Proton therapy is currently used to treat brain, spine, and prostate cancers, as well as many pediatric tumors. Earlier this month, experts from some of the leading U.S. cancer centers gathered to discuss the emerging role of proton therapy in breast cancer.
Standard radiotherapy for breast cancer holds the risk of long-term side effects due to low-level irradiation of the heart and lungs. This risk may be minimized if proton therapy is used.
The two-day workshop sponsored by ProCure Treatment Centers was attended by about 30 physicians -- mostly radiation oncologists, though not all from proton centers -- as well as a few medical physicists.
"We primarily dealt with clinical issues, specifically, what clinical trials would be appropriate," explained Dr. William Hartsell, medical director of the CDH Proton Center in Warrenville, IL. "There were also presentations from physicists about the technical issues of treating breast cancer."
"We talked about potential advantages and downsides, and the problems of performing the treatment," he told medicalphysicsweb. "It's good to get perspectives from people other than those already using proton therapy. Everyone agreed that, in certain circumstances, treating with protons makes more sense."
While most proton therapy centers already have the capability to perform breast cancer treatments, some technical challenges remain. These include, for example, dealing effectively with respiratory motion, minimizing skin dose, and ensuring that the breast tissue is in exactly the same position for each treatment, as most patients are treated more than once.
The attendees also considered which treatment position is preferable. For example, sometimes it's advantageous to treat the patient lying on her front, which pulls the breast tissue away from the heart, lung, and chest wall. In other cases, it's better to treat the patient lying on her side.
Another key issue, particularly when treating young women, is how to gauge the relative success of proton therapy when side effects may not manifest until many years later. "We need to determine what we can look at now that will tell us whether we've been successful, whether we can prevent people from having heart problems 20 or 30 years down the line," Hartsell explained.
The workshop participants considered two groups of breast cancer patients. For women with more advanced breast cancer, where the tumor is larger than 5 cm or multiple lymph nodes are involved, they agreed that proton therapy is a suitable option. The next step is to figure out how to design clinical studies to prove this premise.
Hartsell noted that there was more discussion regarding women with earlier stage breast cancer, and whether, in some situations, proton therapy would improve upon standard treatments.
"There are a lot of good treatments for early-stage breast cancer," he said. "We clearly recognize that protons would not be the best for all these patients, and we're trying to figure out in which circumstances protons would be more appropriate."
Currently, there are two trials in progress examining proton therapy for breast cancer. A study at Loma Linda University Medical Center, running for five years to date, is evaluating women with early-stage breast cancer. At Massachusetts General Hospital, a study looking at high-risk patients has been running for two years, with about 25 patients treated to date.
The CDH Proton Center will also be opening two trials in the next few months, in collaboration with ProCure centers in Oklahoma City and Somerset, NJ -- one for women with advanced breast tumors and the other including women with early-stage tumors. Hartsell noted that these trials will in part be guided by input from the Loma Linda and Mass General representatives who attended the workshop.
"Part of the discussions we had looked at how we can compare data from these studies to make sure we are answering the questions appropriately," he said. "There were certain end points in our study that others didn't have, and there were certain end points in their studies that we didn't have. One of the best parts of this collaboration was that we identified small things missing that we can improve going forward."
The workshop attendees concluded that there is definitely promise for proton therapy in certain breast cancer cases, but that more research is needed to define such situations. "One of the main outcomes from the meeting was that we need to do collaborative research to try to answer these questions," said Hartsell. "By pooling resources we can get the answers more quickly and get a better handle on how best to treat patients."
© IOP Publishing Limited. Republished with permission from medicalphysicsweb, a community website covering fundamental research and emerging technologies in medical imaging and radiation therapy.
Kwa sasa tiba ya protoni hutumiwa kutibu kansa za ubongo, uti wa mgongo, na tezi-kibofu, na vilevile uvimbe mwingi wa watoto. Wataalamu kutoka vituo kadhaa vya juu vya saratani nchini Marekani wamekusanyika kujadili jukumu linalojitokeza la tiba ya protoni katika saratani ya matiti. Radiotherapy ya kawaida kwa kansa ya matiti ina hatari ya athari za muda mrefu kutokana na mionzi ya kiwango cha chini ya moyo na mapafu. Hatari hii yaweza kupunguzwa ikiwa tiba ya protoni inatumiwa. Mkutano huo wa siku mbili ulioshirikiwa na ProCure ulihudhuriwa na madaktari 30 - wengi wao walikuwa wataalamu wa radiation oncology, ingawa si wote kutoka vituo vya protoni - pamoja na wataalamu wa fizikia wa matibabu. "Hata hivyo, kwa sababu ya hali ya afya, hakuna utafiti wa kutosha uliofanywa, ""alisema William Hartzell, mkurugenzi wa matibabu wa Kituo cha Proton cha CDH huko Warrenville, Illinois." "Kulikuwa pia na maonyesho kutoka kwa wataalamu wa fizikia kuhusu masuala ya kiufundi ya kutibu kansa ya matiti". "Tuliongea juu ya faida na hasara zinazowezekana, na matatizo ya kufanya matibabu", aliiambia medicalphysicsweb. "Ni vizuri kupata maoni kutoka kwa watu wengine isipokuwa wale ambao tayari wanatumia tiba ya protoni. Kila mtu alikubali kwamba, katika hali fulani, kutibu kwa kutumia protoni kunafaa zaidi". Ingawa vituo vingi vya tiba ya protoni tayari vina uwezo wa kufanya matibabu ya kansa ya matiti, baadhi ya changamoto za kiufundi bado zipo. Hii ni pamoja na, kwa mfano, kushughulikia kwa ufanisi na harakati ya kupumua, kupunguza kipimo cha ngozi, na kuhakikisha kwamba tishu ya kifua iko katika nafasi sawa kwa kila matibabu, kama wagonjwa wengi ni kutibiwa zaidi ya mara moja. Washiriki pia walitafakari ni nafasi gani ya matibabu inayopendekezwa. Kwa mfano, wakati mwingine ni bora kumtibu mgonjwa akiwa amelala mbele, ambayo huondoa tishu ya kifua kutoka kwa moyo, mapafu, na ukuta wa kifua. Katika visa vingine, ni afadhali kutibu mgonjwa akiwa amelala kando. Suala jingine muhimu, hasa wakati wa kutibu wanawake wachanga, ni jinsi ya kupima mafanikio ya upasuaji wa protoni wakati athari za upande zinaweza kuonekana tu miaka mingi baadaye. """Tunahitaji kuamua nini tunaweza kuangalia sasa ambayo itawaambia kama tumekuwa na mafanikio, kama tunaweza kuzuia watu kutoka kuwa na matatizo ya moyo miaka 20 au 30 chini ya mstari,""Hartsell alielezea." Washiriki wa warsha hiyo walichunguza vikundi viwili vya wagonjwa wa kansa ya matiti. Kwa wanawake walio na saratani ya matiti ya hali ya juu, ambapo uvimbe ni mkubwa kuliko cm 5 au kibofu cha lymph nyingi vinahusika, walikubali kwamba tiba ya proton ni chaguo linalofaa. Hatua inayofuata ni kujua jinsi ya kubuni masomo ya kliniki ili kuthibitisha nadharia hii. Hartsell alisema kuwa kuna majadiliano zaidi kuhusu wanawake walio na saratani ya matiti ya hatua ya mapema, na kama, katika hali fulani, tiba ya protoni ingeweza kuboresha matibabu ya kawaida. "Kuna matibabu mengi mazuri ya kansa ya matiti katika hatua ya mapema", akasema. "Tunajua wazi kwamba protoni hazingekuwa bora kwa wagonjwa hawa wote, na tunajaribu kujua ni katika hali gani protoni zingekuwa sahihi zaidi. """ Kwa sasa, kuna majaribio mawili yanayoendelea kuchunguza tiba ya protoni ya kansa ya matiti. Utafiti uliofanywa na Chuo Kikuu cha Loma Linda, Marekani, unaonyesha kuwa wanawake wengi wana ugonjwa wa kansa ya matiti. Katika hospitali ya Massachusetts General Hospital, utafiti uliofanywa kwa wagonjwa wenye hatari ya kuambukizwa virusi vya corona umekuwa ukiendelea kwa miaka miwili, na wagonjwa 25 hivi wametibiwa hadi sasa. Kituo cha Proton cha CDH pia kitafungua majaribio mawili katika miezi michache ijayo, kwa kushirikiana na vituo vya ProCure huko Oklahoma City na Somerset, NJ - moja kwa wanawake wenye uvimbe wa matiti uliopitishwa na nyingine ikiwa ni pamoja na wanawake wenye uvimbe wa hatua ya mapema. Hartsell alisema kuwa majaribio hayo yatategemea maoni ya wawakilishi wa Loma Linda na Mass General waliohudhuria semina hiyo. """Sehemu ya majadiliano tuliyofanya ilikuwa ni jinsi tunavyoweza kulinganisha data kutoka kwa masomo haya ili kuhakikisha kuwa tunajibu maswali kwa usahihi,"" alisema." """Kulikuwa na baadhi ya mwisho katika utafiti wetu kwamba wengine hawakuwa na, na kulikuwa na baadhi ya mwisho katika masomo yao kwamba hatukuwa na." Moja ya sehemu bora za ushirikiano huu ilikuwa kwamba tuligundua mambo madogo yaliyopotea ambayo tunaweza kuboresha kwenda mbele. " Washiriki wa semina hiyo walikubaliana kwamba kuna matumaini ya tiba ya protoni katika baadhi ya kesi za saratani ya matiti, lakini kwamba utafiti zaidi unahitajika kufafanua hali kama hizo. "Mmoja wa matokeo makuu kutoka mkutano huo ulikuwa kwamba tunahitaji kufanya utafiti wa ushirikiano kujaribu kujibu maswali haya", alisema Hartsell. "Kwa kuunganisha rasilimali tunaweza kupata majibu haraka zaidi na kupata udhibiti bora juu ya jinsi bora ya kutibu wagonjwa". IOP Publishing Limited Imechapishwa tena kwa ruhusa kutoka MedicalPhysicsWeb, tovuti ya jamii inayofunika utafiti wa msingi na teknolojia zinazojitokeza katika upigaji picha wa matibabu na tiba ya mionzi.