Biomedical subjects

R B Keus

Publications and source records attributed to R B Keus.

At least 37 records · Page 2Linked to original sources

PubMed1996

Evidence for early and persistent impairment of salivary gland excretion after irradiation of head and neck tumours.

Salivary gland scintigraphy with technetium-99m pertechnetate was used to follow changes in the excretion and uptake function of the major salivary glands until 1 year after irradiation. Twenty-five patients who received radiotherapy for head and neck tumours were included in the study. Seventy-nine salivary glands (39 parotid and 40 submandibular) were evaluated in relation to the average received radiation dose. Salivary gland scintigraphy was performed before and 1, 6 and 12 months after radiotherapy. For each gland the excretion response to carbachol, evaluated by calculation of the salivary excretion fraction (SEF), the cumulative gland uptake (CGU) and the absolute excreted activity (AEA) at various intervals after radiotherapy were compared with the baseline values. The excretion response decreased in 20 of 25 patients at 1 month after radiotherapy. One month after radiotherapy both SEF and AEA decreased significantly in relation to the radiation dose. These decreases in excretion parameters persisted during the follow-up period. Parotid excretion was affected significantly more than submandibular excretion. CGU values did not change significantly until 6 months after radiotherapy, but at 12 months a significant decrease related to radiation dose was observed. Xerostomia was assessed during radiotherapy and on the days of the scintigraphic tests. The incidence of xerostomia did not correspond to the effects observed in the scintigraphic studies. It is concluded that radiotherapy induces early and persistent impairment of salivary gland excretion, related to the radiation dose. This impairment is stronger in parotid glands than in submandibular glands.

Dose-Response Relationship, Radiation↗

PubMed1996

Survival of adult patients with head and neck soft tissue sarcomas.

A retrospective review and survival analysis is presented of 58 adult patients referred between 1963 and 1993 for treatment of a head and neck soft tissue sarcoma. The 5 year overall and disease-free survival was 60% and 52% respectively. Univariate analysis indicated that age, positive margins, bone invasion, distant metastases, single modality treatment, histological grading, sites below the deep fascia and size might be predictors of survival. On multivariate analysis, age, histological grade, distant metastases, site and referral for recurrent disease emerged as prognostic factors known before treatment. By including variables known after treatment, age remained the most important independent prognostic factor followed by the presence of free margins, histological grading and distant metastases at presentation.

Adolescent↗

PubMed1996

Management of cervical metastases in supraglottic cancer.

A retrospective review of patients from 1979 to 1988 was performed to assess the efficacy of neck dissection, prognostic factors, and the philosophy of treatment of the neck in supraglottic cancer. Of the 89 patients available for analysis, 26 were managed by horizontal partial laryngectomy (HPL), 44 by primary radiotherapy (RT), and 19 by total laryngectomy (TL). A total of 41 patients from the group had 63 neck dissections (NDs); 22 had bilateral and 19 unilateral dissections. A correlation of the pN with N staging revealed that when presenting with N2a nodes (> 3 cm), one third had contralateral metastases, and with N2b (multiple), 100% had contralateral metastases. In multivariate analysis of the disease-free interval, age and staging emerged as independent prognostic variables. Although we observed no increased morbidity by dissecting the opposite side, our results did not support routine bilateral neck dissection in NO patients. However, when the nodes are larger than 3 cm, or ipsilateral and multiple, bilateral neck dissection is recommended.

Carcinoma, Squamous Cell↗

PubMed1996

Telephone-based nursing intervention improves the effectiveness of the informed consent process in cancer clinical trials.

PURPOSE: Here we report the results of a randomized study undertaken to test the efficacy of a supplementary, telephone-based nursing intervention in increasing patients' awareness and understanding of the clinical trials in which they are asked to participate. METHODS: During a 12-month period, 180 cancer patients who were approached to participate in a phase II or III clinical trial were randomized to undergo either of the following: (1) standard informed consent procedures based on verbal explanations from the treating physician plus written information (controls); or (2) standard informed consent procedures plus a supplementary, telephone-based contact with an oncology nurse (intervention). For purposes of evaluation, face-to-face interviews were conducted with all patients approximately 1 week after the informed consent process had been completed. RESULTS: The two groups were comparable with regard to sociodemographic and clinical variables. Both groups had a high level of awareness of the diagnosis and of the nature and objectives of the proposed treatments. The intervention group was significantly (P < .01) better informed about the following: (1) the risks and side effects of treatment; (2) the clinical trial context of the treatment; (3) the objectives of the clinical trial; (4) where relevant, the use of randomization in allocating treatment; (5) the availability of alternative treatments; (6) the voluntary nature of participation; and (7) the right to withdraw from the clinical trial. The intervention did not have any significant effect on patients' anxiety levels or on rates of clinical trial participation. Patients reported high levels of satisfaction with the intervention. CONCLUSION: The use of a supplementary, telephone-based nursing intervention is a feasible and effective means to increase cancer patients' awareness and understanding of the salient issues that surround the clinical trials in which they are asked to participate.

Adult↗

PubMed1995

[Consensus soft tissue tumors. Dutch Workgroup Soft-Tissue Tumors].

Soft-tissue sarcomas constitute a rare group of malignant tumours with histopathological features of connective, muscular, fatty or peripheral nervous tissue. The prognosis at manifestation depends on only two factors: the spread, both local and remote, and the biological behaviour of the tumour. The latter factor cannot be influenced but the former can: by inexpert manipulation. Consequently, tumours suspected of being soft-tissue sarcomas require multidisciplinary management from the beginning, with the team members familiar with each other's diagnostic and therapeutic skills. Imaging diagnostic methods should precede invasive methods for collection of material for pathological examination. The number of mitotic figures observed at microscopical examination of the tissue is an important prognostic feature. Surgical resection is the treatment of first choice. Radiotherapy is indicated in grade 3 tumours, after recurrence surgery, and when radical resection would involve too much mutilation. Chemotherapy is only given in the context of clinical trials. Surgical treatment of lung metastases may be indicated in selected patients. Regional isolated perfusion with tumour necrosis factor may be an alternative for limb amputation.

Biopsy↗

PubMed1995

Lymphedema-induced lymphangiosarcoma.

A series of eight patients with chronic lymphedema-related lymphangiosarcoma is presented. All but one case showed a typical rapid progression and fatal outcome, as has been reported in other series. In one patient the lymphangiosarcoma developed on the chest wall, the axilla and the arm where persisting lymphedema and fibrosis occurred after bilateral mastectomy and bilateral postoperative radiotherapy. In this patient an asymptomatic course and slow locoregional progression of lesions was seen. The clinical picture, the etiological considerations and the therapeutic options of the lymphedema-induced lymphangiosarcoma with regard to the literature are discussed.

Aged↗

PubMed1995

Report of a symposium on diagnosis and treatment of adult soft tissue sarcomas in the head and neck.

A series of presentations and discussions was held during a symposium on the diagnosis and treatment of adult soft tissue sarcomas in the head and neck (HNSTS). The purpose of this meeting was to define guidelines on diagnosis and treatment of HNSTS. The results of this symposium are summarized and condensed in this report. Recommendations are made for diagnostic strategies and for treatment. Diagnostic efforts in PET scanning and dynamic MRI need to be expanded to detect early recurrences. Firm pathological diagnosis remains the basis for further treatment strategy. Wide surgical excision, if feasible, in combination with radiotherapy is the treatment of choice.

Adult↗

PubMed1995

Fibromatosis of the head and neck.

Fibromatosis is a locally infiltrative fibrous tissue proliferation with a tendency to recur locally. From a large series of head and neck patients treated between 1977 and 1994 in our institute, we retrieved the records of nine adult patients diagnosed with this disease. They serve as examples to demonstrate this rare entity in the head and neck. Five out of nine lesions were localized in level V (posterior triangle of the neck). The majority of patients were treated by surgery in combination with radiotherapy. None of the patients died of the disease.

Adult↗

PubMed1995

Carcinoma of the pyriform sinus: a retrospective analysis of treatment results over a 20-year period.

One hundred and one patients with pyriform sinus carcinoma treated at the Netherlands Cancer Institute were studied retrospectively. The patients were staged according to the UICC criteria of 1987: there were no stage I, 23 stage II, 30 stage III, and 48 stage IV patients. The treatment consisted of radiotherapy (n = 45), a planned combination of surgery and post-operative radiotherapy (n = 47) or surgery alone (n = 9). The crude 5-year survival was 27%, whereas the 5-year disease-free survival was 37%. The locoregional disease-free survival was 52%. Stage according to the UICC 1987 criteria is an important prognostic variable (P = 0.0026). Furthermore, significantly less locoregional recurrences and a better disease-free survival were seen in the combined surgery and radiotherapy group than in the exclusively irradiated group (P < 0.0001).

Adult↗

PubMed1994

Scintigraphic assessment of salivary function and excretion response in radiation-induced injury of the major salivary glands.

BACKGROUND: Both loss of the secretory function and impairment of the excretion may play a role in radiation-induced injury of the major salivary glands after radiotherapy for head and neck malignancies. Therefore, quantitative 99mTc-pertechnetate (99mTc) salivary scintigraphy to assess trapping, secretion, and excretion, was used to analyze irradiation-induced changes in relation to the radiation dose and the time interval after radiotherapy. PATIENTS AND METHODS: Salivary scintigraphy was performed on 25 patients who had been irradiated to the neck and head for various malignancies with irradiation of the major salivary glands and in 6 nonirradiated patients. Excretion was induced by stimulation with carbachol (Carbacholum, Pharmachemie BV, Haarlem, The Netherlands). As a parameter for salivary glandular trapping and secretion, the cumulative 99mTc-pertechnetate glandular uptake in the first 12 minutes was used. Scintigraphic data were analyzed for each patient and for each individual gland at three radiation dose levels (range, 5-70 Gy), and at short (range, 2-7 months) and long (range, 10-50 months) intervals after radiotherapy. RESULTS: The excretion response to the stimulant carbachol was totally or partially disturbed in 84% of the irradiated patients. For individual glands, excretion was maintained in all glands irradiated with 25 Gy or less, in nearly half of the glands at doses of 25-45 Gy, and was almost invariably impaired at doses higher than 45 Gy, regardless of the time interval after radiotherapy. Although cumulative 99mTc glandular uptake tended to decrease at higher radiation dose levels (z = -3.059, P < 0.0022), at 45 Gy or more, cumulative 99mTc uptake was considerably higher in glands examined at a short postirradiation interval compared with glands examined after a long time interval (P = 0.0001). This tendency, seen for both parotid and submandibular glands, was not observed at doses lower than 45 Gy. CONCLUSION: These data suggest that in the first period after high dose irradiation, xerostomia is based predominantly on the failure of the gland to excrete saliva, whereas in the later period, a decreased trapping ability together with loss of secretory function play an additional role. Salivary scintigraphy using 99mTc-pertechnetate is a suitable method to assess radiation-induced salivary gland injury. The test is able to detect salivary glandular dysfunction in an early phase and may be useful to predict which patients will respond symptomatically to salivary stimulants.

Adolescent↗

PubMed1994

Resectable retroperitoneal soft tissue sarcomas. The effect of extent of resection and postoperative radiation therapy on local tumor control.

BACKGROUND: Soft tissue malignancies of the retroperitoneum are rare. Surgery is commonly considered the first choice of treatment. There is still no consensus concerning the precise value of the extent of surgery and the value of additional treatment modalities. METHODS: From 1973 to 1990, 34 patients were initially treated by surgery for retroperitoneal soft tissue sarcomas at the Netherlands Cancer Institute. In a retrospective study, the prognostic effect of extent of primary surgery and postoperative radiation therapy was examined. RESULTS: Liposarcomas (47%) and leiomyosarcomas (29%) were the histologic types most commonly found. Grade of malignancy was defined as medium to high (II/III) in 44% and as low (I) in 38%. Complete (extended or marginal) resection of the tumor was achieved in 29 patients. After complete resection, the 5-year survival rate and the local recurrence rate were 35% and 63%, respectively. Extended surgery (performed in eight patients) showed a local recurrence rate of 50%. Thirteen patients received high-dose postoperative radiation therapy, which was found to have a significant favorable effect on the recurrence-free interval (P < 0.01). CONCLUSIONS: We conclude that complete (extended) resection followed by high-dose postoperative radiation therapy improves the prognostic outcome of patients with retroperitoneal soft tissue sarcomas.

Adult↗

PubMed1994

Limb-sparing therapy of extremity soft tissue sarcomas: treatment outcome and long-term functional results.

The purpose of this study is to assess the long-term success rate and functional results of limb-sparing therapy in a group of 156 patients with soft tissue sarcomas of the extremities in the Netherlands Cancer Institute, treated according to a standard protocol of surgery and radiotherapy, if indicated. The patients (79 females and 77 males) were treated between 1977 and 1983 by an intended wide local excision with a margin of at least 2 cm. Postoperative radiotherapy was applied in 117 patients; 26 patients had surgery only, including 13 patients who had to be treated by amputation. The total dose was 60 Gy, with 40 Gy to a large volume and a boost of 20 Gy to the tumour bed at 2 Gy per fraction, five fractions per week. Most sarcomas were located in the proximal part of the lower extremity (51%). The group comprised 50 liposarcomas, 47 malignant fibrous hystiocystoma (MFH) and 59 other histologies; 69 (44%) had high-grade tumours. Three treatment groups with limb-sparing treatment were defined: group I (n = 26) patients who had a complete excision receiving no further treatment, group II (n = 64) with narrow surgical margins and radiotherapy and group III (n = 53) with incomplete resection and radiotherapy. The 10-year actuarial overall survival and local control rate for all patients was 63 and 81%, respectively. Multivariate analysis showed that histological grade (P < 0.0001), age (P = 0.0005) and location deep to the fascia (P = 0.0008) were independent prognostic factors for survival, while local control was predicted by grade (P = 0.0014) and treatment group (p = 0.028). Patients with surgery only (group I) had 81% 5-year local control as compared to 92% with radiotherapy after narrow surgery (group II) and 74% with incomplete surgery and radiotherapy (group III). Limb preservation when attempted was achieved in 90% of the patients. After limb-sparing treatment, 7% had severe impairment of mobility, 3% had lymph oedema and 16% marked fibrosis. Fractures in the irradiated bone occurred in 6% of the patients. The combination of limited surgery followed by radiotherapy resulted in a high local control rate with good functional results. Ultimately limb sparing treatment was successful in 83% of all patients with extremity sarcomas.

Adolescent↗

PubMed1994

Carcinoma of the soft palate and the posterior oropharyngeal wall.

Between 1966 and 1984, 14 patients with carcinoma of the soft palate and eight patients with a posterior oropharyngeal wall carcinoma were treated at the Netherlands Cancer Institute. In the soft palate group, the majority of patients (10) had small tumours T1-T2; the median patient delay was 1 month (range 0-5). Eleven patients were treated with radiotherapy and three with surgery, as single treatment modalities. Tumour control was achieved in 10 patients following initial treatment. Five-year results for tumour control and overall survival were 67% and 41%, respectively. In the posterior wall group all patients had advanced tumours (T3-T4), after a median patient delay of 4 months (range 0-6). Six patients were treated with radiotherapy, one with surgery only and one with a combination of these. Following the initial treatment, tumour control was achieved in half of the patients. Five-year tumour control was 50%, and overall survival at 5 years was 38%. In conclusion, the tumours in these two sub-sites of the oropharynx differ significantly in the extent of the primary tumour (P < 0.01), posterior wall tumours being more advanced on admission, after a significantly longer history (P < 0.01).

Adult↗

PubMed1993

Pectoralis major muscle transposition: an adjunct to laryngeal preservation in severe chondroradionecrosis.

Radiation-induced chondronecrosis of the larynx in early glottic cancer is a rare but serious complication, sometimes requiring total laryngectomy. We describe two patients who developed the major complication of chondroradionecrosis of the larynx 11 and 18 years after completion of radiotherapy. Both cases underwent excision of the overlying skin and of all infected and devitalized thyroid cartilage, followed by pectoralis major muscle transposition and split thickness skin grafting. This procedure resulted in a preservation of all laryngeal functions and also an acceptable cosmetic outcome.

Adult↗

PubMed1993

Malignant schwannoma of the parapharyngeal space in von Recklinghausen's disease: a case report and review of the literature.

Neurofibromatosis (NF) or von Recklinghausen's disease is frequently accompanied by malignant tumours, which can occur at any site in the body. These malignancies are mainly of soft tissue origin. Of all head and neck malignancies, the number of soft tissue sarcomas is limited and in combination with NF this type of tumour is a rare event. In this report we describe the clinical course of a young female patient with NF, who presented with a massive malignant schwannoma in the parapharyngeal space, and review the pertinent literature.

Adolescent↗

PubMed1992

Late effects of radiotherapy on hearing.

The effect of radiotherapy on hearing was studied in 30 patients who were treated by surgery and radiotherapy for a parotid neoplasm. Functions of the irradiated ear were compared with those of the non-irradiated ear in the same patient. Tympanometry showed a small but significant reduction of static compliance on the irradiated side when compared with the non-irradiated side. Audiometry showed a significant increase in hearing loss in the 1-2, 4-8 and 10-20 kHz ranges that increased with frequency. This hearing loss was mainly sensorineural in contrast to hearing loss at 250-500 Hz, where it was more of a conductive type. There appeared to be a significant dose-effect relation in sound perception at 4-8 kHz. Doses to the cochlea of less than 55 Gy seldom caused a hearing loss, in contrast to doses exceeding 65 Gy. Overall, radiotherapy was found to cause significant, mainly sensorineural hearing losses, which were partly dose-dependent.

Acoustic Impedance Tests↗

PubMed1992

Radiation therapy, an important mode of treatment for head and neck chemodectomas.

Between 1970 and 1990, 22 patients with 44 chemodectomas in the head and neck region were seen at the Netherlands Cancer Institute in Amsterdam. All patients were treated with radiation therapy (17 patients with radiation therapy only and 5 in combination with surgery). One patient was treated two times with an interval of 12 years at each side of the neck. Standard dose was 50 Gy in 25 fractions over 5 weeks. A radiation portal arrangement with oblique fields with paired wedges was used most frequently. The follow-up period ranged from 1 year to 20 years. Two recurrences at 2 and 9 years after treatment were observed. The actuarial local control rate was 88% at 10 years follow-up. Comparison of the results of surgery and radiotherapy demonstrates that radiation therapy is an effective treatment modality without mutilation or severe late morbidity for chemodectomas in the head and neck region.

Adult↗

PubMed1991

The simultaneous boost technique: the concept of relative normalized total dose.

The simultaneous boost technique in radiotherapy consists of delivering the boost treatment (additional doses to reduced volumes) simultaneously with the basic (large-field) treatment for all treatment sessions. Both the dose per fraction delivered by the basic-treatment fields and by the boost-treatment fields have to be reduced to end up with the same total dose in the boost volume as in the original schedule, where the basic treatment preceded the boost treatment. These dose reductions and corresponding weighting factors have been calculated using the linear-quadratic (LQ) model and the concept of Normalized Total Dose (NTD). Relative Normalized Total Dose (RNTD) distributions were computed to evaluate the dose distributions resulting for the simultaneous boost technique with respect to acute and late normal tissue damage and tumor control. For the example of the treatment of prostatic cancer the weighting factors were calculated on the basis of the NTD for late normal tissue damage. For the treatment of oropharyngeal cancer the NTD for acute normal tissue damage was used to determine the weighting factors. In this last example a theoretical sparing of late normal tissue damage can be demonstrated. A second advantage of the simultaneous boost technique is that the megavoltage images of the large basic-treatment fields facilitates the determination of the position of the patient with respect to the small boost-treatment fields.

Dose-Response Relationship, Radiation↗