantitative susceptibility (QSM) may be used as an alternative to computed tomography (CT) to detect calcification in prostate cancer patients.