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Update on management of differentiated thyroid carcinoma
248 UPDATE TIIYROID
ON MANAGEMENT CARCINOMA
lndcr J. Chopra. M.D. UCLA Center for Ileald~ Sciences.
OF
HYPERTHERMIA IN CLINICAL ONCOLOGY G. Arcangeli, G. Giovinazzo, Centro Oncologic0 Ospedale S. Maria Goretti, Latina, Italy.
DIFFERENTIATED
Los Angeles.
California,
U.S.A.
We shall review available da1a on lhc followitlg issues concerning I) Is lolaI manaccmen1 of well diffcrentia1ed 1hvroid cancer: thyro&&lomy a mom appmprialc lrcalmenl of 1hymid cancer than h&c~omy? 2) Should radioiodine ( ‘311) bc used bo1h for ablation of lhyroid rcmnanls after 1hyroidcctomy for primary disease and the ~rca~tnen~ of rhyroid melas~ases? 3) What doses of I311 shmlld be employed for 1rea1men1 of pa1ienrs wi1h rhyroid cancer? 4) What arc lhe side effcc1s of 1rcatmcn1 wi1h ‘3’1 for 1hyroid cancer? and S) Whal is 1hc significance of elcva1ed serum 1hyroglobulin lcvcls in 1he absence of visible mcras1ases? How should 1hcsc pa1ien1.r be treated? In our insrilution. we prefer lolaI Ihyroidecromy over lobeclomy in lhc 1rcn1menl of thyroid cancer. Following surgery. pnticms undergo 1hyroid and 1o1al body scanning IO identify thyroid remnants and for melnslascs. If ~hc. la11er arc found. patienls arc tren1cd by radionbln1ion with 1311 (-49.9 mCi). Patiems arc followed -six momhs IO one year Ia1cr wi1h anolher 1o1al body scan with 1311 for me1as1ascs and by serum thyroglobulin. If thyroid remnam and/or me1aslnses arc dcmonslra1ed. palients arc 1rcatcd wirh ‘3’1 (-150 mCi). Similar lrealmenl is given in pa1icms who dcmowrale eleva1ed serum lhyroglobulin levels even though no mctas1ascs arc visible following diagnostic scanoing wi1h 2-10 mCi of 1311. Studies have shown that pulmonary. nodal and/or skcle1al me1as1asis may be visible 4-S days following 1rcatmco1 (-150-200 mCi) ra1her 1han diagnosric (
For the practicing oncologists, the interest in hyperthermia centers around three aspects. First of all, even mildly elevated temperatures by themselves are cytotoxic to cells. Secondly, hyperthermia increases the rate of inactivation by X-irradiation. Thirdly, the cell-killing effect of many anticancer drugs is largely enhanced at elevated temperatures. Hyperthermia has two types of interactions with radiation. A radiosensitizing effect, which is most prominent with simultaneous application of the two modalities, and a direct cytotoxic effect which selectively destroys nutritionally deprived and chronically hypoxic cells! normally found in large tumors. The interactlon between heat and drugs is more complex. Drugs whose mode of action is primarily chemical (as opposed to enzyme-mediated) such as cisplatinum, nitrosoureas and other alkylating agents show an increased rate of the critical chemical reaction and of cell killing that are consistent with the Arrhenius theory. Other drugs such as Adriamycin and Bleomicyn and Doxorubicin, however, show an appreciable increase of cytotoxicity only when the target temperature elevation exceeds a threshold of 43'12. Current clinical experience has shown that heating of tumors superficial (e.g. breast, neck nodes and malignant melanoma) may be an important modality in combination with radiotherapy or chemotherapy. In order to evaluate the role of adjuvant hyperthermia in the primary treatment of advanced superficial several randomized clinical trials have tumors, been activated in Europe, U.S. and Japan. The clinical results so far obtained strongly indicate a place for hyperthermia in general radiotherapy, but the final conclusion must await the outcome of controlled clinical trials.
ON MANAGEMENT CARCINOMA
lndcr J. Chopra. M.D. UCLA Center for Ileald~ Sciences.
OF
HYPERTHERMIA IN CLINICAL ONCOLOGY G. Arcangeli, G. Giovinazzo, Centro Oncologic0 Ospedale S. Maria Goretti, Latina, Italy.
DIFFERENTIATED
Los Angeles.
California,
U.S.A.
We shall review available da1a on lhc followitlg issues concerning I) Is lolaI manaccmen1 of well diffcrentia1ed 1hvroid cancer: thyro&&lomy a mom appmprialc lrcalmenl of 1hymid cancer than h&c~omy? 2) Should radioiodine ( ‘311) bc used bo1h for ablation of lhyroid rcmnanls after 1hyroidcctomy for primary disease and the ~rca~tnen~ of rhyroid melas~ases? 3) What doses of I311 shmlld be employed for 1rea1men1 of pa1ienrs wi1h rhyroid cancer? 4) What arc lhe side effcc1s of 1rcatmcn1 wi1h ‘3’1 for 1hyroid cancer? and S) Whal is 1hc significance of elcva1ed serum 1hyroglobulin lcvcls in 1he absence of visible mcras1ases? How should 1hcsc pa1ien1.r be treated? In our insrilution. we prefer lolaI Ihyroidecromy over lobeclomy in lhc 1rcn1menl of thyroid cancer. Following surgery. pnticms undergo 1hyroid and 1o1al body scanning IO identify thyroid remnants and for melnslascs. If ~hc. la11er arc found. patienls arc tren1cd by radionbln1ion with 1311 (-49.9 mCi). Patiems arc followed -six momhs IO one year Ia1cr wi1h anolher 1o1al body scan with 1311 for me1as1ascs and by serum thyroglobulin. If thyroid remnam and/or me1aslnses arc dcmonslra1ed. palients arc 1rcatcd wirh ‘3’1 (-150 mCi). Similar lrealmenl is given in pa1icms who dcmowrale eleva1ed serum lhyroglobulin levels even though no mctas1ascs arc visible following diagnostic scanoing wi1h 2-10 mCi of 1311. Studies have shown that pulmonary. nodal and/or skcle1al me1as1asis may be visible 4-S days following 1rcatmco1 (-150-200 mCi) ra1her 1han diagnosric (
For the practicing oncologists, the interest in hyperthermia centers around three aspects. First of all, even mildly elevated temperatures by themselves are cytotoxic to cells. Secondly, hyperthermia increases the rate of inactivation by X-irradiation. Thirdly, the cell-killing effect of many anticancer drugs is largely enhanced at elevated temperatures. Hyperthermia has two types of interactions with radiation. A radiosensitizing effect, which is most prominent with simultaneous application of the two modalities, and a direct cytotoxic effect which selectively destroys nutritionally deprived and chronically hypoxic cells! normally found in large tumors. The interactlon between heat and drugs is more complex. Drugs whose mode of action is primarily chemical (as opposed to enzyme-mediated) such as cisplatinum, nitrosoureas and other alkylating agents show an increased rate of the critical chemical reaction and of cell killing that are consistent with the Arrhenius theory. Other drugs such as Adriamycin and Bleomicyn and Doxorubicin, however, show an appreciable increase of cytotoxicity only when the target temperature elevation exceeds a threshold of 43'12. Current clinical experience has shown that heating of tumors superficial (e.g. breast, neck nodes and malignant melanoma) may be an important modality in combination with radiotherapy or chemotherapy. In order to evaluate the role of adjuvant hyperthermia in the primary treatment of advanced superficial several randomized clinical trials have tumors, been activated in Europe, U.S. and Japan. The clinical results so far obtained strongly indicate a place for hyperthermia in general radiotherapy, but the final conclusion must await the outcome of controlled clinical trials.