Iodine-. 13 1 Therapy for Parotid Oncocytoma Shigeru Kosuda, Masazumi Ishikawa, Kohei Tamura, Miwako Mukai, Atsushi Kubo, and Shozo Hashimoto Department ofRadiology, Okura National Hospital and Keio University Hospital, Tokyo, Japan We presenta rarecaseofa patientwithcoexistingparotidoncocytomaandchronic thyroiditis who received two therapeutic doses of [131ljiodidefor a recurrent oncocytoma (oxyphilic granular cell adenoma), resulting in a definite reduction in tumor volume. We suggest thatradiolodinetherapyfora recurrentoncocytomais an effectiveformof tumor therapy. J Nucl Med 29: 1126—1129,1988 oxic thyroid adenomas represent the only benign SecondAdmission(February2, 1985) lesions ofthe thyroid which have been reported to have From3 mo priorto thesecondadmission,thepatienthad been treated with radioactive iodine therapy (1—4). complained of pain and swelling at the same site due to Parotid oncocytoma, or oxyphilic granular cell ade recurrence. Iodine-l23 (1231)scintigraphy revealed extrathy noma, is an uncommon and benign tumor. It is known roidal accumulation in the recurrent left parotid mass. No activity was seen in the region of the thyroid gland. The that the parotid oncocytomas, as well as Warthin's recurrent tumor did not discharge 1231on washout by lemon. tumors, take up both radioiodine and pertechnetate The patient refuseda second surgicalprocedure. because they originate from salivary duct epithelium (5—9). Iodine-131 Therapy We have encountered an unprecedented case of a Before we tried a new approach of radioiodine therapy for patient who received a therapeutic dose of radioiodine the recurrentparotid oncocytoma, we studied the tumor up for a recurrent,unresectableparotid oncocytoma which takeratioof 1231withdifferentpreparationswhichseemedto showed improvement following therapy. have an influence upon tumor retention time of radioiodine (Table 1). The counts in the tumor were compared with a standard ofthe administered dose; the percentage taken up by CASE REPORT the tumor, the tumor uptakeratio, was then calculated.From the results, we selected the preparationof both iodine-deple First Admission (April 21, 1984) tion regimen and administration of anticholinergic drug in A 69-yr-oldfemale wasadmitted becauseofa tendernodule orderto maximize tumor uptakeand prolongtumor retention at the angle of the left mandible. Six years before entry she of radioiodine. She actually received an iodine-depletion reg was told that she had chronic thyroiditis. Since then, she has imen beforeand afterthe administrationofa therapeuticdose been treated with Thyroid USP (dessicatedthyroid), 200 mg of iodine-l3 1 (‘@‘I)for 14 days. She was also administered daily, because of evidence of thyroid hypofunction. atropine sulphate, 2.4 mg a day, for 7 days afterthe adminis Physical examination showed a mobile tumor measuring tration of ‘@‘iThe effective half-lifeof ‘@‘iwas 1.2 days. The 3 x 2 cm in the tail of the left parotid gland. At surgery, the effective half-life was determined by plotting the cpm of the facialnervewasfirmlyinvolvedwiththe tumor and thus only tumor on a semilog graph paper, at 3 hr, 24 hr, and 7 days partial resection of the mass was possible. The pathology afterthe administrationof 131! report indicated that the tumor was an oxyphilic granular cell Wefirstaimedatdelivering‘@-400@iCipergramofestimated adenoma (oncocytoma). Figure 1 shows the histologic char weight of the tumor. Therefore, at first she was administered acteristics of the tumor. 71.3 mCi of[1311]sodiumiodide. The estimated absorbed dose in the tumor was 39 Gy which was calculated on the basis of the Quimby's formula (10,11) (Fig. 2, Table 2). A slight @ Received Sept. 21, 1987; revision accepted Feb. 8, 1988. reduction in the tumor volume was observed 1 mo after the Forreprintscontact ShigeruKosuda,MD, Dept.of Radiology, firstadministrationof ‘@‘I.Six months afterthe firsttreatment, Okura National Hospital, 2-10-1 Okura Setagaya-ku, Tokyo 157, we performed the second treatment with the dose of 249.7 Japan. mCi of 1311We believe that that dose is probably the maxi 1126 Kosuda,Ishikawa,Tamuraetal TheJournalof NuclearMedicine @a •@ @ ‘- ‘ \4'f. a a •@@•••a , @‘ •. a • • .@ . ;@,@4I. @ 4 • a ,. ••,@$ ,O )@/• @ • _• ‘@.•“:‘,•@aI%@ ••‘ @ S •b. @‘,,,• • ;. , # 2.@ ... @ ‘13' . a ,,1e • ‘,,,., ...•I:@ a.@ •@ø@:a.6. @ . af@ .% It.. .@a ‘.@. @ • I @. •• .. , •@• • . @ • ‘‘b. • a.a @•@‘ ‘@ ;‘@ S @ . • • •0 I @‘@i‘.. @ a @.s • • • @-h@ •S.. O. • j a @ @S•@ •D I • @, &w4@4d_.,@ • @ 0 • S. • •• l'j •@ I @ • @‘Ia@ .a I FSl.a. • •• @ $ - • b V @b•@ a ,@ @ •‘ 4' S • @. V FIGURE 1 @ * a •‘ • , a wA I a S a . • ‘#,‘@.‘a @ ,@ • ‘@ $.. .“1.@. .•• , a Histologicsection with hematoxylin f•P. :@4P••.••••9@@1:,i: •@at,•,5@@t@j/•i.lP!@$.. eosin stain shows large cells with @ .,e•• , .*.;@. @.. V. •‘ .@ eosinophilic granular cytoplasm @ 4 a •, ‘ ••, • ,. - . P4 •@ ••%• ‘.e. which is histologicallycharacteristic @ •1 ‘ • ‘ ‘ Is @:‘. ‘@ • a • -‘a• @ • • #a • @, @ql@a. picture in oncocytoma. The tumor @ 6$.*@ & • Ow a • , j@, . a. cells show monomorphic pattern @ - •.,‘•..a ?,!_@ ,@ •‘a p• •, •@ “p without malignantchanges. TABLE 1 tis, impairmentofgustation, epigastralgia,leukopenia, throm TumorUptakeof 123I(%) bocytopenia, and anemia. The lowest white blood cell and 3hr24hrNo platelet counts and lowest hemoglobin which were recorded, were 1,800/mm3, 48,000/mm3 and 9.6 g/lOO ml, respectively. administration5.22.2Administration With the exception ofa slightly dry mouth, all symptoms and .60.3daysIodine-depletionof potassium iodidefor 71 signsdisappearedwithin 1to 3 ma. regimen6.83.0Iodine-depletion 7.75.5tration regimen and adminis ofanticholinergicdrugs DISCUSSION Parotidoncocytoma is also called oxyphilic granular mum dose of LilJthat we can deliver at a time in safety. A cell adenoma. It is an uncommon, benign tumor, ac definite reduction in the tumor volume was observed 1 mo counting for no more than 1%of parotid tumors. The after the second treatment which relieved the patient of her rare malignant oncocytoma known as an oxyphilic pain (Fig. 3 A, B, C, D). The estimated absorbed dose of the second treatment was 87.8 Gy (Table 2). granular cell adenocarcinoma has been described in the No acute thyroiditis was encountered, nor did the patient salivary, thyroid, and adrenal gland (12,13). experiencea sorethroat or thyroidglandenlargement.Minor Although the mechanism of hyperconcentration of and temporaryuntowardresponseswere seen afterthe second radioiodine and pertechnetate in Warthin'stumor and treatment. She developed general malaise, anorexia, stomati oncocytoma is not known precisely, there is speculation FIGURE 2 Twenty-four hours after the admin istration of 71 .3 mCi of 1311there is j;@.. anextrathyroidalaccumulationof 1311 which is avidly trapped by the onco cytoma of the left parotid gland. No @ rT@ @1‘ activity is seen in the region of the LHT ERAL thyroid gland. Volume 29 a Number 6 •June 1988 1127 TABLE 2 the tumor demonstrated a number of malignant char Radiation Dose Calculation acteristics such as facial nerve involvement and severe ofadministereddoseFraction pain. The patient declined to undergo re-operation despite our repeated recommendation. The 23!scintig inEffectiveDoseVolumetumor raphy revealed a “hotspot―corresponding to the tumor @(mCi)(cm3)hr(days)GyFirst at 241311 and no accumulation of 23!in the region ofthe thyroid gland on account of hypothyroidism. In addition, the treatment .3 .20 patient fervently wanted medical treatment rather than Secondtreatmen71t 249.712.311.32.90 1.471 1.3539.087.8 surgical excision, so that we decided to try a new approach of radioiodine therapy for this recurrent tu mor. The patient required no ablation ofthe thyroid gland that both radioiodine and pertechnetate are trapped by because she already had hypothyroidism from chronic the tumor cells because they originate from salivary thyroiditis treated with thyroid hormone for -@-6yr. The duct epitheium. The tracers cannot be secreted because failure ofthyroid uptake may be a consequence of both of the lack of communication between the tumor cells thyroiditis and administration of thyroid replacement. and the duct systems. The oncocytoma avidly took up radioiodine, but its Surgical excision is the treatment of choice for this retention time in the tumor was short and the tumor tumor. With resection, prognosis is excellent. However, uptake of radioiodine was low, compared with that of in the case where the tumor cannot be totally removed, toxic thyroid adenoma (1—4).The relatively short reten recurrenceis not uncommon. In our case, although the tion time by the tumor is presumably due to the fact pathology report indicated a benign lesion, clinically, that while it shows ‘@‘Itrapping, there is no organifica FIGURE 3 A: The film taken just before the first treatment of 1311shows a protruding tumor in the region of the left parotid gland. B: The filmtaken I mo after the second treatment of 1311shows that the tumor definitely became smaller in size. C: The TCT scan taken before the first treatment of ‘@‘lshows a solid mass with a homogeneous density in the lower part of the left parotid gland. D: The TCT scan taken 3 wk after the second treatment shows the reduction of the tumor volume. The tumor volume was reduced from 12.3 cm@to 6.9 cm@(44% reduction in volume). 1128 Kosuda,lshikawa,Tamuraetal The Journal of Nuclear Medicine tion as is the case with thyroid adenomas which are REFERENCES able to synthesize thyroid hormones. We preparedour patient by means ofboth an iodine 1.