Acute mucositis in the stimulated oral mucosa of patients during radiotherapy for head and neck cancer.

In 16 patients treated for squamous cell carcinoma of the oral cavity or oropharynx with an accelerated split course regimen, acute mucosal reactions were significantly less in the left buccal mucosa which had been repeatedly painted with 2% silver-nitrate solution for several days before radiotherapy than in the unpainted right buccal mucosa.

Randomized clinical trial on accelerated 7 days per week fractionation in radiotherapy for head and neck cancer. Preliminary report on acute toxicity.

PURPOSE: Toxicity of an accelerated 7 days per week fractionation schedule (arm A) was evaluated and compared with a conventional 5 days per week treatment (arm B) in a randomized trial. MATERIALS AND METHODS: Forty-four patients with squamous cell carcinoma of the head and neck in stage T2-4Nzero-1Mzero were included in the study. Total dose and dose per fraction of 2.0 Gy given once-a-day at 24 h intervals were the same in both arms of the trial. The only difference was the overall treatment time being 5 weeks in arm A and 7 weeks in arm B. RESULTS: Analysis of severe mucosal reactions shows significant difference between arm A and B, with regard to both maximum score and duration of severe mucositis. Confluent mucositis (score > 15 according to the Dische system) lasting longer than 3 weeks developed in 48% of patients in arm A and only in 5% in arm B. In group A seven (30%) late effects (osteo- and soft tissue necrosis) occurred during 7-12 month follow-up with two reactions (10%) in group B being suspected as late effects. There was significant association between acute reactions and late effects in arm A, suggesting that the late effects are consequential. CONCLUSION: The high incidence of severe acute reactions and consequential late effects suggests that the accelerated treatment in arm A (using daily fractions of 2.0 Gy, 7 days per week) gives unacceptable toxicity.

Radiobiological predictors of tumor and acute normal tissue response in radiotherapy for head and neck cancers.

Importance of two assay of the measurements of potential doubling time (Tpot.) and survival fraction at 2.0 Gy (SF2) and a method modifying acute radiation response of normal oral mucosa are discussed. Tumor clonogen repopulation accelerates around day 28 of treatment and the rate of repopulation is not constant but continuously increases from about 0.3 Gy/day to 1.0-1.3 Gy/day between day 28 and 65 of treatment. It may suggest that Tpot. values decrease respectively. The relevance of the Tpot. measurements prior to the treatment to clinical situations is discussed. The SF2 value reflects the intrinsic radiosensitivity of human tumors. The SF2 values are expected to be valuable as a predictors for tumor response to radiation. Variations in the SF2 values depending on tumor characteristics and assay methods are discussed in relation to the dose-response and tumor cure probability. The effect of modification of an accelerate repopulation in the oral mucosa by stimulation with 2% silver nitrate solution is presented. Although the presented prognosticators are different in their nature, they might provide a rational basis for selecting patients into optimal radiation treatment and might allow to modify radiation response of dose-limiting normal tissues.

ROC analysis of benefit and limitation in radiotherapy for cancer of the oral cavity.

The ROC analysis of optimalization of radiation treatment of cancer of the oral cavity was carried out. Material of 210 patients with squamous cell carcinoma (SCC) of the oral cavity was included into the study. Based on dose-response curves for tumor and late mucosal reactions, iso-utility curves and optimal k values were estimated. Optimal k values decreased from 0.792 to 0.584 with extension of overall treatment time from 35 to 49 days. It may suggest that the planning of additional dose to compensate tumor clonogens repopulation during prolonged treatment time does not improve therapeutic gain in radiotherapy for cancer of the oral cavity. The ROC is a useful model to estimate optimal radiation treatment for a given tumor because it is independent of any arbitrary consensus or theoretical assumption.

Normobaric oxygen as a sensitizer in radiotherapy for advanced head and neck cancer.

The aim of this study was to evaluate radiosensitizing effect of normobaric oxygen breathing in radiotherapy for advanced head and neck cancers. Forty seven patients with advanced squamous cell carcinomas of the head and neck (7% in Stage III and 93% in Stage IV) were entered in the study. Breathing the pure, normobaric oxygen was given for 15-20 min in the treatment room. Irradiation started immediately after oxygen breathing. Conventional, megavoltage radiotherapy to the total doses in the range of 46-67.5 Gy was used. The control group was 46 patients with the same diagnosis and stage treated by radiotherapy alone. Locoregional tumor control was 36% in the study group compared to 15% in the control (p < 0.05). Mean survival time was 15.8 and 11.8 months, and 3-year survival was 19% and 2%, respectively (p < 0.05). Survival depended on total tumor dose and total nodal dose. No significant influence of the tumor location on local control and importance of the size of dose per fraction and overall treatment time were found. The most common failure in both groups was persistent tumor. Mean recurrence time was 5 months in the study group and 8 months in the control. Present results suggest that the use of normobaric oxygen breathing prior to irradiation could increase effectiveness of conventional radiotherapy for advanced squamous cell carcinomas of head and neck.

Importance of tumor size and repopulation for radiocurability of skin cancer.

Data on 946 skin cancers treated by radiation were used to estimate the importance of repopulation. Six different treatment regimes were used from a single dose to 74 Gy given in 47 fractions. High local control of the small skin cancers (L 1 cm) was independent of dose fractionation. For large tumors, only 74 Gy in 47 fractions was the optimal treatment. Time factor analysis showed a steep increase in the NTD50 values between day 28 and 65 of treatment. This implies that tumor clonogen repopulation starts around 4 weeks of treatment. The present results showed a three-component dose response curve instead of the two-component curves which were found for head and neck and bladder cancer.

Hyperfractionated radiotherapy for Burkitt-type lymphoma. Radiobiological aspects.

A case of Burkitt-type lymphoma treated by accelerated hyperfractionated irradiation combined with the COP chemotherapy is presented. The effectiveness of treatment was evaluated on the basis of the growth curve and the radiobiological aspects are discussed. During the treatment, the initial volume doubling time (Td) of 15 days was shortened to 4.5 days suggesting accelerated tumor growth. From dose response curve estimated for clinical data taken from literature, an effDo of 1.37 Gy was calculated. Surviving fraction after 58 Gy given in the twice-a-day regimen (b. i. d.) was 10(-19) suggesting local tumor control. However, only partial remission was observed. This nonradical effect may likely result in accelerated repopulation of surviving tumor clonogenic cells. This suggests that such a fast growing tumor as Burkitt-type lymphoma (Tpot = 1 day) should be irradiated using three instead two fractions per day combined with adjuvant or concomitant chemotherapy with a short intervals between cycles.

Sequential combination of radio-chemotherapy (5-fluorouracil, cis-platinum and irradiation) in the management of locally advanced head and neck cancers.

Thirty-seven previously untreated patients with advanced, inoperable head and neck were treated with a sequential courses combining hypofractionated irradiation with chemotherapy (5-fluorouracil and cis-platinum). Each course was repeated every 4 weeks. Tumor response was evaluated and for 15 patients (41%) with a partial or complete regression after 3 radio-chemotherapy courses conventional radiotherapy was added. Eleven percent of all patients were in complete remission at the end of a treatment. This tumor response rate and the 50% rate of pain subside after first course for symptomatic patients contributed for a good palliative effect in the present study. However, the median survival of 7.2 months was considered unsatisfactory.

The ability of ethanolic extract of propolis (EEP) to protect mice against gamma irradiation.

Ethanolic extract of propolis (EEP) was tested as a protective agent against gamma irradiation in mice. The mice were exposed to 6 Gy gamma irradiation from a 60Co source, and were treated intraperitoneally with EEP, administered before and after their irradiation. While the non-treated mice expired within 12 weeks, the mice that received a series of EEP treatments survived the irradiation, and their leucocyte count as well as their spleens' plaque-forming activity returned to normal. It is suggested that an antioxidant and a free radical scavenger in the EEP are responsible for the radiation protective effect of the extract of this natural product.

Recombinant human TSH for the treatment of differentiated thyroid cancer metastatic to the spine.

The diagnostic use of recombinant human TSH (rhTSH) in follow- up of differentiated thyroid cancer (DTC) is already approved, however its application in (131)I therapy is still to be evaluated. We report results obtained in four patients with DTC metastatic to central skeleton, in whom 5 courses of rtTSH aided 131I therapy were administered.

[Cobalt teletherapy of patients with pharyngeal cancer]. / Telekobaltoterapia u chorych na raka gardla.

127 patients with pharyngeal cancer were irradiated in the years 1970-1979 with telecobalt-60 in total doses of 60-65 Gy. In the group with not advanced pharyngeal cancer 34% of patients survived during 5 years without any symptoms of neoplasm. In the group with advanced pharyngeal cancer and lymph nodes metastases the 5 years survival was within 15%. The 5-years survival depended mainly upon the extensiveness of the neoplasm. The therapeutic results were influenced also by the age of the patient; 35% were above 60 years of age and 17.3% died before the 5 years period without any symptoms of cancer.

[Efficiency evaluation of radiotherapy of recurrences after surgery in head and neck cancer]. / Ocena skutecznosci radioterapii wznów po leczeniu operacyjnym nowotworów regionu glowy i szyi.

An analysis of 200 consecutive patients with head and neck squamous cell cancer treated after surgery with radiation at the Centre of Oncology, Maria Sklodowska-Curie Memorial Institute in Gliwice was performed. At the beginning of radiotherapy recurrences were found in 67 (33.5%) patients. Recurrences were diagnosed at the primary site exclusively in 30 patients, in lymph nodes only in 21 patients, in both localizations in 14 patients, and in 2 patients in the tracheostomy. Conventional 60Co radiation treatment to the mean total dose of 62.5 Gy was applied. Three year disease-free survival probability was 22% for patients with recurrences comparing to 54% for patients with no relapse. In the group of patients with recurrences better prognosis was found for patients with preoperatively early stages, and with early recurrences, located in the primary tumour site, which completely responded to radiotherapy. High rate of recurrences after surgery for head and neck cancer and low probability of recurrence control with radiotherapy indicate the necessity of more careful qualification for surgical treatment.

[Prognostic factors in radiotherapy of supraglottic cancer]. / Czynniki prognostyczne w radioterapii raka górnego pietra krtani.

In 971 patients with squamous cell carcinoma of supraglottic larynx several clinical and physical prognostic factors were evaluated. There were 55% of patients with advanced primary tumours and 71% of patients with no regional neck metastases. All patients were irradiated radically using external megavoltage beam. The total dose was in range 60-70 Gy for 95% of patients. The 3-year local control rate and 3-year overall in whole group were 41% and 50% respectively. Clinical stage, haemoglobin level at the end of treatment, overall treatment time, sex and total dose were estimated as an independent and important prognostic factors for the outcome in radiotherapy of supraglottic larynx cancer.

[The usefulness of MIBI scintigraphy for postoperative monitoring of patients with thyroid cancer]. / Przydatnosc scyntygrafii MIBI w monitorowaniu pooperacyjnym chorych na zróznicowanego raka tarczycy.

Metoxyizobutyloizonitrile labelled with technetium 99mTc is a radio-pharmaceutical that was shown to accumulate in benign and cancerous thyroid tissue. As it can be applied without thyroid hormone withdrawal this gave a stimulus to the investigations on its usefulness in diagnostic and follow up procedures for thyroid cancer patients. The goal of this study is to evaluate the efficacy and benefit of 99mTc-MIBI whole body scintigrams in post surgery follow-up of patients with differentiated thyroid cancer. One hundred and twenty eight 99mTc MIBI scintigraphy were performed and evaluated. Sensitivity of MIBI scans was the highest for bone metastases--79%. Good results were also obtained for lymph node metastases (sensitivity--73%, specificity--90%). In case of lung metastases the sensitivity and specificity were 21% and 94% respectively. Sensitivity of detection of clinically apparent recurrent disease in thyroid bed was 70% and specificity of visualization 78%. Results of our study demonstrate that 99mTC-MIBI is valuable tool in follow up of thyroid cancer patients, but can not replace 131I scintygraphy.