Ryochi Ishibashi

The modified tangential irradiation technique for breast cancer: how to cover the entire axillary region

PURPOSE The two-portal tangential irradiation technique has usually been applied to breast cancer patients after breast-conserving surgery (1, 2) and is expected to irradiate the axillary lymph node region to some extent (3). We investigated the range of the axillary region covered by this technique and tried to devise an optimal irradiation technique (modified tangential irradiation) that would cover the axillary lymph node region properly. METHODS AND MATERIALS We checked the status of the surgical clips left at axillary lymph node sites by reviewing the simulator films and planning CT scans of 63 patients who underwent axillary dissection of level I, I-II, or I-III lymph nodes. Then we created the modified tangential irradiation technique and applied this technique to 16 patients and checked the irradiation volume by CT scans. RESULTS We found that all of the surgical clips on lateral-view simulator films were on the ventral side of the dorsal edge line of the humeral head. All but one clip were on the caudal side of the caudal edge line of the humeral head. Accordingly, it is possible to irradiate almost all axillary lymph node regions by setting the dorsal edge of the irradiation field on lateral-view simulator films at the dorsal edge of the humeral head and the cranial edge at the caudal edge of the humeral head. CONCLUSIONS All breast tissue and the entire axillary lymph node region can be covered by the modified tangential irradiation technique without increasing the lung volume irradiated.

Comparison of cationic myocardial perfusion agents: Characteristics of accumulation in cultured smooth muscle cells

The uptake and washout kinetics of two cationic lipophilic99mTc-labeled myocardial perfusion agents,99mTc-methoxyisobutylisonitrile (99mTc-MIBI) and99mTc-l,2-bis[bis-(2-ethoxyethyl)-phosphino]ethane (99mTc-Tetrofosmin), were studied in cultured smooth muscle cells and compared to the conventional myocardial perfusion agent,201Tl. Both99mTc-MIBI and99mTc-Tetrofosmin had a 4-fold greater uptake than201Tl, and they were washed out of cells through similar kinetics which had slower rates than201T1. Incubation with metabolism inhibitors had a modest influence on the uptake of these two99mTc-labeled agents, although their extent and inhibited sites were slightly different. Ion transport inhibitors did not affect the uptake of99mTc-MIBI, although the99mTc-Tetrofosmin uptake was slightly inhibited when the Ca2+ channel was blocked. Our studies indicate that99mTc-MIBI and99mTc-Tetrofosmin were taken up by smooth muscle cells in similar pharmacokinetic patterns, but their accumulation reflected a different meaning for cell viability.

Radiotherapy after breast-conserving surgery without axillary disection for T1-2, no breast cancer patients: comparison of the tangential and three-field irradiation technique

150 patients, HER2/neu epxression was not associated with estrogen receptor (ER) or progesterone receptor (PR) status (p 0.98 and 0.62 respectively). HER2/neu status did not significantly impact either the incidence of local recurrence (LC)(p 0.13) or the type of first failure (p 1.0). Kaplan-Meier curves for overall survival (OS), cause-specific survival (CSS) and freedom from distant metastases (FFDM) did not show a significant difference in outcome between HER2/neu positive and negative patient groups (p 0.86, 0.42, and 0.63 respectively).