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S U R G I C A L R E S E A R C H

Vol. IV, No. II Nouember, 1964

Systemic Thiosulfate Protection during Fractionated Regional Nitrogen Mustard

WALTER LAWRENCE, J R . , M.D., MANUEL S. TAYAO, M.D., DHAN RAJ MAItAJAN, M.B., B.S. , ROY PAGE, M.D., DANIEL G. MILLER, M.D., AND P A U L C L A P P , M.D., Sloan. Kettering Institute for Cancer R esearcb

The purpose of regional cancer chemotherapy is primarily that of achieving high local concen- tration of effective agents with minimal systemic toxicity. Although isolated regional pedusion can achieve this end to the point of |ocally toxic concentrat ions with some agents , the total dose one can administer is limited by the s ingle or infrequent, relatively short exposures inherent in this method. Protracted intra-arterial infusion of antimetaboli tes achieves a longer contact be- tween effect ive agent and tumor t issue, but a s ignif icant regional concentration advantage is achieved only in infusion systems that ut i l ize smaller arteries.

The use of a neutral izing agent to counteract the systemic effect from active agent in the venous efflux of the region treated would not only s i m p l i f y therapy, but would a lso aIlow fractionated, and ultimately greater, dosage. Such an approach seems feasible for fractionated intra-arterial nitrogen mustard therapy s ince i t has been known for some time that sodium thio- sulfate is a specif ic antagonis t of nitrogen mustard and its transformation products, s A major concern with such a system, however, is that the t i m i n g and s i t e of administration of these agents should be so arranged that the regional effect is not neutral ized or diminished to such a degree that no advantage is produced

From the Department of Surgery, Memorial Hospi-

by the combination. The purpose o f this report is to describe our laboratory and clinical efforts to es tabl ish an effective regional r0 u t l n e for uti l izing the n i t r o g e n mustard- thiosulfate combination.

The effect iveness of sodium thiosulfate for

and Pearee; a In view of this observation,several at tempts were ma effect of sodium I

v L

nitrogen mustard with such a system, and Fos t e r and his co-workers 4 demonstrated s y s t e m i c pro- tec ti on with into the her we have no regional effect was achieved, Hat iboglu and co-workers s desc r ibed local effects from nitro- gen ystemic pretreatment with hether th is de gree of local c h a n g e could h a v e b e e n ~ a c h i e v e d a t a lower, sys temical ly nontoxic dosage of nitrogen mustard, without sodium thiosulfate, cannot be determined. A clinical of nitrogen mustard by Owens and Hatib did suggest some systemic p r o t e c t i o n by thiosulfate, but the dosage employed in these carotid artery infu-

York, New York.

Presented at the 37th Annual Meeting of the Hal- sted Society, B os t on, Massachusetts, October 1 8, 1963.

Submitted for publication February 27, 1964.

the degree of limitation st i l l unclear. Can a regiol age be a c h i e v e d by a n i t r thiosuifate combination?

effect is ic advant-

o g e n mustard-

483

484 LAWll ENCE, ET AL.

Since the action of the nitrogen mustard in the regional area should be diminished by any thiosulfate present there, it would seem ideal to initiate the administration of s o d i u m thio- sulfate into the venous return at the same time that the nitrogen mustard begins toappear tttgre. In addition, the rate of administration of nitrogen mustard should be adjusted so as to allow com- plete c i r c u l a t i o n of this agent through the

r e g i o n a l area before the sodium thiosulfate appears in its arterial inflow. At the same time, however, the venous outflow of nitrogen mustard from the regional area would mix with "venous blood of high thiosulfate concentration by virtue of the choice of si te for sodium thiosulfate in- ject ion. Since circulation time in normal d o ~ (determined by fluorescein) is in the range of 9 to 16 seconds (Wang et al. ~ 1), these experi- ments were planned on the supposition that completion oftheintra-ar ter ial injection of nitro- gen m u s t a r d within 10 seconds would allow signif icant regional contact before appearance of sodium thiosulfate in the arterial inflow. To allow a persistent high regional venous concen- tration of thiosulfate initially and for a reason- able period after the nitrogen mustard injection, th~ s o d i u m thiosulfate injection was b e g u n simultaneously with m u s t a r d injection and protracted over a period of one minute. Since clearance of thiosulfate is determined by the glomerular filtration rate, a relatively small fraction of the a&ninistered thiosulfate would actually be cleared during the time that nitrogen mustard was s t i l l in circulation, but it would be completely c l e a r e d long before the next administration of agent, if t r e a t m e n t were given daily.

Admittedly, t h e significance of the details of the p r o t o c o l for injections could not be determined without extensive study of many variations. It was thought, however, that results obtained from the procedure as outlined should allow the maximum opportunity to demonstrate a local advantage for nitrogen mustard-thiosulfate combinations if, i n d e e d , such a therapeutic advantage did exist.

METIIODS

Laboratory Studies

For these studies the femoral artery of the dog was chosen as the site of intra-arterial administration of nitrogen mustard and evalua- tion of the regional drug effect was determined by observations of the treated limb.

J S R - Vo l . IV , No . I1 - N o v e m b e r , 1964

i F:/g. I. Diagram of chamber utilized for deter..

mining changes in limb volume.

Determination of Limb Volume

Edema and limb enlargement does occur as a local manifestation of nitrogen mustard, and this was estimated by limb volume measurement. q~nis was determined by volume displacement of water in a large glass cylinder filled completely prior to immersion of the well clipped hind limb to a preselected- l e v e l (Fig. 1). The depth of immersion of the limb was established by a pre- determined bony prominence, and skin sutures served as an additional guide. Both hind limbs were measured at predetermined intervals and the volume changes were expressed as a ratio (treated limb volume/control limb volume).

Surgical Preparation of the Dog

Under general anesthesia and aseptic tech- nique, laparotomy w a s performed and the left common i liac artery mobilized. A large b~nch of this artery was always present just proximal to the inguinal ligament and t h i s branch was isolated and ligated. A small polyvinyl catheter was introduced retrograde into a lumbar artery and threaded distally into the lumbar aorta and left lilac artery so that the tip of the catheter would lie just above the inguinal ligament (Fig. 2). A vascular clamp across the right lilac and middle sacral arteries facilitated this introduc- tion, It was also found necessary to employ a wire s tyle t in this small catheter during intro- duction. Inaccurate placement due to kinks in

J S R - VoL IV, No. I I - N o v e m b e r , 1964 NITROGEN MUSTARD T H E R A P Y ,t85

f i l led with h e p a r i n solut ion when not in use . The e x t e r n a l port ions of these c a t h e t e r a s s e m b l i e s were pro tec ted by a circumferen- tial d ress ing ,

Fig. 2. Diagram e l operative procedure /or ia- s ta | l lng arterial an,'] venous catheters for |raetionated intra-arterial n i t r o g e n mustard therapy of the dog hind limb,

the ca the te r t ip occas iona l ly occurred, but this was d e t e c t e d by means of in jec t ing f tuorescein (10%) into the ca the te r at the completion of the operation and observ ing tlle area of f luorescence with an ul traviolet light (Fig. 3). A venous p o l y v i n y l c a t h e t e r was inser ted into a right lumbar vein and advanced several cent imeters proximally in the lumbar vena cave for later adminis t ra t ion of the sodium th iosul fa te . After secur ing both ca the te r s with su tu res , t h e y w e r e brought out dorsa l ly through tiny s tab wounds , s ecu red with skia s u t u r e s , s topco'cks were a t tached , and the ca the te r s y s t e m s were kept

Drug Administration

The s tandard course of f ract ionated therapy with t h i s preparat ion cons i s t ed of five equal daily d o s e s of nitrogen mustard solut ion, each dose in jec ted ar ter ia l ly with an immediate sa l ine flush in a total time of 8 to 10 seconds . Solu- t ions of n i t r o g e n mustard w e r e prepared by d i s so lv ing the c o n t e n t s of a 10 rag. vial of Mustargen hydrochlor ide in 5 cc, i so tonic sa l ine . The solut ion was prepared two to three minutes prior to administrat ion. The first dose was ad- minis tered on the day of surgery after determining proper datheter posi t ion with a f luorescein in- j ec t ion . The f luorescein inject ion was repeated on the last day of therapy to e s t a b l i s h mainte- nance of proper ca the te r pos i t ion during the entire treatment course , If the preparat ion did not demons t ra te pe r s i s t en t accura te posi t ion of the ca the ter during the cour se of f rac t ionated therapy and a t au topsy , the dog was el iminated from the s tudy.

The ~odium th iosul fa te solut ion (100 m g , / c c . ) was adminis te red through the v e n a c a v a ca the te r descr ibed. The injection was begun prior to or s imul taneous ly with the intra-arterial nitrogen mustard inject ion and the total dose adminis- tered over a one minute period.

of fractiohated ~ntra-arterial nitrogen mustard therapy. ~cou rse

486 LAWRENCE, ET AL.

E~ ALUA1 ION

Volumes of both hind limbs were determined on the third or fourth day, one week, and two weeks after initiaOon of therapy. White blood cell counts were determined daily. An attempt also was made to evaluate the local changes in the limb by obtaining skin, muscle and femur bone ma~ow biopsies from both hind limbs at the time of autopsy two weeks edter treatment (or sooner if early death occurred). The degree of e d e m a or necrosis observed histologically in the soft t i ssues only confirmed the gross observations to be d e s c t b e d .

RESULTS

Thirty-one dogs completed a fractionated course of nitrogen mustard ~herapy in a ~atis- factory fashion. The following groups were evaluated: (I) intra.-arterial nitrogen mustard, 1.25 mg./kg, t o ta l dose g i v e n over a 5 day period without addition of sodium thiosulfate p r o t e c t i o n - 6 dogs; ([I) intra-arterial nitrogen mustard carried out as in Group I but, in addi- tion, simultaneo~s intravenous sodium thiosul- fate injections (dosage of s o d i u m thiosulfate was 20t3 rag. for each 1 rag. of nitrogen mus ta rd ) - 8 d o g s ; ~(III) intra-arterial nitrogen mustard as in Group I with sodium thiosulfa~e pretreaUment 5 minutes before the nitrogen mustard injection (thiosulfate dosage same a~ in Group I I ) - 1 0 dogs; (IV) intra-arter~al nitrogen mustard, total dose 1.0 mg./kg, g~ven o v e r a 5 day period (no s ~ i u m thiosal fate p r o t e c t i o n - 7 d o ~ .

Group I. (Fractionated intra-arLeria| nitrogen mustard without sodimn thiosulfate). Th;.s dos- age ( I . ~ m g . / k g . ) w a s poorly tolerated. Of the original 6 dogs, 2 died in less than one week and only 2 lived more than two weeks after" therapy was init iated. Systemic toxicity as man- ifested by WBC depression below four thousand bccu_rred in all dogs (Fig. 4.) Because of the high mortality at this dosage, data concerning volume changes were incomplete, but the pat- tern of these data is s h o w n graphically in Figure 5.

Group I!. ( F r a c t i o n a t e d intra-arterial nitrogen mustard therapy with simultaneous sodium thiosuifate administration). There were 8 dogs satisfying all criteria for inclusion in this group.

J S R - Vo l . IV , No,. I1 -~ N o v e m b e r , 1964

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White blood cell counts in Group I (I.A. Fig. 4, nitrogen mustard, 0.25 mg./kg, daily for five days). Leukopenia occurred in all dogs.

Systemic protection was achieved by the simultaneous sodium thiosulfate injections as evidenced by abs.enee ~f leukopenia in all 8 dogs i , thi~ group. Ald~o, gl5 changes in WBC did occur (see Fig. 6), particularly a lcukocy- tosis during the early part of the fractionated treatment, none of the animals had white blood cell counts below four thousand at any time during course. This was in marked contrast to the hematologic 'course in Group I. (Fig. 4).

Volume changes in the treated limbs were quite variable in degree, as can be seen in Fig- ure 7, but there was no question that a signifi- cant local effect was achieved. Considering the individual vm'iability in volume observed in this group and G r o u p I, it appeared as if the local effects were r e a s o n a b l y similar to those achieved w i t h o u t the simultaneous sodium thiosulfate adminislzation.

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Fig. 5. Ahcration in limb volumes of dogs in Group 1 (1.A. nitrogen mustard, 0.25 mg./kg, daily [or {ire days).

J S R - Vol. IV, No. I I - N o v e m b e r , 1964

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~'fg. 6. t?hite blood cel l counts in Group 11 (I,A. nitrogen mustard,0.25 mg./kg, daily for five days and simultaneous 1.V. sodium thlosulfate, 200:1). None of these dogs develol~d leukopenia.

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Fig. 7. Alteration in limb volume of dogs in Group I! (LA. nitrogen mustard, 0.25 mg./kg, daily for f ive days, and simu]taneoua I.V. sodium thlosul- fate, 200:1).

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Fig. 8. White blood cell counts inGrouplll (I.A. nitrogen mustard, 0.25 mg./kg, daily for five days, five minutes after intravenous sodium thiosulfatc. 200:1). Four of the 10 dogs died as a result of sys- temic toxicity.

NITROGEN MUSTARD TI IERAPY

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Fi 9. 9. Alteration in limb v o l u m e of dogs in Group III (!.S. nitrogen mustard, 0.25 mg./kg, daily for five days, five minutes ~ intravenous sodium thiosulfate, 200:1).

Group !!1. (Frac t iona ted intra-arterial nitro- gen mustard therapy with intravenous sodium th iosu l fa te f ive minutes p r i o r to nitrogen mustard injection). Of the 10 dogs sa t i s fy ing cr i ter ia for inclusion in th is group, 2 dogs died in l e s s than one week (5 d a y s ) a n d 2 d ied at s e y e n and eight days a f t e r ini t iat ion of ther- apy, all of sy s t emic toxic i ty . The hematologic course of the s ix dogs that survived was sim- ilar to that observed in Group II (Fig. 8). None of these surviving animals has leukopenia(WBC 4.0 thousand) during the course of the exper iment .

Volume changes in t reated l imbs were qui te s imilar to those observed in Group II, al though the mean volume ratio w a s somewha t smal le r af ter two weeks in the surviv ing animals of Group III (Fig. 9). Again , the var iabi l i ty oh-

sign i fi can t di fferen c e be twee n • e s e two group s .

Group IV. As a means of determining local advantage from the nitrogen mus ta rd- th iosu l fa te sys t em, this group of dogs was given a lower dosage of nitrogen mustard ( f r ac t i ona t ed )wi th - out the benef i t of sodium th iosu l fa te protec t ion. At a total d o s e of 1 mg. /kg, intra-arterial ly, no s u b s e q u e n t leukopenia was noted in this s e r i e s of 7 dogs (Fig. 10). The local e f f e c t s obse rved , by virtue of the var iabi l i ty of volume change among individual animals in th is s e r i e s , showed no important d i f ference from t h o s e volumes obtained with the dosage ut i l ized in Groups 1

488 LAIM1LNCE, ET. AL.

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JSR - I/ol. IV, No. II - November, 1964

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Fig. ]tO, XNhite blood cell counts in Group IV (I.A. nitrogen mustard, 0.20 mg./kg, daily for five days). None of these dogs developed significant leukopenia.

Fig. lI. Alteration in limb volume of dogs in Group IV (I.A. nitrogen mustard, 0.20 mg./kg, daily for five days).

and I1 (Fig. l l ) . It would appear that sys temic effect , measured by the presence or absence of leukopenia, can be modified b y a m i n i n t a l change in dosage, and the degree of "protec- t i o n " produced by sodium thiosulfate adminis- tration can be matched by sl ightly lowering nitrogen mustard dosage in dogs not receiving the protective agent without appreciably reduc- ing local drug effect (Table 1).

p~ t rea tment with this agent. Ahhough the local chetnodlerapeutic effect of the nitrogen mustard did not appear to be significantly reduced when sodium thiosulfate was added to the treatment in this manner, a minimal reduction in nitrogen mustard dosage could achieve a similar local effect without systemic toxicity.

C L I N I C A L STUDIES

Summary of Rcsu l | s of I raetmnatcd Nitrogen Muslard Sludies in Dogs

These experiments demonstrated the protec- tive a c t i o n of sodium t h i o s u l f a t e a g a i n s t the systemic toxicity (leukopenia) of high fraction- ated doses of nitrogen mustard. Th i s protect ive action would appear to beachieved most reliably with s imultaneous administration rather than by

Leukopenic dosages of nitrogen mustard have been administered intra-arterially in some re- gional areas in man without pronounced local toxicity. Since variability in sys temic sensi t iv- ity of individual pat ients to the same dosage of nitrogen mustaM is much more likely in man than in heahhy dogs, each pat ient had to serve as his own control for courses of nitrogen mus- t a~ therapy, wid~ and without protect ive agent.

Table 1.

Zontrol

5imuhaneous I'.S. (200:1) Pretreatment F.S. (200:1) Zontrol

Summary of Data Regarding Limb Volume Increase and Systemic Toxici ty in Dogs Given a 5 Day Fractionated Course o/ Intra-arterial (tliac) Nitroge,~ Mustard

(with and without Intravenous Sodium Tbiosul[ate)

HN2 Dosage

1.25 mg./kg. (0.25 × 5) 1.25 mg./kg. (0.25 × S) 1.25 mg./kg. (0.25 x 5) 1.0 mg./kg. (0.20 x 5)

No. Dogs

6

8

10

7

No. with Systemic Tox ie ity Survival

. . . . Local Change --' Mean

7 days

Leg Volume Ratio (Rx vs. Control)

14 days

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8 (1 wk,) 6 (2 wks.) 7

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]SR - Vol. IV, No. 11 - NotJember, 1964

Whichever course were given first would have some advantage in regard to the sys temic toler- ance , s ince peripheral white blood cell counts or marrow smears are insuff ic ient means for determining the complete return of marrow func- tion af ter a first course of chemotherapy. For this reason, the protocol for patient s tud ies wM as follows: ( 1 ) a n init ial fractionated nitro- gen mustard course ( i n t r a - a r t e r i a l )0 .12 rag./ kg. × 5. The arterial in jec t ions of n i t r o g e n mustard were all given in a 10 second interval. (2) After recovery, a second course was given that was ident ical to the first course except for the addition of a s imultaneous intraveneous sodium dliosulfate i n j e c t i o n , protracted over a period of one m i n u t e . The dose of sodium thiosulfate employed was 400 rag. for each 1 rag. of nitrogen mustard.

Observat ions During Intra-artcrial Treatment of Extremity Neoplasms

Case l. This was a 60 yea r old woman with metas ta t ic melanoma in the left thigh proven by biopsy. The primary lesion was excised 30 months before from the dorsum of the foot. She had no evidence on physical examination ofother meta- s ta t ic d isease , but x-ray of the ches t showed pul- monary me tas t a ses . A brachial artery ca the te r was inserted into the left external il iac ar tery under fluoroscopy and the treatment w a s initi- a t ed .The re was a 40 to 50 per cent redaction in s ize of the nodules as determined by palpation af ter fl~e first coume ofth erapy, a slight dec rease in the s ize of the pulmonary metas tases , and a mild leukopenia (Fig. 12). After the peripheral white blood cell count had returned to normal, the second course of therapy was carried out with simultaneous sodium thiosulfate inject ions (400=l) into the opposite il iac vein via a saphe- nous vein c a t h e t e r . There w a s no further observable change in the local les ions or the pulmonary me ta s t a se s after this second course . The onset of the leukopenia with this course was earlier and i ts duration longer than with the first course .

NITROGEN MUSTARD TIIERAPY ,t89

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Fig. 12. Course of white blood cell counts in Case No. 1 (S.A.)during fraetionsted intra~arterial

to protect the patient from leukopenia during the second course of therapy,

pal l iat ive reexcis ion rather than amputation. In less than two months local recurrence was again noted (Fig. 13),and a left external i l iac ca the te r was inserted via the brachial artery as in Case 1 (Fig. 14). The leukopenia induced by this first course of fractionated nitrogen mast/lrd therapy is shown in Fig'ar e.15. There was dimi- nution in the palpable local d i sease and after recovery of the ~PBC a second course of frac- t ionated nitrogen mustard therapy was given with s imultaneous sodium thiosulfate in ject ions into the l i lac vein. Leukopenia was again induced after this therapy, and it was ourcl in ica l impres- sion that further regression in the nodules did occur af ter this course. At completion o f treat- ment. there was one hard residual nodule that

Case 2. This 68 yea r old man had ex tens ive soft t i ssue resec t ion of an ext raosseous osteo- gen icsa rcoma of the sof t t i s sues in the le f tpos- terior thigh on October 30, 1962. Local r e c u r ~ n c e occurred promptly ~ d the presence of pulmonary metas tases led t h e pa t i en t ' s surgeon to attempt

Fig* 13, Case 2 (S.W,) before (left) and after (right) fractionated intraarterial nitrogen mustard therapy for recurrent~ extra0sseous osteogenic sat* coma of the posteri metastases and major amputation*

490 LAWRENCE, ET AL.

F] 9, 14. Arteriogram through Cournand catheter placed in left common iliac artery via the brachial artery route (Case 2).

felt ca lc i f ied on palpat ion (Fig. 13). Aspirat ion biopsy of d~e nodule did not reveal neoplasm. Two months af ter complet ion of therapy, there was c l in ica l ev idence of some regrowth of the lesion in the regionally treated area

Ana lys i s of the Role of ~ d i u m Thiosu i fa te in C a s e s 1 and 2

Although s imuhaneous sodium thiosulfa te administration conce ivab ly may have g ivensome degree of protect ion d u r i n g the second course in each of these pa t i en t s , if we a s sume a more vulnerable marrow, the degree of protect ion must be considered i n s i ~ i f i c a n t . The dif f icul ty in ach iev ing protect ion with this sys tem is empha- s i zed by obse rva t ions from a n o t h e r pat ient treated in a somewhat different manner.

C a s e 3. S.I[. had a large epidermoid carcinoma present for two or three months in the pos ter ior tJfigh. It had d e v e l o p e d at the s i te of many chronic inflammatory s i nu s t racts in this area secondary to granuloma inguinale. I lemipelvec-

J S R - VoL IV, No. 11 - November, 1964

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Fig. 15. Course of white blood cell counts in Case 2 (S.W.) during fractlouated intra-arterial nitro- gen mustard therapy for recurrent sarcoma. Simulta- neous intravenous sodium thiosulfate failed to protect the patient from leukopenia daring the second course of therapy.

tomy was recommended for this large neoplasm, but the pat ient re fused this surgery .Therefore , a Cournand ca the ter was p laced in the external iliac artery, and a cour se of fract ionated intra- arterial nitrogen mustard therapy was given over a 6 day p e r i o d . Sodium thiosul fa te (200rag. th iosul fa te for each 1 rag. nitrogen musta rd)was given s imul taneous ly with each nitrogen mustard injection ¢.10 s e c o n d s per injection) in much the same fashion a s in c a s e s 1 and 2. In this pat ient , however, sodium th iosul fa te was admin- i s t e r e d with the init ial c o u r s e of nitrogen mustard and bone marrow aspira t ion before treatment was cons idered normal. Total dose of nitrogen mustard was 0 .6 mg. /kg .

A striking regress ion in the les ion occurred (t?ig. 16), b u t the s imul taneous administration of sodium th iosul fa te at this dosage did not prevent leukopenia (Fig. 17). A second course of 0.6 mg. /kg, was ini t iated af ter complete re- covery of the white blood cel l count, us ing a ~ t i o of 2000 mg. of sodium th iosul fa te to each I rag. of nitrogen mustard. During both this course and a s u b s e q u e n t s imilar course employ- ing 0.9 mg. /kg . , no leukopenia was noted. Most of the local r e sponse in the lesion w a s a c h i e v e d during the first course of therapy, but there did appear to be addi t ional regress ion w i t h the second course a s well . Multiple b iops ie s of residual s inus t racts a s well a s healed a r ea s showed only one small res idual focus of epid.er- mold carcinoma. In view of this, the pa t ien t was given radiation therapy to the pos ter ior thigh,

J S R - Vol. IV, No. 11 - November , 1964 NITROGEN MUSTARD T H E R A P Y 491

Fin. 17. Course of w h i t e blood cell counts in Case 3 ~5,Ii.) ¢luring |racti0uated intra-arterial nitro- gen mustard therapy for e p i d e r m o i d carcinoma. Simultaneous intravenous sodium thiosulfate (200:1) failed to protect the patient from leukopenia during the f i r s t course o| t h e r a p y , but massive dosage (2000:1) did p r o t e e ~ fromleukopenia d u r i n g t w o subsequent courses.

Fig. 16. Case 3 (S.H.) before (above) and after (below) ffactionated intra-arterlal nitrogen mustard therapy for a large epidermoid carcinoma of the pos- terior thigh. Residual carcinoma in one of multiple biopsies prompted addition of irradiation therapy after this photograph was taken.

and multiple b iops i e s taken in tile 15 months s ince that time have fai led to show carcinoma.

T h i s pa t i en t ' s cour se demonst ra tes at l e a s t part ial protect ion from the sys t emic toxic i ty of intra-arterial nitrogen mustard if the in t ravenous dose of s o d i u m th iosul fa te i s cons iderab ly higher than h a s been recommended. I t i s qui te doubtful that this protec t ion was accompl i shed w i t h o u t cons ide rab le diminution of t he loca l e f fec t of the nitrogen mustard, but this must

* St L ~ . ~ * l i l t r e m a t n a c h m e a l ~xmpress~on.

C a s e 4. W.C .was a 4 1 y e a r old male with ad- vanced l i v e r m e t a s t a s e s from a primary carcinoma of the renal pe lv i s . A Cournand ca the ter w a s ad- vanced into thec~epat ic artery from the brachial artery us ing f luoroscopic guidance. The pa t ient was then given a 6 day cour se of f rac t ionated iatra-arterial ni trogen mustard (total dose of 0 .6 mg. /kg.) with s imul taneous in t ravenous i n j e c - t ions of sodium th iosul fa te (200 rag. sodium thiosulfate to 1 nag. of nitrogen mustard). The th iosul fa te was in jec ted into a s aphenous vein catheter s o there would be a high concentra t ion maintained in the inferior vena cava a t thehe- patic vein outflow. In view of the lack of a control s tudy for compar ison, i t would he obvi- ously imposs ib l e to claim protect ion from the sodium th iosul fa te in this s tudy, although there was no leukopenia . T h e s e c l in ica l obse rva t i ons are qui te s i m i l a r to those reported by .Owens and Hatiboglu 9 in that they t rea ted pa t i en t s by infusion., " "* ~tard in t he carot id arteri e s p ati en t s wi th sodium thiosulfa f ieukopenia" iu their s tud ies c o u l d hardly be a t t r ibuted to th iosu l fa te administrat ion wi thou t some a s s u r a n c e that the

. . . . . . . . . . . . . . . . . . zard a lone would 1 of t h i s c r i t i c i s m i_ :quent exper ience

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with another p a t i e n t given f rac t ionated intra- arterial nitrogen mustard therapy into the hepa t ic

,~92 LA~JRENCE, ET AL.

artery (0.6 mg./kg, total dose) without thiosul- fate. Despite nausea, vomiting and debili ty from this course, he did not develop hematologic eviden ce of systemic toxi city.

Clinical Trial of Thiosulfa te Protection with Chlorimine Mustard

Sodium t h i o s u l f a t e was util ized during a course of regional c h e m o t h e r a p y with an intermediate metabolite of n i t r o g e n mustard, c h l o r i m i n e mustard ( m e t h y l - 2 ~ h l o r e t h y l - ethy|euimonium). The dosage of this compound sufficient to produce an LDs0 in rats was con- siderably elevated by pretreaunent with sodium ttfiosulfate (Bonnadonna and Miller~).

Case 5. Th i s 49year old patient with severe advanced Kaposi ' s d isease involving both lower extremities, perineum, genitalia and the lower abdominal wall had been treated by irradiation therapy and multiple trials of systemic chemo- therapy over a period of 15 years . Both lower extremities were completely covered with fibre.- nodular t i s sue and multiple avascutar ulcerated lesions. After an unsuccessfu l effort to place a Cournand ca theter in the distal aorta by the brachial artery route, the patient had operative insertion of a small polyvinyl catheter into the distal aorta. The left hypogastric artery was catheterized in a retrograde fashion atoperation and the catheter tip was advanced into the lumbar aorta. The position of the catheter tip was confirmed by fluorescein injection.

The first course of therapy with chlorimine mustard (as chlorimine picryl sulfonate*) was in 10 daily doses , each given with appropriate catheter flush, in a time period of 8 to 10 sec- onds. The t o t a l d o s e was 2 m g . / k g . Marked leukopenia occurred following this course as can be seen in F i b r e 18. After recovery of the WBC, a second identical course was ~ v e n with simultaneous intravenous sodium thiosulfate (cephalic vein) given in the same fashion as in the previously described cases . The dosage of tMosu|fate was in the ratio of 200 nag. of thio- sulfate to each 1 rag. of c h l o r i m i n e picryl sulfonate, but s ince the molecular weight of this compound is twice that of nitrogen mustard, this ratio was essent ia l ly the same as that uti l ized

- 7 - - . . . . . . . . . . . . . . . . .

*Obtained through t h e courtesy of Merck Sharp & Dohme.

J S R - VoL IV, No. I ! - N o v e m b e r , 1964

6

W a C

i '

WSC

0

Fig. 18. Course of white blood cell counts in Case 5 (ll .S.) during fractionated intra-aortic therapy with intermediai'y metabolite of nitrogen mustard (as chlorimine pieryl sutfonate) for advanced Kaposi 's sarcoma of both lower limbs. Simultaneous intrave- nous administration of sodium thiosulfate (200:1) protected the patient from leukopenia during both courses of therapy in which it was employed.

in cases l and 2. As can be seen in Figure 18, there was no leukopenia following this course and so a third 10 day course was ~ven with a higher total dose of chiorimine picryl sulfonate (3mg./kg.) .Sodium thiosulfatc was given in the same proportion as in the second course a n d again no leukopenia was o b s e r v e d . Although further ulceration and some other acute changes did o c c u r over the entire course of therapy, there was no really beneficial effect and no means of making c o m p a r a t i v e objective ob- servations r e g a d i n g changes with the different courses descri bed.

DISCUSSION

Although the use of a known antagonist of nitrogen mustard is an appeal ing concept for re~ona l therapy, the findings in these initial studies with nitrogen mustard were somewhat disappointing. There was no definite evidence from these s tudies that enhanced local effect- i v e n e s s can be accomplished by combining simultaneous sodium thiosulfate administration with intra-arterial fracdonated nitrogen mustard therapy. Astudy recent lypubl ished by Anderson 1 describes local limb volume and systemic hema- tologic effects after v a r i o u s intra-arterial nitrogen mustard dosages combined with intra- venous sodium thiosulfate. T h e interprbtation of the data in this study, in regard to signif icant systemic effects, is based on relative changes

JSR - VoL IV, No. 11 - November, 1964

in white blood cell count radjer than establish- ing an arbitrary level for leukopenia as we have done. The method for presentat ion of hematologic data ut i l ized by Anderson has led him to con- clude that the hematopoiet ic t i s s u e s can be s ignif icant ly damaged by intra-arterial nitrogen mustard w i thou t ev idence of local t issue injury in the treated limb. Our findings with fraction- ated drag administration in dogs do not support the conclusions he has drawn. Some degree of protection from leukopenia has been accom- plished by sodium thiosulfa te in our s tud ies , and this has o c c u r r e d without appreciable diminution of damage to the local limb t i s sues . The margin between the dose of nitrogen mus- tard i n c a p a b l e of p r o d u c i n g s igni f icant leukopenia and the dose producingle tha l toxicity in the dog is apparently quite small. Th i s ap- pears to bc the major factor in our inability to conclusively es tabl ish a s ignif icant degree of protection with this system.

Turning to pat ient s tudies , in which systemic ef fec ts can occur without s ignif icant local damage, the efficiency of sodium thiosulfate as a neutral izing agent was also disappoint ing (Cases 1 and 2). Although mass ive s imultaneous sodium thiosul fate a&ninistration did p r o t e c t pat ient #3 from leukopenia after lower thiosul- fate dosage did not, it is extremely difficult to determine whether the local effect from nitrogen mustard during such high sodium thiosulfate dosage was equal to that achieved by similai- dosage without the protect ive agent. It appears doubtful. T h e s e s tud ies with nitrogen mustard and sodium thiosulfate nei ther es tabl ish prac- tical value for this combination nor completely refute claims that have been made by others, but they do seem to demonstrate l imitations in what appears to be a simple concept .

Our initial clinical trial of s i m u l t a n e o u s intravenous sodium thiosulfate during intra- arterial therapy with the intermediate metaboli te of nitrogen mustard, chlorimine mustard, was quite in teres t ing to us. Th i s clinical study dem- o n s t r a t e d clear-cut e v i d e n c e of systemic protection with chlorimine mustard dosage that previously produced s ignif icant bone marrow depression when no thiosulfate was given. T h e s e findings may help explain the disappointments encountered in our s t u d i e s with th iosu l fa t e - nitrogen mustard combinations. Bonnadonna and Miller 2 have demonstrated significantly greater systemic protection in rats from pretreatment with sodium thiosutfate when toxic dosage of chlorimine mustard is given rather than nitrogen ~nustard. An explanation they advance for this finding is that sodium thiosulfate " p r o t e c t s " by

NITROGEN MUSTARD THERAPY 493

HN2

PLASMA [ ECF

T $ . . . . . . . . . . . . . . . . . . . . . . . . . y

CELL

F i g . 19, Diagrammatic representation of distri- bution of nitrogen mustard and sodium thiosulfate after intravascular administration. That portion of nitrogen mustard reaching the intracellular space before transformation to intermediates is unavailable for a "neutraliz~ation ' ' reaction with thiosulfate.

reacting with fl~e ac t ive intermediary metaboli te of nitrogen mustard and not the nitrogen mustard i tself , s A s ignif icant proportion of injected nitrogen mustard would probably distr ibute i t se l f into the intracel lular space before transforma- tion to intermediary metabol i tes , capable of being neutral ized, does occur. The agent would then be avai lable in the cell to p roduce i ts toxic action without being exposed to thiosulfate , s ince the distribution of thiosulfate is pureIy extracel lular (Fig. 19).

If the metabolite adminis tered in C a s e 5 (chlorimine mustard) were capable of rapid neu- tralization by sodium thiosulfa te , it would also follow that it would be cri t ical for the intra- arterial chlorimine mustard to be given adequate time to circulate through the regional area being treated before it comes in contact with this neutral izing agent. Additional cl inical s tud ies are obviously needed to es tab l i sh the ideal protocol. However, the initial observat ions with the intermediary metaboli te of nitrogen mustaid do sugges t a poss ible fruitful area for future clinical trial.

FllblMARY

A laboratory s t u d y in dogs of the effect of intravenous sodium thiosulfate during fraction- ated intra-arterial nitrogen mustard treatment revealed partial protection from systemic tox-

not appear to reduce s ignif icant ly the local effect of the nitrogen mustard in treated limbs.

494 LAWRENCE, ET AL.

However, avoidance of systemic toxicity without significant reduction in observed local effect was also achieved without thiosulfate simply by a minimal reduction of the total dose of ltN2 administered fractionally.

Similar s tud ies in man with equivalent doses of sodium thiosulfate failed to reveal protection from systemic effects of intra-arterial nitrogen mustard. Since inactivation by sodium thiosulfate in vitro is accomplished by a reaction with the active intermediary metabolite of nitrogetr mus- tard (chiorimine mustard), this agent was a lso employed in a clinical d~iosulfate study, and good protection from systemic t o x i c i t y was achieved. Alteration of tumor response in man by the addition of sodium thiosulfate to the treatment could not be completely evaluated by these s tudies .

It is concluded that sodium thiosulfate is of little practical value during fractionated intra- arterial nitrogen mustard therapy, but the use of this protective agent during regional therapy with d~e active intermediate (chlorimine mustard) is worthy of further clinical trial.

REFERENCES

1. Anderson, J.M.: The k i n e t i c s of the specific antagonism in vivo of intra-arterial methyl-bis /3-chloroethyl) amine hydrochloride by intra- venous solutions of hydrous sodium thiosul- ~ate. Cancer, 16:1281, 1963.

2. Bonadonna, G., and Miller, D.G.: Protective ef- fect of sodium thiosulfate against nitrogen

JSR - Vol. IV, No. I I - November , 1964

mustards. Proe. A.M.Ao Cancer lies. 4: 6, 1963 (Abstract).

3. Callaway, S., and P e a r c e , K.A.: Protection against systemic poisoning by mustard gas, bis(2-chloroethyl)-sulphide, bysodium thiosul- fate and thiocit in albino rat. Brit. J. Pharma- col., 13:395, 1958.

4. Foster, J.ll., Lewis, M.R., and Jacobs, J. K,: Thiosulfate protection against the toxic ef- teets of nitrogen mustard in perfusion of the liver. Am. Surgeon, 28:461, t962.

5. |tatiboglu, I.,Mihich, E., Moore, G.E., and Nichol, C.A.: Use of sodium thiosulfate as a neutral- izing agent during regional administration of nitrogen mustard: an experimental study. Ann. Surg., t56:994, 1962.

6. Ogston, A.G., ltoliday, E.R., Philpot, J. St. 1 .... and Stoeken, L.A.: The replacement reactions of fl-~'-Diehlorodiethylsulphide and of some analogues in aqueous solution; the isolation of/~-Chloro-/3 -hydrox T d i e t h y I s u I p h i d e. Trans. Faraday Sot., 44: 45, 1948.

7. Owens, G., and llatiboglu, I.: Clinical evaluation of sodium thiosulfate as a system neutralizer of nitrogen m u s t a r d (report of 12 patients). Ann. Sarg., 154:895, 1961.

8. Philips, F.S.: Recent contributions to the phar- macology of the bis(2-haloethyl) amines and sulfides. J. Pharmacol. Exper. Therap., 99: 281, 1950.

9. Ross, C.A., Carberry, D.M., and Kraus, G.E.: Protection against systemic toxicity due to nitrogen mustard. Surg. Forum., 11:43, 1960.

10. Sehultz, P.E., Bones, R,L., Falken, M.S., and Scanlon, E.F.: The in vivo and in vitro neu- tralization of nitrogen m u s t a r d for use in cancer chemotherapy perfusion. Surg., Gynec. & Obst., 115:91, 1962.

11. Wang, S.C., Painter, E.E., and Overman, I1.R.: F|uoreseeln circulation time as a prognostic sign in experimental traumatic shock. J. Ex- per. Med., 84:549, 1946.