Local recurrence after surgery for primary extra-abdominal desmoid-type fibromatosis.

BACKGROUND: Desmoid-type fibromatosis is a locally aggressive soft tissue tumour with a biological behaviour that varies between relatively indolent and progressive growth. Although there is a trend towards conservative treatment, surgery remains the standard treatment for extra-abdominal desmoid tumours. METHODS: Databases of three hospitals were searched to identify patients who had been treated for desmoid-type fibromatosis between November 1989 and May 2011. The risk of local recurrence was evaluated and predictive factors were assessed in patients who underwent surgical resection as initial treatment for a primary tumour. RESULTS: A total of 132 patients had surgical treatment for a primary tumour. A complete resection (R0) was achieved in 87 patients (65.9 per cent). In addition to surgery, 54 patients received radiotherapy. During a median follow-up of 38 months, 18 local recurrences were detected. The estimated 5-year cumulative risk of local recurrence was 17.6 per cent. Univariable Cox regression analysis demonstrated that the risk of local recurrence increased for extremity lesions compared with desmoids on the trunk (odds ratio 6.69, 95 per cent confidence interval 1.42 to 31.54). No significant influence of age, resection margins or adjuvant radiotherapy on the risk for local recurrence was observed. CONCLUSION: Following surgical treatment of a primary extra-abdominal desmoid tumour, the 5-year risk of local recurrence is modest and not influenced by microscopically clear resection margins or adjuvant radiotherapy.

[Palliative treatment of esophageal cancer with dysphagia: more favourable outcome from single-dose internal brachytherapy than from the placement of a self-expanding stent; a multicenter randomised study]. / Palliatieve behandeling voor slokdarmkanker met passageklachten: gunstiger uitkomsten van eenmalige inwendige brachytherapie dan van plaatsing van een zelfexpanderende stent; multicentrisch, gerandomiseerd onderzoek.

OBJECTIVE: To compare the results of single-dose internal irradiation (brachytherapy) and self-expanding metal stent placement in the palliation of oesophageal obstruction due to cancer of the oesophagus. DESIGN: Randomised trial. METHOD: In the period from December 1999-Jun 2002, 209 patients with dysphagia due to inoperable carcinoma of the oesophagus were randomised to placement of an Ultraflex stent (n = 108) or single-dose (12 Gy) brachytherapy (n = 101). Primary outcome was relief of dysphagia; secondary outcomes were complications, persistent or recurrent dysphagia, health-related quality of life, and costs. Patients were followed up by monthly home visits from a specialised nurse. RESULTS: Dysphagia improved more rapidly after stent placement than after brachytherapy, but long-term relief of dysphagia was better after brachytherapy. Stent placement resulted in more complications than did brachytherapy (36/108 (33%) versus 21/101 (21%); p = 0.02), due mainly to an increased incidence of late haemorrhage in the stent group (14 versus 5; p = 0.05). The groups did not differ with regard to the incidence of persistent or recurrent dysphagia or median survival (p > 0.20). In the long term, quality-of-life scores were higher in the brachytherapy group. Total medical costs were also similar for both treatments: Euro 8,215 for stent placement and Euro 8,135 for brachytherapy. CONCLUSION: Brachytherapy provided better long-term relief of dysphagia than did stent placement and also produced fewer complications. Brachytherapy is therefore recommended as the preferred treatment for the palliation of dysphagia due to oesophageal cancer.

The combined use of the natural and the cumulative dose-volume histograms in planning and evaluation of permanent prostatic seed implants.

BACKGROUND AND PURPOSE: To investigate prostate dose coverage and overdosage in planned and realized permanent iodine seed prostate implants and to explore the use of the natural dose-volume histogram (NDVH) and the cumulative dose-volume histogram (CDVH) as tools to optimize prostate implants. MATERIALS AND METHODS: The optimal prescription dose (PD) or natural prescription dose (NPD) was derived from the NDVH. The mismatch between the NPD and the given PD was called the natural dose ratio (NDR). For an ideal implant the NDR should be 1. The target is overdosed if NDR >1 and underdosed if NDR <1. The NDR and prostate coverage were evaluated in implants of nine patients. Prostate coverage was determined from the CDVH based on pre-implant ultrasound or post-implant MRI for the planned and realized implants, respectively. The use of the NDVH to further optimize the planned prostate implants was also explored. RESULTS: The mean values of the NDRs were 1.30+/-0.34 (range 0.76-1.79), 1.22+/-0.31 (0.76-1.74) and 1.22+/-0.12 (0.98-1.33) for the planned, realized and optimized seed distributions, respectively. The realized prostatic implants showed smaller prostate coverage than the planned implants. The prostate volume fractions receiving 100% of the prescription dose were V(100)=79+/-6% and V(100)=97+/-3% for the realized and the planned implants, respectively. CONCLUSIONS: The NDVH and the CDVH proved to be valuable tools in plan evaluation. The NDVH and its derived parameter NDR quantify the risk of under or overdosage for a given PD. The CDVH is valuable in evaluation of prostate coverage realized prostate. Our strategy to implant just the prostate and not the prostate plus a margin led to NDR values between 1.1 and 1.3 and a prostate coverage of V(100)=79+/-6% in the nine patients. The planned coverage of V(100)=95% was not realized, mainly due to inadequate coverage of the base of the prostate.

Evaluation of permanent I-125 prostate implants using radiography and magnetic resonance imaging.

PURPOSE: The aim of this study is the evaluation of permanent I-125 prostate implants using radiography and magnetic resonance imaging (MRI). METHODS AND MATERIALS: Twenty-one patients underwent radiography on the simulator and MRI within 3 days after implantation of the I-125 seeds. Isocentric radiographs were used for reconstruction of the seed distribution, after which registration with the seed-induced signal voids on MRI provided the seed positions in relation to the prostate. The prostate was contoured on the transversal magnetic resonance images, and dose-volume histograms were computed to evaluate the implants. The validity of the ellipsoidal prostate volume approximation, as applied in preimplant dose calculation, was assessed by comparison of ellipsoidal volumes given by prostate width, height, and length and prostate volumes obtained by a slice-by-slice contouring method, both on postimplant MRI. Prostate volume changes due to postimplant prostate swelling were assessed from radiographs taken at 3 days and 1 month after the implantation. RESULTS: The seeds were readily identified on T1-weighted spin-echo images and matched with the seed distribution reconstructed from the isocentric radiographs. The matching error, averaged over 21 patients, amounted to 1.8 +/- 0.4 mm (mean +/- standard deviation). The fractions of the prostate volumes receiving the prescribed matched peripheral dose (MPD) ranged from 32 to 71% (mean +/- standard deviation: 60 +/- 10%). Prostate volumes, obtained by the contouring method on postimplant MRI, were a factor 1.5 +/- 0.3 larger than the ellipsoidal volumes given by the prostate dimensions on postimplant MRI. Prostate volumes 3 days after the implantation were a factor 1.3 +/- 0.2 larger than the prostate volumes 1 month after the implantation. Registration of the reconstructed seed distribution and the MR images showed inaccuracies in seed placement, for example, two or more seeds clustering together or seeds outside the prostate. CONCLUSIONS: Registration of the reconstructed seed distribution and the MR images enabled evaluation of target coverage, which amounted to 60 +/- 10%. The discrepancy between prescribed dose and realized dose was caused by underestimation of the preimplant prostate volume due to the ellipsoidal approximation, postimplant prostate swelling at the time of evaluation, and inaccuracies in seed placement.

Analysis and correction of geometric distortions in 1.5 T magnetic resonance images for use in radiotherapy treatment planning.

The aim of this study is to investigate and correct for machine- and object-related distortions in magnetic resonance images for use in radiotherapy treatment planning. Patients with brain tumours underwent magnetic resonance imaging (MRI) in the radiotherapy position with the head fixed by a plastic cast in a Perspex localization frame. The imaging experiments were performed on a 1.5 T whole body MRI scanner with 3 mT m-1 maximum gradient capability. Image distortions, caused by static magnetic field inhomogeneity, were studied by varying the direction of the read-out gradient. For purposes of accuracy assessment, external and internal landmarks were indicated. Tubes attached to the cast and in the localization frame served as external landmarks. In the midsagittal plane the brain-sinus sphenoidalis interface, the pituitary gland-sinus sphenoidalis interface, the sphenoid bone and the corpora of the cervical vertebra served as internal landmarks. Landmark displacements as observed in the reversed read-out gradient experiments were analysed with respect to the contributions of machine-related static magnetic field inhomogeneity and susceptibility and chemical shift artifacts. The machine-related static magnetic field inhomogeneity in the midsagittal plane was determined from measurements on a grid phantom. Distortions due to chemical shift effects were estimated for bone marrow containing structures such as the sphenoid bone and the corpora of the cervical vertebra using the values obtained from the literature. Susceptibility-induced magnetic field perturbations are caused by the patient and the localization frame. Magnetic field perturbations were calculated for a typical patient dataset.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain tumor delineation based on CT and MR imaging. Implications for radiotherapy treatment planning.

This paper deals with the impact MRI may have on radiotherapy treatment planning of brain tumors. The authors analyzed differences in size and position of treatment fields as indicated by three observers (two radiotherapists and one neuroradiologist) using CT or MR based radiotherapy planning procedures for cerebral-gliomas. Large differences in field size and position were found in non CT contrast enhancing tumors, all low grade gliomas. Small differences were found in contrast enhancing lesions including the high grade gliomas. We conclude that implementation of MRI in radiotherapy treatment planning leads to a greater precision in treatment fields for non CT contrast enhancing lesions.

Human breast cancer in vivo: H-1 and P-31 MR spectroscopy at 1.5 T.

To assess the potential of in vivo magnetic resonance (MR) spectroscopy for breast cancer, hydrogen-1 and phosphorus-31 MR spectra of five malignant human breast tumors were compared with those of unaffected breast tissue. The water-to-fat ratio was high in the tumors (average, 2.2) but low in the unaffected tissue (average, 0.3). The P-31 spectrum of normal breast tissue showed low levels of phosphomonoesters (PMEs), inorganic phosphate, phosphodiesters (PDEs), and ATP. In addition, an intense phosphocreatine (PCr) signal was observed in breast tissue of young women: The relative intensities of the PCr and ATP signals had a mean value of 1.9. The tumor spectrum showed elevated levels of PMEs, Pi, and PDEs, while no PCr was seen (PCr/ATP less than 0.2). In two breast cancers treated with radiation therapy, resulting in a decrease of tumor volume of more than 50%, a similar change in the tumor P-31 spectrum was observed: An intense PCr signal developed (PCr/ATP = 1.1). Control experiments indicated that the appearance of PCr after radiation therapy was the result of a radiation-induced metabolic change in the tumor itself.

Multiple slice MR imaging as an aid in radiotherapy of carcinoma of the cervix uteri. A case report.

In recent years MRI has developed into an imaging modality with great potential for several medical disciplines including radiotherapy. A feature of particular relevance to radiotherapy is the possibility to depict arbitrarily orientated slices. Using multislice imaging techniques one can determine and describe tumour volume and extension in several directions. By doing so prior to and during radiotherapy it is possible to monitor response to treatment. In this case report of a patient treated for carcinoma of the uterine cervix the use of this MRI information is demonstrated.