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Results for “RADIOTHERAPY DOSAGE”

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At least 55 records · Page 3Linked to original sources
PubMed1996

[Clinical and radiobiologic evaluation of radiation dosage in radiotherapy of vaginal cancer].

The investigation has been concerned with the results of combined (distant + contact) treatment and contact low-, medium-, and high-dosage radiotherapy alone in 133 patients with primary tumors of the vagina (VT). Time-dose-fractionation (TDF), cumulative radiation effect (CRE) and linear-quadratic (LQ) ("extrapolated dose of response") models were employed to evaluate the response of normal tissue. There was no correlation between survival in VT patients treated with radiation only and the tolerance limits for connective tissue estimated using TDF, CRE and LQ models being exceeded. The incidence of late-onset radiation injuries rose significantly by 20% (p < 0.05) when the TDF- and CRE-based limits of tolerance were exceeded. The LQ model had no similar predictive value. The TDF model proved more convenient in radiobiological assessment of different patterns of total focal dose fractionation, selection of similarly effective modalities as well as in prediction of late-onset radiation injury.

Dose-Response Relationship, Radiation↗
PubMed1998

Tumour volume: implications in T2/T3 glottic/supraglottic squamous cell carcinoma.

OBJECTIVE: In this study, tumour volume was investigated to determine if it predicts locoregional control of T2/T3 glottic/supraglottic laryngeal carcinoma treated with radiotherapy or surgery. The effect of radiotherapy dosage was also assessed in those patients treated with primary radiotherapy. The ability to identify a subset of patients suitable for primary radiotherapy and, hence, voice preservation based on pretreatment computerized axial tomography (CT) would be valuable. METHOD: The charts of 55 patients referred to the London Regional Cancer Centre (LRCC) between 1988 to 1994 were reviewed. Each presented with a previously untreated T2 or T3 squamous cell carcinoma (SCC) of either the glottic or supraglottic larynx. Tumour volume was calculated from pretreatment CT scans by observers unaware of the clinical data associated with each radiograph. Wilcoxon t test and univariate and multivariate Cox regression analyses were performed. RESULTS: Mean tumour volume differed between those patients treated with radiotherapy and those treated surgically (4.5 cm3 and 11 cm3, respectively; p < .01). Mean tumour volume also differed between T2 and T3 tumours in the primary radiotherapy group (3.8 cm3 and 9.3 cm3, respectively; p < .01). Tumour volume > 4.0 cm3 was a significant predicator of local failure in T2 laryngeal tumours treated with radiotherapy (p < .05). This volume effect was not abolished with increasing radiotherapy dosage. Tumour volume was not a significant predictor of local control in the T3 tumours treated with radiotherapy or when all tumours, irrespective of T stage, that were treated with radiotherapy were considered together. There was no similar volume effect found in the surgical group. CONCLUSIONS: Tumour volume > 4 cm3 predicts local failure in T2 laryngeal tumours treated with radiotherapy regardless of radiotherapy dosage. This volume effect is not seen in those tumours treated with surgery. Inclusion of tumour volume data may eventually augment our current classification system.

Adult↗
PubMed1993

Timing and dosage of postoperative radiotherapy for squamous cell carcinoma of the upper aerodigestive tract.

Seventy patients who received postoperative irradiation (PI) after curative surgery for stage III or IV squamous cell carcinoma of the upper aerodigestive tract were studied retrospectively to compare the rate of local and regional recurrence (LRR) and the effect of total dose on LRR rate in patients irradiated timely (n = 40) with those who were not (n = 30). Overall, the LRR rate was higher when PI was delayed than when timely (37% vs 20%). No advantage resulted from increasing total dose when PI was delayed; the LRR rate in the primary site and upper neck was 18% with less than 60 Gy and was 26% with 60 Gy or more; the LRR rate in the lower neck was 13% with 50 Gy or less and was 14% with more than 50 Gy. These data seem to corroborate the findings of other investigators regarding the importance of initiating timely PI, but not the observation that a pronounced delay is not detrimental provided higher tumoricidal doses are used.

Adult↗
PubMed2003

[The effect of laryngectomy and postoperative radiotheraphy on thyroid gland functions].

OBJECTIVES: We investigated the frequency of hypothyroidism in patients treated with total laryngectomy, hemithyroidectomy-isthmectomy, and postoperative radiotherapy for T3 or T4 larynx cancers. PATIENTS AND METHODS: Twenty-nine male patients (mean age 54 years; range 43 to 72 years) with T3 or T4 larynx cancers were prospectively included in the study. Preoperatively, thyroid function tests were normal in all the patients. Following radiotherapy, serum thyroid-stimulating hormone (sTSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels were measured every three months at least for a year. Detection of an increased level of sTSH together with decreased or normal levels of FT3 and/or FT4 indicated clinical and subclinical hypothyroidism, respectively. The relationship was assessed between hypothyroidism and both age and radiotherapy dosage. Statistical analyses were made with the use of the Student's t- test and Mann-Whitney U-test. RESULTS: Following radiotherapy, thyroid function tests remained normal in 12 patients (41%), while 12 patients (41%) and five patients (18%) developed subclinical and clinical hypothyroidism, respectively. No significant relationship was found between age and thyroid dysfunction (p>0.05), whereas radiotherapy dosage was found in significant relationship with the development of hypothyroidism (p<0.05). CONCLUSION: Due to high rates of subclinical or clinical hypothyroidism following combined therapy, thyroid functions should be closely monitored in patients undergoing laryngectomy for T3 or T4 larynx cancers.

Adult↗
PubMed1989

[High-dosage chemo-radiotherapy with autologous bone marrow transfusion in malignant lymphoma: indications and personal experience].

We report the results of a pilot study of dose intensification with autologous bone marrow support in patients with malignant lymphoma. Since January 1988 11 patients with malignant lymphoma have been treated by intensive chemoradiotherapy or combination chemotherapy followed by autologous bone marrow support. 6 of the patients had non-Hodgkin's lymphoma in first remission with unfavorable histology and/or unfavorable clinical prognostic factors, and 5 patients were in second or subsequent remission (2 non-Hodgkin's lymphoma, 3 Hodgkin's disease). Bone marrow harvest and cryopreservation of marrow cells were uneventful. 10 patients showed full hematologic recovery, while one patient with Hodgkin's disease died early of pneumocystis pneumonia. With the exception of one interstitial pneumonitis of unknown etiology, the clinical course during hospitalization was otherwise uncomplicated. The mean duration of hospital stay was 33 days. 2 patients relapsed after dose intensification, while the others are in continued remission (median 7 months, range 2-14 months).

Adolescent↗